road bridges

Ministry of Surface Transport(Roads Wing)

SPECIFICATIONSFOR ROADAND BRIDGEWORKS

(Third Revision)

Published by

Indian Roads CongressNew Delhi 1997

Ministry of Surface Transport(Roads Wing)

SPEd FICATIONSFOR ROADAND BRIDGEWORKS(Third Revision)

Published by the Indian RoadsCongress on behalf of the Govt.of India, Ministry of SurfaceTransport (Roads Wing)

Copiescan behadfromthe Secretary,indianRoadsCongress,JamnagaiHouse,Shahjahan Road,NewDelJzi.119Oil

NEW DELHI-lgg7 Prk~eRs. 400/-Plus packing & postage charges

LIBRARY & DOCUMENTATION CENTRELARSEN & TOUBRO LTD.EGG CONSTRUCTION GROUP

P.B. No. 979MOUNT PC~NAMALLEEROADMANi~riKKAM, CHENNAI-600 089

Rec’E r~’

Acc. No. - ...

First PublishedReprintedFirst RevisionReprintedReprintedReprintedSecondRevisionReprintedReprintedReprintedReprintedReprintedThird RevisionReprinted

ReprintedReprinted

Reprinted

Repri ntccl

April, 1973November,1975May, 1978September,1981October,1983April, 1986February,1988August, 1988April, 1990June,1992February,1993July, 1993April, 1995January,1997 (IncorporatesCorrigendumNoJ&2andCol. 12&l5ofp.662)January,1998January,1999

May, 1999

February,2000

(The Rights of Publication and Translation are rese,ved)

Printed at M/s Dec Kay Printers, New Delhi-hO 0151000 Copies

PREFACETO THE THIRD REVISION

“SpecificationsforRoadandBridgeWorks” firstpublishedin 1973has alreadyundergonetwo revisionsin the past.With the adventof theexternallyaidedprojectsbasedon internationalcontractdocumentsandmodernisationofHighwayConstruction,it becamenecessarytorevisetheSpecificationsto beconsistentwith equipmentbasedconstructiontech-niques.Manyof theserevisedspecificationswereincludedin thebiddingdocumentsof individual projects. The specificationshavenow beencompletelyrevisedincorporatingall the changesrequiredto take intoaccountthelatestconstructionpracticesandthesuggestionsreceivedfromvarioususers.A few additional chapters on topics not covered earlierhave also been added.

Revisionof thesespecificationscouldbe carriedout in ashorttimeonly dueto the concertedeffortsof officers of theRoadsWing andtheconsultantswhowereintimatelyconnectedwith thiswork. I wishtorecordmy appreciationof theefforts put in by all concerned.

As with all specifications,the Third Revisionof the Specificationswilt alsonodoubtneedfurtherupdatingin courseof time.Feedbackandsuggestions(or improvementwould be welcome from all usersof thedocument.

New Delhi M. V. SASTRYNovember,1994. DirectorGeneral( Road Development)

CONTENTS

SECTION SECTION CLAUSE CLAUSE TITLE PAGENO. TITLE NO. NO.

100 GENERAL 101 IN1RODUCTION 3102 DEFINITIONS 3103 MATERIALS AND TEST STANDARDS 6104 SIEVEDESIGNATIONS 6105 SCOPEOF WORK 7106 CONSTRUCTION EQUIPMENT 8107 CONTRACTDRAWINGS 9108 SITE INFORMA11ON 9109 SET11NGOUT 10110 PUBLICUTILITIES 11111 PRECAUTIONS FORSAFEGUARDING 13

THE ENVIRONMENT112 ARRANGEMENTFORTRAFFIC 14

DURINGCONSTRUCTION113 GENERAL RULES FORTHE 17

MEASUREMENTOF WORKS FORPAYMENT

114 SCOPEOFRATHSFOR 19DIFFERENTITEMS OFWORK

115 METHODOLOGYAND SEQUENCEOF 21WORK

116 CRUSHED STONEA~GGREGAThS 21117 APPROVALOF MATERIALS 21118 SUPPLYOFQUARRYSAMPLES 21119 USE OFSURFACESBY 22

CONSTRUCTION TRAFFIC120 SITEOFFICEFOR ENGiNEER AND 22

OTHER SUPERVISORY STAFF121 FIELD LABORATORY 26122 SFTE RESIDENTIAL 30

ACCOMMODATION FORENGINEERAND OTHERSUPERVISORYSTAFF

123 PROVIDING AND MAINTAINING 32WIRELESSCOMMUNICATIONSYSTEM

124 PROVIDING AND MAINTAINING 33VEHIQ..ESFORTHE ENGINEER

125 SUPPLYOF COLOURRECORD 35PHOTOGRAPHSAND ALBUMS

126 SUPPLY OF VIDEOCASSETIES 36

11 Contents

200 SITECLEARANCE

300 EARTH WORK~EROSION

CONTROL ANDDRAINAGE

400 SUB-BASES,BASES(NON-

BITUMINOUS)AND

SHOULDERS

500 BASESANDSURFACECOURSES

(BITUMINOUS)

201 CLEARING AND GRUBBING202 DISMAN1UNG CULVERTS.

BRIDGES ANDOTHERSTRUCFURESIPAVEMENTS

301 EXCAVATION FOR ROADWAY ANDDRAINS

302 BLASTING OPERATIONS303 PRESPLITI1NGROCK EXCAVATION

SLOPES304 EXCAVATION FOR STRUCTURES305 EMBANKMENT CONSTRUCTION306 SOIL EROSION AND

SEDIMENTATION CONTROL307 TURFING WITH SODS308 SEEDING AND MULCHING309 SURFACE/SUB-SURFACEDRAINS310 PREPARATIONAND SURFACE

TREATh(ENTOF FORMATION311 WORKS TO BE KEPT FREE OF WATER312 WATER COURSESATCULVERTS313 CONSTRUCTiON OF ROCKFILL

EMBANKMENT

401 GRANULAR SUB-BASE402 LIME TREATEDSOIL FOR IMPROVED

SUB-GRADE/SUB-BASE403 CEMENT TREATED SOIL SUB-

BASE/BASE404 WATER BOUND I ACADAM

SUB-BASE/BASE405 CRUSHED CEMENTCONCRETE

SUB-BASE/BASE406 WET MIX MACADAM SUB-BASE!

BASE407 SHOULDERS,ISLANDS AND MEDIAN408 CEMENTCONCRETE KERB AND

KERB WITH CHANNEL409 FOO11~ATHSAND SEPARATORS410 CRUStIER-RUNMACADAM BASE

501 PREPARATION OF SURFACE502 PRIME COAT OVERGRANULAR BASE503 TACK COAT504 BITUMINOUS MACADAM505 BITUMINOUS PENETRATION

MACADAM506 BUILT-UPSPRAY GROUT

4144

49

5761

636783

85879094

959596

101

105

109

112

121

123

128130

132133

139145148149157


160

Contents ill


507 DENSE BITUMINOUS MACADAM 163508 SURFACEDRESSING 170509 OPEN GRADED PREMIX CARPET 177510 MIX SEALSURFACING 185511 SEMI-DENSE BITUMINOUS 186

CONCRETE512 BITUMINOUS CONCRETE 189513 SEAL COAT 192514 SUPPLY OF MINERAL AGGREGATES 194

FOR PAVEMENTCOURSES515 BITUMEN MASTIC 197516 SLURRYSEAL 202517 RECYCLING OFBiTUMINOUS 204

PAVEMENT

600 CONCRETE 601 DRYLEANCEMENTCONCRETE 211PAVEMENT SUB-BASE

602 CEMENT CONCRETEPAVEMENT 220603 ROLLED CEMENT CONCRETEBASE 247

700 GEOSYNTHETICS 701 GEOSYNTHETICS IN ROAD AND 255BRIDQEWORKS

702 GEOTEXTILESIN SUB-SURFACE 257DRAINS

703 REINFORCED EARTH 259704 GEOSYNTIIETICS FOR HIGHWAY 263

PAVEMENTS705 PROTECTION WORKS WITH 266

GEOSYNTHETICS

800 TRAFFIC SIGNS, 801 TRAFFIC SIGNS 273MARKINGS & 802 OVERHEADSIGNS 278OTHER ROAD 803 ROAD MARKINGS 282

APPURTENANCES 804 I-IECTOMETREJIULOMETRESTONES 288805 ROAD DELINEATORS 289806 BOUNDARY STONES 289807 FENCING 289808 TUBULAR STEELRAILING 290809 CONCRETECRASH BARRIER 291810 METAL BEAM CRASH BARRIER 292811 ROAD ‘TRAFFIC SIGNALS 295

900 QUALITY 901 GENERAL 299CONTROL 902 CONTROLOF ALIGNMENT LEVEL 301FOR ROAD AND SURFACE REGULARITY

WORKS 903 QUALITY CONTROLTESTS DURING 305CONSTRUCtiON

iv Contents

SECTION SECTION CLAUSENO. TITLE NO.

1000 MATERIALS 1001.FOR 1002.

STRUCTURES 1003.1004.1005.1006.1007.1008.1009.1010.1011.1012.1013.1014.1015.

1100 PILEFOUNDATIONS

1200. WELLFOUNDATIONS

GENERALSOURCESOF MATERiALBRICKSSTONESCAST iRONCEMENTCOARSEAGGREGATESSANtVFINE AGGREGATESSTEELWATERTIMBERCONCRETE ADMLXTURESREINFORCEDCONCRETE PIPESSTORAGE OF MATERIALSTESTSAND STANDARDOFACcEPTANCE

1101. DESCRIP’IlON1102. SUIT-SURFACEINVESTIGATION1103. TYPE OFPILES1104. MATERIALS1105. TEST PILES1106. PRECASTCONCRETEPILES1107. CAST.!N.SITU CONCRETE PILES1108. STEEL PILES1109. TIMBERPILES1110. DRIVING EQUIPMENT1111. DRIVING1112. RAKER(INCLINED) PILES1113. P1LETESTS1114. PILECAP1115. IMPORTANTCONSIDERATIONS,

INSPECTION/PP..ECAU11ONSFOR DIFFERENTTYPES OFPILES

1116. TOLERANCES1117. TESTS ANDSTANDARDSOF

ACCEPTANCEIlls. MEASUREMENTSFORPAYMENT1119. RATE

1201. DESCRIPTION1202. GENERAL1203, SElliNG OUT ANDPREPARATIONS

FOR SINKING1204. CUlliNG EDGE1205. WELLCURB1206. WELL STEIN ING1207. WELL SINKING

PAGENO.

323323323323324324325326326329330330331331334

339339340340341341344347348348349352353353354

356357

357358

361361362

364364365366

CLAUSETITLE

Contents V


1208 BO11’OMPLUG 3751209. SANDFILLING . 3761210. TOPPLUG 3761211. WELLCAP 3761211 TOLERANCES . 3771213, TESTS AND STANDARDS 377

OF ACCEPTANCE1214. MEASUREMENT FOR PAYMENT 3771215. RATE 377

BRICK 1301. DESCRIPTIONMASONRY 1302. MATERIALS

1303. PERSONNEL1304. CEMENTMORTAR1305. SOAKINGOF BRICKS1306, JOINTS1307, LAYING130& JOINTING OLD AND NEWWORK1309, CURING1310. SCAFFOLDING1311. EQUIPMENT1312. FINISHING OF SURFACES1313. ARC}IITEC11JRALCOPING FOR

WING/RETURNiPARAPETWALL1314. ACCEPTANCE OF WORK1315. MEASUREMENTSFOR PAYMENT1316. RATE

STONE 1401. DESCRIPTIONMASONRY 1402. MATERIALS

1403. PERSONNEL1404, TYPEOFMASONRY1405. CONSTRUCTIONOPERATIONS1406. ARCHITECTURAL COPING FOR

WING/RETURN/PARAPETWALLS1407, TESTSAND STANDARD

OF ACCEPTANCE1408. MEASUREMENTSFOR PAYMENT1409. RATE

1501, DESCRIPTION 4011502. MATERIALS 401

1503. DESIGNOF FORMWORKE 4011504. WORKMANSHIP 4021505. FORMEDSURFACEAND FINISH 4031506. PRECAUTIONS 4041507. PREPARATIONOF FORMWORK 404

BEFORECONCRETING

1300

1400

381381381381382382382383383384384384386

386386387

391391391391391397

397

397398

1500 FORMWORK

‘Ti (.on tenIs

1508. REMOVAL OF FORMWORK1509. RE-USE OFFORMWORK1510. SPECIALISED FORMWORK1511. TESTS AND STANDARDS

OF ACCEPTANCE1512. MEASUREMENTSFOR PAYMENT1513. RATE

DESCRIPTIONGENERALPROTECTIONOFREINFORCEMENTBENDING OF REiNFORCEMENTPLACINGOF REINFORCEMENTBARSPLICESTESTINGAND ACCEPTANCEMEASUREMENTSFORPAYMENTRATE

405406406407

407407

411411411411412413415415415

1700 STRUCTURALCONCRETE

1701. DESCRIPTION1702. MATERIALS1703. GRADES OF CONCRETE1704. NOPORTIONINGOFCONCRETE1705. ADMIXTURES1706. SIZE OFCOARSEAGGREGATE1707. EQUIPMENT1708. MIXING CONCRETE1709. TRANSPORTING,PLACING AND

COMPACTION OF CONCRETE1710. CONSTRUCTION JOINTS1711. CONCRETING UNDER WATER1712. ADVERSEWEAThER CONDITIONS1713. PROTECTIONAN!) CURING1714. FINISHING1715. TOLERANCES17 16. TESTSAND STANDARDS OF

ACCEPTANCE1717. MEASUREMENTSFOR PAYMENT1718. RATE

41941941942!424424425426427

428428430431432433433

435435

1801. DESCRIPTION1802. MATERIALS1803. TESTING OF PRESTRESSING

STEEL AND ANCHORAGES1804. WORKMANSHIP1805. SUPERVISION1806. TENSIONINGEQUIPMENT1807. POST.TENSIONING

439439441

441445445446

SECTION SECTION CLAUSE CLAUSETITLE PAGENO. TITLE NO. NO.

1600 STEEL REINFOR- 1601.CEMENT 1602.

(UNTENSIONED) 1603.l6O~1605.1606.1607.1608.1609.

1800 PRESTRESSINC

(‘ont~’n S vii

SECTiON SECTION CLAUSE

NO. T1TLE NO.

1808.

1809.1810.

1811,

1812.1813.

1814.1815.

1900 STRUCTURAL 1901.STEEL 1902.

1903.1904.1905.1906.1907.

1908.1909.

2000 BEARINGS 2001.2002.2003.2004.2005.2006.2007.2008.

2009.2010.

2100 OPEN 2101.FOUNDATIONS 2102.

2103.2104.2105.

2106,2107.2108.

2200. SUB-STRUCTURE 2201.2202.

GROUTING OF PRESTRESSEI)TENDONSPRE-TENSIONINGSAFETY PRECAUTIONSDURINGTENSIONINGTRANSPORTATIONANI)STORAGE OF UNITSTOLERANCESTESTS AND STANDARDSOF ACCEPTANCEMEASUREMENTSFOR PAYMENTRATE

DESCRIPTIONGENERALMATERIALSFABRICATIONERECrIONPAINTINGTESTS AND STANDARDSOF ACCEPTA ICEMEASUREMENFSFOR PAYMENTRATE

DESCRIPTIONGENERALSTEEL BEARINGSSPECIAL BEARINGSELASTOMERICBEARINGSPOTBEARINGSINSPECTIONAND TESTINGTESTS AND STANDARDS OFACCEPTANCEMEASUREMENTS FOR PAYMENTRATE

DESCRIPTIONMATERIALSGENERALWORKMANSHIPTESTS AND STANDARDS OFACCEPTANCETOLERANCESMEASUREMENTSFOR PAYMENTRATE

DESCRIPTIONMATERIALS

PAGENO.

447

447

450451

451451

451452

455455455458471481488

488489

493493493498500513519519

519519

523523523523525

52652.6526

529529

CLAUSE TITLE

U Contents


2203. GENERAL 5292204. PIERS ANDABUTMENTS 5292205. PIER CAP ANDABUTMENT CAP 5302206. DIRT/BALLAST WALL, 531

RETURN WALL & WING WALL2.207. TESTS AND STANDARDS OF 531

ACCEPTANCE2208. TOLERANCES IN CONCRETE 531

ELEMENTS2209. MEASUREMENTSFOR PAYMENT 5322210. RATE 532

2300 CONCRETE 2301. DESCRIPTION 535SUPER- 2302. MATERIALS 535

STRUCTURE 2303 GENERAL 5352304. REINFORCEDCONCRETE 535

CONSTRUCTION2305. PRESTRF.SSED CONCRETE 536

CONSTRUCTION2:306. TOLERANCES 5382307. TESTS ANDSTANDARDSOF 538

ACCEPTANCE2308. MEASUREMENTSFOR PAYMENT 5392309, RATE 539

2400 SURFACEAND 2401. GENERAL 543‘,UB ~URFA( F 2402 PR! 1 IMINARY INVISTIGA I tON ~41

GEOTECEJNICAL 2403. DETAILED EXPLORATION 546EXPLORATION 2404, EXPLORATION FORBRIDGE 547

FOUNDATIONSRESTiNGONROCK

2405. BORING 5502406. RECORDS OFBORINGS 550

AND TRIAL PITS2407. METHODS OFSAMPLING 5512408. PROCEDURE FOR 552

TAKiNG SAMPLES2409. PROTECTION,HANDLING 554

AND LABELLING OF SAMPLES2410. TESTSFOREXPLORATION 555

OF SHALLOWFOUNDATIONSOFBRIDGES

2411. TESTSFOREXPLORATION 555FORDEEP FOUNDATIONSOF£1RIDGES

CEontents 5 ix

SECTION SECTION CLAUSE CLAUSETITLE PACENO. TITLE NO. NO.

2412. TESTINGOFMATERIAL FOR 556GUIDE BIJND AND HIGHEMBANKMENT ANDITS FOUNDATIONS.

2413. MEASUREMENTSFOR PAYMENT 5592414. RATE 559

2500 RIVER TRAINING 2501. DESCRIPTION 563WORK AND 2502. GUIDE BUND 563

PROTECTION 2503. APRON 564WORK 2504 PITCHING/REVEThIENT 566

ON SLOPES2505 RUBBLESTONE/CEMENT 569

CONCRETE BLOCKFLOORINGOVER CEMENTCONCRETEBEDDING

2506. DRY RUBBLE FLOORING 5702507. CURTAIN WALL AND 570

FLEXIBLE APRON2508. TESTS AND STANDARDSOF 571

ACCEPTANCE2509. MEASUREMENTSFOR PAYMENT 5712510. RATE 571

2600 EXPANSION 2601. DESCRIPTION 575JOINTS 2602. GENERAL 575

2603. REQUIREMENTS 5762604. STEELPLATE SLIDING 577

EXPANSICdtJOINTS2605. FILLER JOINTS 5782606. ELASTOMERICSLAB 578

SEAL EXPANSIONJOiNT26p7. STRIP SEAL EXPANSION JOINT 5832608. TESTS ANDSTANDARDSOF 587

ACCEPTANCE2609. MEASUREMENTSFOR PAYMENT 5872610. RATE 587

2700 WEARING 2701. DESCRIPTION 591COAT AND 2702. WEARING COAT 591

APPURTENANCES 2703, RAILINGS 5922704. APPROACHSLAB 5932705. DRAINAGE SPOUTS 5942706. WEEPHOLE 5952707. TESTS AND STANDARDSOF 595

ACCEPTANCE2708. MEASUREMENTSFORPAYMENT 5952709. RATE 595

x CEontents

2800 REPAIR OFSTRUCTuRES

2801. DES~R1PTION2802. GENERAL2803, SEALING OFCRACKS

BY INJECTION OF EPOXY RESIN2804. EPOXYMORTARFOR

REPLACEMENTOF SPALLEDCONCRETE

2805. EPOXY BONDING OFNEWCONCRETETOOLD CONCRETE

2806. CEMENT GROUTING2807. GUNITING/SHOTCRETE2808. REPLACEMENT/RECTIFICATiON

OP BEARINGS2809. DISMANTLING OFCONCRETE

WEARINGCOAT2811). EXTERNALPRESTRESSING2811. TESTS ANDSTANDARDS OF

ACCEPTANCE2812. MEASUREMENTSFORPAYMENT2813. RATE

599599599

606

609

609612614

615

616617

617618

3000 MAINTENANCEOF ROA [)

SCOPEMATERIALSEXCAVATION FOR PIPEBEDDING FORPIPELAYING OFPIPEJOINTINGBACKFILLINGHEADWALLSANI) OTHERANCILLARY WORKS

2909. OPENINGTO TRAFFiC2910. MEASUREMENTSFOR PAYMENT2911. RATE

3001. GENERAL3002. RESTORATION OFRAIN.CUTS3003. MAINTENANCEOFEARTHF.N

SHOULDERS3004. BITUMINOUS WORK IN

CONNECTiON WITHMAINTENANCE AND REPAIRS

3005. MAINTENAINING OF CEMENTCONCRETE ROAD

621621621622622623623624

624624624

627627628

629


2.900 PIPE 2901.CU1.,VESTS. 2902.

2903.2904.2905.2906.2907.2908.

631

xi

SECTiON SECTION C1.,AIJSE (ELAL SETITLF, PAGENO. HIITLE NO. NC).

A PPFENDEC ‘ES

APPENDIX I. LIST OF I.R,C, PUBI.ICATIONS 637RIIIRRID1OIN IIIFSPFUIKAI1ONSCODES& STANDARDS

APPENDIX 1,15 OFINDIAN ANDFOREIGN 640SIANDARDSRIZIRRFDTOI\1’IlESPFCEIFICATIONS

~\PEI.ENDI\3. Ni F.’flRlI) OF SIEVING FOR 647VQI 1 SOlES IODFIIRMINI nilDEGREEOFPCELVERISATION

APPENDIX 4. GEIDEI.JNESON SELECTION 648OFTBE GRADEOF BFTIJMEN

APPENDIX 5. ANTI STRIPPING AGENTS USFEI) FOR 6 0BITUMINOUS MATFERIALS AND MiXES

APPENDIX 1 (X)i-1 IE)RAF’F DOCUMENT ON ISC9077-1979CODE 65501 PRA( 1 ICI FOR CORROSION PROEEC lIONOFSTEELREINFORCEMENTZN RB ANDRCC (EONSTRUCTION(REVISED)

APPENDIX 1 2oO/I~ HISTOR N’ GE SINKINGOi~\\rI.:I .1. 666P00/I 2 P1 ANOI WEll NOS 661

200/LI 111:1& SPIEL IN )~rEIINOS. 662

APPIEN~DIX 500/I INFORMATION 1’O BE SEPPLTEI)TOTi] F 663MANt I k( 111(1RI, UI PROPRII1 NRNSYSTIJ.MS

A PP1EE\ iTX I 700/I SPECIEICAJ’I(IN FORCONSTRUCTiONJOINTS 6651700/TI PF.R.MF.ABIL1TY TES’I 667

APPENDIX 1800/I ‘EFESTS ON’ SIIEA’I’IIING DCEC1’S 66818(X)/tI PRESTRESSINGREPORT 6741800/Ill SPFECIFICA11ONSFORGROUTINGOF POST- 675

TENSIONED CABLES TN PRESTRESSEDCONCRETE

I 8(X)/IT GROUTING RECORD 681

General

100

General

General Section 100

101.. INTRODUCTION

These Specificationsshall apply to all such road and bridge worksas are requiredto be excctltecl underthe Contractor otherwisedirectedby the F:~ngineer-in-Charge(hereinafterreferredto is the Fngineer). inevery case, the work shall be carried out to the satisfaction of theEngineerand conform to the location, lines.., dimensions.,gradesandcross-sectionsshown on the drawingsor as indicated by the Engineer. Ticquality of materials, processing of materialsas may be neededat the,site,saiient featuresof the constructionwork and quality of finishedwork shall comply with the requirementsset forth in succeedingsec-tions. Where the drawings and Specifications describea portion of he.work in only general terms, and not in complete detail, it shall be:understoodthat only thebestgeneralpracticeis to prevail, materiab andworkmanshipof the best quality are to be employed and instructionsof the Engineer are to be fully complied with,

A lisl of Indian RoadsCongressSpecificationsand RecommendedCodes of Practicewhich have been made use of in the preparationof theseSpecificationsis given at Appendix-i. The latest e,dition of allSpecifications/Standardstill 30 (thirty) days before the final dale ofsubmission of the tender, shall be adopted.

102. DEFINITiONSThe words like Contract,Contractor, Engineer(synonymous with

Eng.’neer-in-charge), Drawings,Employer,Government,Works’ and \Vcrk

Si to used in these. Specifications shall he consideretito have the meaning

as understood Ironi the definitions of these terms given in the Genera

Conditions of Contract,

The following abbreviations shall have the meaningas seIbelow E

ASSI ITO American Associationof State highway and ‘I”ran~Ei~’!.~t.oiooi’)IticiaE;45151 American Society for Testing and Materials

PS British Standardpublished by the British Startddrls Institut’iorCml c~ur~~j~Bearing RatioPlC Indian RoadsCongressIS IncIi~aStandardpublished by he Bureau of Indian SL’indari

The various elementsin the cross-sectionof a road re.ferrHitheseSpecificationsare shown in the cross-sections in Figs. 0’ ~. ‘~

100-2,

‘l

General

UEUU-~U.~.~CI)EUUCaUU~

,

I.,

2,-,

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~CCUU5)5)-CC-~Ut5

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CUEUC0UU0U-~0U.0UU-a0C0CC,

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ral

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U~

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LUU

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C—C

LULU

CCN5

Section 100 General

Treated shoulders shown in the cross-section shall be of two typesE-

(I) “Hanf’~ shoulders which have select gravel/moorsam,any other conip~scsed

granular layer or bricks.

“Paved” :shouiders which have a hiruminou, surfacing over granular layers.

103. MATERIALS AND TEST STANDARDS

The relevant standards for materials, as well .as the tesling

procedures, have been indicated at appropriate places in the Spec ifi-eations. A list of these slandardswith their full title and the year of

publication applicable is included at Appendix-2.

104. SIEVE DESIGNATIONS

Thes ieve designations referred to in the Specifications correspond

to those specified by Bureauof Tndian Standards in IS: 460. TahieIOU-I gives the list of the commonly used IS sieves.

TABLE 100-1. DESIGNATION OF TEST SIEVES

iS Designation conforming to IS: 464)

u iron) (in micron)

* 125’ 850106

* 710* 90 600

75~ 500

* 63 42553 355

300* 45

375 * 250212

* ‘31.526.5 * 180

1St)“ 224

19.0 * 125106

~ 16..’O13.2 ~ 90

7511:29_So * 63

53* 8.00

6.70 * 45

6

General Section 100

* 5.60

4.75

* 400

3,35

* 2.802.36

2.001.70

* 1,40

Its

* 1.00 _______________

Noses 1. ~‘ are the principal sizesstated in 1SO~565and are preferred.2. Sieve sizes given in BS:410 & ASTM -E 11 are same as in 15:4603. Only sieves with squareopenings shall be used.

105. SCOPE OF WORK

105]. The work to be carried out under the Contractshall consistof the. various items as generally describedin the Tender Documentsas well as in the Bill of Quantitiesfurnished in the Tender Documents.

105.2. The works to be performed shall also include all generalworkspreparatory to theconstructionof roads,bridges.., canal crossings,

drainageand all other related works, The works shall include work ofany kind necessaryfor thedueandsatisfactory construction,completionandmaintenanceof the worksto the intent and meaning of thedrawingsand theseSpecificationsand further drawings and orders that may heissuedby theEngineerfrom time to time. Thescopeof work shall includecompliance by the Contractorwith all GeneralConditions of Contract,whether specifically mentionedor not in the various clauses of theseSpecifications, all materials, apparatus,plant, equipment, tools, fuel,water, strutting, timbering, transport,offices.,.stores,workshop,staff,labour

andthe provision of properand sufficient protectiveworks, diversions,temporary fencing, andlighting. It shall also include:safetyof workers,first-aid equipment, suitable accommodationfor thestaff and workmenwith adequatesanitary arrangements,the effecting and maintenanceofall insurances, thepayment of all wages,salaries,fees, royalties,duties

or other chargesarising out of the erection of works and the regularclearance of rubbish, reinstatementand clearing-upof the site as maybe requiredon completion of works, safety of thepublic and protectionof the works and adjoining land.

7

Section100 General

105.3. The Contractorshall ensurethatall actionsare taken to buildin quality assurancein the planningandexecutionof works.Thequalityassuranceshall cover all stagesof work such as setting out, selectionof materials, selection of constructionmethods,selectionof equipmentandplant,deploymentof personnelandsupervisorystaff, quality controltesting, etc. The work of building in quality assuranceshall be

deemed to he covered in the scope of the work.

105.4.The Contractor shall furnish,at least 15 days in advanc.e,hisprogramme of commencementof item of work, the methodof workinghe intendsto adopt for various items of work such as site clearance,construction forembankment,sub-base,base,surfacing,culverts,bridges,retaining walls, well-sinking, cast-in-situpiling, constructionof cast-in-situ prestressedconcrete simply supportedgirders,cantilever constructionof prestressedconcretesuperstructure,and such other items for whichthe Eagineerdemandsthesubmissionof themethodof working. He shallprovide information regarding the details of the method of workingand equipment he proposes to employ and satisfy the Engineeraboutthe adequacyand safety of the same.The sole responsibility for thesafety and adequacy of the methodsadoptedby the Contractor will,however, rest on the Contractor, irrespectiveof any approval given by

the Engineer.

i06. CONSTRUCTION EQUIPMENTIn addition to the generalconditionsindicatedin the ContractDocu-

ments, the following conditionsregarding use of equipment in works

shall be satisfied:(a) The Contractor shall he required to give a trial run of the equipment for establishing

their capability to achieve the laid clown 5peciflc.atior~and tolerances to thesatisfaction of the Engineer before commencement o~the work;

~h) All equipmcnt provided shall be of proven efficiency and shall he operatedand maintained at all times in a manner acceptable to the Engineer;

(c) All the plant/equipment to be deployed on the works shall be got approvedfrom the Engineer for ensuring their fitness and efficiency before commencernent of work;

(4) Any material or equipment not meeting the approval of the Engineer shall beremoved from the site forthwith;

(e) No equipment will be removed from site without permission of the Engineer;and

(1) The Contractor shall also make available the equipment for site quality controlwork as directed by the Engineer~

8

General Section 100

107. CONTRACT DRAWINGS

107.1. The ContractDrawingsprovidedfor tenderingpurposes shallbe as containedin the TenderDocumentsandshall be usedas a referenceonly. The Contractor should visualisethe natureandtype of work con-templatedand to ensure that the ratesand prices quotedby him in theBill of Quantities have due considerationof the qualitative and quan-titative variations,as may be found at the site and complexitiesof workinvolved during actual execution/construction.

107.2. The tendered rates/pricesfor the work shall be deemedto include the cost of preparation,supply anddelivery of all necessarydrawings, prints, tracingsandnegativeswhich theContractoris requiredto provide in accordancewith the Contract,

107.3. Two copies of drawings, on the basis of which actualexecutionof the work is to proceed,shall be furnished free. of costto the Contractorby the Engineer progressively according to thework programme submittedby the Contractorand acceptedby the En-girteer. Drawings for any particular activity shall be issued to theContractorat least 30 days in advanceof the scheduleddate of the startof the activity.

107,4. Examinationandfor approvalby theEngineerof anydrawingsor otherdocumentssubmittedby theContractorshall notrelieve theCon-tractor of his responsibilitiesor liabilities under the ~ontracL

108, SITE INFORMATION

108.1.. The information about the site of work and site conditionsin the Tender Documents is given in good faith for guidanceonly huttheContractorshallsatisfy himselfregardingall aspectsof site conditions.

108.2. The location of the works and the general site particularsare as generally shown on the Site plan/Index plan enclosedwith theTender Documents.

108.3. Whereasthe right-of-way to thebridge sites/roadworks shallhe provided to the Contractorby the Engineer, the Contractor shallhave to makehis own arrangementfor the land requiredby him for siteoffices, labour camps,stores,etc.

108.4. The quarry charts enclosed with the Tender Documentsindicatethe location of quarriesandother sourcesfrom which naturallyoccurring materials are available,for guidanceof the Contractor.Theleads indicated in the said charts are only approximate. It is assumed

9

Section tOO General

that the. Contractor has inspected the quarries, borrow areas etc , heforequoting his rates for the work to assess the availability of con,stnict ionmaterials in required quantity and quality.

109. SETTING OUT

1091. The Contractor shall establish working Bench Marks tied

wtth the Reference Bench Mark in the area soon after taking possession

of the site, The Reference Bench Mark for the area shall he as indicated

tn the ContractDocumentsand the values of the same shall he obtainedhy the Contractor from the Engineer.The working Bench Marks shall

be at the rate of four per km andalso at or nearall drainagestructures,over.hndges and underpasses. The working Bench Marks/levels should

he got approved from the Engineer. Checks must he made on these

Bench Marks once every month and adjustments, ii any, got agreed ecit

the Engineerand recorded.An up-to-date record of all Bench Marks

including approved adjustments, if any, shall he maintainedby the

Contn.ictor and also a copy supplied to the Engineer for his record

1092.The lines and levels of formation,side slopes.,drainageworks,earriageways and shouldersshall he care lully set out and frequentlychecked, care being taken to ensurethat correctgradientsand cross-sectionsare ohtainedeverywhere.

109.3. In order to facilitate the setting out of the works, the centreline of the carriageway or highway rntist be accuratelyc ieiblished bythe Contractor and approvedby the Engineer.It must theit he accuratelyreferencedin a mannersatisfactoryto the Engineer,every 50 in intervalsin plain and rolling terrainsand 20 in intervals in Ii illy terrain andin all curve poinis as directed by the Engineer,with marker pegs andchainagehoards set in or near the fenceline, and a scheduleof referencedimensionsshall be prepared and supplied by the Contractorto theEngineer.These markers shall he maintained until the works rea.ch

finished formation level and are acceptedby the Engineer

109A. On constructionreachingthe formation level stage,the centre

line shall again he set out by the Contractor and when approved by the

iEngineer, shall be accurately referenced in a mannersatisfactory tothe Engineerhy marker pegs set at the outer limits of the formation,

109.5. No reference peg or marker shall he moved or withdrawnwithout theapprovalof the Engineerandno earthworkor structural work

shall be commenceduntil the centre line has been referenced,

199,6. The Contractorwill 6e the sole responsible party for safe-

to

General Sieetion100

guarding all survey monuments, bench marks, beacons, etc. The Engineerwtll provide the Contractor with the data necessary for setting outof the centre line, All dimensionsand levels shown on the drawingsor

mentioned in documents forming part of or issued under the Contract

shall he verified by the Contractoron ihe site and he shall immediately

inform the Engineer of any apparent errors or discrepancies in such

dimensions or levels The Contractor shall, in connection with the staking

c.iut of the centre line, survey the terrain along the road and shall subniit

to the Engineer for his approval, a profile along the road centre line

and cross-sectionsat intervals as required by the Engineer.

109.7. After obtaining approval of the Engineer, work on earthwork

can commenceand the profile and cross-sectionsshall form the basisfor measurements and payment. The Contractor shall he responsible forensuring that all the basic traverse points are in place at the

comniencementof the contract and if any are missing,or appear to have

been disturbed, the Contractor shall make arrangements to re-establishthese points. A “Survey File” containing the necessarydata will he

made available for this purpose. If in the opinion of the Engineer, designmodifications of the centre line or grade are advisable, the Engineer

will issoe detailed instructions to the Contractorand the Contractorshallperform the modifications in the field, as required,and modify the groandlevels on thecross-sectionsaccordinglyas many times as required.Therewill he no separatepayment for any survey work performed by theContractor. The cost of theseservicesshall he considered as beingincluded in the cost of the items of work in the Bill of Quantities.

109,8. The work of setting out shall be deemedto be a part ofgeneral works preparatory to the executionof work and no separatepayment shall he made for the same.

109.9. Precisionautomatic levels, having a standarddeviation of±2mni per kin, and fitted with micrometer attachmentshall he usedfor all double run levelling work. Setting out of the road alignmentand measurementof angles shall be done by using Iheodolite withtraversing target, having an accuracyof one second. Measurement ofdistances shall be done preferably using precision instruments likeDistomat.

110. PUBLIC UTILITIES

110.1. Drawings schedulingthe affectedserviceslike water pipes,sewers, oil pipelines, cables,gasductsetc. ownedby variousauthoritiesincluding Public Undertakingsand Local Authorities included in the

ti

SCL iUfl I General

(~iiti ~‘t Doe ~mentsshall be verified by the Contractor for the accuracyof uie information prior to the commencementof any work.

110.2. Notwithstandingthe fact that the information on affectedservices may not be exhaustive,the final position of these serviceswithin the works shall be supposedto havebeen indicatedbasedon theinformation furnished by different bodiesandto theextent the bodiesare familiar with the final proposals.The intermediatestages of the worksare, however,unknownat the design stage, these being dictatedby theContractor’s methods of working. Accordingly, the Contractor’s pro-gramme must take into account the period of notice and duration ofdiversionary works of each body as given on the Drawings and theContractormustalso allow for any effect of theseservices aadaltera-tions upon the Works and for arrangingregular nieetingswith thevarioushodies at the commencementof the Contractand throughoutthe periodof the Works. in order to maintain the required co-ordination. Duringthe period of the Works, the Contractorshall have no objection if thepublic utility bodiesvary their decisionsin theexecutionof their proposalsin terms of programme and construction,provided that, in the opiniou

of the Engineer, the Contractor has receivedreasonablenotice thereoFbefore the relevant alterationsare put in hand.

110.3. No clearanceor alterationsto the utility shall be carried outunless specially orde.red by the Engineer.

110.4, An~ services affected by the Works must be temporarilysupportedby the Contractorwho must also take all measuresreasonahlyrequired by the various bodies to proteci their servicesand propert)during the progressof the Works,

110.5. The Contractormay be required to carry out certain workstor and on behalf of the various bodies and he shall also provide,with the prior approvalof theEngineer,suchassistanceto the variousbodies as may be authorisedby the Engineer,

liM. The work of temporarilysupportingandprotecting the publicutility services during cxecuiionof the Works shall be deemedto bepart of the Contractand no extrapaymentshall be made for the same.

110.7. The Contractor may he required to carry out the removalor shifting of certainservieesfutilitieson specific ordersfrom theEngineerfor which paymentshall be madeto him, Such works shall be takenup by the Contractoronly after obtainingclearance from the Engineerand ensuring adequatesafety measures.

12

General Section100

111. PRECAUTIONS FOR SAFEGUARDING THEENViRONMENT

111.!. General

The Contractorshall take all precautionsfor safeguarding the en-vironment during the courseof the constructionof the works. Heshall abide by all laws, rulesand regulationsin force governingpollutionand environmental protection that are applicable in the area where theworks are situated.

111.2. Borrowpits For Embankment Construction

Borrowpits shall not be dug in the right-of-way of the road. Thestipulations in Clause305.2.2. shall govern.

111.3. Quarry Operations

The Contractorshall obtain materialsfrom quarriesonly after theconsent of the Forest Departmentor other concernedauthorities isobtained.The quarry operations shall be undertaken within the purview

of the rules and regulationsin force.

111.4.Control of Soil Erosion, Sedimentationand Water Pollution

The Contractorshall carry out the works in such a manner that soiler.osion is fully controlled, and sedimentationand pollution of naturalwater course,s,ponds, tanksandreservoirsis avoided. The stipulationsin Clause 306 shall govern.

111.5. Pollution from Hot-Mix Plants and Batching Plants

Bituminous hot-mix planis and concrete batching plants shall belocated sufficiently away from habitation, agricultural operations orindustrial establishments. The Contractor shall take every precautiont.o reduce the levels of noise,vibration, dustand emissionsfrom hisplant and shall he fully responsiblefor any claims for damagescausedto the owners of property, fields and residencesin the vicinity.

111.6. SubstancesHazardousto Health

The Contractorshall not useor generateany materialsin the workswhich are hazardousto the health of persons, animals or vegetation.Where it is necessaryto usesomesubstanceswhich can cause injuryto the healthof workers, the Contractor shall provideprotectiveclothingor appliancesto his workers.

111.7. Use of Nuclear Gauges

Nuclear gauges shall be usedonly wherepermittedby the Engineer.

13

Section ItS) General

The (.‘ontraetc.ir shall provide the Engineerwith a copy of the regulationsgovern ir~g the. safe use of nucleargaugeshe intends to employ aridshall abide by such regulations,

111,8, The Contractormust take all reasonablesteps to minimisedust nuisanc.eduring the construction of the works.

111.9. All existing highways and roads used by vehicle of theCon uaeti.:ir or any of his sub-contractorsor suppliersof materialsor plant,and similarly any new roadswhich are part ot ihe works and whichare being u sed by traffic, shall be kept clean and clear of all dust/mudor other exiraneous materialsdroppedby the said vehiclesor their tyres.Sinularly, all dust/mudor other extraneous materialsfrom the worksspreading on these highways shall he immediately cleared by theContractor.

111.10.Clearanceshall be effected immediatelyby manualsweepingandremoval of debris,or, if so directedby the Engineer,by mechanicalsw~. e ping and clearing equipment, and all dust, mud an ‘1 other debrisshEll I he removed entirely from the road surface. Add i donally, if sodirected by the Engineer, the road surface shall he hosed or wateredusing suitable equipment.

111.11. Any structural damage caused to the existing roads bythe Contractor’s (EonstrlliL:i on rqaipnlent shall be made geo.:t withoutany extra cost.

ill. 12. Compliance with the foregoing wilt not relieve the Contractorof any responsibility for complying with the requirenients of any HighwayAuthority in respect of the roads used by hi in,

112. ARRAN(WMENT FOR TRAFFICDURING CONSTRUCTION

112.1. General

The Contractor shall at all times carry out work on the highwayin a manner creating least interference to the flow of traffic whileconsistent with the satisfactory execution of the same. For all worksinvolving improvements to the existing highway, the Contractor shall,in accordance with the directives of the Engineer, provide and maintain,during execution of the work, a passage for traffic either along a partof the existing carriagewayunder improvement,or along a temporar)diversion constructedclose to the highway. The Contractorshall takeprior approval of the Engineerregarding traffic arrnn~!ementsduringconstruction

4

General Section100

112.2. Passage of Traffic along a part of the Existiug Car-riageway under Improvement

For widening/strengtheningexisting carriageway where part widthof the existing carriageway is proposedto be. usedfor passageof traffic,treatedshouldersshall be provided on the side on which work is notin progress. The treatment to the shouldershall consistof providingatleast 150 mni thick granular base course covered with bituminoussurface dressing in a width of atleast 1.5 m and the surf.ace shallhe. n dintamed throughoutthe periodduring which traffic uses the sameto the satisfactionof the Engineer. The continuouslength in whichsuch work shall he carried out, would he limited normally tt.500 ma.t a place. However,where work is allowed by the Engineer in longerstretchespassingplace...satie.ast20 m long with additional paved widthof 2.5 m shall be. provided at every 0.5 km interval.

In case of widening existing two-lane to four-lane, the additionaltwo laneswould he constructedfirst and the traffic diverted to it andonly thereafter the required treatmentto the existingcarriagewaywouldht. carriedout, However, in casewhereon the requestof the Contractor,work on existing two-lane carriageway is allowed hy the Engine.e.rwith traffic using part of the cx isting carriageway, stipulations as in

para ahove shall 01)131 y.

After obtaining permission of the Engineer, the treatedshouldershall be. dismnr.ntled, the debris disposedof and the areaclearedasper the direction of the Engineer.

112.3, Passageof Traffic along a TemporaryDiversion

in stretcheswhere. it is not possible to pass the traffic on partwidth of the carriageway, a temporary diversion shall be constructe.dwith 7 mu carriagewayand 2..5 m.. earthenshoulderson each side (totalwidth of roadway 12 m) with the following provision for road crustin the 7 in widthE

(I) 200 miii (compacted)granular subbase;

(ii) 225 mm (compacted)granular basecourse; and

ciii) Premix carpetwith Seal CoamlMix Seat Surracing.

The alignment and longitudinal section of diversion includingjunctions and temporary crossdrainageprovision shall he as approvedby the Engineer.

15

Section100 Genera]

112.4. Traffic Safety and Control

The Contractor shall take all necessary measures for the safetyof traffic during construction and provide, erectand maintain such bar-ricades, including signs, markings, flags, lights and flagmen as mayhe required by the Engineer for the information and protection oftraffic approachingor passing through the section of the highwayunder improvement.Before taking up any construction, an agreedphased programmefor the diversionof traffic on the highway shallbe drawn up in consultation with the Engineer.

The barricades erectedon eitherside of the carriageway/portionofthe carriagewayclosed to traffic, shall be of strong design to resistviol ation,andpaintedwith alternate blackandwhitestripes.Redlanternsor warning lights of similar type shall he mountedon the harricadesat night and kept lit throughout from sunset to sunrise.

At the pointswheretraffic is to deviatefrom its normal path(whetheron temporarydiversion or part width of the carriageway) the channelfor traffic shall be clearly marked with the aid of pavementmarkings,painted drums or a similar device to the directions of the Engineer.At night, the passageshall be delineatedwith lanterns or other suitablelight source.

One-way traffic operationshall be establishedwhenever the trafficis to be passedover part of the carriageway inadequate for two-lanetraffic, This shall be donewith the help of temporarytraftic signalsor fiagmen kept positioned on opposite sides during all hours, Forregulationof traffic, the flagmenshall be equippedwith red and grec.nflags and lanterns/lights.

On both sides,suitableregulatory/warningsignsas approvedby theEngineer shall be installed for the guidanceof road users. On eachapproach,at least two signs shall be put up, one close to the pointwhere transition of carriagewaybegins and the other 120 m away. Thesignsshall be of approveddesignand of reflectory type, if so directedby the Engineer.

112$, Maintenanceof Diversionsand Traffic Control Devices

Signs, lights, barriersand other traffic control devices, as well asthe riding surfaceof diversions shall be maintained in a satisfactorycondition till such time they are required as directed by the Engineer.The temporary travelled way shall be kept free of dust by frequentapplicationsof water, if necessary.

t6

General Section100

112.6. Measurements for Payment and Rate

All arrangementsfor traffic during construction includingprovisionof temporary cross drainage structures, if required, andtreated shoulderas described in Clause 112.2 includingtheir maintenance,dismantlingand clearing debris,where necessary, shall be consideredas incidentalto the works and shall be the Contractor*sresponsibility.

The construction of temporary diversion including temporary crossdrainage structures as describedin Clause 112,3, shall be measuredin linear metreand the unit contractrate shall be inclusive of full com-

pensat~on for construction(including supply of material, labour, toolsetc.), maintenance,final dismantling,and disposal.

113, GENERAL RULES FOR THE MEASUREMENT OFWORKS FOR PAYMENT

113.1. GeneralAll measurementsshall be madein the metric system.Different items

of work shall be measuredin accordance with the procedures set forthin the relevant sections read in conjunction with the General Conditionsof Contract. The same shall not, however, apply in the case of lumpsuricontracts.

All measurements and computations, unless otherwise indicated, shallbe carried nearest to the following limits:

(I) length and breadth 10 nun

(iii height, depth or thickness ofearthwork, subgrade, sub-bases,bases,surfacing and structural members 5 mm

(ia) areas 001 sq. rn.

(iv) cubic contents aoi cu. m.

In recordingdimensionsof work, the sequenceof length, width andheight or depth or thicknessshall be followed.

113.2. Measurement of Lead for Materials

Where lead is specified in the Contract for construction materials,the same shall be measured as described hereunder:

Lead shall be measured over the shortest practicable routeandnot the oneactually taken and the decision of the Engineerin this regardshall be taken as final. Distancesupto and including 100 m shall bemeasuredin units of 50 m, exceeding 100 m but not exceeding 1 kmin units of 100 m and exceeding 1 km in units of 500 m, the half

17

Section1 00 General

andgreaterthan half of the unit shall be reckonedas one and less thanhalf of the unit ignored. In this regard,the source of the materialshallbe divided into suitable blocks and for each block, the distancefromthe centreof the block to the centreof placing pertaining to that blockshall be taken as the lead distance.

113.3. Measurementof PavementThickness for Payment onVolume Basis

The finished thicknessof sub-base,baseand bituminouscoursestohe paid on volume basis shall be computedin the following manner:

Levels shall be takenbefore andafter construction,at grid of points10 m centreto centrelongitudinally in straightreachesbut 5 m at curves.Nornìally, on two-laneroads, the levels shall be taken at four positionstransversely, at 0,75 and2.75 m from eitheredge of the carriageway;and on single lane roads, these shall be. taken at two positionstransversely, being at L25 in from either edgeof the carriageway. Formultilane roads, levels shall be taken at two positions transverselyfor e.ach lane at locations specified by the Engineer.

S. uitahlc references for the transversegrid lines should be leftin the form of embeddedbricks on either ends or by other means sothat it is possible to locate the grid points for level measurementsalier each successive course is laid.

For pavementcourseslaid only over widening portions, atle.ast onelire of levels shLill he takenon eachstrip of widening,or moredependingon the width .~fwidening a.s decided by the Engineer.

Notwithstanding the above, th.emeasurementsmay he takena.t closermtervals also, if SO desiredby the Engineer,the needfor which mayarise particularly in the case of estimationof the volume of the materialbr profile. corrective cours.e (levelling course). The. averagethicknessof the pavementcourse. in any areashall he the arithmetic mean of thedifference.of levels before and after constfliclion at all the grid pointsfalling in that area, provided that the thicknessof finished work shallhe. limited to those shown on the drawingsor approvedby the Engineerin writing.

As supplementto level measurements,the Engineershall have theoption to takecores/makeholesto check the depthof construction. Theholes madeand the portions cut for taking cores shall be made goodby the Contractorby laying fresh mix/material including compactingasrequiredat no extracostimmediatelyafter themeasurementsare recorded.

General Section100

113.4. Checking of Pavement Thickness for Payment Oil AreaBasis

Where paymentfor any bituminouscoursein Section 500 is allowedto be made on area basis,the Engineermay haveits thicknesscheckedwith the help of a suitable penetration gauge at regular intervals orother meansas he may decide.

113.5. Measurement of Bituminous Courses for Payment onWeight Basis

Plantmixed bituminous materials for pavementcourseswhere des~ignated to be paid on weight basisshall be weighedon accuratescales

approved by the Engineer.Approved scalesshall me~in scalesthatare of size, capacity,kind and type suitablefor the weighingto he done,and theseshallbe properlyandadequatelyinstalledandmaintained.Priorto the use. of the scalesand as frequently thereafteras the Engineermay deem necessaryto ensure accuracy, the scalesshall be checkedandapprovedby theEngireer,or the Engineermay direct the Contractorto have the scales checked by other competentagencyat the cost

of the Contractor.

Locationof thescalesshall he asdesignatedby the Pngineer.Trucksused for hauling the material to he weighed shall be weighed emptydaily at such times as the Engineerdirects,and each truck shall beara plainly legible identification mark.

For materialsspecified to be measuredby weight, the Engineerwillhave theoption to makemeasurementsof the finished work by volumein accordancewith Clause113.3andsuch volumes shall he convertedinto weight for paymentpurposes.The factor for conversionfrom volumemeasurementto weight measurementshall be computed from the..representativedensity of the compacted material at site deterniinedat locations approvedby the Engineer.

114. SCOPE OF RATES FOR DIFFERENTITEMS OF WORK

114.1.. For item rate contracts, the contract unit rates for differentitems of work shall be paymentin full for completingthe work to therequirementsof theSpecificationsincludingfull compensationfor all theoperationsdetailed in the relevant sectionsof theseSpecificationsunder“Rates”. In the absenceof any directionsto the contrary, the rates areto be consideredas the full inclusive rate fir finished work coveringall labour., materials,wastage,temporary work, plant, equipment,over-

19

Section 100 General

hew] chargesand profit as well as the general liabilities, obligations,insuranceand risks arising out of General Conditionsof Contract,

114,2.The itemratesquotedby the Contractorshall,unlessotherwisespecified, also include compliancewith/supply of the following

(i) Generalworkssuch assettingout,clearanceof site beforesetting out andclearanceof works after completion;

(ii) A detailedprogrammefor theconstructionandcompletion of thework(usingCPM!PERT techniques)giving, in addition to constructionactivities,detailednetwo:rkactivities for the submissionand approval of materials, procurement of criticalmaterialsand equipment,fabrication of special products/equipmentand their tn~stallation andtesting,and for all activitiesof theEmployerthat are likely to affectthe progressof work, etc., including updating of all such activities on the basisof the decisionstakenat the periodic site review meetings or as dircetedby the Engineer;

(ii) Samples of various materialsproposedto Ft used on the Work for conductingtests thereona.s required as per the provision:sof the Contract;

(iv) Design of mixesasper therelevantClausesof th.eSpecificationsgivingproportionsof ingredients, sourcesof aggregatesandbinderalong with accompanying trialmites as per the relevantClautesof these Specificationsto hesubmittedto the.Engineer for his approval before use on the Works;

~v) Detaileddesigncalculationsanddrawings for all TemporaryWorks (suchasform..work, staging, centering; specislisedconstructional handling and launchins,’equipment and the like);

(vi) Detaileddrawingsfor temptatcs,supportandendanchorage,detailsfor ~‘ restressinge:ahleprofiles, bar bendingandcutting schedules for reinforcement,matrrial lists(or fabrication of stnsctssralsteel, mc;

(sir) Mill test reportsfor all mild andhigh tensilesteeland.cast steel asper the relevantprovisionsof the Specifications;

(sitti Testing of various finished items and materials including bitumen, cement,concrete, bearings as required under these Specifications and furnishing testreçxsrtsfeertifieates;

(is) Inspection Reports irs respect of fo nnwork, staging, reinforcement and otheritems of work as per the relevantSpecifications;

(a) Any other data which may he required. as per these.Speeiiieasions orthe Conditions of Contract or any otherannexures/sehedulesforming part of the(.‘ontract;

(xi) Any other item of work which is not specifically provided in the Bill of Quantitieshut which is necessaryfor complying with she provisionsof she Contract;

(,sii) All tesnporary works, formwork and false work;

(xiii) listahlishing and running a laboratorywith facilities for testing for various itemsof works as specified in Section 9~)and other relevantClauses,where thereis no separateitem in the Bill of Quantities for establishing and ntnning alaboratory;

General Section 100

(xiv) Cost of in~buihprovisions for Quality Asaurance;

(xv) Cost of safeguarding the environment;and

(xvi) (ost of providing “aa-boitt drawings” in original and two sets of prints.

114.3, Portions of road works beyondthe Limits and/or any otherwork may be got constructed by the Employer directly throughotheragencies.Accordingly, otheragenciesemployed by the Employermay be working in the vicinity of the Works being executed by theContractor. The Contractor shall liaise with such agencie.sand adjusthis constructionprogrammebr the completion of work accordinglyandno claim or compensation due to any reason whatsoevcr will beentertained on this account.The Employerwill he indemnified by the.Contractor for any claims from other agencieson this’ account.

115, METHODOLOGY AND SEQUENCE OF WORK

Prior to start of theconstructionactivities at site, the Contractorshall, within 30 daysafter thedateof theLetterof Acceptance,submitio the. Engineer for approval, the detailed constructionmethodologyincluding tnechanica.lequipmentproposedto be used, sequenceof vari~ous activities and schedulefrom start to endof lhe. project. Programmerelating to pavementand shoulderconstruction shall be. an integratedEtCEl.ivity to he done~ sii~~ultancouslyin a coordinated manner, Thenielho.dology and the sequence. shall he.soplanned as to provideproper safety, drainage and free flow of traffic..

116. CRUSHED STONE AGGREGATES

\Vhere, the termscrushedgravel/shingle,crushedstone, brokenstoneor stone aggregateappear in any part of the Tender Documents orDrawings issued for work, they refer to crushed gravel/crushedshm pIe/crushed stone aggregateobtained from. .integrated crushingplant having appropriate primary crusher, secondary crusher andvibratory screen.

117. APPROVAL OF MATERIALS

Approval of all sourcesof material for work shall be obtained inwriting from the Engineer before their tise on the project.

118. SUPPLY OF QUARRY SAMPLES

Raw andprocessedsamplesof the mineral aggregates from theapproved quarry shall be submittedby the Contractorat no extra cost.

21

Section100 General

119. USE OF SURFACES i.Y CONSTRUCTION TRAFFIC

119,1. Ordinarily, no construction traffic shall be allowed onpavementunderconstructionunlessauthorisedby the Engineer,Even inthat casethe load and intensity of construction traffic should be soregulatedthat no damageis caused to the subgradeor pavement layersalready constructed. Wherenecessary,service roadsshall be constructedfor this purposeand the same shall be consideredas incidental tothe work,

119.2. The wheels or tracks of plant moving over the variouspavementcoursesshall be kept free of deleterious materials,

119.3. Bituminous base courseshall be kept clean and uncontami-natedas long as the sameremainsuncoveredby a wearing courseorsEurface treatment.The only traffic permitted accessto the base courseshall be that engagedin laying and compactingthe wearing course orthat engaged on such surface treatmentwhere the base~courseisto be blinded and br surfacedressed.Should the basecourseor tackcoat on the basecoursebecome contaminated,the Contractorshall makegood by clearing it to the satisfactionof the F.~~ngineer,and if this isimpracticable,by removing the layer and replacing it to Specificationwithout any extra cost.

120. SITE OFFICE FOR ENGINEER AND OTHER

SUPERVISORY STAFF120.1. Scope

The work coversthe constructionandprovision of furnishedsiteoffice. acéommodation for the supervisorystaff of Engineer and main-taining the same.

120.2. Description

The Contractorshail arrange to provide fully furnished officeaccommodation constructed as shown in drawings. Work includesprovidingelectricsupply,all electricalitemslike lights, fansandcompletewiring, providing water supply including all pipes, flttings, tanks, tubewell, pumps, valves etc. complete,. septic tank, sewer lines., drains,fencing, internal surfacedroadsetc. completeas shown on the drawings.The. Contractorshall provide the office accommodationwithin 4 monthsfrom the date of the commencementof work or 3 months from the.dateof providing the land .and the working drawingsfor the constructionof office accommodation,whichever is later. List of furniture to he

22

General Section100

providedand maintainedfor Engineer’s site office shall be as in TableI O&-2.

Table IOO~2.LIST OF FURNITURE TO BE PROVIDED AND MAINTAINEDFOR ENGINEER’S SITE OFFICE

SNo. item SpecifIcations Nos. Reqd.*

01 Executive table(for the Engineer)

02. Executive chair(for the Engineer~

03. Table 11or SiteEngineer, Aecountantand Head Clerk)

04, Ordinary chairTypeI(For the Engineer,Accountant, ReadClerk and visitors)

05. Table (for allother staff)

06. Ordinary ehair~TypeII (for all otherstaff and visitors)

Make - Godrej ModelNo, T-I08 or equivalent

Make-Godrej ModelNo, PCH-701 or equivalent

Make-Godrej Model No.T-104 or equivalent.

Make-Godrej Model No.CHR-6 or equivalent.

Make~OodrejModel NoT-i0l or equivalent

Make-Codrej ModelNo. CITR-6 or equivalent

137. Stool Make-Godrej Model No.ST-2 or equivalent.

OS Steel Almirah1980mm a 915mm a485mm

09. Steel Atmirtth1270mm a 765 rum a440 mm

11). Racks 5 Tie.r1800 mm a 900 mm x355 mm

Il. Typewriter

Make-Oodrej ModelNo.1 Storewel plainor equivalent

ilako’Godrej Model Minorp1ant or ccitt iv alent

Made of slottedangles and MS. Sheetsof Godrej make

Electronic—Bilingual(English & Rindi)Network make or equivalent.

23

Section 100 General

S.No. Item Specifications Nos.Reqd.0

12. Steel Cash Chestof size 1.5 x 1.5@50 mm s 450 mm)

(approx.)

13. Air Coolers

1 4. Room Heaters

5. Ceiling Pans1400 mm sue

16. CEompu cr withprinter

7. Phoroc:opier

Make-CktdrejStorewelor equivalent

The coolers shall have 24”(60cm) size fan with suitablepump and shall be of eitherGEC, Khaitan or CoolHome make or equivalent

The heatersshall be of2(100 W capactty - Bajajmake or equivalent

Ceiling fans shall be ofapprovedmake and colour

PC 486 with hard disc capacity230 MB, Maths eoprocessor,Two disc drives of 5.25” (132 mm)and 3.5’ (88 mm), 14” (350 mm)size colour VGA monitor letter-quality dotmatnEx pritster of 132columns and 101 Key board

Make RICOH Model FT 4065 orequivalent

Numbers to be decidedby the Engineeras çxrr requirementsof the Project.

120.3. Ownership

The sile office with all services, furniture anti fittings shall he theproperty of the Employer. The land for the site office shall he providedby the Engineer and the location shall he as indicated in the Drawings.

120.4, Maintenance

The Contractor shall arrange to maintain the site office until theissue. of Taking over Certificate for the complete work, Maintenanceincludes the day to day upkeep of the building and the surroundings,attending to repairs to various parts of the building, furniture, fittings,office equipment and the connected services as and when necessary.,.including the periodic white/colour washing of building and painting ofwood work, steel work, replacing the broken window/door/ventilator

24

General Section 100

glasses, furniture and other hardware and maintaining necessary watchand ward during day and nighL

The Contractor shall arrange to provide uninterrupted supply ofelectricity and water for the office building. In case of failure of mainpower/water supply, alternate source shall be available for providinguninterrupted supply. All sources, tappings and connected equipment andfittings, piping, tanks, wiring and all accessories of the main alternatepower/water supply, for the site office accommodation shall be theproperty of the Employer.

1.29.5. Measurements for Payment

The measurement for construction and provision of site office shallbe in square metres of the plinth area of the office accommodationand the payment shall be made after the completion and handing overof the buildings with connected services fully furnished including office.,equipment for occupation.

if the Contractor fails to hand over the furnished office accommo-da.tion within the period stipulated under Clause 1202, an amountoURs. 15,000 per month or part thereof shall be debited to the Contractor’saccount for the period of delay.

The. measurement for maintenance of F..~ngin~r’ssite office ac—commodation shall be on maintenance months and shall be niade oncompletion of satisfactory maintenance every month,

if at any stage, the Contractor fails to carry out the requiredmaintenance satisfactorily, an amount of Rs. 5000 per month or partthereof shall be debited to the Contractor’s account. In addition, themonth/months during which the Contractor fails to carry out therequired maintenance satisfactorily shall not be measured for payment.

If the Contract works are not completed within the stipulated periodor within the granted extended time of completion, maintenance of siteoffice accommodation in accordance with Clause 120.4 shall be carriedout by the Contractor at his own cost and as such no payment shallhe made for thc same. In case of any failure by the Contractor to doso, an amount of Rs, 15,000 per month or part thereof shall be debitedto the Contractor’s account.

1.20,6. Rate

l’he Contract unit rate f.or constructing and providing Ihe site officeaccommodation shall include the expenses of all the operations involved

25

Section 100 General

in construction of the building including all services, fittings, fixtures,furniture, fencing, internal surfaced roads, as mentioned under Clause120.2.

The Contract unit rate for maintenance shall include expensestowards all items of works detailed in Clause 120.4 including powerand water charges for supply from the mains and for providinguninterrupted supply of power and water from alternate sources in caseof failure of main supply.

121, FIELD LABORATORY

121.1. Scope

The work covers the provision and niaintenance of an adequatelyequipped field lab.mtory as required for site control on the quality ofmaterials and the works..

121,2. Description

The Contructor shall arrange to provide fully furnished and adequatelyequipped field laboratory constructed as shown in drawings. The foldlaboratory shall preferably be located adjacent to the site office of theEngineer and provided with amenities like water supply, electric. supplyetc. as for the site office of the Engineer in Clause 120.2.

The floor space requirement for the feld laboratory shaU he. asindicated in the drawing ., It shall include office space for the MaterialsEngineers, one from the Contractor’s side and another from the Engineer’sside and a store for the storage of samples. The remaining space shallbe provided for the. installation of equipment, laboratory tables andcupboards, working space for carrying out various laboratory tests,besides a. wash basin, toilet facility and a curing tank fOr the curingof samples, around 4m x 2m x im in size and a fume chamber. The,furnishing in each of two offices of the Materials Engineers shall heas provided for the Site Engineer in Table 100-2.. Wooden/concrete work-ing table with a working platform area of about Tm x TOm shall heprovide.d against the wails’, also providing wooden cupboards above andbelow the working tables to store accessories such as sample mouldsetc. Atleast 4 racks of slotted angles and! MS. sheets as at SINo. IDof Table 100-2 and atleast 6 stools for laboratory test operators asat Sl,No 7 of Table 100-2 shall also be provided.

121.3. LaboratoryEquipment

The. following items of laboratory equipment shall he providedin the field laboratory..

26

General Section 100

121.3.1. General(I) Oven - Electrically operated,

thermostatically controlled, rangeopto 200°Csensitivity 1°C 1 No.

(ii) Platform balance300 kg capacity 1 No.

(iii) Balance 20 kg capacity-selfindicating type 1 No.

(iv) ElectronicBalance 5 kg capacity accuracy 0.5 gm 2 Nos.

(v) Water bath-electricallyoperated and 1 No.thennostaticallycontrolled with adjustableshelves, sensitivity 1°C

(vi) Thennometers: 4 Nos.Mercury-in-glass thermometer range0° LO 250°cMercury-in-steelthermometerwith 30 cmstem, rangeupto 300°C

(vii) Keroseneor gas stoveor electric hot plate 1 Nn,

(viii) Glasswares,spatulas, wire gauzes, As requiredsteel scales, measuring tape, casseroles,karahis, enamelledtrays of assorted sizes,pessle.mortar,porcelain dishes,gunny bags,plasticbags, chemicals,digging tools likepickaxes,shovels etc.

(it) Set of IS sieveswith lid and pan:450 mm diameter: 1 set

63 mm, 53 mm, 37.5 mm, 26.5 mm, 13.2 mm, 93 mm,6.7 mm and 4.75 nun size200 mm diameter: 2 sets2.36 sum, 2.0 mm, 1.18 mm, 6(1) micron, 425 micron,300 micron, 150 micron, and 75 micron

(4 Water testing kit i set

(xi) Hrst aid box 1 set

121,3,2. For soils and aggregates(i) Riffle Box I No.

(ii,) Auerhcrg Limits (liquid and planiclimits) determinationapparatus 1 set

27

Sechost 100 General

(iii) C~ompaetionTessEquipmentboth 2.5 kg and 4.5 kgrammers(1..ight and Heavy compactiveefforts) I set

(iv) Dry Bulk D.nsisy Test apparatus(sand pouringcylinder, tray, can etc.) complete I set

(v) Speedy Moisture Meter completewith chemicals I set

(vi) Post ~holeAuger with extensions 1 set

(vii) Core cutter apparatus10 cm dia, 10/IS cmheight, complete with dolly, rammer etc. I set

(viti) AggregateImpact Value Test apparatus/LosAngeles Abrasion Test apparatus I set

)is) Flakeess and Elongation Test Gatiges I set

(x) Standardmeasuresof 30, 15 and 3 litrescapacity alongwith standard tar ping rod 1 set

lsi) California Bearing Ratio test apparatus 1 set

(tii) l.;scoifined compressiontest apparatus I set

121.3,3. For bitumen and bituminous mixes(i) F’cnetronseterwith standard needles I set

(ii) Riffle box small size 1 No.

(iii) Centrifuge type bitumen extractor,handoperated,complete wish I setpetroh/cosssmereial henzene

(iv) Marshall stability te.st apparatus, complete I setwitis all accessories

(v) l.:ic,ld density bottle aiongwith cutting tray,chisel, hamnscrand standardsand 2 Nos.

(vi) 3 rn straight edge I No.

(vii) Camberhoard I No.

(viii) Core cuttistg machine witls 10 an dia diansond I setcutting edge

(is) Vacuum pump and El specific gravity bottles I set

28

General Section100

121.3.4, For cement and cement concrete(i) Vicat apparatus for testing setting times I set(ii) Slump testing apparatsts 4 mets(iii) Compression and Fleitttral strength testing

machine of 200 ton.ne capacity with additionaldial for flettssral testing 1 No.

(is) Needle Vibrator 2 Nos,(v) Air Meter 1 No,(vi) Vihrating hammer for vibrating dry mix as

for Dry Least Cementconcrete stab-base I No.

r.~rote .~ The items andtheir numberslisted shovein this Clause shall be decidedby

she Engineeras per reqstirementsof the Project and modified accordingly.

121,4, Ownership

if provided as a separatepayable item in the Bill of Quantities,the field lab. ratory building andequipmentshall be the propertyof the.Employers and the land for laboratorywill he provided by the Employer.

121.5. Maintenance

if çtrovide.d for as a separatepayableitem in the Bill of Qttantities,the Contractor. shall .t.rrange. to maintain the field laboratory ~n asaltsfac.tory rnanne.r until the. issue of Taking Over Certificate for theconiplete. work, Maintenanceincludesall activities described itt Clause120,4,

121.6. Measurementsfor Payment

If provide..d a..s’a separatepayable item in the Bill of Quantities,the. measurementfor paymentfor the constrtsction of the field laboratoryshall be on square metresof plinth area.

‘l’he sttpplv of testing equipment,the erection, maintenanceand.running the. sante shall he on a lump sum basis.

121.7. Rate

If provide.d in the Bill of Quantitiesas a separate payableitem,thd~contract unit rate for constructingandproviding the field laboratoryshall include, expensesof all operationsinvolved in construction ofthe httilding includingall services,fittings, fixtures, furnitureandfencingas mentioned in Clause 121.2,

The Contract unit rate for maintenanceshall include expensestowards’ all items of works and equipmentin Clauses. .121.2 and 121.3including powerand water chargesfor supply from the mains and forproviding uninterrupted supply of power and water from alternatesourcesin case of failure of main supply.

29

Section 100 General

The. Contract lumpsumrate for the supply, erection,maintenanceand runningof testingequipments,hall include costof supply, installationand running including all consumableslike chemicalsand reagents.

122. SITE RESIDENTIAL ACCOMMODATION FOR

ENGINEER AND OTHER SUPERVISORY STAFF122.1. Scope

The work covers theprovision and maintenance of unfurnishedsile residential accommodation for the Engineer and other supervisorystaff.

The Contractor shall arrange to provide residentialaccommodationconstructed asshown in the drawings,

Work includes providing electric supply,all electrical items likewiring, switches,all fittings, lights, fans, etc.complete;providing watersupplyand sanitation includingall pipes, littings, tanks,tube well, pumps,valves etc. complete; septic tank, sewer lines,drains,fencing, internalroadsetc.., complete asshown in the drawings.

122.2. Ownership

The. site residential accommodationwith all services andfittingsetc., shall he the propertyof the Employer.The land for the residentialacconi modat ion shall be provided by the Engineerand the location shallbe as indicated by the Engineer. TheContractor shall provide theresidentialaccotnmodationwithin 4 months from the date ofcommence~me.nt of the. work or 3 months from the date ofproviding land andthe working drawings for the constructionof residentialaccommo~dation, whichever is later.

122.3. Maintenance

The Contractor shall arrange tomaintain the supervisory staffresidential accommodationuntil the issue of Taking OverCertificat.e fbrthe complete work.

Maintenance includes attending to repairs to variousparts of thebuilding, fittings etc. and the connectedservices as and whennecessary,including the annualwhite/colour washing of the building and periodicpainting of wood and steel work; replacing the broken window/door,ventilator glassesand otherhardware;andmaintenanceof internal roads.

The Contractor shall arrange to provide uninterruptedsupply ofelectricity and water forthe buildings. In case offailure of main wateror power supply, suitable alternate arrangementshall be made for

30

General Section100

providmg uninterrupted supply. All sources/tappings and connectedenuipment and flttings, piping, tanks, wiring and all other accessoriesof the. main and alternate power/water supply for the residentialaccommodation shall be the property of the Employer.

122,4, Measurementfor Payment

The measurement forconstructionof the residentialaccommodationshalt be on squaremetresof piinth area of theaccommodation.Thepayment shall bemade after the residential accommodation,completewith all services, fencing etc., is constructed and handed over foroccupation.If the Contractorfails to completeand hand over thecompleteresidential accommodation within theperiod stipulated under Clause122.2, an amountof Rs. 50,000 per month orpartthereof shallbe. debitedto the Contractor’saccount for the peiiod of delay.

The measurement formnaintenanceof supervisory staffresidentialaccommodation shall be inmaintenancemonths and shallbe made oncompletion of satisfactory maintenance everymonth. If at any stagethe Contractor fails to carryout the required maintenance satisfactorily,an a.mount of R.s, 25,000 per month or part thereofshall he debitedtc.~ the Contractor’s account. In addition, the month/months duringwinch the tontractor fails to carry out the requiredmaintenancesatisfactorily shall not be measured forpayment.

If theContractworks are notcomnpletedwithin the stipulatedperiodor within the granted extended time of completion, maintenance ofre.si-den ti~daccommodationin accordancewith Clause122.3shall be carriedout by the C.ontractorat his own cost and as suchno paymentshallhe. made. for the same.in case of any failureby the Contractorto doso, an amount ofRs, 60,000 per month orpart thereof shall bedebitedto the Contractor’saccount.

122.5. Rate

The Contractunit rate for constructingand providingresidentialaccommodation forthe Engineer and other supervisorystaff shall in-elude cost ofall the. operationsinvolved in construction of buildingsand connected services and fittings,fencing etc. complete.

The Contract unitratefor maintenanceshall include the expensesfor all items of work detailed in Clause122.3 including provisionof uninterrupted supply of power andwater.

31

Section100 General

123. PROVIDING AND MAINTAINING WIRELESSCOMMUNICATION SYSTEM

123.1. Scope

The work coverstheprovision and maintenance of wirelesscoinmunieation systemswith necessarymobile/basetrans-receiversand otheraccessories,

123.2, Supply

The Contractorshall arrangeto supply, install and commissiontheeimpletewirelesssysteniof approvedquality suitable for a rangeof upto65 km. The system shall consist of the foltowingE

(a) Mobile ‘t’rans.~receiversuitablefor mounting on 4 wheelers with Microphone st...sembly, Mobile Antenna with Oable and External Speakerassembly(3 \V audiooutput) with all necessaryfittings and accessories- IC sets.

(h) Base Trans-receiverswith Microphone assembly suitable Antenna, csternatspeakertush (3 SY audio output) with all necessaryfittings a.r,.d accessories- 3sets,

(c) I-land held radio sets .. to Not,

The Contractor shall provide the complete wireless system within12 months from the date of commencement of work or 8 months fromthe ttate. on which frequency is allotted to him by the Coy L Department,whichever is later. FTc shall submit a guarantee for replacement of anyd,e.feclive. trans-receiver/trans-receivers during the hurrency of the. con----tract.

123.3. Approval

The Contractor shall. arrange to obtain all necessary statutory

approvalsFrom various Governmentbodies for operatingthe system,. Heshall also fulfil the requirementslaid down hy various GovernmentDepartmentsand obtain the frequency to operatethe wirelesssystem.

123.4. Maintenance

The Contractorshall arrangeto maintain the entire wirelesssystemincluding the mobile and base trans—receiversandall accessoriesuntilthe issue of the Taking Over Certificate for the completework, Heshall replaceany Trans-receiveror accessory which goes out of order,at his own cost andprovideall necessarysparesand attendto all repairsnecessaryfor keeping the complete system in satisfactory workingcondition, On issue of the Taking Over Certificate after obtainingclearancefrom theEngineer,theContractorshall dismantlethe completewireless system and hand over to the Engineer.

32

General Section100

1233. Measurements for Payment

The measurementfor supply and installation of wire:iecs system shallbe on lumpsum basis for the complete system as described in theprecedingpans.

If the Contractor fails to commission and hand over the completewireless systemin the stipulated time, an amountof Rs, 10000permonthor part thereof shall be debited to the Contractor’s account.!

The measurement for maintenance of the wireless system shall beon maintenance monthsand shall be made on completion of satisfactorymaintenanceeverymonth. If the Contractorfails to carry out the requiredmaintenanceas directedby the Engineerat any stageof work, an amountof Rs, 5000~ermonth or part thereof shall be debited to the Contractor.In addition, the month/months during which the Contractor fells to

carry out therequiredmaintenanceshall not be measured for payment!if the ContractWorks are not completed within the stipulatedperiodor within grantedextended time of completion, the maintenanceofwireless systemin accordancewith Clause 1214 shall be carried outby the Contractorat his own cost andas such, nopayment shall bemade forthe same. In case ofany failure by the Contractor to doso, an amount ofRs. 8000 permonth or part thereof shall be debitedto the Contractor’saccount.

1216. Rates

The Contract unit rate forthe supply and installation of wirelesssystemshall cover all the expenses towardsthe supply oF all necessaryitems and expenses towards obtainingstatutory approvakand operatingtrequency erection ommis’aoning ‘~nd h mud~n°o~ U it inn c orreplacementof the trans~receiverftrans-receivcrs (which arc frmund defec~the) during the currency of the Contract md all other incidentals,

The Contractunit rate for the maintenanceof wireless system shallbe payment infull for carrying out periodic servicing and checkingof the system!!, replacement of components,attending to all necessaryrepair,paymentof taxes, ifany,andotherinddentals to keepthe completesystem in satisfactory working condition.

124. PROVIDING AND ML% INTAI:NENG VEHICLES FORTHE ENGINEER

124.1. Scope

The work coversprnvtd~ng and maintaining of hard top ~es~cnger

3:1

Section 100 (ieneral

cars and br hard top leeps for use by the Engineeras describedunderthe Bill of Quantities,

124,2, Description

The passenger cars shall be petrol or diesel driven and may he Am.hassadoror equivalenthaving cylinder capacity of minimum 1400 ccThe hard top jeeps shall be 4 \V Drive either petrol or diesel drivenand may be Maruti Gypsy Model MG 410, Mahindra& Mahindra leepModel MM540/MM~440or equivalent. The number of vehicles to h1’pm idc.d by the Contractor shall be decided hy the Engineer at van nolimes, out of the total provision in the B ill of Quantities and md tEntedin writing.

The Contractor shall provide within one month from the due oforder by the Engineer,vehicles as indicated above, l’he vehiclesshal Ihe provided and maintained unhl issue of the Taking Over (‘ertifitEatLfix the complete Work. Initially, new vehicles shall he provided, incase of vehicles of Indian make. a velt ide shall be replaced with anew xrc’hiclt~ after a maxim tim run of 75,001 km or two years whiche ciis earlier, in caseot vehuElesof lbreign make approvedb~’the Engineerthe vehicle shall be replaced with a new vehicle after a maximum runuI 1,00,0110 km er three Lears u~hicheveris earlier. All necessary taxesfor operating the vehieic’ shall he hilly prod anti all necessary papers,shal be prosided as reru red hy prevailing Motor Vehicles Act tvi thiEomprrhensivc in~u rance :ov er for the vehicles. The vehicles shall heprovided da> and night a’i required by the Engineer The Contractorshall also makE’ as ailEd~lc. ~lnvrrs hEEivmne valid licence at such tunes andor such duration as I nstruER d by the Engineer.

124.3. Ma i ritena mit

The vehicles shall hi’ “Pain tainet:l in a smooth rurning condoinn \l Iexpenses required ha kecping the vehicles in smooth runnine tEui](lltil)fl

such as fus’l, luhrieati.eu oil and oi her consumables, necessarx ~ o teeantI maintena.rtt’e, dri,ers, rep:.iirs and rei:dacenient etc. are to IL’ nihy the Coiitraetor. In the evcx I of any x’r’hiele being off the reidbr main lenan ?s’ or on acEe 01tnt of breakdown the Contractor shall pro V disubstitute vehicic(s) immediately, If the Contractor at any time tah sprovide vehicle(s) or substitute vehic Ic(s) as specified above, an anioni’~t

of Es. 500 per day dir part thereef for each vehicle (that the Contra trirfailed to pro~’~tie) shall he del’ i ted U the Contractor’saccount. Also thenumher of days for which the sehicle(s’l were not prov iderl shaltnot he mel tided for pay me nt.

.34

Ocncrat Secuon (Xi)

If the ContractWorks arenotcompletedwithin the stipulatedpenodor within the grantedextendedlime of completion, provision and mauitcnanceof vehicles in accordancewith Clause124.,! through 124 4 shallbe carriedoot by the Contractorat his own cost and no payment shallhe made for the same. In caseof any failure by the Contractor todo so an amount of R s, 700 per clay or part thereof per vehicle s ft illhe debited to the Contractor’saccount.

124.4. Withdrawal of Vehicles

the Contractor shall withdraw particular cc hide/vehicles fbr thenon-use by the Engineer if so directed by the Engineer. In such ca~e’~the instructionsfor non-useof vehicleshall be given in writing 15 c1a~in advanceand the withdrawal of vehiclesshall not be for a period Hle.ss than 1,5 days continuouslyat a time.


The payment for providing and maintaining vehicles shall b1vehicle clay basis for actualnumberof clays the vehicleswere prn’;ri satisfiictory working order, No paymentshall be male for the ~:~e

of withdrawal as per Claus..: IN ~1irrespectiveof the fact wlte:hc~rehiclewas available or not

124,6. Rates

lhe Contract unit ratc tor providing and maintaining vehicle”:Engineer shall include all expensestowards providing and eel’I!ng lLhL,

vehicles in smooth running condition including taxes dc rn “ni’ ‘iI ri the. preceding paras.

125. SUPP[.X OF COLOUR RECORD PF1OTOGRAPIISAND ALBUMS

125.1. Scope

The work coversthe s ippl of photographs,negati e~~. ani I all ‘~into serve a.s a permanentrec orit of various stages/1”acet~ c’; I he c~‘~r

neecled br an authentic dricumentat ion as approvedb~ h a r’ ng I

125,2. Description

The Contractor shall arrangeto take colour photographsacvstages/facets of the worl: including interesting and no’ H (cat ‘resof the work’ as desired h) the Engineer. The. photograph.’;; shalt heacceptablequality and they shall he tal•:en by a professiorally ci rrrrpe.en’

photographerwith caineri having the facility ro reeoriI te U t “ ‘1

Section 1(X) General

photographstakenin theprintsandnegative.The Contractorshall supplytwo colour prints of each of the photographs taken to the standardpostcard sizemounted in albums of acceptablequality. Also the negativein 35 mm size shall be supplied for each photograph. Each photographin the album shall be suitably captioned.


Supply of two copiesof colour record photographs mounted inthe albums and the negative thereof shall be measured in numberof record photographssupplied.

Supply of additional prints of cokiur record photographsshall bemeasured in number of additional prints supplied.

125.4. Rate

The rate for the supply of record photographsshall include the costof taking the photographs.developing and obtaining colour printscost of album, mounting of photographsand captioning the same etc.

The rate for additionalcolour prints shall similarly includeall ensisincurred..

The photographsandmaterialsincluding negativesshall form a partof the recordsof the Departmentand the prints o..f the samecannothe suppliedto anybedvelse or publishedwithout the written permissionof the [)epartment

126. SUPPLY OF VIDEO CASSETTES

126.1. i)escription

The work consktsof taking video films of important activities ofthe work asdirectedby the Engineerduring, the currency of the proiectandediting them to a vidpo film of playing time not less than 60 minutes‘md upto 180 minutes as directed by the Engineer. It shall containnaiTation of thenetivities in English by a competentnarrator. Theedition of the video 1dm and the script for narration shall be as approvedby the Engineer.The video cassettesshall be of acceptable qualityand the film shaL he capable of producing: colour pictures.

126.2. Measurenients for Payment

The nlea’anement shall be by numberof sets of edited mastercassetteseach . with four copies thereof.

36

General Section11)0

126.3. Rates

The contractunit rateshall includeall expensesfor making videofilms with the help of a professionallycompetent photographer,editing,narration and supplying the final edited master cassetteaiongwiihtour copies thereof..

Site Clearance

200

Site Clearance

Site Clearance Section 200

201. CLEARING AND GRUBBING

201.1. Scope

This work shill consist of cutting,,, removing and disposing of allmaterials such as Lrees, hushes,shrubs,stumps, roots, grass,weeds,toporganic soil not exceeding150 mm in thickness,nibbish etc., which inthe opinion of the Engineerare unsudable for incorporation in theworks, fnmi the. areaof road land containing road embankment, drains,crossdrainage, structuresand such other areasas may be specifIed onthe drawings or by the Engineer. it shall include necessaryexcava-tion, backlilling of pits resulting from uprootingof treesand stumpstorequired compaction, handling, ‘salvaging, and disposal of clearedmaterials, Ck.arin,g and grubbing shall be performed in advanceofearthworkoperationsand in accordancewith the requirementsof theseSpecifications.

20L2. Preservatkniof Property/Amenities

Roadsidetrees,shrubs,any otherplants,pole lines, fences,signs,monuments,buildings,pipelines.,.sewer~andall highway facilities withinor adjacentto the highway’’~.vhichare not to bedisturbedshall be protectedfrom injury or damage. The Contractorshall provide and install athis own expense, suitable safeguzudsapprovedby the Engineer forthis purpose.

During clearing and grubbing, the Contractor shall takeall adequateprecautionsagainstsoil erosion,waterpollution, etc., andwhererequired,undertakeadditional works to that effect vide Clause306. Before startof operations,the Contiactor shall submit to ‘the Engineerfor approval,his work plan including the procedureto be followed for disposalofwaste materials,etc.., and the schedules for carrying out temporaryand permanenterosion control works as stipulatedin Clause 306.3.

2013, Methods,Tools and Equipments

Only such methods,tools and equipmentas are approvedby theEngineerand which will not affect the property to ‘be preserved shallbe adopted for the Work. If the area has thick vegetation/roots/trees,acrawler or pneumatictyred dozerof adequatecapacitymay be used forclearancepurposes.The dozershall haveripper attachments for removalof tree stumps,All trees,stumps,etc., falling within excavationandfill lines shall be cut. to such depth below ground level that in no easethesefall within 500 mm of the subgrade.Also, all vegetationsuch as

41

Section 200 SiteClearance

roots, indeNgrowth, grass and otherdeleteriotis matter unsuitable forincorporation in the embankment/subgradeshall be removed betweenfill lines to the satisfactionof the Engineer.On areas beyond theselimitiE, trees andstumps required to be removedas directed by theEngineershall be cut down to I m below ground level so that thesedo not present an unsightly appearance.

All branches of trces extending abovethe roadway shallhetrimmed as directed by the Engineer.

All excavations below the general groundlevel arising out of theremoval of trees,stumps,etc., shall be filled with suitable material andcompactedthoroughlyso as to makethe surfaceat these points conformto the surrounding area.

Antli ills both aboveand below the ground,as are liable to collapseand obstructfree subsoil water flow shallbe removedand their workings,which may extend to severalmetres, shall be suitably treated.

201.4. Disposal of Materials

All materials arising from clearing and grubbing operationsshallhe the propertyof Governmentand shall hedisposedof by theContractora.s hereinal’ter provided or directed by the F...ngineer.

Trunks, branches and stumpsof trees shall be cleaned of limbs androots and stacked,Also boulders,stones and other materialsusablein road construction shall beneatlystacked as directedby theEngineer.Stackingof stumps,boulders,stones etc., shall he done atspecified..spotswith all lifts and upto alead of 1000 m.

All products ofclearing and grubbing which, inthe opinion of theEngineer, cannot be used orauctionedshall be clearedaway from theroadsidein a manneras directedby the Engineer. Care shall he takento see that unsuitable wastematerialsare disposedof in such a mannerthat there is no likelihood of lhese gettingmixed up with the materialsmeant for embankment,subgradeand road construction.

201,5. Measurementsfor Payment

Clearing and grubbing for road embankment, drains andcross-drainage structures shall bemeasuredon area basis in terms of hectares.Clearing and grubbing of borrow areas shall bedeemedto he a partof works preparatory toembankmentconstruction and shallbe deemedto havebee.nincludedin theratesquoted for the embankmentconstructionitem and no separatepayment shall he made forthe same. Cutting of

42

SiteClearance Section20()

trees upto 300 mm in girth including removalof stumpsandroots, andtrimming of branchesof tmes extendingabove the roadway shall beconsideredincidental to the clearingand grubbing operations.Removalof stumpsleft over after treeshave been cut by any other agencyshall also be consideredincidental to the clearing and grubbingoperations.

Cutting, including removal of stumpsandroots of trees of girthabove 300 mm andhackfilling to requiredcompaction shall he measuredin ten-os of number according to the sizes given below:-

i) Above 3(X) mm to 6()0 mm

ii) Above 6(X) mm to 900 mm

fl) Above 9(X) mm to 1800 mm

iv) Above 1800 mm

For this purpose,the girth shall be measuredat a height of 1 metreabove ground or at the top of the stump ii the height of the stumpis less than one metre from the ground.

201.6. Rates

201.6.1, The Contract unit rates for the various items of clearingand grubbing shall be paymentin full for carrying out the requiredoperations including full compensation for all labour, materials,tools,equipmentand incidentalsnecessaryto complete the work, These~vi11also include removal of stumps of trees less than 300 mm in girth aswell as stumps left overafter cutting of trees carried out by anotherag:ncy, excavationandback-filling to requireddensity,wherenecessary,and handling, salvaging,piling and disposing of the clearedmaterialswith all lifts and upto a lead of 1000 m.

201.6.2.The Contractunit rate for cutting (including removal ofstumps and roots) of trees of girth above 300 mni shall includeexcavation andhackfilling to requiredcompaction,handling,salvaging,piling and disposingof the cleared materialswith all lifts and uptoa lead of 1000 m.

201.6.3.Wherea Contractdoesnot includeseparateitemsof clearingand grubbing, the sa.me shall be consideredincidental to the earthworkitems and the Contractunit prices for the sameshall be consideredasincluding clearing and grubbing operations.

.:j 1

Section200 Site Clearance

21)2. DISMANTLING CULVERTS, BRIDGES ANDOTHER STRUCTURES/PAVEMENTS

21)2.1. Scope

This work shall consistof removing,as hereinafterset forth,existingculverts, bridges,pavements,kerbs and other structureslike guard~rails.,fences, utility services.,manholes,catch basins, inlets, etc.~~)which arein place but interferewith the new constructionor are not suitable toremainin place..~,andof salvaginganddisposingof the resulting materialsand back filling the resulting trenchesand pits.

Existing culverts, bridges,pavementsand other structureswhichare within the highway and which are designated for removal, shallbe removedupto the limits and extent specified in the drawingsor asindicated by the Engineer.

Dismantling and removal operationsshall hecarried out with suchequipment and in such a manner as to leave undisturbed, adjacentpavement,structuresaud any other work to be left in place.

All operationsnecessaryfor the removal of any existingstructurcwhich might endangernew constructionshall be completedpnor w.the start of new work.

20L2. Dismantling Culverts and Bridges

The structures shall be d~srnantledcarefully and the resuhmymaterials so removedas not to causeany damageto the serviceable’materials to he salvaged, the part of the structureto be retained andany other propertiesor structuresnearby.

Unless otherwise specified, the superstnictureportion of eulvcrts/bridges shall he entirely removedand other parts removedbelowthe ground level or as necessarydependingupon the interference,theycauseto the new construction.Removalof overlying or adjacentmaterial,if required in connectionwith the. dismandingof the structures,.~shallbe incidental to this item.

Where existing culvert.sfbridgesare to be extended or otherwiseincorporatedin the new work, only such part or parts of the existingstructureshall he removedasare necessaryanddirectedby the Engineerto providea properconnectionto the new work. The connecting edgesshall be. cut,chippedandtrimmedto the requiredlines andgradeswithoutweakening,or damaging any part of the structureto be retained,Duecare should he taken to ensurethat reinforcing bars which are to he

44

SiteClearance Section200

left in place so as to project into the new work as dowels or tiesare not injured during removal of concrete,

Pipeculvertsshall hecarefully removedin sucha manneras to avoiddamageto the pipes.

Steel structuresshall, Unless otherwiseprovided, be carefully dis-mantled in such a manneras to avoid damageto membersthereof. Ifspecified in the drawings or directed by the Engineer that thestructure is to be removedin a condition suitable for re-erection,allrnemhersshall be match-markedby the Contractorwith white leadpaintbefore dismantling; endpins, nuts loose plates,etc., shall be similarlymarke.d to indicatetheir proper location; all pins, pin holes an.dmachinedsurfacesshall be paintedwith a mixtureof white lead and tallow andall looseparts shall be securely wired to adjacentmembersor packedin boxes,

Timber structuresshall he removed in such a manneras’ to avoiddamageto such timber or lumber as is designatedby the. Engineertobe salvaged.

202.3. Dismantling Pavementsand Other Structures

In removing pavements, kerhs, gutters. and other structureslikeguard-rail’;, f~.nces,manholes,catch basins, inlets, etc., where portionsof the c~istingconstructionare to be leSt in the finished work, thesame ‘thall be removedto an existing joint or cut and chipped toa true line, with a face perpendicularto the surface of the existingstructure,Sufficientremoval shall be madeto provide for proper gradesand connectionswith the new work as directed by the Engineer

AU concretepavements,basecoursesin carriageway and shouldersi.acE. desoEnate.dfor removal shall he brokento pieceswhosevolume shallnot ‘.‘ scce.d 0 02 cu. m, ~mci stockpiled at designate.dlocations ifthe material is to he used later or otherwise arrangedfor disposal asdirected (see Clause202,5)

202.4. Back-filling

Holes anti depre ‘eons LEaused by dismantlin,g operationsshall hehackfilled with ~ ,‘OE other approvedmaterialsand compactedtorequired density as dire~ted by the Engineer.

292.5. Disposal of Materials

All materials obi unto by disin totlu .. ‘ di h th n otGovernnitnt lJnlessoth twi o s; II s imE~,

Section 2110 SiteClearance

value shall he placed in neatstacksof like materialswithin the righ ocThway, as directed by the Engineer withall lifLs and uptoa lead of1000

Pipe t: ulverls that are removedshall he cleanedand neatly piledon the nght•~of~wayat points’ designatedby the Engineerssith all liftsand lead upto 1000 in.

Structura.i steel removedfrom old structuresshall, unlessotherwisespec’ibed or directed, he stored in a neat and presentablemanneronblocks in locations suitable for loading. Structuresor portions thereofwhich are specified in the Contract for re~erectionshall he storedinseparate ~i1e~,

‘Timber or lurn her from old structures whichis desig naledby theE: ng ineeras rnateria Is to hesalvagedshall haveall nails and bolts remove.iltheret’roin and shall be stored in neat pilesin locations suitalElle forloading.

Al I materia.ls obtained from dismantling operati015 which, ut theip in i miii of the En~ineer, cannothe tised or auctionedsl all be disposed

of as cI ireeted hy the f.i.ngineer with all lifts and upto a lead of 10011nEt


The work of ilisniantling structuresshallbe paid for ut units indicated‘I miw hy ok inc iu easiu’ernentsbefore anil after. asapplicable’

ot Osinarililig t’rtck/sinnc masonry!sonorole (1iliiri rid reinforced) cci in

tot Disinani irrg fte~Ste and cernciiiconcreie pas’ririent en. in

jut nsrnarrwnt.~sleet siruciiire~ ionrie(iv) tE)irrnarrikinii i rnher srmcruret cii in

(v) t)isrnarittirig nlrxrs tonrit rails,kerb.s, guilL rs Mid iitriciig irrear ft

(vi) t.Jiitiiy senices Nor

202.7. Rates

The Contract i nit rates for the various i teins of disinantiing shallpaid in hill for carrying out the required operations includinghill

a ipen sation for all labour, materials, tools, ec~tupnlent, safeguards andneidentals necessary tocompletethe work. Thesewill also include cx.‘avation and back lilling wherenecessaryto the required compacLionanti for handling, salvaging, piling and disposing ofthe cli.smantlta:lmaterials within all lifts and upto a lead of1000 rn,

Earthwork, Erosion Control andDrainage

300

Earthwork, ErosionControl and Drainage

Earthwork, Erosion Control Section 300and Drainage

301. EXCAVATION FOR ROADWAY AND DRAiNS

301.1. Scope

This work shall consist of excavation, removal and satisfactorydisposalof all materialsnecessaryfor the constructionof roadway,sidedrains and waterwaysin accordancewith requirements of these Speci~fications and the lines, gradesandcross-sectionsshown in the drawingsor as indicatedby theEngineer. It shall include the haulingand stackingof or hauling to sites of embankmentandsubgradeconstruction,suitablecut materialsas required,as also thedisposalof unsuitablecut materialsin specified manner, trimming and finishing of the road to specifieddimensionsor as directed by the Engineer.

301,2. Classification of ExcavatedMaterial

301.2.1. Classification All materialsinvolved in excavation shallhe classified by the F...~gineerin the following manner:

(a) Soil

This shalt comprisetopsoil, turf, sand,silt, loam, clay, mud, peat, black cottonsoil, soft shale or loosemoomna,a mixture of these and similar material whichyields to the ordinary applicationof pick, spade and/or shovel, rake or oth,e.rordinary digging implement. Removal of gravel or any other nodular materialhaving dimension in any one directionnot ‘exceeding75 mm occurring in suchstrata shall be deemedto be covered under this category.

(It) Oniinaxy Rock (not reqttiring blast.ing)This shall include:

(i) rock typessuchas laterites,shalesand conglomerates,varieties of limestoneand sandstoneetc.,, which may be quarried or split with crow bara,alsoincluding any rock which in dry slatemay be hard, requiring blastinghutwhich, when wet, becomessoft and manageable by means other thanblasting;

(ii) macadam surfaces suchas water bound and bitumen/tar bound; solingof roads, paths etc. and hard core; compact’moorumor stabilisedsoilrequiring grafting tool or pick or both and shovel,closely applied; graveland cobble stonehaving maximumdirt. ensionin any one directionbetween75 and 300 mm;

(iii) lime concrete,stonemasonryin lime mortar and brick work in lime/cementmortar below groundlevel,reinforcedcementconcretewhich may be brokenup with crow bars or picks and storw masonry in cement mortar belowground level; and

(iv) boulderswhich do not require. biaating having maximum dimension in anydirection of morethan 300mm, found lying looseon thesurfaceor embeddedin river ‘bed,soil, talus, slopewashand terrace material of dissimilar origin.

.49

Section 300 Earthwork,ErosionControl and Drainage

(c) Hard Rock (reqsüringblasting)

This shall comprise:

(i) any rock or cement concrete for the excavation of which the usc ofmechanicalplant and/or blasting is required;

(ii) reinforced cementconcrete (reinforcement cut throughhut not separatedfrom the concrete) below ground level; and

(iii) lxsulders requiring blasting.

(il) Hard Rock (blasting prohibited)

I-lard rock requiringblastingas describestunder(c) but whereblasting is prohibitedfor any reason and eacavation has to be carried out by chiselling, wedging orany other agreed method,

(c) Marshy Soil

This shall include soils like soft clays and pearseacavatedbelow theoriginalground level of marshes and swamps and soils excavated from other areasrequiring continuouspumpi g or bailing out of water,

301,2.2. Authority for classification The classification of exca-vation shall he decidedby the Engineerand his decisionshall be finalandbindingOn theContractor.Merelythe~useof explosives in excavationwill not be consideredas a reasonfor higherclassificationunlessblastingis clearly necessaryin the opinion of the Engineer.

301.3. Construction Operations

301.31. Sedingout After the site hasbe.e.nclearedas per Clause201., the. limits of excavationshall he set out hueto lines, curves,slopes,

grades and sectionsas shown on the drawings or a.s directed by theEngineer.,The Contractor shall provideall labour, survey instrtimentsand materials such as strings, pegs., nails, bamboos,stones,lime,, r.orl.ar,concrete,etc.., required in connectionwith the settingotit of work,s andthe e.,sl.ablishmentof bench marks. The Contractor shall be responsiblefor the maintenance,of benchtnarksand othermarksand stakesas” long.as in t.he. opinion of the Engineer,they are required for the work.

301,3.2. Stripping and storing topsoil W’’hen so directed by the.Enginte.,the topsoil existingoverthe silesof excavationshall be strippedto spe.cifieddepthsconstituting Horizon “A” and stockpile.dat designatedlocations for re-usein coveringembankmentslopes, cut slopes,berrnsand olher disturbedareaswherere-vegetationis desired.Prior to strippingthe topsoil, all trees,shrubsetc. shall be removedalong with their roots,with approval of the Engineer.

301,3.3.Excavation - General All excavations shall he carrie.dout in conformity with the directions laid here’.-in~underand in a manner

50

Earthwork,ErosionControl andDrainage Section300

approvedby the Engineer,The work shall beso done that the suitablematerialsavailable from. excavationare satisfactorilyutilized as decidedupon beforehand.

While planningor executingexcavations,the Contractor shall takeall adequateprecautionsagainstsoil erosion, water pollution etc. as perClause306, and take appropriatedrainagemeasures to keep the sitefree of water in accordancewith Clause 3li.

The excavationsshall conform to the lines, grades,side slopesandlevels shown on the drawings or as directed by the Engineer. TheContractor shall not excavateoutsidethe limits of excavation.Subjectto the pennitted tolerances,any excessdepth] width excavatedbeyondthe specified levels/dimensionson the drawingsshall be madegood atthe cost of the Contractorwith suitablematerialof characteristicssimilarto that removedand compacted to the requirementsof Clause 305.

All debris and lose material on the slopesof cuttings shall beremoved. No backfilling shall be allowed to obtain required slopesexceptingthat when boulders or soft materials are encOunteredin cutslopes,theseshall be excavatedto approveddepth on instructionsof theEngineer and the resulting cavities filled with suitable material andthoroughly compactedin an approvedmanner..

After excavatior,the sides of excav.atedareashall be trimmed andtheareacontouredto minimise erosionandponding, allowing for naturaldrainageto t4ke.place. If treeswere removed,new treesshall be planted,as directed by the Engineer.The cost of planting new trees shallhe deemed to be incidental to the work.

301.3.4,Methods,toolsandequipment Only such methods, toolsand. equipmentas approvedby the Engineershall be adopted/usedinthe work.. If so desired by the Engineer,th..eContractorshall demonstratethe efficacy of the. type of equipmentto be usedbeforethe commencementof work.

301.3.5. Rock excavation Rock, when encounteredin roadexcavation,shall be removedupto the formation level or as otherwiseindicatedon the drawings.Where, however,unstableshalesor other un~suitablematerialsare encounteredat the fonnation level, theseshall beexcavatedto the extent of 500 mm below the formation level or as

otherwisespecified.In all cases,the excavationoperationsshall be socarried out that at no point on cut formation the rock protrude.sabovethe specifiedlevels. Rocksand large boulderswhich are likely to cause

51

Section300 Earthwork,ErosionControlandDrainage

differential settlement and also local drainage problems should heremoved to the extent of 500 mm below the formation level in fullformation width including drains and cut through the side drains.

Whereexcavationis done to levels lower than those specified, theexcessexcavationshall be madegood as per Clauses3013 3 and 301.6to the satisfaction of the Engineer.

Slopesin rock cutting shall be finished to uniform linescorrespond~ing to slope lines shownon the drawingsor as directed by the Engineer.Notwithstanding the foregoing, all lose piecesof rock on excavaledslopesurfacewhich move when piercedby a crowbar shall be removed,

Whereblasting is to be resortedto, the sameshall he carried outto Clause 302 and all precautions indicated therein observed.

Where presplitting is prescribed to he donefor the establishmentof a specified slope in rock excavation,the same shall be carriedoUt

to (:latise 303.

3411.3.6.Marshexcavation The excavationof soils from marshes/swamps shall be carned out as per the programmeapproved by theEngineer.

Excavationof marshesshall begin at one end and prot~eedin oneJirecnunaLEross tIlL’ entire marsh immediately aheadof backhlling. Themethod and sequenceof excavatin and hackfilling shall he such as toensure, to the extent practicable,the completeremoval or displacementof aM muck from within the lateral limits called for on the drawingsor as stakedby tlie Eonineer,antI to the botton of the marsh.I’i rm s upportor levels indicated,

301 J,7, Excavation of roadshoulders~verge/medianfor wideningof pavement or providing treated shoulder.s:ln work’s involvingwidening of esisting pavementsor providing treated shoulders,unlessot.herwisespel,Eihed the shoulder/scrgc/mcdian shall he reniovedto theirfull width and to levels shown on drawings or as intlicated by theEngineer.While doing so, care shall he takento seethat no portionof the existingpavementdesignatedbr retentionis loosenedor disttirbed,II’ the existing pavementgets d isttirhedor loosened,it shall he dis mantletlanrl cut to a regular shapewith sides verticaland the. disttirhed/loosenetlportion removedcompletely and relaid as directed by the Engineer,atthe cost of the Contractor.

301.18. Excavation for surface/sub-surfacedrains Where theContractprovidesfor constructionof surface/sub-surfacedrainsto Clause

52

Earthwork,ErosionControl and Drainage Section300

:309, excavation for these shall be carried out in propersequencewithother works as approvedby the Engineer.

301.3.9. Slides If slips, slides, over-breaksor subsidenceoccurin cuttings during the processof construction,they shall be removedat the cost of the Contractoras orderedby the Engineer. Adequateprecautionsshall be taken to ensure that during construction,the slopesarenotrenderedunstableor give rise torecurrentslidesafterconstruction.if finished slopesslide into theroadwaysubsequently,such slides shallhe ri~mnovedandoaid for at the Contractrate for the class of excavationinvolved, provided the. slide.s tire not due to any negligenceon the partof’ the Contractor.The classification of the debris ‘material from theslips, slides etc. shall conform to its condition at the time of removaland payment made accordingly regardless of its cOndition earlier.

301.3,10. Dewatering If water is met with in the excavationsdue. to springs, seepage, rain., or other causes,it shall he removedby suitablediversions, pumping or bailing out and the excavationke.pt dry whene.verso requiredor directed by the. Engineer.Care shallhe taken to ciistEharge the. thained water into suitable outlets as ‘notto causedamage to the works, crops or any other property. Dueto any negligence on the part of the Contractor,if’ any such damage.is caused, it shall he the. sole responsibility of the Contractor tore.pair/restore.to the. origtnal condition at his own cost or compensate(Or the damage.

301.3.11- Disposalof excavatedmaterials All the excavatedmaterialsshall be the propertycf the Employer. The. material obtainedfrom the excavation of roadway,shoulders,verges. drains’, cross~drainagesvorks etc.., shall be used for filling up of (i) roatiway emhank~me.nt, (ii) the. existing pits in the right~of~’wayand (iii) for landscapingof the roadasdirected by the Engineer, including levelling andspreadin,gwith all lifts and lead upto 10(X) in and no extra payment shall bemade for the same.

All hard niaterials, suchashardmoortim,rubble, etc., not intendedfor use as above, shall be stackedneatly on ~peeified land as directe.dby the Engineer svith all lifts anti lead upto 1000 m.

UnsuitableantI surplusmaterial not intendedfor use within th.e leadsçieciiied above.sh.al.l also, if necessary,he transportedwith all lifLs antilead beyond initia.i 1000 m, disposed of or tised as directed by theEngineer.

.53

Section300 Earthwork, Erosion Controland l)rainagc

301,3,12. Backfllling Backfilling of masonryfconcrete/humepipedrain excavationshall be done with approved material after concrete/masonry/humepipe is fully set and carried out in such a way as notto causeunduethmst on any part of the structureand/or not to causedifferential sett.lement.All spacebetweenthe drain walls and the sideof the excavationshall be refilled to the original surface making due,allowance for settlement,in layers generally not exceeding 150 mmcompactedthicknessto the required density, usingsuitable compactionequipmentsuch as mechanicaltamper, rammer or plate compactorasdirected by the Engineer.

301.4, Plying of ConstructionTraffic

Construction traffic shall not use the cut formation and finishedsubgrade without the prior permission of the Engineer. Any damagearisingout of such use shall he madegood by the Contractorat his ownexpense.

301.5. Preservationof Property

The Contractor shall undertake all reasonableprecautionsfor theprotection andpreservationof any or all existing roadside trees,drains,sewers or. other sub~surfacedrains, pipes, conduits and any otherstructures underor aboveground,which may be affected by constructionoperationsand which, in the opinion of the Engineer,shall be continuedin use without any change.Safety measurestaken by the Contractorin this respect,shall be got approved from the Engineer.However,if any of these objects is damaged by reason of the Contractor’snegligence, it shall be replacedor restored to the original conditionat his expense.if the Contractor fails to do so, within the requiredtimeas directed by the Engineeror if, in the opinion of theF ngineer,the actions initiated by thO Contractor to replacefrestorethe damagedobjectsare not satisfactory, theEngineer shall arrangethe replacement!restoration directly through any other agency at the risk and cost ofthe Contractorafter issuing, a prior notice to the effect.

301.6. Preparationof Cut Formation

The cut lormation, which servesas a subgrade,shall be prepare.dto receive th( sub-base/basecourse as directed by the Engineer.

Where the material in the suhgracle(that is within 500 mm fromthe lowest level of the pavement)has a density less than specified inTable 300.2, the sameshall he loosenedto a depth of 500 mm andeam pacted in layers in accordantEe with the requirenientsof CIause 305

54

Earthwork,ErosionControl an,dDrainage Section300

Any unsuitable material encounteredin the subgradelevel shall beremoved as directed by the Engineer and replaced with suitablematerial compactedin accordancewith Clause305.

in rocky formations, the surface irregularities shall be correctedand the levels broughtup to the specified elevation with granularbaseniaterial as’ directedby t.he Engineer,laid and compactedin accordancewith the respectiveSpecifications for these materials, The unsuitablematerial shall be disposedof in accordancewith Clause301.3.11. Aftersatisfyingt.he densityrequirements,the cut formation shall be preparedto receivethe subbase/basecourse in accordancewith Clauses310 and311 to receive the sub-base/basecourse.

391,7. Finishing Operations

Finishingoperationsshall include the work of properly shapinganddressing all excavatedsurfaces,

When completed, no point on the slopes shall vary from thede.signatedslopesby more than 150 mm measuredat right anglesto the.slope., except where excavationis in rock (hard or soft) where nopoint shall vary more than 300 mm from the designatedslope.. Inno case sEhail any portion of the slope encroachon the roadway.

The finished cut formation shall satisfy the surface tolerancesdescribed in Clause 902.

Where directed, th..e topsoil removed earlier and conserved(Clauses :301,3,2and 3053.3) shall be spreadover cut slopes, wherefeasible,herm.sandotherdisturbedareas,..Slopesmay be roughenedandmoistened slightly, pri.or to the applicationof topsoil, in order to Providesatisfactorybond.Thedepth of topsoil shall be sufficient to sustain plantgrowth, the usual thicknessbeing from. 75 mm. to 100 mm.

301,8. Measurementsfor Payment

Excavation for roadway shall be measured by taking cross-sections at suitable intervalsin the original position before the workstarts and after iLs completion and computing the volumes in cu. m,by the. method of average end areas for each class of materialencountered,Whereit is not feasibleto computevolumes by this methodbecauseof erratic location of isolated deposits, the volumesshall hecomputed by other acceptedmethods.

At the option of the Engineer,the Contractorshalt teave. depthindicators during excavations of such shapeand size and in such

.55

Section300 Earthwork, Erosion Controland Drainage

positions as direCted so as to indicate the origina] ground level asaccurately as possible.The Contractorshall see that these remainintact till the final measurementsare taken.

For rock excavation, the overburden shall be removedfirst so thatnecessarycross-sectionscould be taken for measurement. Where crosssectional measurementscould not be taken due to irregularconfigurationor where the rock is admixedwith other classes of materials, thevolumes shall he computedon thebasis of stacks of excavatedrubbleafter making 35 per cent deduction therefrom, When volumes arecalculated in this manner for excavatedmaterial other than rock,deductionmadewill be to the extentof 16 per cent of stackedvolilimes.

Worksinvolved in thepreparationof cut formation shall be measuredin units indicated below

(i) Loosening and recompacdng the ... as.m.loosened material at subgrade

ii) Loosening and removal of unsuitable as. m.material and replacing with asuitable material and compactingto required density

(iii) Preparingrocky subgrade ...sq. m.

(iv) Stripping including storing and ... cu. m.reapplicationof topsoil

(v) Disposal of surplus material ... cu. m.heyood initial I 000 ns lead

301.9. Rates

301,91. The Contractunit ratesfor the itemsof roadway and drainexcavation shall he paymentin full for carrying out the operationsrequired for the individual items including full compensation for

(i) selling out;

(ii) transporting the excavated materials and depositing the same on sites ofembankment,, spoil banksor stacking as directed within att lifts and lead uptot000 m or as otherwisespecified;

(in) trimming bottoms antI slopes of excavation;

(iv) dewatering;

~v) keeping the work free of water as per clause3tl; and

(vi) all labour,materials,tools,equipment,safetymeasures,testingandincidentatsnec~cssaryto complete the work to Specifications.

Provided, however,where presplitting is prescribed to achieve a

56


~pecifledslope in rock excavation,the sameshall be paid for vide Clause3015.

3019.2. The Contractunit rate for looseningand recompactingtheloosened materialsatsubgradeshall include full compensation forioosenmgto the specified depth, including breaking clods, spreading inlayers, watering where necessary and compacting to therequirements.

301.93. Clauses301.9.1 and 305.8 shall apply as regards Contractunit. rate for item of removal of unsuitable material and replacementwith suitable material respectively.

301.9.4. TheContractunit rate for item of preparingrocky suhgradeas per Clause301.6shall be full compensationfor providing, laying andcompacting granular base material for correcting surface irregularitiesincluding all materials, labour and incidentalsnecessaryto completethe work and all leadsand lifts.

301.93.The Contractunit rate for the itemsof stripping and storingtopsoil and of reapplication of topsoil shall include full compensationfor all the necessaryoperationsincluding all lifts, hut leads upto 1000m

301,9.6. The Contractunit rate for disposalof surplusearth fromroadway anddrain excavationshall be full compensationfor all labour,equipment, tools and incidentalsnecessaryon accountof the additionalhaul or transportationinvolved beyondthe initial lead of 1000 m.

302. BLASTING OPERATIONS

302.1. General

Blasting shall be carried out in a. manner that completes theexcavation to the. lines indicated in drawings, with the leastdisturbanceto adjacentmaterial.It shall be done only with the written permissionof the Engineer. All the statutory laws, regulations, rules,etc.,pertainingto the. acquisition,transport,storage,handling and use of explosivesshallbe strictly followed.

The Contractor may adopt any method or methods of blastingcons’istentwith thesafetyandjob requirements.Prior to startinganyphaseof the operationthe Contractorshall provide information describingpertinent blasting procedures,dimensionsand notes.

The magazine for the storageof explosivesshall be built to the.designsand specificationsof the Explosives Department concernedandlocated at the~approvedsite. No unauthorizedperson shall be admitted.

57

Sec ion.300 Earthwork,ErosionCcmtrol andDrainage

into the magazine which when not in use shall be kept securelylocked, No matchesor inflammable material shall be allowed inthemagazine.The magazine shall have aneffective lighlning conductorThe following shall be hung in the lobby of the magazine:

(a) A copy of the relevant niles regarding safestorage hot.h itt English and in thelanguagewith which the workers coneented arefamiliar.

(0) A statementof up••to~datestock sn the maga~inc

(c) A certificate showing the lass slate of testing of the lightning conductor.

(to A notice that smok irtg is strictly proh hued.

All explosives shall bestored in a securemannerin cotnpliancewithall laws and ordinances,and all such storageplaces shall he clearlymarked. Whereno local laws or ordinancesapply, storage shallheprovided tothe satisfactionof the Engineeranti in general not closerthan 3PP in from the road or from any building or camping area or

place of human occupancy.In addition to these, the Contractorshallal so observe the following instructions and anyitt Iher additionalinstructionss~’hich may hegiven by the Ene, ineer and shall be responsiblefor damageto property andtiny aecidetitwhich may occur to workrtienor the public on accountof any operationsconnected with the storage,itandlitig or useof explosivesardblasting, The Engineer shallfrequentlycheck the Contractor’scompliance with these precautions.

302,2. Materials, Tools and Equipment

All the materials, tools andequipment used for blastingoperationsshall be of approved type.The, Engineermay specify the type ofexplosives tobe allowed in special casesThe fuse to be used in wetlocations shallhe. sufficiently water-resistantas to he unaffected whenimmersed in water for 30minutes. The Tate of burning of the fuseshall be ttniibrm and definitely known to permit . such a length beingcut as will permit sti fficient time to the firer to reach safety beforeexplosion takes place. Ce,tonatorsshall hecapableof giving effectiveblasting of the explosives. The blastingpo~vder,explosives, detonators,fuses, etc., shall be fresh and not damageddue t.o dampness,moistureor any other cause, They shallbe inspectedbefore use and damagedarticles shall be discarded totally a.i~dremovedfrom the site imrncr1iately.

3023. Personnel

The blasting operationshall remain in the chargeof competentandc ‘iperiencedsupervisorand workmenwho are thoroughlyacquaintedivi ththe details of hartdling explosives and blastingOperations,

58


302,4.. Blasting OperationsTh..e blasting shall be carried out during fixed hours of the day

preferably during the mid-day luncheon hour or at the close of thework as orderedin writing by the Engineer. The hours shall be madeknown to the people in the vicinity. All the chargesshall be. preparedby the man in charge only,

TheContractorshall notify eachpublic utility company havingstruc-ture.s in proximity to the site of the work of his intention to useexplosEives.Such noticeshall be given sufficiently in advance to enablethe companie.sto take such stepsas they may deemnecessaryto protecttheir property from injury. In advanceof any blasting work within50 m of any railway track or structures,the Contractor shall notifythe. concerned Railway Authority of the location, dale., time. andapproximateduration of such blasting operations.

Red danger flags shall be displayed prominently in all directions.during, the blasting operations.The flags shall be planted200 m fromthe blasting site in all dire,ctions.People,exceptthose who actually lightthe fuse, shall he prohibited from entering this area, and ill personsincluding workmen shall he excluded from the flagged areaat least10 minutesbe.fore the firing, a warning siren being soundedlot the.purpose,

The charge hoic.s shall be drilled to requireddepths and atsuitableplaces.Blastingshouldbe as light as possible consistentwith t.horoughbreakageof the material necessaryfor economic loading and hauling.Any method of blasting which leadsto overshooting shall be discon-tinued.

When blastingis donewith powder,the fusecut to the requiredlengthshall he insertedinto the hole and the. powderdropped in. The powdershallbe. gently tampedwith copperrodswith roundedends. The explo.sivc.POwder shall then be covered with tamping material which shall betarnped lightly but firmly.

When blasting is done with dynamiteand otherhig.h explosives,dy-namitecartridgesshall be preparedby inserting the squarecut end ofa fuse. mb the de.tonator and finishing it with nippers at tine opc.tn entl,line. dc.tonatnrgently pushed into the primer leaving 1/3rd of the coppe.rtube expose.doutside. The paperof the cartridge shall then he clc.se.dup anti securely bound with wire or twine. Th..e primer shall be. housr.d.into the explosive.. Boreholesshall be of such size that the cartridgecan easily g.n down. The. holes shall be cleared of all debris and

59

Scetiort300 Earthwork,ErosionControl andDrainage

esplosmveinserted.The spaceof about200 mmn above the chargeshallthen be gently filled with dry clay, pressedhome and the rest of thetampingfOrmed of any convenientmaterial gently packedwith a woodenrammer,

At a time, not more than 10 suchchargeswill be. preparedandiircd. The man in charge shall blow a siren in a recognised mannerfor cautioning the people. All the people.shall then he required to move.to safedIstances.The chargesshall be lighied by the man~in-chargeonly,The man-in-chargeshall countthe numberof explosions.He shall satisfyhintselF that all the charges have been explodedbefore allowing theworkmen 1.0 go hack to the work site,

Alter blastingoperations,the Contractorshall compactthe loose re-Si LI ttal material below suhgrade a.nd replace the material removetibelow stmbgrade with suitable materiaL

302.5. Misfire

In cast’ of misfire, the following procedureshall he observedE

.Suiiieietit tune shall he alloaed to account for the delayedblast, The man—in—~bsrgeshall inspectall the charges and dctenttine the missed c:harge

l~ii~II it is rho hlastin1.; powdercharge, it shall he completely flooded with water

ness Fr ~le shall he drilled at about ~i5tl trios from the old hole and fired. Thisshould lrlasr the ,‘ld charge. Should I I trot hIatt the old charge, the procedureshall ho repeatedtill the old charge is hlr.tstect

11 i lit 5451’ ol ehirges of geltynire, dynamite, etc., the man-itt—chargeshall gentlyrr’nrs’ve the tamping andthe primer with the detortator A frssh detonatorand

u mrr shall then he used to blast the charge. Altsrnattvely, the hole may hreI eared of 10(1 mm of tarrrprngand the drreetisrrr Llten ascertainedby p1wittg

a strel. itt the hole. Anorlrer hole rrr.rs their hedrilled t 50mmaway ,snd parallelor it ibis hole shtall then he ettargedand fired when thte to isfired hole shoeIdexplede.at the same time. ‘fire man-rn-cbarge shall at ortec report to the

ourr,setor’s office artd the Fnrtineer all easesof misfire, the ccrrrse of the sarrrsand ahat steps were taken in ronrreetrontherewith.

If a att sloe has been fOund to he due to defective detonator orilyrnatlirle, the whole quantity in the box from which defective article‘was taken must be sent to the authority directed by the Engineer furinspection 10 ascertainwhether all the remaining materials in the boxare also defective,

302.6. Account

A cLu’eful andday to dayaccountof the explosiveshallhe maintainedlr~y the ConI racior in an approvedregisterand manner which shall heripea to inspection by the Engineer at all times.

60

Earthwork, Erosion Control and Drainage Section300

“‘303. PRESPLITTING ROCK EXCAVATION SLOPES

303.1. General

Presplitting is definedasthe establishmentof a specifiedexcavationslope in rock by the controlled use of explosives and blastingaccessoriesin properly aligned and spaceddrill holes.

The presplittingtechniqueshall beused for forming rock excavationslopes at locationsshown on the plans or as otherwisedecidedby theEngineer,

303.2. ConstructionOperations

Prior to startingdrilling operations for presplitting,the Contractorsha.I I furnish the Engineera plan outlining the position of all drill holes,i:iepth of drilli rig, type of explosives to be used,loading pattern andsequertce of Firing. The drilling and blasting plan is. for record purposesonly andwill not absolvethe Contractorof his responsibility for usingproper drilling and blasting procedures.Controlledblasting shall beginwith a short testsection of a length approved by the Engin.eer The.test sEectiorr shallhe presplit,productiondrilled andblastedand suflTrc. ientmate.naI excavatedsvia’i.reby the Engineercan deier.mnme, if the Contrac-

tor’ s methods haveproduced a.n acceptableslope.

All overburden soil and weathered. rock along the top of ther,.~..xeavatinnfor a distanceof about5 to 15 rn beyond the. drillirrg limits, -

or to the iEm.d of the excavation,as decidedby Engineer shall be removedbelor.e drilling the prespliwng holes, Particularcare and attention sEhaIIhe di recEted to the beginning andend of excavationsto ensurecomplete.removal of all overburdensodand we.athere.drock and to expose I resEhrock to an elevationequal to the bottom of the adjacent lift of the.

lwesplittimtg holes being drilled,

Slope. holes for presplitting shall he drilled along the lin.e of theplanned slope within the specified tolerances,The drill holes shallbe not less than 60 mm nor more. than 75 mm in diameter, Drillingopera.uotts shall be controlled by the use of proper equipmentarldltechmuque to ensure.that no hole shall deviate from the plane of theplanneil slope by more. than 300 mm nor shall any hole deviate frombeing parallel to an adjacenthole by more than two~third of the.planned horizontal spacing betweenholes.

The length of presplit holes for any individual lift shall not excee.d9 ni.

61

Srction 300 Eanhwork,ErosionControl and Drainage

The spacingof presplit holesshall not exceed 900 mm on centresand shall be adjusted to result in a uniform shear facebetweenholes-

Auxiliary drill holesalongthe presplit line, not loaded or stemmed,may be orderedby the Engineer.Exceptfor spacing, auxiliary drill holesshall conform to the provisions for presplit holes.

The line of production holesshall be placed inside thepresplitlines in such a manneras to avoid damageto the presplit face.

If necessary,to reduceshatterand overbreak of the presplit surface,the first line of the production holes shall be drilled parallel tothe slope line at the top of the cut and at each bench level thereafter,

Any blasting technique,which results in damage to the presplitsurface, shall be immediately discontinued,

No portion of any production hole shall be drilled within 2.5 niof a pm’esplit plane exceptas approvedby the Engineer. The bottomof the productionholesshall not be lower than thebottotu of the presplitholes,

A u’taximum offset of 600 mm will he permitted for a constructionworkiog benchat the bottom of each lift for use in drilling the nextIO\5dr presplitting pattern.The dlrilling operationsshall be adjustedtocornperrsatefor drift of previouslevels and for the offset at the startof new levels to maintain the specified slope plane.

‘rhe maximum diameterof explosivesused in presplit holes shallnot be greater than one-half the diameterof the presplit hole,

Only standardcartridgeexplosivespreparedandpackagedby explosiveotaoufacturingfirms shall beused in presplit holes, Theseshall he firedas roconimcndcclby the manufacturer,Ammonium nitrate compositionblasting agentswill not be permitted in presplitting operations.

Stemming may be required to achievea satisfactory presplit face.Stemming materialshall be dry free-runningmaterialall of which passesII mm sieve and90 percentof which is retained on 2.80 mm sieve,Stemnmnedpresplit holes shall be completely filled to the collar,

All charges in each presplitting pattern shall be detonated simul—tarteously,

303.3. TolerancesThe presplit face shall not deviatemorethan300 mm from the plane

passingthrough adjacent drill holes, except where the character of the

62


rock is such that, as determined by the Engineer, irregularities areunavoidable, When completed,the averageplane of the slopes shallconfbrnt to the slopes indicated on the plans and no point on thecumpletedslopes shall vary from the designatedslopes by more than300 mm. Thesetolerancesshall be measuredperpendicularto the planeof the slope. En no caseshall any portion of the slopeencroachonthe side drains.

As long as equally satisfactory presplit slopes are obtained, theneither the. slope facemay be presplit before drilling for productionblasting or presplitting the slope face and productionblasting mayhe done. at the same time, provided that the presplitting drill holesare fired with zero delay and the production holes are delayed startingai the row of holes farthestfrom the slope and progressing in stepsto the row of holesnearestthe presplit line, which row shall he delayedat least 50 milliseconds, In either casethe presplitting holes shallexteod either to the end of the excavation or for a distanceof notlessthan IS m beyondthe limn its of theproductionholesto be detonated,

303.4. Measurements for Payment

The areaof presplitting to bepaid for will be mneasured as squarenietres of acceptablepresplit slope surface.

303.5. Rates

The Contract unit rate for presplitting ~vorkshall be payntteot 0

full for carrying out the required operations for obtainingacceptable

presplit slope surfaces,The qttantity of rock excavatedthrough theproducton/presplit holes shall be paid for as pen’ Clause 301,9,1.

304. EXCAVATION FOR STRUCTURES

304.1. Scope

Excavatiumn for structuresshall consistof the removal of n-iaterialfor the constrtictiun of fotmdationsfor bridges, c nI verts,retaining walls,headwalls,cutoff walls, pipe culverts and other similar structures, inaccordancewith the requirementsof theseSpecifications and the linesand dimnensionsshown on the drawings or as indicatedby theEngineer.The work shall includeconstructionof thenecessarycofferdamsandcribsandtheir suhseqtnentremnoval; all necessarysheeting, shoring, bracing,draining andpumping; the removal of all logs, stumps,gnihs andotherdeleteriousniatler and obstructions,necessaryfor placing the foundations;trimmning bottoms of excavations; hackfilling and clearing up the siteand the disposal of all surplus material.

61

Section300 Earthwork,ErosionControland Drainage

304.2. Classification or ExcavationAll materials involved in excavation shall be classified in accordance

with Clause301.2.

304.3. Construction Operations304,3.1. Setting out A.fter the site hasbeencleared according

to Clause 201, the limits of excavation shall be set out true to lines,curves and slopes to Clause 301.3.1.

304.3.2, Excavation Excavation shall be taken to the width oft,he. lowest step of the footingand the sidesshall be left plunib wherethe nature of soil allows it. Where the nature of soil or the depth ofthe trench and seasonof the year do not perat.it vertical sides, theContractor at his own expense shall put up necessaryshoring,strutting and planking or cut slopesto a safer angle or both with dueregard to the safety of personnel aqd works and to the satisfactionofthe Engineer.

The depth to which the excavation is to be carried out shall be asshown on the drawings,unless the type of materialencountered is sucha.s to requirechanges,in which easethe depth shall be as ordere.dby the Engineer. Proppingshall be -undertakenwhen any foundationor stresse.dzone from anadjoiningstructureis within a line ol 1 vertica,lto 2. horizontal from the. bottom of the excavation,

Where. blasting is to he resorted to, the same shall he carriedoutin accordancewith Clause302 and all precautions indicatedthereinohserved, Where. blastitig is likely to endanger adjoiningfoundationsor other structures,necessaryprecautionssuch ascontrolled blasting,providing rubber mat cover to prevent flying of debris etc, shall he.taken to prevent any damage.

304.3.3. Dewatéring and protection Normally, open foundationsshall he laid dry. Where water is met with in excavationdue to streamflow, seepa.ge,springs, rain or other reasons,the Contractor shall takeadequate measures such as hailing, pumping, constructing diversionchannels,drainagechannels,bunds, depressionof water level by welhpoint system, cofferdarns and other necessary’works to keep theloundation trenches dry when so requiredand to protect the greenconcrete/masonryagainstdamageby erosionor suddenrising of ~iaLerlevel. The methodsto be adoptedin this regard and other detailsthereof shall be left to the choice of the Contractor but subject toapproval of the Engineer.Approval of the Engineershall, however,not

64

dii: cii nijr;:tiE.ior o[ i,hc respt.rfl ,:irhiirii’y For

tie or

Lire. reduircEd.t.hflsr shall Lie LEa rrdc ILLnIE’d arid (‘ii rsti’’iictid MiLl Ii.: inalEle EE’L’’;

is neces’cEa”y l:’nr facilitatinu, constructiontc.i ha carried

of the cofh::rrdarn’~shall he suirEh asfor thi corOnictieri sni:i irirspr’;.” toni and

el i(’i.iLn’i~riny equ.rpincno. ccc.., nude

it dcterminedbeLirchrindtth:.u the.’ l’aiiriidatio ns ~uEisitoit

i.’~ friand that the peri:Erihieon toothe hmndat.iori iE.oncriEtesl’iEill hr

In caseof floycine ‘aater or .uEteslan sprines, the‘c’ siuppe’.F or redi.iiEiE’Li as Far as possible’ Eli the Lint’: of

iii: iEViIiEEi’EE.tir,

any i.iLiridation eneir’rs~iri’‘iFoill F’cdrineiii f’rri.E’EEttide t.h~’.E’ [Eii.ii;:’:iFiititYIEEPF 1..FiiE: T’lt’i’~’~.niiiEi’ii ‘Ed

eonerc.rte.No phlaipiliii shall be permittedderin,i:r‘Ed EEiI]rr rL’F(’ or for a,nv ju~riodolaF least24 honrs thereafc.r.,

;s ii. is i,loiic: fire i’i’’i ri’~~tiit’tiih’st.iniip separatedfruni tI’te IE:’lencr.:t.’.:’IF a watertlh.lht watt ‘.ir odier simdar rrlcatris.

AL the discretion oF the Contractor, cerrtent i.çroutmng or otherpiire%’ell nicrthods may he usedto preventor reduce seepEipe L:ind

to ][l’rotirc i the exiEEal’atic’lil area.

‘rh.. ContractiErrshall t~.tki:rall precautionsin diverting channelsLindin dischareine;the drainei:i wati:~ras FlOt to causedamage to the sr i:rks.,crops or arty other property.

.304.3.4. Preparationof toundahon Thebouornof the bEiundatirirlIi I I hi.:r Fe. i.’elled blEith longitudinally artii transversely or s tepperl L.ts

iliri:LctciEi by the hngini:~er.Be..lore looting is laid, the surface shalt besi htly wateredamid ramined., in the eventot excavation having been

ccper th~.trithat shown on the drawings or as otherwiseordcrei:lby the Engineer, the extra depth shall he made tip with concreteor nr asonryof the fotmndation at the cost of the Contractoras per Clause2104.i. Orrhnary lilling shall not he used for the purposeto hring thefortndatinn to level.

\\rhctrt rock or other hard stratais encountered, it shall he freed

65

Section3t~.t Earthwork,ErosionControland Drainage.

of all soft and loosematerial.,cleanedand cut to a firm surface eitherlevel and steppedas directedby the Engineer,All seamsshall becleanedout and filled with cement mortar or grout to the satisfaction of theEngineer. In thecaseof excavationin rock,annularspacearoundfootingshall be filled with lean concrete (1:3:6 nominal mix) upto the top levelof rock.

If the depth of fill required is more than I .5m above the top ofthe footing, filling upto 1.5m above top of footing shall be done withlean concrete (1:3:6 nominal mix) followed by bouldersgroutedwithcement.

When foundation piles are used, the excavation of each pit shallbe substantially completed before beginning pile-driving operationstherein. After pile driving operations in a given pit are completed, allloose and displaced materials therein shall be removed to the elevationof the bottom of the footings.

304.3.5.Slips and slip-outs : If thereare any slips or slip-outs inthe excavation, these shall be removedby the Contractor at his owncost.

3Q4.3.6.Public safety : Near towns, villages and all frequentedplaces, trenches and foundation pits shall be securely fenced,provided with proper caution signs and markedwith red lights at nightto avoid accidents. Tha Contractor shall take adequate protectivemeasuresto see that the excavation operations do not affect or damageadjoining structures.For safety precautions,guidancemay be takenfrom IS : 3764.

304.3.7. Backfilling : Backfilling shall be done with approvedmaterial after concrete or masonry is fully set andcarried Out in sucha way as not to cause undue thrust on any part of the structure. Allspacebetweenfoundation masonry or concreteand the sidesof excavationshall be refilled to the original surface in.. layers not exceeding150mm compacted thickness. The compaction shall be done with the helpof suitable equipment such as mechanical tamper,rammer, plate vibratoretc., after necessarywatering, so as to achieve a density not less thanthe field density before excavation.

304.3.8. Disposalof surplus excavatedmaterials: Clause 301.3.11shalL apply. -


Excavation for structures shall be measuredin cu. m. for eachclass

66

Earthwork, ErosionControl andDrainage Section300

of material encountered, limited to the dimensionsshown on the drawingsor as directedby the Engineer. Excavationover increasedwidth, cuttingof slopes,shoring, shuttering and planking shall be deemedas conven-iencefor the Contractorin executingthe work andshallnot be measuredand paid for separately.

Preparationof rock foundation shall be measurediti squaremetres.Foundation sealing, dewatering, including pumping shall be deemedto be incidental to the work unless separateprovision is madefor inthe ContracL In the latter case,payment shall be on lumpsum basis asprovided in the Bill of Quantities.

304.5. Rates

304,5.1.The Contract unit rate for the items of excavation forstructures shall be payment in full for carrying out the requiredoperationsincluding full compensation for

(i) setting out;

(ii) constructionof necessarycofferdams, cribs,sheeting, shoring and bracing and theirsubsequent removal;

(iii) removal ofalt togs, stumps, grubs and other deleterious matter and obstructions,for placing the foundations including trimming of bottoms of excavations;

(iv) fotmdation sealing,dewatering including pimping when no separateprovision forit is made in the Contract;

(v) backfilling, clearing up the site and disposalof all surplus material within all liftsand leads upto 1000 m or as otherwisespecified; and

(vi) alt labour, materials, tools, equipment,safetymeasures,diversion of traffic andincidentals necessaryto complete the work to Specification.

304.5.2. The Contract unit rate for preparationof rock foundationshall be fufl compensation for cutting, trimming and cleaning thefoundation surfaceand filling/sealing of all seamswith cement groutor mortar including all materials, labour and incidentals required forcompleting thework.

304.5.3. The Contractunit rate for transporting material from theexcavation for structuresshall be full compensationfor all labour,equip-ment, tools and incidentals necessary on account of the additionalhaul or transportationinvolved beyond the initial lead of 1000 m.

305. EMBANKMENT CONSTRUCTION

305.1. General

305.1.1. Description : These Specifications shall apply to theconstruction of embankments including subgrades, earthen shoulders and

67

Section 300 Earthwork,Erosion Controland Drainage

miscellaneoushackfills with approvedmaterial obtainedfrom roadwayand drain excavation,borrow pits or other sources.All embarikment.s,suhgrades,earthenshouldersand miscellaneoushackfills shall he con-structedin accordancewith the requirementsof theseSpecifications andin conformity with the lines, grades, and cross-sectionsshown on thedrawings or as directed by the Engineer.

305.2. Materials and General Requirements

305.21. Physical requirements:

305,21.!.The materialsusedin emhankments,subgrades,earthen•;houlders and miscellaneousbackfills shall he soil, moorum, gravel, anttxture of theseor any other material approvedby the Engineer. Suchmaterials shall be free of logs, stumps, roots, rubbish or any otherLngredient likely to deteriorateor affectthe stability of the embankment!subgrade.

The following types of material shall be considered unsuitableforembankment:

(a) Materials from swamps, marshes and bogs;

(h) Peat,log, stump and pedshablematerial; any soil that classifies as 01., 01,Oti or Pt in accordance with IS 1498;

Cc Materials susceptibleto spontaneouscombustion;

Cd Materials in a frozen conditioss;

Clay having liquid limit eacceding70 and plasticity index exceeding 45 and

(11 Materials wills salts resulting in leaching in thc embankment.

305.2.1.2, Expansive clay exhibiting marked swell and shrinkageproperties(“free swelling index” exceeding50 per cent when testedasper IS’: 2720 - Part 40) shall not be used as a fill material. Wherean expansiveclay with acceptable“free swelling index” value is usedasa till material,suhgradeandtop 5(X) mm portionof the embankmentjust below subgradeshall be non-expansivein nature.

305.2.1.3. Any fill materialwith asolublesulphatecontentexceeding1.9 grams of sulphate(expressedas SOS) per litre when tested inaccordance with 55 : 1377 Test 10, but using a 2:1 water-soil ratioshall not be deposited within 500 mm or other distance described inthe Contract,of concrete,cementbound materialsor other cementitiousmaterials forming part of the PermanentWorks.

Materials with a total sulphatecontent (expressedas SO3)exceeding0.5 per cent by mass,when tested in accordance with BS : 1377 Test

68

]~5~ FxosionControlandDrainage Section3(X)

shall not be deposited within500 mm, or other distancesdescribeditt the~Contract,of metallic itemsforming part of the PermanentWorks,

305,2.1,4. The size of the coarse material in the mixture of earthill c~id i nan ft ttol exceed75 mm when he int; placedin the embanktnert

and. 50 rnni when placed inthe suhgrade.However, the Engineermayhi discretionPermit the use of maieriaicoarserthan this also if he:‘Eltts [ted that the same will not present any difficulty as regards the

I a:.: EE tit Itt of fill material andits compactton to the requirements of: ~pecifi,caiions, ‘themaximum particle siie shall not he more than

‘c ~ ii i nil I I he compacted layer thickness.

305.2,1.5. OrcI manly, ortly the materials sEatisfying the density‘c ~ i tttenU; g iv ert mn Table3(X)—i shall be employed for the construct]on

te enit bankment and the subgrade.

id liL 300 I. IE)ENSt1’Y REQI,IRESIFNTS’OF KMBASKME%T ANt)SUBGRADE MATERIALS

si[ SYsirk Maxinsum I aborsstorydry ssnttweight wEteti

tested asper IS: 2T20 (Part S~

‘‘.‘i]:”’,]K.srH nts tip to 3 metres Net tess th:sts 15.2 kNCcti m,flit si.ibjec.tirit to

Itosolii it g.

ii.. e’,cei’dirsr, Net less than 16.0 kN/cti, en.srntsanksiettts

is t lit s tihtec’t toeli irmndatiort

md eari.hcn Not tess tts3n t7.5 kS/eu. en.‘ii lie t.i/i’er5e (ls,sckfil

H (1 0’ it t’:.iltle is net applicable for lightweight fill sssateciate.g cinder, ft~ash

‘[he I Ertc sneeretemy relaxtheserel:Iutrclments at his discretton taking into accountits existsi Lilsi lit

5 stE materials for cssitsrnscttonsand other relevant itsce~srs.

is he used in tat:mgrasteslsststld also satisfy designdEeR at diii1.115 ILtOLt wetg,ht appttcable as ~ Tatsle 300’Z,

.305,2,2 General requirements

395,23,1,The tnaterials forembankmentshall heobtainedfroni ap-

“ratieliEl source.’; vs ith preferencegiven to materials becoming availableit nearby roadway excavation oranyother excavationunderthe satne

It ir;Etet.

69

- as--- - -.

Section300 Earthwork,ErosionControl andDrainage

The work shall be soplannedand executedthat the bestavailablematerials are savedfor the subgradeand the embankment portion justbelow the subgrade.

305.2,2.2. Borrow materials Where the materials are to beobtained from designated borrow areas,the location, size and shapeofthese areas shall be as indicated by the Engineer and the sameshallnot be opened without his written permission.Wherespecific borrowareasare not designatedby the Employer/the Engineer, arrangement forlocating the sourceof supply of material for embankment andsubgradeas well as compliance to environmental requirementsin respectofexcavation and borrow areas as stipulated, from time to time by theMinistry of Environment and Forests,Government of India and the localbodies, as applicable, shall be the sole responsibility of the Contractor.

Borrowpits along the road shall be discouraged. If permitted by theEngineer, these shall not be dug continuously. Ridgesof not less than8 m width should be left at intervals not exceeding300 m. Small drainsshall be cut through the ridges to facilitate drainage. The depth ofthe pits shall be so regulated that their bottom doesnot cut an imaginaryline having a slope of 1 vertical to 4 horizontalprojected from theedge of the final section of the bank, the maximum depth in any casebeing limited to 1.5 m. Also, no pit shall be dug within the offset widthfrom the toe of the embankment required as per the consideration ofstability with a minimum width of 10 m.

Haulage of material to embankments or other areas of fill shallproceed only when sufficient spreadingand compaction plant is operatingat the place of deposition.

No excavatedacceptablematerial other than surplus to requirementsof the Contractshall be removed from the site. Should the Contractorbe permitted to remove acceptablematerial from the site to suit hisoperational procedure, then he shall make good any consequentdeficitof material arising therefrom.

Where the excavation revealsa combination of acceptable and un-acceptable materials, the Contractor shall, unless otherwise agreed bythe Engineer, carry out the excavation in such a manner that theacceptablematerials are excavated separately for use in the permanentworks without contamination by the unacccptable materials. Theacceptable materials shall be stockpiled separately.

The Contractor shall ensure that he does not adversely affect the

70

Earthwork,E~sionControlandl)rainage Section300

stability of excavationor fills by the methods of stockpiling materials,use of plantsor siting of temporarybuildings or structures.

The Contractor shall obtain representativesamplesfrom each of theidentified borrow areas andhave these tested at the site laboratoryfollowing a testing programme approvedby the Engineer. It shall beensuredthat the subgradematerial when compacted to the densityrequirementsas in Table 300-2 shall yield the design CBR value ofthe subgrade.

TABLE 300-2. COMPACTION REQUIREMENTS FOR EMBANKMENTAND SUIGRADE

Type of work! material R~iativecompaction asof max. laboratory dryper IS: 2720 (Part 8).

percentagedensity as

1, Subgradeand earthen shoulders Not less than 972. Embankment Not less than 953. Ex

a)

b)

pansive ClaysSubgrade and 500 mmportion just belowthe subgradeRemainingportion

Not allowed

Not less than 90of embankment

The Contractor shall at least7 workingdaysbeforecommencementof compactionsubmit the following to the Engineer for approval:

(i) The values of maximum thy density and optimum moisture content obtainedin accordancewith IS: 2720 (Part 7) or (Part8), asthe case may be, appropriatefor each of the fill materialshe intends to~use

(ii) A graph of density plotted against moisturecontent from which each of thevalues in (I) above of maximum dry density and optimum moisture content weredetermined.

(iii) The Dry density-moisturecontent.CBR relationships for light, intermediate andheavy compactive efforts (light corresponding to IS: 2720 (Part 7), heavycorresponding to IS: 2720 (Part 8) and intermediatein-between the two) foreach of the fill materials he intends to use in the subgrade.

Once the above information has beenapproved by the Engineer,it shall form the basis for compaction.


305.3.1. Setting out : After the site has beencleared to Clause201, the work shall be set out to Clause 301.3.1. The limits ofembankment/subgradeshall be marked by fixing batter pegs on bothsides at regular intervals as guides before commencing the earthwork.The embankmenl/subgrade shall be built sufficiently wider than the

71

Sec kit 300 Earthwork,Erqsion ControlandDrainage

ilesign dimensnan so that surplus materialmay be trimmed, ensuringchat the remainingmaterial is to the desired density andin positionspecifled and conforms to the specified side slopes.

305.3,2. Dewatering lithe foundation of the embankment is inan urea with stagnant water and inthe opin ion of the i...ngineer itis Feasible to removeit, the same shall he removedby bailing out orp1:m pinoi~ di reetciI by the Engineer and theareaof the embankment

II nil at ion hull be k:ept dry. Care shallbe taken to d ~scharge theic.att”r so niL 10 cause daniac 10 the works, crops or any

ci’ property. [)i ie 0 any negligenceon the part of the Contractor,nucEh iI1ifl1aL~E’ ?“~ LEalised, it shall be the sole responsih~Iityol the

1 IC’ re]pair/I”estore U to e.rkEEinal condition or compensateLiL1flW~c ii, his own COSt.

LI’Ii,” LEmi:mnkrnent B5 10 be eIE)nsL.rueted under water, Clause

.0115,.:t .3. Sir~ pmg and storing topsoil In localities where 010.”.I.

1 ‘ ‘ ‘~.‘,I IELHe eI’l]LIE’llkalcIlnent materials arenetconduciveto plant growth.the bng:ne.ei”, chc Lopsoil from all areas of

[ii ‘In all ...e’eas to be covered by ernhankntent leundaLionI”’ ..;irIl{’P

15~...I IrL, ..r]:’lc’I.Eiiielt depths not exr:Eecd~ngi50 mm and .stored

III .“~1...r’..:sp1ler’; ‘1 ~L’lhi’It I’’Iitt ‘csr.Eeecllllll 2 i’ti for covering enthankrnent‘..iIt ‘~,lI:r(rL:’’~. and IE’rther I:E1i1’ltul’lEncLl ~li’e.1Et1r;‘‘~h~rrct re~vef1et.ittieIniS

be c.nn,Erce.ssarlis LralfilEEkc.d either bIEIIL1rL1

hen iii, i stol::Ekpile. StoehpillEls shall not he suichargedoreI’El multiple hanr.ilinft,L.!, shall be kept to a minimum.

.1~115.3.4. Cr.im~wetingi~rourirlsopporting embankment/subgradeE‘.~l,.D,..’,”;’ nEce~sEtr”’. thcr e’riginal grourul :;hall be levelled tiEl Facilitate

hr~~~iIdyLl” of cmhanl’anent sLE1uEiI’iI::ld, tnned with waler’.irr~lthen LEI:inipacted by rollIng ~ a~.te’ ~:ti:hieve:‘ninirnum dry densitl,

spvcn ut Table 1001..

l]llr~,,E’,.o:r,:1, ~ltere (he dilfereneebetween the suhc;radelevel (top of the‘.~vibrradeOil which pi.tvement restst and ground level is less, than U.S

round dc.ie.s not have 97 per cent relative compactionIt rlEi,”i pr..~c I ri ih ‘Ar’,’ density asgiven in Table 30O~2,the ground1.~ic’ li.iosenedLJpLIE1 it level 0.5 rn below the subgrade level,wateretEl

all ii LEcU It piaEted i mu I ayers in aciEEordancewitl’t Clauses305,3.5 and3053.6I ‘El riot less than 97 per cent of’ dry dens,ity as given in Talle 300—2.

“A’ lucre. so directedby the Engineer,any unsuitable materialoccurring

7,

h.Lrth’l’~IITk , E.,r1”lS’ik,T’I I:EOil trot and l)rainage Secliorl .itx:

,in the entharuk n’ue n t foundation shall he removed and replaced byapproveil irtaterialslairl in layersto the requireddegree of compaction.

n’tban k.rtie n t or’ sEubgradework shall not proceed until the fouttdttt~tons fur ‘sin bankmenlJsuhgrrtde have he.eit inspectedby tltc Engineer‘er ‘Lau.i sl:LIIE liEtry i:nttd itiOn and approved.

Friundation treattnentspecifiedfor crnhankmentsespeciallyhighre’ittny on suspect foundations as revealedby horchole

shall’h’e LEarned out iru a rrtanne.r and to the depth as desinsd bythe entElund t:tn ~, hich ait emhankmnentis to he huilt

at’ cr1 IfI~’..’ .Erts.Fte.I tel types ía.) to (I.) in Clause 3052.1,at least 500inasi be rerrioved and replaced by aceclE’Lthlc

~atEbrinkntentconstruction comnlencrt,s,

~pr eri,r.ling material itt layersand bringing to apprn.

1iritittr moisture content‘‘.‘h,,.’: enil.tattkment tori subgradematerial “rhail be spread

teirierat thic’Lness nut ‘~.Etxceeding200 rout cnittpa~.Er...d

Hi Eli.. ~‘ i’’. ‘c ihe .Eotire t’r’trlth tO’ i::attl:tattkntent hy mecl’taruurEal incas.’,;,smiler ,,trti eantpactedas’ per Clause 305J.faThe

have lty’..lrauiic control suitable. ionsattt~,Esc’asto achievethe speedle t.~l’:.:tpc

i.e er’~~.“Thahl itctt be placed until the Layer

. .j~~’qe,t,..tL.’~, Ftu... h’sLtt Lhr’lrt’ugitl5’ compacted to dir:’ s.5 ..‘t’tI” tI ttt L,.’F”ie 1001 curl cot approvedby the Engineer.built

ted tsr ‘.hail lttE litttsl,ed p.rallel 10 the final cruss~s’t:’.,EELirt!tii’ “ . i~I Ku,

Er .51. \ir.ti.t.tI.Jt:L.’ crtttl,etE,i, of the rttal.eriai shall he checked Ert Itoto tEontrttcnce.t’neot of compaction; if fr:’aud tsr

‘‘iL .0 cc rr”:’’H l,,ttets, the satttiEr .‘rltall h’e madegood. Wltere water’is’ Os .,trlLlrEri in sttch rEr.lrtstrutEtLons,watershall he. sprinkled

‘t,tti.:er f;ttcd ‘.t’it.h sprinkler capableof applying‘F, ‘:n lv “.‘r’Ltlt a suncrollahierateof flow’ to variable widths’ of sunia:e

an, fleer’.:Iin,e,. The water shall he added unifbn’nly arid: ml:’, eti use,I hy hiading, discinc or harrowinguntil a uotf’onn

H “,:‘..IJt’tE s.c eut ‘ ‘. d.tlE,tained tltrottghottt. the depth of’ the la’,,”er.

U titt’ P”tdttvrl;.I I r.Iehi”~’et’edtO tlte roatElbed is too wet, it shall he t,,LnietEl,‘tflt antI it ‘ire’,t tire to the enit, till the moisturecontentis acceptable

I [‘aLEtrt:t’rt..Sl’tneiri eirt:Eutrtslances tu’ise, where. owing to wet w’eather,hIts’ n”ot’rtt,rtt LEontertt eEtnno~be reduced to the requiredam’.iuot by the

i’;tOc.:riurC’~ t..ttittpctetittn’w tEnEk shall he suspended.

73

Section 300 Earthwork,ErosionControlandDrainage

Moisture content of eachlayer of soil shallbe checked in accordancewith IS: 2720 (Part 2), and unless otherwise mentioned, shall be soadjusted,making due allowance for evaporation losses,that at the timeof compaction it is in the rangeof 1 per cent above to 2 percent belowthe optimum moisture content determined in accordancewith IS :2720(Part 7) or IS:2720 (Part8) as the case may be. Expansive clays shall,however,be compactedat moisture contentcorresponding to the specifieddry density, but on the wet sideof the optimum moisture content obtainedfrom the laboratory compaction curve.

After adding the required amount of water, the soil shall be processedby means of graders, harrows, rotary mixers or as otherwiseapprovedby the Engineer until the layer is uniformly wet.

Clods or hard lumps of earthshall be broken to have a maximumsize of 75 mm when being placed in the embankment and a maximumsize of 50 mm when being placed in the subgrade.

305.3.5.3.Embankment and other areasof fill shall, unless otherwiserequired in the Contract or permittedby the Engineer, be constructedevenly over their full width and their fullest possible extent and theContractor shall control and direct construction plant and other vehiculartraffic uniformly over them. Damage by construction plant and othervehicular traffic shall be made good by the Contractor with materialhaving the samecharacteristics and strength as the material had beforeit was damaged.

Embankments and other areas of unsupported fills shall not be con-structed with steeperside slopes,or to greater widths than those shownin the Contract, except to permit adequate compaction at the edgesbefore trimming back, or to obtain the final profile following anysettlement of the fill and the underlying material.

Whenever fill is to be depositedagainst the face of a natural slope,or sloping earthworks face including embankments,cuttings, other fillsand excavations steeper than I vertical on 4 horizontal, such facesshall be benched as per Clause 305.4.1 immediately before placing thesubsequent fill.

All permaneni facesof side slopes ofembankmentsand other areasof fill formed shall, subsequentto any trimming operations, be reworkedand sealed to the satisfaction of the Engineer by tracking a trackedvehicle, considered suitable by the Engineer, on the slope or any othermethod approved by the Engineer.

74

Earthwork,ErosionControland Drainage Section300

305.3.6.Compaction : Only the compactionequipmentapprovedbythe Engineer shall be employed to compact the different material typesencountered during construction. Smooth wheeled,vibratory, pneumatictyred, sheepsfootor pad foot rollers, etc. of suitable size and capacityas approved by the Engineer shall t~used for the different types andgrades of materials required to be compactedeither individually orin suitable combinations.

The compaction shall be done with the help of vibratory roller of80 to 100kN static weightwith plain or pad foot drumor heavypneumatictyred roller of adequate capacity capable of achieving required com-paction.

The Contractor shall demonstrate the efficacy of the equipment heintends to use by carrying out compaction trials. The procedure to beadopted for these site trials shall first be submitted to the Engineerfor approval.

Earthmoving plant shall not be acceptedas compaction equipmentnor shall the useof a lighter categoryof plant to provide any preliminarycompaction to assist the use of heavier plant be taken into account.

Each layer of the material shall be thoroughly compacted to thedensitiesspecifiedin Table 300-2. Subsequentlayersshall be placedonlyafter the finished layer has beentestedaccordingto Clause903.2.2 andaccepted by the Engineer, The Engineer may permit measurementoffield dry density bya nuclear moisture/density gaugeused in accordancewith agreedprocedureand the gauge is calibrated to provide resultsidentical to that obtainedfrom testsin accordance with IS: 2720 (Part28). A record of the same shall be maintained by the Contractor.

When density measurementsreveal any soft areasin the embank~mentjsubgrade/earthen shoulders, further compaction shall be carriedout asdirected by the Engineer. If inspiteof that the specified compactionis not achieved, the material in the soft areasshall be removed andreplaced by approved material, compacted to the density requirementsand satisfaction of the Engineer.

305.3.7.Drainage : The surface of the embankrnent/subgradeatall times during construction shall be maintainedat such a cross fall(not flatter thanthat requiredfor effectivedrainageof an earthensurface)as will shed water and prevent ponding.

305.3,8. Repairing of damagescausedby rain/spillage of water:The soil in the affected portion shall be removed in such areas as

75

Section 300 Earthwork, Erosion Control andDrainage

directed by the Engineerbefore next layer is laid and refilled inlayers and compactedusing appropriatemechanicalmeanssuch as smallvibratory roller, plate compactoror powerrammer to achieve therequired density in accordance with Clause 305.16. If the cut is notsufficiently wide for use of required mechanicalmeansfor compaction,the same shall be widened suitably to permit their use for propercompaction.Tests shall be carriedout as directed by the Engineer toascertain thedensity requirementsof the repaired area.The work ofrepairing the damagesincluding widening of the cut, if any, shall beearnedout by the Contractor at his own cost, including the arrangingof machinery/equipmentfor the purpose.

305.3,9. Finishing operations Finishing operationsshall includethe work of shaping and dressingthe shoulders/verge/roadbedandside slopes to conform to the alignment, levels, cross-sectionsanddimensions shown on the drawings or as directed by the Engineer\ubject to the surface tolerance described in Clause 902. Both theupper and lower endsof the side slopesshall be rounded off to

4tnprove appearanceand tb mergethe embankmentwith the adjacentterrain.

The topsoil, removed and conservedearlier (Clause 301.3.2 and) shall be spread overthe fill slopes asper directions of the

Engineerto facilitate the growthof vegetation. Slopesshallberoughenedand niotstened slightly prior to the applicationof the topsoil in orderLa provide satisfactory bond.The depth of the topsoil shall be sufficienta sustain plant growth, the usual thicknessbeing from 75 mm to 150

un rn

Where directed, the slopes shall be turfed with sodsin accordancei~iih Clause307. if seedingand mulching of slopesis prescribed,thisshall he done to the requirementof Claus’e 308.

When earthwork operationshave been substantially completed, theroadarea shallbeclearedof all debris, andugly scars in theconstructionarea responsiblefor objectionableappearance eliminated.

305.4. Construction of Embankment and Subgrade underSpecial Conditions

305.4] Earthwork for widening existing road embankmenuWhen art existing embankment and/or subgrade is to be widenedand its slopesare steeper than 1 vertical on 4 horizontal, continuoushorizontal benches,each at least 300 mm wide, shall be cut into the

76

Earthwork,Erosion Control andDrainage Section300

old slopefor easuringadequatebond with the freshembankment/subgradematerial to be added. The material obtained from cutting of benchescould be utilized in the widening of the embankmeni/subgrade.However,when theexisting slope againstwhich the freshmaterial is to be placedis flatter than 1~vertical on 4 horizontal,the slopesurface may only beploughed or scarified instead of resorting to benching.

Where the width of the widened portions is insufficient to permitthe use of conventional rollers, compaction shall be carried out withthe help of small vibratory rollers/platecompactor~’powerrammersorarty other appropriate equipment approved by the Engineer.End dumpingof material from trucksfor widening operationsshall be avoided exceptin difficult circumstances when the extra width is too narrow to permitthe movement of any other types of hauling equipment.

305.4.2. Earthwork for embankment and subgrade to be placedagainst sloping ground Where an embankment/subgradeis to beplaced against slopingground, the latter shalt be appropriately benchedor ploughed/scarified as required in Clause 305.4,1 before placing theembankrnent/subgradematerial.Extraearthworkinvolved in benching ordtie to ploughing/scarifyingetc.shall beconsideredincidentalto the work.

For wet conditions,bencheswith slightly inward fall and subsoildrains at the lowest point shall be provided as per the drawings,before the till is placed against sloping ground.

Where the Contract requires constructionof transversesubsurfacedrain at the cut~llllinterface, work on the sameshall be carried out toClaose309 in propersequencewith the embankmentandsuhgradeworkas approvedby the Engineer.

305.4.3. Earthwork over existing road surface Where theembankmentis to beplacedoveran existingroad surface,the work shallhe earnedout as indicated below

(ii If the existing road surface is of granular or bituminous type and lies within1 in of the new subgradc level, the same shatl be scarified to a stepth of 50 mmormoreif specified,so asto provide ample bond betweenthe old and new materialensuring that at least SOt) mm portion below the top of new suhgracle levelis compacteslto the desired density.

(ii) If the existing road surface is of cement concrete type and lies within I mof the new subgradelevel the sameshall be removedcompletely.

(iii) If she level difference between the existing road surface and the newformationlevel is snore than tm, the existing surface shall be petmitted to stay in placewithout any modification.

77

Section3(X) Earthwork,ErosionControl and Drainage

305.4.4. Embankment and subgrade around structures Toavoid interference with the constructionof abutments,wing walls orreturn walls of culvert/bridgestructures,the Contractor shall,at pointsto be determinedby the Engineer suspendwork on embankment formingapproachesto such structures, until such time as the construction of thelatter is sufficiently advancedto permit the completion of approacheswithout the risk of damage to the structure.

Unless directed otherwise, the filling around culverts, bridges andother structures upto a distance of twice the height of the road fromthe back of the abutment shall be carriedout independent of the workon the main embankment.The fill material shall not be placed againstany abutment or wing wall, unless permission has been given by theEngineer but in any casenot until the concrete or masonry has beenin position for 14 days.Theembankment andsubgradeshall bebroughtup simultaneously in equal layers on each side of the structure toavoid displacementand unequal pressure. The sequence of work in thisregard shall be got approvedfrom the Engineer.

The material usedfor backfill shall not be an organicsoil or highlyplastic clay having plaiticity index and liquid limit more than 20 and40 respectively when tested accordingto 15:2720 (Part 5).Filling behindabutments and wing walls for all structures shall conform to the generalguidelines given in Appendix 6 of IRC:78 (Standard SpecificationsandCode of Practice for Road Bridges-SectionVII) in respectof the typeof material, the extent of backfill, its laying and compaction etc. Thcfill tnaterial shall be deposited in horizontal layers in loose thicknessand compacted thoroughly to the requirements of Table 300-2.

Where the provision of any filter medium is specified behind theabutment,the same shallbelaid in layerssimultaneouslywith the layingof fill material. The material used for filter shall conform to therequirementsfor filter medium speltout in Clause2502/309.3.2(B) unlessotherwisespecified in the Contract.

Where it may be impracticable to use conventional rollers, the com-paction shall be carried out by appropriate mechanical means suchassmall vibratory roller, plate compactor or power rammer. Care shall betaken to see that the compaction equipment doesnot hit or come tooclose to any structural member so asto causeany damage to themor excessivepressure againstthe structure.

305.4.5. Construction of’ embankment over ground incapable

of supporting construction equipment Where embankmentis to78

Earthwork, Erosion Control and Drainage Section300

be constructed acrossground which will not support the weight ofrepeatedheavy loads of construction equipment, the first layer of thefill may be constructedby placing successiveloads of material in auniformly distributed layerof a minimum thickness required to supportthe construction equipment as permittedby the Engineer.TheContractor,if so desired by him, may also use suitable geosynthetic material toincreasethebearingcapacity of the foundation. This exceptionto normalprocedure will not be permitted where, in the opinion of the Engineer,the embankmentscould be constructed in the approved manner oversuch ground by the use-cf lighter or modified equipment after properditching and drainage have beenprovided. Where this exception ispermitted,the selection of the material and the construction procedureto obtain an acceptablelayer shall be the responsibility of the Contractor.The cost of providing suitable traffic conditions for constructionequipmentover any area of the Contractwill be the responsibility ofthe Contractor and no extrapaymentwill be madeto him. The remainderof the embankment shall be constructed as specifiedin Clause305.3.

305.4.6. Embankment construction under water : Where fillingor backfilling is to be placed under water, only acceptable granularmaterial or rock shall be used unless otherwise approved by theEngineer. Acceptable granular material shall consist of graded, harddurable particleswith maximum particlesize not exceeding75 mm. Thematerial should be non-plastic having uniformity coefficient of not lessthan 10. The material placed in open water shall be deposited by endtipping without compaction.

305.4,7. Earthwork for high embankment : In the caseof high embankments,the Contractorshall normally use the materialfrom the specified borrow area. In case he desires to use differentmaterial for his own convenience,he shall have to carry out neces~arysoil investigations and redesign the high embankment at his own cost.The Contractor shall then furnish the soil test data arid design of highembankment for approval of thb Engineer, who reservesthe right toaccept or reject it.

If necessary,stage construction of fills and any controlled ratesof filling shall be carried out in accordancewith the Contract includinginstallation of instruments and its monitoring.

Where required, the Contractor shall surcharge embankments or otherareas of fill with approved material for the periods specified in theContract. If settlement of surcharged fill results in any surcharging

79

Sec.tion 300 Earhwnrk, ErosionControland Drainage

ntaterial,which is unacceptablefor use in the fill being surcharged, lyingbelow formation level, the ContracEtorshall removethe unacceptablematerial and dispose it as per direction of the Engineer. I-Ic shallthen bring the resultantlevel up to formation level with acceptablematerial,

305,4.8. Settlementperiod \Vhere settlementperiod is specifiediii the Contract,tI-c embankmentshall remain in place for the requiredsLttIeFrlit.nt period before excavating for abutment,wingwall, retainingwall, footings, etc., or driving foundationpiles. The duration of therequired settlementperiod at each location shall be as provided forin the Contractor as directed by the Engineer.

305.5. Plying of’ Traffic

Consiructien and othervehiculartraffic shall not use thepreparedsurLice of the embankmentand/orsubgradewithout the prior permissionof the Engineer.Any damagearising out of such use shall, however,he madegood by the Contractorat his own expenseas directed by theEngineer.

34)5,6. Surface Finish and Quality Control of WorkThe surfacefinish of comaruction of subgradeshall conform to the

u reiuents of Clause 902 Control on the quality of materialsandweeks shall be exercised in accordance with Clau~e903

305.7, Subgrade Strength

305.7.1. It shall be ensured prior to actualexecutionthat the borroware:i material to be used in the subgrade satisfiesthe requirementsofdesign CBR.

305.7.2. Suhgrade shall be compactedand finished to the designstrength consistent with other physical requirements. The acwallaboratory CI3R values of constructed subgrade shall he determined onundisturbeci samplescut out from the compactedsubgrade in CBR mouldfitted with cutting shoe or on remoulded samples,compacted to thefield density at the field moisture content.

3058. Measurements for Payment

Earth emhanknienllsubgradeconstruction shall be measuredsepa-rately by taking crosssectionsat intervals in the original positionbeforethe work startsandafter its completion and computing the volumesof earthwork in cubic metres by the method of average end areas.

80


The measurement of fill materialfrom borrow areasshallbe the dif-ference between the net quantities of compactedfill and the netquantities of suitable material brought from roadway and drainageexcavation.For this purpose,it shall be assumedthat one cu,m. ofsuitable material brought to site from road and drainage excavationforms one cu.m. of cbmpacted fill and all buiking or shrinkageshallbe ignored. —

Construction of embankmentunder water shall be measured inCu,m.

Construction of high embankment with specified material and inspecified manner shall be measuredin cu.m.

Stripping including storing andreapplicationof topsoil shallbe meas-ured in cu.m.

Work involving Looseningand recompacting of ground supportingembankment/subgradeshall be measured in cu. m.

Removal of unsuitablematerial at embankmentisubgradefoundationand replacement with suitable material shall be measured in cu.m.

Scarifyingexisting granular/bituminous road surface shall be meas-ured in square metres.

Dismantling and removal of existing cement concrete pavementshall be measured vide Clause 202.6,

Filter medium and backfill material behind abutments, wing wallsand other retaining structures shall be measured as finished work inposition in cu.m.

305.9. Rates

305.9.1. The Contract unit ratesfor the items of embankment ~ndsubgrade construction shall be payment in full for carrying out therequired operationsincluding full compensationfor

(1) Cost of arrangementof land as a sourceof supply of material of requiredquantity for construction unlessprovided otherwisein the Contract;

(ii) Setting Out;

(iii) Compacting groundsupportingembankment/subgradeexceptwhere removal andreplacement of unsuitable material or loosening and recompacling is involved;

(iv) Scarifyingor cutting continuoushorizontalbenches300mmwide on side slopesof existing embankmentand subgradeas applicable;

(v) Cost of watering or drying of material in borrow . areasandlor embankmentandsubgTadeduring constructionas required;

81

Section300 Earthwork, ErosionControlandDrainage

(vi) Spreading in layers, bringing to appropriatemoisture content and compactingto Specificationrequirements;

(vii) Shaping anddressing top andslopesof the embankmentandsubgradeincludingroundingof corners;

(viii) Restrictedworking at sites o.f structures

(ix) Working on narrow width of embankmentand subgrade;

(x) Excavation in all$oils from borrow pits/designatedborrow areasincluding clearingand grubbing andtransporting thematerial to embankment and subgradesirewith all lifts and leads unlessotherwise provided for in the Contract;

(xi) All labour, materials,tools, equipnent and incidentals necessary to complete thework to the Specifications;

(xii) Dewatering; and

(xiii) Keeping the embankment/completedformation free of water as per Clause 311.

305.9.2. In casethe Contract unit rate specifiedis not inclusive ofall leads, the unit rate for transportingmaterial beyond the initial lead,as specifiedin the Contract for construction of embankment and subgradeshall be inclusive of full compensation for all labour,equipment, toolsand incidentals necessary on account of the additional haul or trans-pertation involved beyond the specified initial lead.

305.9.3. Clause 301.9.5 shall apply as regards Contract unit ratesfor itemsof stripping andstoring top soil and of reapplication of topsoil.

305.9.4.Clause301.9.2shall apply as regardsContractunit rate forthe item of loosening and recompacting the embankmenl/subgradefoundation.

305.9.5.Clauses 301.9.1and 305.8 shall apply as regards Contractrates for items of removal of unsuitable material and replacement withsuitable material respectively.

305.9.6. The Contract unit rate for sÔarifying existing granular/bi-tuminous road surface shall be payment in full for carrying out therequired operationsincluding full compensationfor all labour, materials,tools, equipment and incidentals necessary to complete the work.This will also comprise of handling, salvaging,stacking anddisposingof the dismantled materials within all lifts and upto a lead of 1000 mor as otherwise specified.

305.9.7. Clause202.7 shall apply as regardsContract unit rate fordismantling and removal of existing cement concrete pavement.

305.9.8.The Contract unit rate for providing and laying filtermaterial behind abutments shall be payment in full for carrying out

82

Earthwork,ErosionControl nd Drainagc Section.300therequiredoperationsincluding all materials, labour, tools,equipment

and incidentals to completethe work to Specifications.

305.9.9.Clause305A..6 shallapply as regards Contractunit rate forconstruction of embankment underwater.

305.9.10. Clause 305.4.7 shall apply as regardsContractunit ratefor construction of high embankment. It shall include cost of instru-mentation, its monitoring and settlement period, where specified in theContract or directed by the Engineer.

306. SOIL EROSION AND SEDIMENTATION CONTROL

3061.Description

This work shall consistof measuresas shown on plans or asdirected by the Engineer to conirol soil erosion, sedimentation and waterpollution, through use of berms, dikes, sediment basins, fibre mats,mulches, grasses,slope drains, and other devices.

306.2. Materials

All materials shall meet commercial grade standardsand shall beapproved by the Engineer before being used in the work.

3063. Construction Operations

Prior to the start of the relevant construction, the Contractor shallsubmit to the Engineer for approval his schedulesfor carrying outtemporary and permanentemsion/sedimentationcontrol works as areapplicable for the items of clearing and grubbing, roadway anddrainageexcavation, embankipent/subgrade constructio~i,bridges andother struc-tures acrosswater courses,pavementcoursesand shoulders.He shall alsosubmit for approvalhis proposedmethod of erosion/sedimentation controlon service road and borrowpits and his plan for disposal of wastematerials. Work shallnot bestarteduntil theerosion/sedimentationcontrolschedulesandmethodsof operationsfor the applicable construction havebeen approved by the Engineer.

The surface area of erodible earth material exposedby clearing andgrubbing, excavation, borrowand fill operations shallbe limited to theextentpracticable.The Contractor may be directed to provide immediatepermanent or temporary erosion and sedimentation control measuresto prevent soil erosion and sedimentationthat will adversely affectconstruction operations, damage adjacent propeEties,or causecontami-nation of nearby streamS or ether water cotu~es,lakes, reservoirsetc. Such work may involve the construction of temporary berms,dikes,

83


sediment basins, slopedrains and use of temporarymulches, fabrics,mats,seeding,or other control devicesor methodsasnecessaryto controlerosion andsedimentation.Cut andfill slopesshall beseededand turfedas required on the plans.

The Contractorshallbe requiredto incorporateall permanenterosionand sedimentationcontrol features into the project at the earliestpracticable time as outlined in his accepted schedule to minimize theneed for temporary erosion and sedimentation control measures.

Temporaryerosion/sedimentationand pollution control measureswillbe usedto control the phenomenonof erosion,sedimentationandpollutionthat may develop during normal constructionpractices, but may neitherbe foreseenduring design stage nor associatedwith permanentcontrolfeatureson the Project.

Where erosion or sedimentationis likely to be a problem, clearingand grubbing operationsshould be so scheduledand performed thatgrading operations and permanent erosion or sedimentation controlfeaturescan follow immediately thereafter if theprojectconditions permit;otherwise temporary erosion or sedimentation control measuresmay berequired between successiveconstruction stages. Under no conditionsshall a large surface area of erodible earth material be exposed at onetime by clearing and grubbing or excavation without prior approvalof the Engineer.

The Engineer may limit the area of excavation, borrow and em-bankment operations in progress, commensurate with the Contractor’scapability and progressin keepingthe finish grading, mulching, seedingand other such permanenterosion, sedimentation and pollution controlmeasures, in accordance with the accepted schedule, Should seasonallimitations makesuch coordinationunrealistic;temporary erosion/sedi-mentation control measuresshall be taken immediately to the extentfeasible and justifkd.

in the event temporary erosion,sedimentation and pollution controlmeasuresbecomenecessarydue to the Contractor’s negligence,care-lessnessor failure to install permanentcontrols as a part of ~theworkas scheduled or ordered by the Engineer, these shall be carried out atthe Contractor’s own expense.Temporaryerosion, sedimentationandpollution control work required,which is not attributed to the Contrac-tor’s negligence,carelessnessor failure to install permanentcontrols,willbe performed as orderedby the Engineer.

84

Earthwork, ErosionControlandDrainage Section300

Temporary erosion, sedimentation andpollutioncontrolmay includeconstruction work outside theright-of-way wheresuchwork is necessaryas a result of road construction such as borrow pit operations,service roadsand equipment storage sites.

The temporary erosion,sedimentation and pollution control featuresinstalled by the Contractor shall be acceptably maintainedby him tilltheseare needed,unlessotherwiseagreedby the Engineer.


The soil erosion, sedimentationand pollution control works will bemeasuredin terms of units specified in the Bill of Quantities for therespective items.

306.5. Rates

The Contractunit rate for different itemsof soil erosion, sedimen-tation and pollution control works shall be payment in full for carryingout all requiredoperations including full compensation for all laboui,tools, equipment and incidentals to complete the works to the Specifi-cations.

307. TURFING WITH SODS

307.1. Scope

This work shall consistof furnishing and laying of the live sod ofperennial turf forming grass on embankment slopes, verges (earthenshoulders) or other locatiOns shown on the drawings or as directed bythe Engineer. Unlessotherwisespecifled, the work shall be taken upas soon as possible following constructionof theembankment,providedthe seasonis favourable for establishmentof the sod.

307.2. Materials

The sodshall consistof dense,well-rooted growth of permanent anddesirable grasses,indigenous to the locality where it is to be used, andshall be practically free from weedsor other undesirable matter. At thetime the sod is cut, the grass on the sod shall have a length ofapproximately 50 mm and the sod shall have been freed of debris.

Thicknessof the sod shall be asuniform as possible,with some50-80 mm or so of soil covering the grass roots depending on thenature of the sod, so that practically all the dense root system of thegrassesis retained in the sod strip. The sodsshall be cut in rectangularstrips of uniform width, not less than about 250 mm x 300 mm in sizebut not so large that it is inconvenient to handle and transport these

85

Section3(X) Earthwork, ErosionControlandDrainage

without damage. During wet weather, the sodshall be allowed to drysufficiently to preventrearingduring handling and during dry weathershall bewateredbefore lifting to ensure its vitality and preventthedroppmg of the soil in handling.

307.3, Construction Operations

307.3,1. Preparation of the earth bed : The area to be soddedshall have been previously constructed to the required slope andcrosssection. Soil on the area shall be loosened,freed of all stoneslarger than 50 mm size, sticks, stumpsand any undesirableforeignmatter, and brought to a reasonablyfine granular texture to a depthof not less than 25 mm for receiving the sod.

Where required, topsoil shall be spreadover the slopes. Prior toplacing the topsoil, the slopesshalt be scarified to a depth which, aftersettlement, will provide the requirednominal depth shownon the plans.Spreading shall not be done when the ground is excessivelywet.

Following soil preparation andtop soiLing, whererequired,fertilizerand ground limestonewhen specified shalt bespreaduniformly at therate indicated on the plans. After spreading, the materialsare incorporatedin the soil by discing or other means to the depths shown on the plans.

307.3.2.Placing the sods: The preparedsod bedshall bemoistenedto the loosened depth, if not already sufficiently moist, and the sodshall be placed thereon within approximately 24 hours after the samehad been cut. Eachsod strip shall be laid edge to edge and such thatthe joints causedby abutting ends are staggered.Everystrip, after itis snugly placed against the strips alreadyin position, shall be lightlytamped with suitable wooden or metal tampers so as toeliminateair pockets and to pressit into the underlying soil.

On side slopessteeperthan 2 (horizontal) to I (vertical), the layingof sods shall be startedfrom bottom upwards.At points where watermay flow over a soddedarea, the upper edgesof the sod stripsshall,be turned into the soil below the adjacent areaand a layerof earth placedover this followed by its thorough compaction.

307.33.Stakingthe sods: Where the side slope is 2 (horizontal)to 1 (vertical) or steeperand the distance along the slopeis more than2 m, the sodsshall be staked with pegs or~nails spacedapproximately500 to 1000 mm along the longitudinal axis of the sod strips, Stakesshall be driven approximately plumb through the sods to be almostflush with them.

86

Earthwork,Erosion Control andOrainage Section300

307.3.4.Top dressing: After the sods havebeen laid in position,the surface shall be cleanedof loosesod, excesssoil and other foreignmaterial. Thereafter, a thin layer of topsoil shall be scattered over thesurface of top dressingandthe area thoroughly moistened by sprinklingwith water.

307.3.5. Wateri~igand maintenance : The sods shall be wateredby the Contractor for a period of at least four weeks after laying.Watering shall be so done as to avoid erosion and prevent damageto sodded areas by wheels of water tanks.

The Contractor shall erect necessarywarning signs andbarriers,repair or replacesoddedareasfailing to show uniform growth ofgrass or damagedby his operations and shall otherwisemaintainthe sod at his cost until final acceptance.


Turfing with sods shall be measuredas finished work in squaremetres.

307.5. Rate

The Contract unit rate for turfing with sods shall meanpayment infull for carryingout all therequired operationsexplained aboveincludingcompensation for

(i) furnishing all the materialsto be incorporated in the Works with all leads andlifts; and

(ii) all labour, tools, equipmentsand incidentalsto completethe work in accordancewith these Specificaüons.

The Contract unit rate for application of topsoil shall be as perClause 301.9.5.

308. SEEDING AND MULCHING

308.1. Scope

This shall consist of preparing slopes, placing topsoil, furnishingalL seeds, commercial or organic fertilizers and mulching materials,providing jute netting and placing and incorporating the same onembankment slopes or other locations designated by the Engineeror shown in the Contract documents.

308.2. MaterialsA. Seeds:The seedsshall be of approved quality and type suitable for the soil

on which theseare to be applied,and shall have acceptablepurity andgerminationto requirementsset down by the Engineer.

87


Fertilizer shall consistof standardcommercial materialsandconformto thegradespecified. Organic manureshall be fully puirefied organic masersuch as cowdung.

Mulching materials shall consist of straw, hay, wood shavings or sawdust,and shall bedelivereddry. They shall be reasonablyfree of weedseedand suchforeign materialsas may detract from their effectivenessas a mulch or beinjurious so the plant growth.

B. Topsoil: Topsoil shall not be obtainedfroman areaknownto havenoxious weedsgrowing in it. If treated with herbicides or sterilents, it shall be got testedby appropriate ~griculturalauthority to determinethe residual in thesoil. Topsoilshall not contain less than 2 per centand more than 12 per centorganic matLer.

C. BltumLrtous Emulsion: A suitable grade of bituminous cutback or emulsionusedas a tie down for mulch shall be as described in the Contractdoarmentor as desired by theEngineer. Emulsified bitumen shall not contain any solventor diluting agent toxic to plant life.

D. Netting: Jute netting shall be undyed jute yam woveninto a uniform open weavewith approximate 2.5 cm square openings.

Geonetting shall he made of uniformly extruded rectangularmeshhaving meshopening of 2 cm x 2 cm. The colour may be black or green. It shall weighnot less than 3.8 kg per 1000 sq. m.

308.3. SeedingOperations

308.3.1. Seed-bedpreparation : The area to be seededshall bebrought to the required slope and cross-sectionby filling, reshapingerodedareasand refinishing slopes,mediansetc. Topsoil shall be evenLyspread over the specified areas to the depth shown on the plans,unless otherwise approved by the Engineer. The seed-bedpreparationshall consist of eliminating all live plants by suitable means usingagricultural implements. All stones 150 mm in smallestdimension andlarger shall be removed. The soil shall be excavated on the contour toa depth of 100 mm. All clods larger than 25 mm in diameter shallbe crushedand packed. Where necessary,water shall then be applied.All topsoil shall be compacted unless otherwise specified or approvedby the Engineer. Compaction shall be by slopecompactor,cleated tractoror similar equipment approved by the Engineer. Equipment shall be sodesigned and constructed as to produce a uniform rough texturedsurface ready for seedingand mulching and which will bond the topsoilto the underlying material. The entire area shall be covered by aminimum of 4 passes or 2 round trips of the roller or approvedequipment.

308.3,2.Fertilizer application : Fertilizer to the requiredquantitiesshall be spread and thoroughly incorporated into the soil surface as apart of the seed-bedpreparation.

88

Earthwork,Erosion Control andDrainage Section300

308.3.3. Planting of seeds: All seedsshall be planted uniformlyat the approved rate. Immediately after sowing, the area shall be raked,dragged or otherwise treated so as to cover the seeds to a depth of6 mm.

The operation of seed sowing shall not be performed when theground is muddy or when the soil or weatherconditionswould otherwiseprevent proper soil preparationand subsequent operations.

308.3.4. Soil moisture and watering requirements: Soil-moistureshallexist throughout thezone from 25 mm to at least 125 mm belowthe surface at the time of planting.

Watering of the seededareasshall be carriedout as determinedbythe Engineer.

308.4. Mulching, Applying Bituminous Emulsion and JuteNetting! Geonetting

Within 24 hours of seeding, mulching material mixed with organicmanure shall be placed so as to form a continuous, unbroken coverof approximate uniform thickness of 25 mm using an acceptablemechanical blower. Mulching material shall be held in place and maderesistant to being -blown away by suitable means approved by theEngineer. When called for in the Contract documents,mulch materialshall be anchored in place with bituminous emulsion applied at therate of 2300 litres per hectare. Any mulch disturbed or displacedfollowing application shall be removed,reseeded and remulched asspecified. Jute netting/Geonettingshall be unrolled and placedparallelto the flow of water immediately following the bringing, ta’—finishedgrade, the areaspecifiedon the plans or the placing of seedand fertilizer.Wheremore than one strip is requiredto cover the given areas, theyshall overlap a minimum of 100 mm. Jute netting/ Geonetting shallbe held in place by approved wire staples, pins, spikes or woodenstakesdriven vertically into the soil.

308.5. Maintenance

The Contractor shall maintain all seeded and mulched areasuntil final acceptance. Maintenance shall inciud~ protection oftraffic by approved warning signs or barricades ax~d repairing anyareas damaged following the seeding and mulching operations.If mulched areas becomedamaged, the area shall be reshaped andthen seededand mulched again as originally spe~ified.

89

Section 300 Earthwork, Erosion Control andDrainage

308.6. Measurements for payment

Seedingandmulchingshall be measuredas finished work in squaremetxes.

308.7. Rate

The Contract unit rate for seedingand mulchingshall bepaymentin full for carrying out all the required operations including fullcompensationfor all materials, labour, tools and incidentals.

309. SURFACE/SUB-SURFACEDRAINS

309.1. ScopeThis work shall consistof constructingsurfaceand/or sub-surface

drains in accordancewith the requirements of theseSpecificationsand to the lines, grades,dimensionsandotherparticulars shown onthe drawingsor as directed by the Engineer.Scheduleof work shallbe so arrangedthat the drains are completedin proper sequencewithroad works to ensurethat no excavation of the completedroad worksis necessarysubsequentlyor any damageis causedto theseworks dueto lack of drainage.

309.2. Surface Drains

Surface drains shall be excavatedto the specified lines, grades,levelsanddimensionsto the requirementsof Clause301. The excavatedmaterial shall be removedfrom the areaadjoining the drainsand iffound suitable,utilised in embankment/subgradeconstruction.All unsuit-able material shall be disposed of as directed.

The excavatedbedandsidesof the drainsshall be dressedto bringthesein closeconformitywith the specifieddimensions,levelsandslopes.

Where so indicated, drainsshall be lined or turfed with suitablematerialsin accordancewith details shown on the drawings.

All works on drain constructionshall be plannedand executedinproper sequencewith otherworks as approvedby the Engineer,with aview to ensuringadequatedrainagefor the area andminimising erosion/sedimentation.

3093. Sub-surfaceDralns309.3.1.Scope: Sub-surfacedrains shall be of close-jointedperfo-

rated pipes, open-jointed unperforated pipes, surroundedby granularmaterial laid in atrenchor aggregatedrainsto drainthepavementcourses.Sub-surfacedrains designedusing Geosynthetics and approvedby theEngineer can also be used.

90

Earthwork,ErosionControlandDrainage Section300

309.3.2. MaterialsA. PIpe Perforatedpipes br the drains may be ofmetatlasbestoscement/

cementconcretelPVC,andunperforatedpipes of vitrified claylccmentconcrete/asbestos cement. The type,size and gradeof the pipe to be used shall beas specified in the Contract.In ancase, however,shall the internal diameterof the pipe be less than 100 mm. Holes for perforatedpipesshall be on onehalf of the circumferenceonly and conform to thespacingindicated on thedrawings. Size of the holesshall not ordinarily be greater than half of ~sizeof thematerial surroundingthe pipe, subjectto being minimum 3 mm andmaximum6 mm. l)~~stands for the sizeof the sieve that allows 85 per centof the material to passthroughit.

R, Backfill materIal Backfill material shall consistof sound,tough,hard,durableparticlesof free draining sand-gravel materialor crushedstoneand shall be freeof organic material, clay balls or other deleteriousmatter Unless the Contractspecifiesany particulargradings for the backfill material or requiresthese tobe designedon invertedfilter criteria for filtration andpermeabilityto the approvalof the Engineer,thebackfill material shall be provided on the following lines:

(i) Where the soil met with in the trench is of fine grained type (e.g..silt,clayor a mixture *hereot),the backfill material shall conform to Class I gradingset out in-Table 300-3.

(ii) Where the soil met with in the trenchis of coarse silt to medium sandor sandy type, the backfill material shall correspond to Class 11 gradingof Table 300-3.

(iii) Where soil met with in the trenchis gravelly sand, the backfill materialshall correspondto Class III grading of Table 300-3.

Thicknessof backfill material arounathe pipe shall be as shownon the drawings subject to being at least 150 mm airound in all cases.

Geosyntheticsfor use with subsurface drain shall conform to the re-quirementsas per Section 700.

Table 300-3. GRADING REQUIREMENTS FOR FILTER MATERIAL

SIeve DesignatIon

Par centpassIngby weIght

Class I ClassH Class III

53mm45 mm26.5mm22,4 mm11.2 mm5.6 mm2.8 mm1,4 mm710 micron355 micronl80micron90 micron

—

—

—

—

10092-10083-10059-9635-8014-403-150-5

—.

—

10095-10048-10028-5420-35

—

6-182-9—

0-4

10097.100

—

58-10020-604-320-100-5—

—

—

0-3

91


309.3.3. Trench excavation: Trench for sub-surface drain shallbe excavatedto the specifiedlines, grades anddimensionsshownin thedrawingsprovided that width of trenchat pipe level shall not be lessthan 450 mm. The excavationshall beginat the outlet endof the drainand proceed towardsthe upperend. Where unsuitablematerial is metwith at the trench bed, the sameshall be removed to such depthasdirected by theEngineerand backfiliedwith approvedmaterial whichshall be thoroughly compactedto the specifieddegree.

309.3.4. Laying of pipe and backi’illing Laying of pipe in thetrench shall bestartedat the outlet end andproceedtowards the upperend,true to the lines and gradesspecified.Unlessotherwiseprovided,longitudinal gradient of the pipe shall not be less than1 in 100.

Before placing thepipe,backfill materialof the requiredgrading(s)shall be laid for full width of the trench bedana compacted to aminimum thicknessof 150 mm or as shownon the drawings.Thepipe shall then be embeddedflrmly on the bed.

Perforated pipes,unless otherwisespecified, shall be placedwiththeir perforationsdown to minimise clogging. The pipe Sections shallbe joined securelywith appropriate couplingfittings or bands.

Non-perforated pipes shall belaid with joints as close as possiblewith theopenjoints wrappedwith suitablepervious material(like doublelayer of hessian, suitableGeosyntheticsor some other material ~fnot less than 150 mm width) to permit entry of water but preventfinesentering the pipes.In the caseof non-perforated pipeswith bell end,the bell shall face upgrade.

Upgradeendsectionsof the pipe installationshall be tightly closedby meansof concreteplugsor plugs fabricatedfrom the samematerialas thepipe andsecurelyheld in placeto prevent’ entry of soil materials.

After the pipe installationhas been completed and approved,backfill materialof the requiredgrading(s)(see Clause 309.3.2B) shallbe placed over the pipe to the required level in horizontal layersnot exceding 150 mm in thickness andthoroughly compacted.Theminimum thicknessof material above thetop of the pipeshall be 300mm.

Unlessotherwiseprovided, sub-surface drainsnot locatedbelow theroad pavementshall be sealedat the top by meansof 150 mm thicklayer of compactedclay so asto preventpercolationof surfacewater.

92


309.3.5. Use of geosynthetic in bying of pipe andbackfillingAfter excavatingthe trench for subsurfacedrain, the filter fabric shallbeplaced, the pipe installed and the trenchbackfilled with permeablemate’rial according to dimensionsand details shown on the plans.Surfaces to receivefilter fabricprior to placing shall be free of looseor extraneousmaterial andsharpobjects that may damage the filterfabric~duringinstallation.Adjacentrolls of thefabric shall be overlappeda minimum of 450 mm.The precedingroll shall overlapthe followingroll in the direction the material is being spread.

Damageto the fabricresulting from Contractor’svehicles,equipmentor operations shall be replacedor repaired by the Contractorathis expense.

309.3.6. Drain outlet Theoutlet for a sub-drainshall not be underwater or pluggedwith debris but should be a free outlet discharginginto a stream,culvert or open ditch. The bottom of the pipe shall bekept above high water in the ditch andthe endprotectedwith a grateor screen.For a length of 500 mm from the outlet end, the trench forpipe shall not be provided with granular material but backfilled withexcavatedsoil and thoroughly compactedso as to stop water directlypercolating from the backfill material aroundthe pipe. The pipe inthis section shall not have any perforations.

309.3.7. Aggregatedrains : Aggregate drains shall be placedwithin the verge/shouldersafter completion of the pavement. Depth,thicknessandspacing of the aggregatedrains shall be as shown on theplan.

Trenches for aggregatedrains shall be excavatedto a minimumwidth of 300 mm and to the depth shown on the plans or orderedbythe Engineer.The bottomof the trenchshallbe slopedto drain and shallbe free from loose particles of soil. The trench shall be excavatedsoas to exposeclearly the granularpavementcoursesto be drained.

Aggregatefor the drains shall ~edurablegravel, stone or slag andshall be free from vegetablematter and other deleterioussubstances.The grading requirementsare given at Table 300-4. Type B gradingmay be usedonly where the drain is designed to interceptsurfacewater [lowingto the pipe and is likely to get slowly blocked.Type Agrading allows a much wider range.

93

Section300 Earthwork, ErosionControl an4Drainage

TABLE 300.4. GRADING REQUIREMENTS FOR AGGREGATE DRAINS

SieveSize Per cent passing by weight

TypeA TypeB

63mm37.5 mm19mm9.5 rum3.35 mm600 micron150 micron75 micron

—

100—

45-10025-808-450-100-5

10085-100

0-200-5—

—

—

—


Measurement for surfaceand sub-surfacedrains shall be perrunning metre length of the drain. Disposalof surplusmaterial beyond1000 m shall be measuredin cu. m.

309.5. Rates

The Contract unit ratesfor surfaceand subsurfacedrains shall bepayment in full for all itemssuchas excavation,dressingthe sides andbottom; providing lining, turfing, pitching,masonry,concreteand plas-tering; providing, laying and jointing pipes; providing, laying andcompacting backfill and bed of granularmaterial; providing, fixingandpainting of coveretc. including full compensationfor all materials,labour, tools, equipment and other incidentals to completethe workas shown on drawings with all leadsand lifts exceptfor removal ofunsuitablematerial for which the lead shall be 1000 m. Provision ofinlets, gratings,sumps,outlet pipes,bedding, disbursersetc. whereverrequiredshall be incidental to constructionof drain. The Contractunit rate for disposalof surplusand unsuitable material beyond theinitial 1000 m lead shall be in accordancewith Clause304.5.3.

310. PREPARATION AND SURFACE TREATMENT OFFORMATION

Preparationand surfacetreatmentof the formation, that is top ofthe subgrade,shall be carriedout only aftercompletionof anyspecifiedsubgrade drainage and unless otherwise agreedby the Engineer,immediately prior to laying the sub-baseor the road basewherenosub-baseis required.The sequenceof operationsshall be as follows:

(a) All surfacesbelow carriageway,laybyes, footways and hard shouldersshall,after reinstatementof any soft areasto the requiredSpecificationsbe well cleanedand freed of mud and slurry.

94


(b) The surfaceshall be compactedby 4 passesof a smoothwheeledroller of 80to 100 kN weight after spraying requisite amount of waler, if required, beforethe commencementof rolling.

(c) The formation shall, wherever necessary,be regulatedand trimmedto the re-quirementsof Clause 505.3.9 with motor grader.

(d) The trimmed formation shall be rolled by one pass of smooth wheeled rollerof 80 to 100 kN weight after sprayingrequisite amountof water, if required,before the commencementof rolling.

Wherethe completedformation is not immediatelycoveredwith sub-base or road base material, its moisture content shall bemaintainedto preventcrackingin the formation by suitable measuresas approvedby theEngineer.Theentire work of surfacetreatment of formation shallbe deemedas incidental to the work of sub-base/basecourse to beprovidedon the subgradeandas suchno extra paymentshall bemadefor the same.

311. WORKS TO BE KEPT FREE OF WATER

311.1. The Contractor shall arrange for the rapid dispersal of watercollected/accumulatedon the earthworkor completedformation duringconstructionor on the existing roadwayor which entersthe earthworkor any other item of work from any source,and where practicable, thewater shall be dischargedinto the permanentoutfall of the drainagesystem. The arrangementsshall be madein respectof all earthworkincluding excavation for pipe trenches,foundationsor cuttings.

311.2. The~Contractorshall provide, wherenecessary,temporarywatercourses, ditches,drains,pumping or othermeansfor maintainingthe earthwork free from water. Such provisions shall include carryingout the work of forming the cut sectionsand embankmentsin suchmanner that their surfaces have at all times a sufficient minimumcrossfall and, where practicable, a sufficient longitudinal gradient toenable them to shed water,and prevent ponding.

The works involved in keepingthe earthworkor any other itemof works free of water shall be deemedas incidental to the respectiveitem of work and as such no separatepaymentshall be made forthe s~me.

312. WATER COURSES AT CUL’TERTS

312.1, Excavation carried out in the diversion, enlargement,deepeningor straighteningwater coursesat culverts,wherenecessary,shall include the operationssuch as clearing, grubbing, removal ofvegetation,trimming of slopes, grading of beds,disposal of excavated

95


materials,pumping,timbering etc. necessaryfor dealing with the flowof water.

312.2. The beds and sloping sides of water coursesshall, whereshown on the Drawings, be protectedagainstthe action of water byrubble paving to form a flat or curved surface as indicated. Theprotectionshall consist of large smoothfacedstonesor of blocks ofprecastconcrete. Stonesfor rubble paving shall be roughly dressedsquare. No stone shall be less than 255 mm in depth nor less than0.02 cu. m. in volume and no roundedbouldersshall be used. Aftercompletion of constructionof culverts, temporary diversion of water-course,if any,shallbe closedandwatercourserestoredfor flow throughthe culvert as per the direction of the Engineer.


The work for water coursesat culverts as stated above shall bemeasuredin termsof unitsspecifiedin theBill of Quantitiesfor respectiveitems.The temporarydiversionof channel to facilitate construction ofculverts, its closureand restoration to original watercourseshall beconsidered incidental to the work of construction of cülverts andnoextra paymentshall be made for the same.

312.4. Rates

The Contract unit ratesfor di:fferent items for water coursesatculverts shall bepaymentin full for carrying out all j~equiredoperationsincluding full compensationfor all cost of materials, laboUr, tools,equipmentandother incidentalsto completethework to the Specification,

313. CONSTRUCTION OF ROCKFILL EMBANKMENT

313.1, Scope -

In normal circumstances,theembankmentshouldnot beconstructedwith rockfill material.However,where specificallypermittedby theEn-gineerbecauseof imperativeeconomicor technicalreasons,constructionof rockfill embankmentsshall be in accordancewith th~lines, gradesandcross-sectionsas shown in drawingsor asdirectedby theEngineer.

Rockfill shall not be used at least for a depth of 500 mm belowtheformation level. Theresho~ildbea minimumof 500 mm thick earthencushion over the rocklill.

313.2. Material

The size of rock piecesused in rockfihl embankmentsshall besuch that they can be deposited in layers so as to suit the conditions

96


evaluatedin the field compaction trials or asdirected by theEngineer.The rockfill shall consistof hard, durableandinert~aterial,preferablymaximum size not exceeding300 mm andper cent finer than 125 mmnot exceeding 10 per cent.

Argillaceousrocks(clay,shalesetc.),unburntcolliery stockandchalkshall not be used in rockfill.

The rock fragmentsand blinding material requiredfor filling thevoids shall also satisfy the above requirements.

313.3. Spreadingand Compaction

The material shall betipped,spreadandlevelled in layersextendingto the full width of embankment by a suitable dozer. Fragmentsof rock shall thenbe spreadon thetop of layer to the required extentand layer compactedby minimum of 5 passes of vibratory rollerhaving Static weight 8-10 tonnes. The compactedthicknessof eachlayershall not exceed500 mm. After compactionof each layer, thesurfacevoids shall be filled with broken fragments.Next layer, whererequired,shallbe placedin the samemanner,abovetheearliercompactedlayer.

The top layerof rockfill, on which normal earth fill will rest shallbe thoroughlyblinded with suitablegranularmaterial to seal its surface.


Measurementshall be madeby taking cross-sectionsat intervals inthe original position beforethe work starts and after its completionand computing the volume in cu. m. by the method of averageendareas.

313.5. RateThe Contract unit rate shall be paid in full for carrying out all

the above operationsincluding cost of rockfill, broken fragmentsandblinding material and shall provide full compensationfor all itemsasper Clause305.9.1 and 305.9.2.

97

Sub-Bases,Bases (Non-Bituminous) andShoulders

400

Sub-Bases,Bases(Non-Bituminous) and Shoulders

Sub-Bases,Bases(Non-Bituminous)andShoulders Section400

401. GRANULAR SUB-BASE

401.1. Scope

Thiswork shall consistof laying andcompactingwell-gradedmaterialon preparedsubgradein accordancewith therequirementsof theseSpeci-fications. The material shall be Laid in oneor more layersas sub-baseor lower sub-baseand upper sub-base(termed as sub-basehereinafter)as necessary accordingto lines, grades and cross-sectionsshownon the drawings or as directedby the Engineer.

401.2. Materials

401.2.1. The material to be used for the work shall benatural sand,moorum, gravel, crushedstone,or combinationthereofdepending uponthe gradingrequired.Materialslike crushedslag,crushed concrete,brickmetal and kankar may be allowed only with the specific approval ofthe Engineer.Thematerialshall be free from organicor otherdeleteriousconstituents andconform to oneof the three gradingsgiven in Table400-1.

While the gradingsin Table 400-1 are in respectof close-gradedgranularsub-basematerials,one each for maximumparticlesize of 75mm, 53 mm and 26.5 mm, the correspondinggradingsfor the coarse-graded materials for each of the threemaximum particle sizes aregiven at Table 400-2. The grading to be adoptedfor a project shall beas specifiedin the Contract.

401.2,2.Physicalrequirements: The materialshall havea 10 percent fines value of 50 kN or more (for samplein soaked condition)whentested in compliancewith BS:812(Part Ill). Thewater absorptionvalueof thecoarseaggregateshall be determinedas per IS 2386 (Part3); if this value is greaterthan 2 per cent, the soundnesstest shallbe carried Out on the material deliveredto site as per IS : 383.For Grading II and Ill materials, the CBR shall be determined atthedensity and moisturecontentlikely to be developed in equilibriumconditions which shall be taken as being the density relating to auniform air voids contentof 5 per cent.

101

Section400 Sub-Bases,Bases(Non-Bituminous)andShoulders

TABLE 400-1. GRADING FOR CLOSE-GRADED GRANULARSUB-BASE MATERIALS

IS Sieve

Designation

Percentby weight passing the IS sieve

Grading I Grading H G radingHI

75.0mm53.0 mm26.5 mm9.50 mm4.75 mm2.36 mm

0.425 mm0.015 mm

10080-10055-9035-6525-5520-4010-253-10

—

10070-100

50-8040-6530-5015-253-10

—

—

10065-9550-8040-6520-353-10

CBR Value (Minimum) 30 25 20

TABLE 400-2. GRADING FOR COARSE GRADED GRANULAR SUB-BASEMATERIALS

IS Sieve

Designation

Per cent by weight passingthe IS Sieve

Grading I Grading II Gm ding III

75.0 mm53.0 mm26.5 mm9.50 mm4,75 mm2.36 mm0.425 mm0.075 mm

100

55-75

10-30

<10

—

10050-80

15-35

<10

—

100

25-45

<10

CBR Value (Minimum) 30 25 20

Nate The material passing425 micron (0.425 mm) sieve for all the three gradingswhen tested according to IS 2720 (Pail 5) shafi have liquid limit and plasticityindex not more than25 and 6 per cent respectively.

401.3. Strength of sub-base

It shall be ensuredprior to actual executionthat the material to beusedin thesub-basesatisfiesthe requirementsof CBR andotherphysicalrequirementswhen compactedand finished.

When directedby theEngineer,this shallbe verified by performingCBR tests in the laboratory as required on specimensremouldedat field dry density and moisture content and any other tests for the“quality” of materials, as may be necessary.


401.4.1. Preparationof subgrade Immediatelyprior to the layingof sub-base,the subgradealready finished to Clause 301 or 305 asapplicable shall be prepared by removing all vegetation and other

102

Sub-Bases,Bases (Non-Bituminous)andShoulders Section400

extraneous matter, lightly sprinkledwith water if necessaryand rolledwith two passesof 80 -100 kN smooth wheeled roller.

401.4.2, Spreading and compacting The sub-base material ofgrading specifiedin the Contract shall be spread on the prepared subgradewith the help of a motor grader of adequate capacity, its blade havinghydraulic controls suitable for initial adjustmentand for maintainingtherequiredslopeandgradeduring theoperationor other means asapprovedby the Engineer.

When the sub-basematerial consistsof combination of materials men-tioned in Clause401.2.1,mixing shall be done mechanically by the mix-in-place method.

Manual mixing shall be permitted only where the width of layingis not adequatefor mechanical operations, as in small-sizedjobs. Theequipment used for mix-in-place construction shall be a rotavator orsimilar approved equipment capableof mixing the material to the desireddegree. If so desired by the Engineer, trial runs with the equipmentshall be carried out to establish its suitability for the work.

Moisturecontentof the loosematerialshallbe checked in accordancewith IS:2720(Part 2) and suitablyadjustedby sprinkling additional waterfrom a truck mounted or trailer mounted water tank and suitable forapplying water uniformly andat controlled quantitiesto variablewidthsof surMceor other meansapprovedby the Engineerso that, at the timeof compaction,it is from I per cent above to 2 per cent below theoptimtim moisturecontent correspondingto 15:2720 (Part 8). Whileaddingwater,due allowanceshall be madefor evaporationlosses.Afterwater has been added, the material shall be processedby mechanicalor otherapprovedmeanslike disc harrows, rotavatorsuntil the layeris uniformly wet.

Immediatelythereafter,rolling shall start.If the thicknessof thecom-pacted layer does not exceed 100 mm, a smooth wheeled roller of80 to 100 kN weight may be used. For a compactedsingle layer upto225 mm the compactionshall be donewith the helpof a vibratoryrollerof minimum 80 to 100 kN static weight with plain drum or pad foot-drum or heavy pneumatic tyred roller of minimum 200 to 300 kN weighthaving a minimum tyre pressure of 0.7 MN/m2 or equivalent capacityroller capable of achieving the required compaction. Rolling shallcommenceat the lower edgeand proceedtowards the upper edgelongitudinally for porthnshaving unidirectional crossfall and super-.

103


elevation and shall commence at the edges and progress towardsthe centre for portions having crossfall on both sides.

Each passof the roller shall uniformly overlapnot less than one-third of the track madein the precedingpass.During rolling, the gradeandcrossfall(camber)shallbecheckedandanyhigh spotsor depressions,which becameapparent,correctedby removing or addingfresh material.The speed of the roller shall not exceed 5 km per hour.

Rolling shall be continued till the densityachieved is at least 98per centof the maximum dry density for the materialdeterminedas perIS:2720 (Part 8). The surfaceof any layerof material on completionof compactionshall be well closed,free from movementunder compactionequipment and from compactionplanes,ridges,cracksor loosematerial.All loose,segregatedor otherwisedefectiveareasshall he madegoodto the full thicknessof layer and re-compacted.

401.5. SurfaceFinish andQuality Control of Work

The surfacefinish of constructionshall conform to the requirementsof Clause902.

Control on the quality of materials and works shall be exercisedby the~Engineer in accordancewith Section 900.

401.6. Arrangementsfor Traffic

During the period of construction,arrangementof traffic shall bemaintainedin accordancewith Clause112.


Granular sub-baseshall be measuredas finished work in positionin cubic metres.

The protectionof edgesof granularsub-baseextendedover the fullformation as shown in the drawing shall be considered incidental tothe work of providinggranularsub-baseand as such no extrapaymentshall be made for the same.

401.8. Rate

The Contractunit rate for granular sub-baseshall be paymentinfull for carryingout the requiredoperationsincluding full compensationfor

(i) making arrangementsfor traffic to Clause 112 exceptfor initial treatmentto verges,shoulders and construction of diversions;

104

Sub-Bases,Bases(Non-Bituminous) and Shoulders Section400

(ii) furnishing all materials to be incorporatedin the work including all royalties,fees,rents where necessaryand all leads and lifts;

(iii) all labour, tools, equipment and incidentals to complete the work to the Speci.fications;

(iv) carrying out the work in part widths of road wheredirected; and

(v) carrying out the required tests for quality control.

402. LIME TREATED SOIL FOR IMPROVEDSUB-GRADFJSUB-BASE

402.1. Scope

This work shall consistof laying andcompactingan improved sub-grade/lowersub-baseof soil treatedwith lime on preparedsub-gradeinaccordancewith the requirementsof theseSpecificationsandin confor-mity with the lines, gradesand cross-sectionsshown on the drawingsor as directed by the Engineer.Lime treatmentis generally effectivefor soils which contain a relatively high percentageof clay and siltyclay.

402.2. Materials

402.2.1.Soil : Except when otherwisespecified,the soil used forstabilisationshall be thelocal clayeysoil havinga plasticity index greaterthan 8.

402.2.2.Lime Lime for lime-soil stabilisationwork shall be com-mercial dry lime slaked at site or pre-slakedlime delivered to the sitein suitable packing.Unless otherwisepermitted by the Engineer,thelime shall havepurity of not lessthan 70 per cent by weight of Quick-lime (CaO) when tested in accordancewith IS :1514, Lime shall beproperly stored to avoid prolonged exposureto the atmosphere andconsequentcarbonationwhich would reduceits binding properties.

402.2.3. Quantityof lime in stabilisedmix Quantity of lime tobe addedas percentageby weight of the dry soil shall be as specifiedin the Contract,Thequantityof lime usedshall be related to its calciumoxide content which shall be speãified. Where the lime of differentcalciumoxidecontentis to beused,its quantityshall besuitably adjustedto the approval of the Engineerso that equivalent calcium oxide isincorporated in the wotk, The mix design shall be done to arrive atthe appropriatequantity of lime to be added,havingdue regard to thepurity of lime, the type of soil, the moisture-density relationship, andthe design CBRiUnconflnedCompressiveStrength(UCS)valuespecifiedin the Contract.The laboratory CBR/UCS value shall be at least 1.5times thc minimum field value of CBR/UCS stipulatedin the Contract.

105


402.2.4. Water : The water to be used for lime stabilisationshallbe clean and free from injurious substances.Potable water shallbe preferred.


402.3.1.Weather limitations : Lime-soil stahilisation shall not bedone when the air temperaturein the shade is less than 100 C.

402.3.2. Degree of pulverisation: For lime stabilisation, the soilbefore addition of stabiliser,shall be pulverisedusing agricultural im-plements like disc harrowsandrotavatorsto the extent that it passesthe requirementsset out in Table 400-3 when tested in accordancewith the method describedin Appendix3.

TABLE 400-3. SOIL PULVERISATION REQUIREMENTS FOR LIMESTABILISATION

IS Sievedesignation Minimum per cent by weightpassingthe IS Sieve

26.5 mm 100

5.6 mm 80

40233. Equipment for construction: Stabilised soil sub-basesshall be constructedby mix-in-place method of construction or asotherwiseapprovedby the Engineer.Manual mixing shall be permittedonly wherethe width of laying is notadequatefor mechanicaloperations,as in small-sizedjobs.

Theequipmentusedfor mix-in-placeconstructionshall be arotavatoror similar approvedequipmentcapableof pulverising and mixing thesoil with additive and water to specifieddegree to the full thicknessof the layer being processed,and of achieving the desired degreeofmixing anduniformity of the stabilisedmaterial. If so desired by theEngineer,trial runswith the equipment shall be carriedout to establishits suitability for work.

The thicknessof any layer to be stabilisedshall be not less than100 mm when compacted.The maximum thicknessshall be 200 mm,provided the plant used is acceptedby the Engineer.

402.3.4. Mix-in-place method of construction:. Before deployingthe equipment, the soil after it is made free of undesirablevegetationor other deleterious mattershall be spreaduniformly on the preparedsubgrade in a quantity sufficient to achieve the desired compactedthicknessof the stabilised layer. Where single-passequipmentis to beemployed,the soil shall be lightly rolled at thediscretionof the Engineer.

106


The equipment usedshall either be of single-passor multiple passtype. The mixers shall be equipped with an appropriate device forcontrolling the depth of processingand the mixing blades shall bemaintained or reset periodically so that the correct depth of mixingis obtainedat all times.

With single-pass equipment the forward speedof the machineshallbe so selectedin relation to the rotor speedthat the requireddegreeof mixing,pulverisationanddepth of processingis obtained. In multiple-passprocessing,the preparedsubgradeshallbe pulverisedto the requireddepthwith successivepassesof the equipmentand the moisture contentadjusted to be within prescribed limits mentioned hereinafter. Theblendingor stabilisingmaterialshall then be spreaduniformly andmixingcontinuedwith successivepassesuntil the required depth anduniformityof processinghave been obtained.

The mixing equipmentshall be so set that it cuts slightly into theedge of the adjoining lane processedpreviously so as to ensurethatall the material forming a layer has been properly processed for thefull width.

402.3.5. Construction with manual means:Where manual mixingis permitted, the soil from borrow areasshall first be freed of allvegetation and otherdeleteriousmatterand placedon the preparedsubgrade.The soil shall then be pulverised by meansof crow-bars,pick axesor other meansapprovedby the Engineer.

Water in requisite quantities may be sprinkled on the soil for aidingpulverisation.On thepulverisedsoil, the blending material(s) in requisitequantitiesshall be spreaduniformly and mixed thoroughly by workingwith spadesor othersimilar implementstill the whole mass is uniform.After adjustingthe moisturecontentto be within the limits mentionedlater, the mixed materialshall be levelled up to the required thicknessso that it is ready to be rolled.

402.3.6. Addition of lime: Lime may be mixed with the preparedmaterial either in slurry form or dry stateat the option of the Contractorwith the approval of the Engineer.

Dry lime shall be preventedfrom blowing by adding water to thelimc or other suitable means selectedby the Contractor,with theapproval of the Engineer.

The tops of windrowedmaterialmay beflattenedor slightly trenchedto receivethe lime. The distance to which lime may be spread upon

107

Section400 Sub-Bases, Bases(Non-Bituminous) andShoulders

the preparedmaterialaheadof themixing operationshall bedeterminedby the Engineer.

No traffic other than the mixing equipment shallbe allowed to passover the spreadlime until after completionof mixing.

Mixing or remixing operations,regardlessof equipment used,shallcontinue until the material is free of any white streaksor pockets oflime and the mixture is uniform,

Non-uniformity of colour reaction,whenthe treatedmaterial is testedwith the standard phcnolphthalein alcohol indicator, will be considerede~’idenceof inadequate mixing,

402.3.7. Moisture content for compaction:The moisture contentat compaction checked vide IS :2720 (Part 2) shall neither be less thanthe optimum moisture content correspondingto IS: 2720 (Part 8) normore than 2 per cent above it.

402.3.8. RoIling: Immediatelyafterspreading, gradingand levellingof the mixed material,compactionshall be carried Out with approvedequipment preceded by a few passesof lighter rollers if necessary.Rolling shall commenceat edgesand progress towards the centre,exceptat superelevatedportions where it shall commenceat the inneredgeand progresstowardsouter edge. During rolling the surfaceshallbe frequently checked for grade and crossfall (camber) and anyirregularities corrected by looseningthe material and rebioving/adding fresh material. Compaction shall continue until the densityachieved is at least 98 per cent of the maximum dry density for thematerial determinedin accordancewith IS: 2720 (Part 8).

Care shall betaken to see that the compactionof lime stabilisedmaterial is completedwithin threehours of its mixing or such shorterperiod as maybe found necessary in dry weather.

During rolling it shall beensured thatroller does not beardirectlyon hardenedor partially hardenedtreatedmaterialpreviously laid otherthan what may be necessaryfor achieving the specified compactionat thejoint. The final surfaceshall be well closed,free from movementunder compaction planes, ridges, cracksor loosematerial. All looseor segregated orotherwisedefectiveareas shall bemadegood to thefull thicknessof the layer and recompacted.

402.3.9. Curing: The sub-basecourseshall besuitably cured fora minimum period of 7 days afterwhich subsequentpavementcoursesshall he laid to prevent the surfacefrom drying out and becoming

108


friable. No traffic of any kind shall ply over the completed sub-baseunlesspepnittedby the Engineer.

402.4. Surface Finish and Quality Control of WorkThe surfacefinish of constructionshall conform to the requirements

of Clause902.

Control on the quality of materials and works shall be exercisedby the Engineerin accordancewith Section 900.

402.5. Strength

When lime is used for improving the subgrade,the soil-lime mixshall be tested for its CBR value. When lime stabilisedsoil is usedin a sub-base,it shall be tested for unconfinedcompressive strength(UCS) at 7 days. In caseof variation from the designCBR/UCS,in situvaluebeing lower, thepavementdesignshall be reviewedbasedon theactua.l CBR/UCS values. The extra pavementthickness needed onaccount of lower CBR/UCS value shall beconstructedby theContractorat his own cost.

402.6. Arrangementsof Traffic

During the period of construction,arrangementof traffic shall bemaintainedin accordancewith Clause 112.

402.7, Measurements for Payment

Stabilisedsoil sub-baseshall be measuredas finished work in positionin cubic metres.

402.8. Rates

The Contract unit rate for lime stabilised soil sub-baseshall bepaymentin full for carrying out the requiredoperations includingfullcompensationfor all components listedin Clause401.8 (i) to (v).

403. CEMENT TREATED SOIL SUB-BASE/BASE

403.1. ScopeThis work shall consistof laying and compactinga sub-base/base

courseof soil treatedwith cementon preparedsubgrade/sub-base,in ac-cordancewith the requirementsof theseSpecificationsandin conformitywith the lines, grades andcross-sectionsshown on the drawingsor asdirected by the Engineer.

403.2. Materials403.2.1. Material to be stabilised:The material used for cement

109


treatment shall besoil includingsandand gravel,laterite, ,kankar,brickaggregate, crushedrock or slag or any combination of these. For usein a sub-basecourse,the materialshall havea gradingshown in Table400-4; it shall havea uniformity coefficient not less than5, capable ofproducing a well closed surface finish, For use in a basecourse,thematerial shall be sufficiently well gradedto ensurea well-closed surfacefinish and have a grading within the range givenin Table 400-4. Ifthe material passing425 micron sieveis plastic, it shall have aliquidlimit not greater than 45 per cent and a plasticity index not grater than20 per cent determined in accordance with IS:2720 (Part 5).Thephysicalrequirements for the material to be treated with cement for use in abase courseshall be same as for Grading I Granular Sub-base, Clause401.2.2.

403.2.2.Cement: Cementfor cementstabilisation shalt comply withthe requirementsof IS: 269, 455 or 1489.

Table 400-4. GRADING LIMITS OF MATERIAL FOR STABILISATIONWITH CEMENT

IS Slave size Percentageby mass passing

Sub-base Base

FIner than: Within the range:

53.0mm37.5 mm19.0 mm9.5 mm4.75 mm600 micron300 micron75 micron

10095453525

X50

10095-10045-10035-10025-100

8-655-400-10

403.2.3.Lime: If neededfor pre-treatment of highly clayey soils,Clause402.2.2. shall apply.

403.2.4. Quantity of cement in stabilised mix: The quantity ofcementto be addedas per cent by weight of the dry soil shall bespecified in the Contract. Also if lime is used as pretreatment forhighly clayey soils, the quantityas per cent by weight of dry soil shallbe specifiedin theContract. The mix designshall be doneon the basisof 7-day unconfined compressivestrength (UCS) anWor durability testunder 12 cycles of wet-dry conditions.The laboratory strength valuesshall be at least 1.5 times the minimum field UCS value stipulated inthe Contract.

110


403.2.5.Water: The water to be used for cementstabilisationshallbe clean and free from injurious substances.Potable water shallbe preferred.

4033.Construction Operations403.3.1.Weather limitations : Stabilisation shall not be done when

the air temperaturein the shade is less than 10°C.

403.3.2. Degreeof pulverisation : For stabilisation, the soil beforeaddition of stabilizer,shall be pulverised,wherenecessar~,to theextentthat it passesthe requirements as set out in Table 400-5 when testedin accordance with the method described in Appendix3.

TABLE’ 400.5.SOIL PULVERISATION REQUIREMENTS FOR CEMENTSTABILISATION

IS Sieve designation Minimum per centby weight passing the IS sieve

26.5 mm 100

5.6 mm 80

403.3.3. Clauses402.3.3to 402.3,5shall apply as regards spreadingand mixing the stabiliser except that cement or lime plus cement asthe casemay be, shall be used as the stabilising material.

403.3,4. Moisture contentfor compaction: The moisture contentat compaction checked vide IS: 2720 (Part 2) shall not be less thanthe optimum moisture content corresponding to IS: 2720 (Part 8) normore than 2 per cent above it.

403.3.5. Rolling: Clause402.3.8shall apply exceptthat care shallbe taken to see that the compactionof cement stabilised material iscompleted within two hours of its mixing or such shorter period as maybe found necessaryin dry weather.

403.3.6. Curing : The sub-base/basecourse shall be suitably curedfor 7 days.Subsequentpavementcourseshallbe laid soonafter to preventthe surface from drying out and becoming friable. No traffic of anykind shall ply over the completed sub-baseunless permitted by theEngineer.

403.4. Surface Finish and Quality Control of Works

The surface finish of constructionshall conform to the requirementsof Clause 902.

111


403.5. Strength

Control on the quality of materials and works shall beexercisedby the Engineer in accordancewith Section 900.

Cement treatedsoil sub-base/baseshall be testedfor theunconfinedcompressivestrength (UCS) value at 7 days, actually obtained in situ.In caseof variation from the designUCS, in situ valuebeing on lowerside, prior to proceeding with laying of base/surface cotfrse on it,the pavementdesignshall be reviewed for actual UCS value. The extrapavementthicknessneededon account of lower UCS shallbeconstructedby the Contractor at his own cost.

403.6. Arrangements for Traffic

During the period of construction,arrangementof traffic shall bemaintainedin accordancewith Clause112.

403.7~Measurements for Payment

Stabilised soil sub-base!baseshall be measured as finished workin position in cubic metres.

403.8. Rates

The Contractunit rate for cementtreated soil sub-base/basewithpretreatmentwith lime if requiredshall be paymentin full for carryingout the requiredoperationsincluding full compensation for all com-ponents listed in Clause401.8 (i) to (v).

404. WATER BOUND MACADAM SUB-BASFJBASE404.1. Scope

404.1.1.This work shall consistof clean, crushed aggregatesme-chanically interlocked by rolling and bondingtogetherwith screening,binding material wherenecessaryand water laidon aproperly preparedsubgrade/sub-base/baseor existing pavement, as the casemay beandfinished in accordancewith the requirementsof theseSpecificationsandin closeconformity with thelines,grades,cross-sectionsandthicknessas per approvedplans or as directed by the Engineer.

404.1.2. It is, however, not desirableto lay water bound macadamon an existing thin black toppedsurface without providing adequatedrainagefaciljty for waterthat would get accumulatedat theinterfaceof existing bituminous surface and water bound macadam.

112

Sub-Bases,Bases(Non-Bituminous) andShoulders Section400

404.2. Materials

40&2.I. Coarse aggregates : Coarse aggregatesshall be eithercrushedor brokenstone,crushedslag,overburnt(Jhama)brick aggregatesor any other naturally occurring aggregatessuchas kankarand lateriteof suitable quality. Materials other than crushedor broken stone andcrushed slag shall be used in sub-basecoursesonly. If crushedgravel!shingle is used,not less than 90 per cent by weight of the gravel!shingle piecesretainedon 4.75 mm sieveshall haveatleasttwo fracturedfaces. The aggregatesshall conform to the physical requirementssetforth in Table 400-6. The type and size rangeof the aggregateshallbe specifiedin the Contract or shall be as specifiedby the Engineer.if the water absorptionvalue of the coarseaggregateis greater than2 per cent, the soundnesstest shall becarriedout on the material deLiveredto site as per IS : 2386 (Part 5).

404.2.2. Crushed or broken stone: The crushedor broken stoneshall be hard, durable and free from excess flat, elongated, softand disintegratedparticles, dirt and other deleteriousmaterial.TABLE 400.6. PHYSICAL REQUIREMENTS OF COARSE AGGREGATES FOR

WATER BOUND MACADAM FOR SUB.BASE,’BASE COURSES

Test Test Method Requirements

1. Los Angeles IS :2386 40 per cent (Max)Abrasion value (Part-4)OrAggregate IS: 2386 30 per cent (Max)Impact value (Part-4) or

IS:5640**2. Combined

Flakinessand IS:2386 30 per cent (Max)Elongation (Part-i)Indices (Tetal)***

* Aggregate may satisfy requirements of either of the two tests.

Aggregateslike brick metal,kankar,lateriteetc. which gel softenedin presenceof walershall be testedfor Impact value underwet conditions in accordancewith IS: 5640.

~ The requirementof flakinessindexand elongationindex shall be enforcedonly in the

case of crushed broken stone and crushedslag.

404.2.3. Crushed slag : Crushedslag shall be made from air-cooledblastfurnaceslag. It shall be of angularshape,reasonablyuniformin quality and densityand generally free from thin, elongated andsoft pieces, dirt or otherdeleterious materials. The weight of crushedslagshall not he less than ii.2 kN per l11~and the percentageof ~lossy

113


material shall not be more than 20. It should also comply with thefollowing requirements:

(i) Chemical stability

(ii) Sulphur content

(iii) Water absorption

To comply with requirementsofappendixof BS 1047

Maximum 2 per cent

Maximum 10 per cent

404.2.4. Overburnt (Jhama) brick aggregates : Jhama brickaggregatesshall be made from overburnt bricks or brick bats and befree from dust and other objectionableand deleterious materials.

404.2.5. Grading requirement of coarse aggregates Thecoarse aggregatesshall conform to one of the Gradings given inTable 400-7 as specified, provided,however,the useof Grading No.1shall be restrictedto sub-basecoursesonly.

TABLE 400-7. GRADING REQUIREMENTS OF COARSE AGGREGATES

Grading Size Range IS Sieve Per cent byNo. Designatktn weight passing

1. 90 mm to 45 mm 125 mm 10090 rum 90-10063 mm 25-6045 mm 0-1522.4 mm 0-5

2. 63 mm to 45 mm 90 mm 10063 mm 90-10053 mm 25.7545 mm 0-1522.4 mm 0-5

3. 53 mm to 224 mm 63 mm 10053 mm 95-10045 mm 65-9022.4 mm 0-1011.2 mm 0.5

Note : The compactedthicknessfor a layer with Grading I shall be 100 mm while forlayer with other Gradingsi.e. 2 & 3, ii shall be 75 mm.

404.2.6.Screenings:Screeningsto fill voids in the coarse aggregateshall generally consistof the same material as the coarseaggregate.However, wherepermitted,predominantlynon-plasticmaterial such asmoorumor gravel (other than rounded river borne material) may be usedfor this purposeprovided liquid limit and plasticity index of suchmaterial are below 20 and 6 respectivelyand fraction passing 75micron sieve does not exceed 10 per cent.

114

Sub-Bases,Bases(Non-Bituminous) andShoulders Section400

Screeningsshall conform to the grading set forth in Table 400-8.The consolidateddetailsof quantityof screenings required for variousgradesof stoneaggregatesaregiven in Table400-9. The table alsogivesthe quantitiesof materials(loose) requiredfor 10 m2 for sub-base/basecompactedthicknessof 100f75 mm.

The use of screeningsshallbeomittedin the caseof softaggregatessuchasbrick metal,kankar,laterites,etc.as theyare likely to get crushedto a certain extent under rollers.

TABLE 400-8. GRADING FOR SCREENINGS

GradingClassifi-cation

Size ofScreenings

IS SieveDesignation Per cent by weightpassing the IS Sieve

B

13.2 mm

11.2 mm

13.2 mm11.2 mm5.6 mm

180 micron

11.2 mm5.6 mm

180 micron

10095-100

15-350-10

10090-100

15-35

TABLE 400.9. APPROXIMATE QUANTITIES OF COARSE AGGREGATES ANDSCREENINGS REQUIRED FOR I00t75 MM COMMCTEDTHICK.NESS OF WATER ROUND MACADAM (WBM) SUB-BASFIBASECOURSE FOR 10W AREA

Classlfl.catIon

SizeRange

Compactedthickness

LooseQty.

Screenings

Stone Screening CrushableType suchas Mooruni or Gravel

GradingClassI..ficalion& Size

For. WBMSub-base!base course(Loosequantity)

GradingCf assi-ticatlon& Size

LooseQty.

Grading I

Grading 2

-do-

Grading 3

90 mm to45 mm

63 mm to45 mm

-do-

53 mm to22.4 mm

100 mm

75 mm

-do-

75 mm

1.21 to1.43 mt

0.91 to1.07 m5

-do-

-do-

Type A13.2 mm

Type A13.2 mm

Type B11.2 mar

-do-

0.27 to0.30 m1

0,12 so0.15 rn3

0.20 to0.22 sn’

0.18 to0.21 mt

Notuniform

-do-

-do-

-do-

030 to0.32 rn1

0.22 to0.24 &

-do-

-do-

A

115

Section400 Sub-Bases,Bases(Non-Bituminous) andShoulders

404.2.7. Binding material : Binding material to be used for watcrbound macadam as a filler material meant for preventing ravelling,shall comprise of a suitablematerialapprovedby the Engineer havinga Plasticity lndex(PI)valueof less than6 as determinedin accordancewith IS: 2720 (Part-5).

The quantity of binding material where it is to be used, willdependon the type of screenings.Generally, the quantity requiredfor 75 mm compactedthicknessof water bound macadamwill beOA)6-0.09 m3/lOm2 and0.08-0.lOmVlOm2for 100 mm compactedthick-ness.

The above mentionedquantities should be taken as a guide only,for estimationof quantities for constructionetc.

Application of binding materials may not be necessarywhenthe screenings used are of crushable type such as moorum orgravel.

4043. Construction Operations

404.3.1. Preparation of base: The surface of the subgrade/sub-base/baseto receive the water bound macadam course shall bepreparedto the specifiedlines and crossfall(camber)and made free ofdust andotherextraneousmaterial.Any rutsor soft yielding places shallbe correctedin, an approvedmannerand rolled until firm surface isobtained if necessaryby sprinkling water. Any sub-base/base/surfaceirregularities, where predominant,shall be made good by providingappropriate type of profile correctivecourse(levelling course) to Clause501 of these Specifications.

As far as possible,laying water bound macadam courseover anexisting thick bituminous layer may be avoided since it will causeproblemsof internal drainageof the pavementat the interfaceof twocourses. It is desirable to completely pick out the existing thinbituminous wearingcoursewhere waterbound macadamis proposedtobe laid over it. However, where the intensity of rain is low andthe interface drainagefacility is efficient, water bound macadamcanbe laid over the existing thin bituminous surfaceby cutting 50 mm x50 mm furrows at an angle of 45 degreesto the centre line of thepavementatone metre intervals in the existingroad. The directionsanddepth of furrows shall be suchthat they provideadequatebondageandalso serve to drain water to the existing granular basecoursebeneaththe existing thin bituminous surface.

116


404.3.2. Invertedchoke : If water bound macadamis to be laiddirectly over the subgrade, without any other intervening pavementcourse, a 25 mm course of screenings(Grading B) or coarse sandshall be spread on the prepared subgradebefore application of theaggregatesis takenup. in caseof a fine sandor silty or claycy subgrade,it is advisable to lay 100 mm insulating layer of screeningor coarsesand on top of fine grainSsoil, the gradationof which will dependupon whether it is intended to act as a drainagelayer as well. As apreferredalternative to inverted choke, appropriate geosyntheticsper-forming functions of separationand drainagemay be used over theprepared subgradeas directed by the Engineer. Section 700 shall beapplicable for use of geosynthetics.

404.3.3, Spreadingcoarseaggregates: The coarseaggregatesshallbe spread uniformly andeventy upon the prepared subgrade/sub-base/baseto proper profile by using templatesplacedacrossthe road about6 in apart, in such quantities that the thicknóss of each compactedlayer is not more than 1(X) mm for Grading I and 75 mm for Grading2 and 3, as specified in Clause404.2.5. Wherever possible,approvedmechanicaldevices such as aggregate spreadershall be used tospread the aggregatesuniformly so as to minimise the need formanual rectification afterwards. Aggregatesplacedat locations whichare inaccessibleto the spreadingequipment,may be spreadin one ormore layersby any approvedmeansso as to achievethespecifiedresults.

The spreadingshall be done from stockpilesalong the side of theroadway or directly from vehicles, No segregationof large or fineaggregates shall be allowed and the coarse aggregateas spread shallbe of uniform gradationwith no pocketsof fine material.

The surfaceof the aggregatesspreadshall be carefully checkedwithtemplates and all high or low spotsremedied by removing or addingaggregatesas may be required.Thesurfaceshall be checkedfrequentlywith astraightedgewhilespreadingandrolling so as to ensureafinishedsurface as per approveddrawings.

The coarseaggregatesshall not normally be spreadmore than 3days in advanceof the subsequentconstructionoperations.

404.3.4, Rolling: Immediatelyfollowing thespreadingof the coarseaggregate, rolling shall be started with three wheeledpower rollersof 80 to 100 kN capacityor tandemor vibratory rollers of 80 to 100kN static weight. The type of roller to be used shall be approved bythe Engineerbased on trial run.

117


Except on superelevatedportions where the rolling shallproceedfrom inner edge to the outer, rolling shall begin from the edgesgradually progressingtowards the centre.First the edge/edgesshall becompacted with roller running forward arid backward. The roller shallthenmove inward parallel to the centreline of the road, in successivepassesuniformly lapping precedingtracks by at least onehalf width,

Rolling shall be discontinuedwhenthe aggregatesare partially com-pacted with sufficient void space in them to permit application ofscreenings.However, where screeningsare not to be applied, as in thecase of crushed aggregates like brick metal, laterite and kankar,compaction shall be continued until the aggregates are thoroughlykeyed. During rolling, slight sprinkling of water may be done, ifnecessary. Rolling shall not be done when the subgrade is soft oryielding or when it causesa wave-likemotion in the subgradeor sub-basecourse.

The rottedsurfaceshall be checked transverselyandlongitudinally,with templatesandany irregularitiescorrectedby loosening the surface,adding or removing necessary amount of aggregatesand re-rollinguntil the entire surfaceconforms to desiredcrossfail (camber)andgrade.in no case shall the use of screeningsbe permitted to make updepressions.

Material which gets crushed excessivelyduring compaction orbecomes segregatedshall be removed and replaced with suitableaggregates.

It shall be ensuredthat shouldersare built up simultaneouslyalongwith water bound macadam coursesas per Clause407.4.1.

404.3.5. Application of screenings: After the coarse aggregatehas been rolled to Clause404.3.4,screeningsto completelyfill theinterstices shall be applied graduallyover the surface.These shall notbe damp or wet at the time of application.Dry rolling shall be donewhilethe screeningsarebeingspreadsothatvibrationsof theroller causethem to settle into the voids of the coarse aggregate.The screeningsshall not be dumpedin pilesbut be spreaduniformly in successivethinlayerseither by the spreadingmotionsof handshovelsor by mechanicalspreaders,or directly from tipper with suitable grit spreading arrange-ment. Tipper operating for spreadingthe screeningsshall be so drivenas not to disturb the coarseaggregate.

The screeningsshall be appliedat a slow anduniform rate (in threeor more applications)so as to ensurefilling of all voids. This shall be

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Sub-Bases,Bases(Non-Bituminous)and Shoulders Section400

accompaniedby dry rolling andbroomingwith mechanicalbrooms, hand-brooms or both. In no caseshall the screeningsbe applied so fast andthick as to form cakesor ridges on the surfacein such a manneraswould preventfilling of voids or preventthe direct bearingof the rolleron the coarseaggregate.Theseoperations shall continueuntil no morescreeningscan be forced into the voids of the coarse aggregate.

The spreading, rolling, andbroomingof screenings shall becarriedout in only such lengthsof the road which could be completedwithinone day’s operation.

404.3.6. Sprinkling of water and grouting : After the screeningshavebeen applied, the surfaceshall be copiouslysprinkled with water,swept and rolled. Hand brooms shall be used to sweep the wetscreeningsinto voids and to distribute them evenly. The sprinkling,sweeping and rolling operation shall be continued, with additionalscreenings applied as necessaryuntil the coarse aggregate has beenthorougl.ly keyed, well-bondedand firmly set in its full depth and agrout has been formedof screenings.Careshall be taken to see thatthe base or subgradedoes not get damageddue to the additionof excessivequantities of water during construction.

In caseof lime treatedsoil sub-base,constructionof water boundmacadamon top of it can causeexcessivewater to flow down to thelime treatedsub-basebefore it has picked up enoughstrength (is still“green”) and thus causedamageto the sub-baselayer. The laying ofwaterbound macadamlayer in suchcasesshall be done after the sub-base attains adequatestrength,as directedby the Engineer.

40&3.7. Application of binding material: After the applicationof screeningsin accordancewith Clauses404.3.5 and404.3.6.the bindingmaterial where it is required to be used (Clause 404.2.7) shallbe applied successivelyin two or more thin layers at a slow anduniform rate. After each application, the surface shall be copiouslysprinkledwith water, the resulting slurry swept in with hand brooms,or mechanical brooms to fill the voids properly, and rolled duringwhich watershall beappliedto the wheels of the rollers if necessaryto wash down the binding materialsticking to them. Theseoperationsshall continueuntil the resulting slurry after filling of voids, forms awave aheadof the wheelsof the moving roller.

404.3.8.Setting and drying: After the final compactionof waterboundmacadam course,the pavementshall be allowed to dry overnight.Next morning hungry spots shall be filled with screenings or binding

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Section400 Sub-Bases,Bases(Non-Bituminous)and Shoulders

material as directed,lightly sprinkled with waterif necessaryandrolled.No traffic shall be allowed on the road until the macadam has set. TheEngineershall have the discretion to stop hauling traffic from usingthe completedwater bound macadamcourse,if in his opinion it wouldcauseexcessivedamageto the surface.

The compacted water bound macadam course should be allowedto completely dry andset beforethe next pavementcourseis laid overit.

404.4. SurfaceFinish and Quality Control of Work

404.4.1.The surface finish of constructionshall conform to thcrequirementsof Clause 902.

404.4.2.Control on the quality of materials and works shall beexercised by the Engineer in accordancewith Section 900.

404.4.3. The water bound macadamwork shall not be carried out~shenthe atmospherictemperatureis less than 0°Cin the shade.

404.4.4. Reconstructionof defectivemacadam:The finishedsurfaceof water bound macadamshall conform to the toleranceof surfaceregularity as prescribedin Clause902. However, where the surface ir-regularity of the courseexceedsthe tolerancesor where the course isotherwisedefectivedue to subgradesoil mixing with theaggregates,the courseto its full thicknessshall be scarified over the affected area,reshaped with added material or removed andreplaced with freshmaterialas applicableand recompacted. En no caseshall depressionsbefilled up with screeningsor binding material.

404.5. Arrangement for TrafficDuring the period of construction, the arrangementof traffic shall

be done as per Clause 112.

404.6. Measurements for paymentWater bound macadam shall be measuredas finished work in

position in cubic metres.

404.7. RateThe Contract unit rate for water bound macadamsub-base/base

course shall be payable in full for carrying out therequiredoperationsincluding full compensationfor all componentslisted in Clause401.S(i) to (v) including arrangementof water usedin the work as approvedby the Engineer.

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SubBases,Bases(Nonilituminous) and Shoulders Section400

405, CRUSHED CEMENT CONCRETE SUB-BASE/BASE

405.1. Scope

This work shall consistof breakingand crushing the damagedcement concrete slabsand recomp~tingthe same as sub-base/basecourse in one or more layers. Where specified, it shall also includetreating the surface of the top layerwith a penetrationcoatof bitumen,The work shall be performed on such widths and lengths as may bespecified, in accordance with the requirementsof theseSpecificationsand in conformity with the lines, grades and cross-sectionsshownon the drawingsor as otherwise directed by the Engineer.

405.2. Materials

405.2.1. Coarse aggregate: Coarseaggregatefor this work shallbe hrokcn cementconcreteslabscrushedto a size not exceeding75 mmandas far as possible,conformingto oneof the gradingsgiven in Table4(X)-?.

405.2.2. Key aggregate: Key aggregatefor the penetration coatshall consist of crushedstone, crushedgravel, shingle or other stones.it shall be clean, strong, durable, of fairly cubical shapeand free ofdisintegratedpieces, organic or other deleteriousmatter and adherentcoatings.The aggregateshall be hydrophobic and of tow porosity.

The aggregateshall be of 11.2 mm size definedas 100 per centpassingthrough 13.2mm sieve andretainedon 5.6 mm sieveand shallsatisfy the physical requirementsset forth in Table 500-3.

405.2.3. Binder: Binderfor the penetrationcoat for the top layershall be bitumen of a suitable grade,as directed by the Engineerandsatisfying the requirementsof IS: 73,217 or 454, as applicableor anyapprovedcutback or emulsion,satisfying the requirementsof IS:8887.


405.3.1. General: Crushedcement concrete sub-base/basecoursemay be constructedin one or two layers, dependingupon the thicknessof the concrete slabs dismantledandcrushed.The thicknessof eachlayer shall, however, not exceed100 mm in caseof sub-baseand75mm in caseof basecourse.

The course shall be constructedas waterboundmacadamto Clause404, using crushedcementconcreteas coarseaggregate exceptthat noscreenings or binding material need be applied. Where specified,

12t

Section400 Sub-Bases, Bases (Non-Bituminous)andShoulders

the top layer shall be treatedwith a penetrationcoat of binder describedin Clause4053.2.

405.3.2. Application of penetration coat over the top layer:Beforetheapplicationof thepenetralioncoat, thesurfaceshallbe cleanedof dust, dirt and other foreign matter,using mechanicalbroom or anyotherequipmentspecifiedby the Engineer.Dust removedin the processshall be blown off with the help of compressedair.

The binder shall be heatedto the temperature appropriate to thegradeof bitumenusedandsprayedon the dry surfacein a uniform mannera~the rate of 25 kg per 10 m2 area in terms of the residual bitumenwith the help of either self-propelled or towed bitumen pressuresprayer with self-heating arrangementand spray nozzle capableofsprayingbitumen at specifiedratesand temperaturesso as to providea uniform, unbroken spreadof bitumen.Excessive depositsof bindercausedby stopping or starting of the sprayer or through leakageorany other reasonshall be suitably corrected.

Immediately after the application of binder, the key aggregates,in a clean and dry state shall be spreaduniformly on the surface atthe rateof 0,13 m3 per 10 m2 area, preferablyby meansof a mechanicalgritter, capableof spreading aggregate uniformly at specified ratesor otherwise manually with the approval of the Engineer,so asto cover the surfacecompletely. Immediatelyafter theapplicationof thekey aggregates,the entire surfaceshall be rolled to Clause506.3.8.

405.4. Surface Finish and Quality Control of WorksThe surfacefinish of constructionshallconform to therequirements

of Clause902.

Control on the quality of material and works shall be exercisedbythe Engineer in accordancewith Section 900.


During the period of construction,arrangementof traffic shall bedone as per Clause 112.


Breakingthe existingcementconcretepavementslabs, crushingandrecompactingtheslabmaterialassub-base/basecourseshall bemeasuredas a single item in termsof the volume of sub-base/baselaid in positionin cubic metres.

122


Penetration coat shall be measuredas finished work in squaremetres.

405.7. Rates

405.7.!. The Contract unit rate for crushed cement concrete sub-base/base courseshalL be payment in full for carrying out therequired operations including full compensationfor:

(0 making arrangements for traffic to Clause 112 except for initial treatment toverges/shouldersand constructionof diversions;

(ii) breaking the cementcsiricrete slabs, crushing, sieving and recompacting theslab material as suh-base)basecourse;

(iii) all labour, tools, equipment and incidentals to complete the work to theSpecifications; and

(iv) carrying out the work in part widths of road where directed.

405.7.2. The Contractunit rate forpenetrationcoat shaltbe paymentin full for carrying out the required operations including fullcompensationfor all componentslisted in Clause504.8.

406. WET MIX MACADAM SUB-BASE/BASE

406.1. Scope

This work shalt consist of laying and compacting clean,crushed,graded aggregateand granularmaterial, premixedwith water,to a dense masson a prepared subgrade/sub-base/baseor existingpavement as the casemay be in accordancewith the requirementsof theseSpecifications.The materialshall be laid in oneor more layersas necessaryto lines, gradesand cross-sectionsshown on the approveddrawings or as directed by the Engineer.

The thicknessof a single compactedWet Mix Macadam layershallnot be less than 75 mm. When vibrating or other approved typesof compacting equipmentare used, the compacteddepth of a singlelayer of the sub-basecoursemay be increasedto 200 mm upon approvalof the Engineer.

406.2. Materials

406.2.!. Aggregates

406.2.1.!. Physical requirements:Coarse aggregatesshall be,rushedstone.If crushedgravel/shingleis used,not lessthan90 per centby weight of the gravel/shinglepiecesretainedon 4.75 mm sieve shalthave at least two fractured faces. The aggregates shall conformto the physical requirementsset forth in Table 400-10 below.

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-

Sub-Bases, Bases (Non-Bituminous) and Shoulders

PHYSICAL REQUIREMENTS OF COARSE AGGREGATES FORWET MIX MACADAM FOR SUB-BASE/BASECOURSES

- -Test TestMethod Requirements*Los Angii IS: 2386(Part-4) 40percent(Max,)Abrasionvalueor*Aggregate IS: 2386(Part-4) 30per cent (Max.)tmpactvalue or15:5640

2. CombinedFlakinessand IS: 2386(Part-I) 30per cent(Max.)”’Elongation indices(Total)

* Aggregate may satisfy requirementsof eitherof the two tests.** To determine this combinedproportion, the flaky stone from a representative

sample should first be separated out Flakiness index is weight of flaky stonemetal divided by weight of stone sample. Only the elongated particles beseparatedout from the remaining (non-flaky) stone metal. Elongation index isweight of elongatedparticlesdivided by total non-flaky particles. The valueofflakiness index and elongationindex so found areaddedup.

If thewaterabsorptionvalueof thecoarseaggregateis greaterthan2~percent, the soundnesstestshallbecarriedouton thematerialdeliveredtositeasper IS: 2386(Part-5).

406.2.1.2.Grading requirements: The aggregatesshall conform tothegradinggiven in Table400-11.TABLE 400-Il. GRADING REQUIREMENTS OF AGGREGATES FOR WET MIX

MACADAMtS SieveDesignation Percent by weightpassingtheIS sieve53.00 iiiiii 10045.00 mm 95-1002650 mm —

22.40 mm 60-80lt.20 mm 40-604.75 mm 25-40236 mm 15-30

600.00 micron 8-2275.00 micron - 0-8

Materialsfiner than 425 micron shall havePlasticityIndex (P1) notexceeding6.

The final gradationapprovedwithin theselimits shall be wefl gradedfrom coarseto fine andshall not vary from the low limit on onesieveto thehigh limit on theadjacentsieveor vice versa.

406.3. Construction Operations406.3.1.Preparationof base:Clause404.3.1.shallapply.

406.3,2.Provisionof lateral confinement ofaggregates: While con-structingwetmix macadam,arrangementshall be madefor the lateral

Section 400

TABLE 400-10.

124


confinementof wet mix. This shall be done by laying materials inadjoining shoulders along with that of wet mix macadamlayer andfollowing the sequenceof operationsdescribedin Clause407.4.1.

406.3.3.Preparatk)n of mix : Wet Mix Macadamshallbe preparedin an approved mixing plant of suitable capacity having provisionfor controlled addition of waterand forced/positive mixing arrangementlike pugmill or pan type mixer of concretebatchingplant, For smallquantity of wet mix work, the Engineermay permit the mixing tohe done in concrete mixers.

Optimum moisture for mixing shall be determinedin accordancewith IS:2720 (Part-8) after replacing the aggregatefraction retainedon 22.4 mm sieve with material of 4.75 mm to 22.4 mm size, Whileadding water, dueallowanceshouldbe madefor evaporation losses.However, at the time of compaction,water in the wet mix should notvary from the optimum valueby morethanagreed limits. The mixedmaterial shotild be uniformly wet and no segregation shouldbe permitted.

406.3.4. Spreading of mix Immediately after mixing, theaggregatesshall be spread uniformly and evenly upon the preparedsubgrade/sub-base/basein requiredquantities. In no caseshould thesebe dumpedin heapsdirectly on the area where theseare to be laid norshall their hauling over a partly completed stretch be permitted.

The mix may be spreadeither by a paver finisher or motorgrader. For portions wheremechanicalmeanscannotbe used,manualmeansas approvedby the Engineershall be used. The motor gradershall be capableof spreadingthe materialuniformly all over thesurface.Its blade shall have hydraulic control suitable for initial adjustmentsandmaintainingthe sameso as to achieve thespecifiedslopeandgrade.

The paver finisher shall be self-propelled,having the foliowingfeatures

(i) Loading hoppersand suitable distribution mechanism

(ii) The screedshall havetamping andvibrating arrangementfor initial compactionto the layer as it is spread without ruuing or otherwise marring the surfaceprofile.

(iii) ‘I’he paver shall be equipped with necessaly control mechanism so as toensurethat the finished surface is free from surfaceblemishes.

The surfaceof theaggregateshall be carefullycheckedwith templatesand all high or low spotsremediedby removing or addingaggregateas may be required.The layer may be tested by depth blocks during

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Section400 Sub-Bases,Bases(Non-Bituminous) andShoulders

construction. No segregationof larger and fine particlesshould beallowed, The aggregatesas spreadshould be of uniform gradationwithno pockets of fine materials.

406.3.5. Compaction:After themix hasbeenlaid to the requiredthickness,gradeand crossfatl/eamberthe sameshall be uniformly com-pacted, to the full depth with suitable roller. If the thicknessof singlecompactedlayerdoes not exceed100 mm, a smoothwheel roller of 8010 100 kN weight may he used.For a compactedsingle layer upto 200mm, the compaction shall be done with the help of vibratory rollerof minimumstatic weightof 80 to 1(X) kN or equivalentcapacityroller.The speed of the roller shall not exceed5 km/h.

In portions having unidirectional cross fall/superelevation,rollingshall commencefrom the lower edge and progress gradually towardsthe upper edge.Thereafter,roller should progressparallel to the centreline of the road, uniformly over-lapping each precedingtrack by atleastonethird width until the entire surface has beenrolled. Alternatetrips of the roller shall be terminatedin stopsat least I m away fromany precedingstop.

In portions in camber,rolling should beginat the edge with theroller running forward andbackwarduntil the edges have beenfirmlycompacted.The roller shall then progressgradually towardsthe centreparallel to the centreline of the road uniformly overlapping each ofthe precedingtrack by at leastone-third width until the entire surfacehas been rolled.

Any displacementoccurringas aresultof reversing of the directionof aroller or from any othercauseshall be corrected atonceas specifiedand/or removed and made good.

Along forms, kerbs,walls or other placesnot accessibleto the roller,the mixture shall be thoroughly compactedwith mechanicaltampersor a plate compactor.Skin patching of an area without scarifyingthe surface to permit proper bonding of the added material shall notbe permitted.

Rolling shouldnot be donewhenthe subgradeis soft or yieldingor when it causesa wave-like motion in the sub-base/basecourse orsubgrade.If irregularitiesdevelopØuring rolling which exceed 12 mmwhentestedwith a 3 metrestraight edge, the surfaceshouldbe loosenedandprenlixedmaterialaddedor removedas requiredbeforeroiling againso as to achievea uniform surfaceconforming to the desired gradeand

126

Sub-B ases,Bases (Non-Bituminous)and Shoulders Section40()crossfall. In no caseshould the use of unmixed material be permitted

to make up the depressions.

Rolling shall be continuedtill the density achieved is at least98 per cent of the maximum dry density for the material as determinedby the method outlined in IS: 2720 (Part—8)

After completion,the surfaceof any finished layer shall be well-closed, free from movement under compaction equipment or anyconlpaetionplanes,ridges,cracksandloosematerial.All loose,segregatedor otherwisedefectiveareasshall be made good to the full thicknessof the layer and recompaeted.

406.3.6.Settinganddrying: After final compactionof wet mix mac-adam course, the road shall be allowed to dry for 24 hours.

406.4. Openingto Traffic

Preferably no vehiculartraffic of any kind should be allowed onthe finished wetmix macadamsurfacetill it has dried and the wearingcourse laid.

406.5. Surface Finish and Quality Control of Work

406.5.!. Surfaceevenness: The surfacefinish of construction shallconform to the requirementsof Clause902.

406.5.2. Quality control : Control on the quality of materialsandworks shallbe exercisedby theEngineerin accordancewith Section900.

406.6. Rectification of SurfaceIrregularity

Where the surfaceirregularity of the wet mix macadam courseexceeds the permissibletolerancesor where the course is otherwisedefective due to subgradesoil getting mixed with the aggregates, theftill thicknessof the layer shall be scarifiedover the affectedarea, re-shaped with addedpremixed material or removedand replaced withfresh premixedmaterial as applicableandrecompaeted in accordancewith Clause406.3. The areatreated in the aforesaidmannershall notbe less than 5 m long and 2 m wide. In no caseshall depressionsbe filled up with unmixed and ungradedmaterial or fines.

406.7. Arrangementfor Traffic

During the period of construction,arrangementof traffic shall bedone as per Clause112.

127



Wet mix macadam shall be measuredas finished work in positionin cubic metres.

406.9. Rates

The Contractunit rate for wet mix macadam shallbe payment infull for carrying out the required operations including lullcompensationfor all componentslisted in Clause4018.

407. SHOULDERS, ISLANDS AND MEDIAN

407.1. Scope

The work shall consistof constructingshoulder (hard/paved!earthenwith brick or stone block edging) on either side of the pavement,median in the road dividing the carriagewayinto separatelanes andislands for channelisingthe traffic at junctions in accordance withthe requirements of these Specifications and in conformity withthe lines, gradesand cross-sections shownon the drawingsor asdirectedby the Engineer.

407.2. Materials

Shoulder on either side of the road may be of selectedearth/granular material/ paved conforthing to the requirements ofClause305/401 and the median may be of selectedearth conforming to therequirements ofClause305.

Median/Traffic islandsshall he raised and kerbed at theperimeterand the enclosedarea filled with earthand suitably coveredwith grassturf/shrubs asper Clause307 and/or paved as per Clause409.3.4 or409.3.5.

Pavedshoulders shallconsistof sub-base,baseandsurfacingcourses,as shown in the drawingsand materials for the same shall conform torelevant Specificationsof the correspondingitems. Wherepaved orhard shoulders are not provided, the pavement shall be providedwith briclçi’stone block edgingsas shown inthe drawings. The bricksshall conform to Clause1003 of these Specifications. Stone blocksshall conform to Clause 1004 of these Specificationsand shall be ofsize 225 mm x 110 mm x 75 mm.

407.3. Size orShoulders/Median/Islands

Shoulder(earthen/hard/paved)/median/trafficisland dimensionsshallbe as shownon ihe drawings or as directed by the Engineer.

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Sub-Bases, Bases(Non-Bituminous)andShoulders Section400

407,4. Construction Operations

407.4.1. Shoulder: The sequenceof operationsshall be such thatthe construction of paved shoulderis done in layers each matchingthe thicknessof adjoiningpavementlayer,Only afteralayerof pavementand correspondinglayers in paved and earth shoulderportion have beenlaid and compacted,the constructionof next layerof pavement andshoulder shall be taken up.

Where the materialsin adjacentlayers are different, theseshallbe laid togetherandthe pavementlayershall be compactedfirst. Thecorrespondinglayer in paved shoulder portion shall be compactedthereafter,which shall befollowed by compactionof earthshoulderlayer.The adjacentlayers having samematerial shall be laid and compactedtogether.

In all caseswhere paved shouldershave to be provided alongside of existing carriageway, the existingshouldersshall be excavaledin full width and to the required depth as per Clause301.3.7.Underno circumstances,box cuttingshall bedonefor constructionof shoulders.

Compaction requirement of earthenshouldershall beas per Table300-2, In the caseof bituminouscourses,work on shoulder(earthenJhardJpaved), shall start~only after the pavementcourse has been laidand compacted.

During all stagesof shoulder(earthen/hard/paved)construction,therequiredcrossfall shall be maintained to drain off surfacewater.

Regardlessof themethodof laying, all shoulderconstructionmaterialshall be placed directly on the shoulder.Any spilled material draggedon to the pavementsurface shall be immediately removed, withoutdamageto thepavement,andthe area so affectedthoroughlycleaned.

407.4.2, Median and Islands : Median and Islands shall beconstructed in a manner similar to shoulder up to the road level.Thereafter the median and islands, if raised,shall be raisedat least300 mm by using kerb stonesof approvedmaterialand dimensionsand suitably finished and paintedas directedby the Engineer.If notraised,the medianandislandsshall be differentiatedfrom the shoulder/pavementas the casemay be, as directedby the Engineer.The confinedarea of the medianandislandsshall be filled with local earthor granularmaterial or any other approved material and compacted by platecompactor/powerrammer.The confinedareaafter filling with earthshallbe turfed with grass or planted with shrubs and in caseof granularfill it can be finished with tiles/slabsas directed by the Engineer.

129

Section4(X) Sub—Bases,Bases(Non-Bituminous)andShoulders

407,4.3, Bricklstone block edging: The bricks/stone blocks shallbe laid on edge, with the length parallel to the transversedirection ofthe road, Theyshall belaid on a bedof 25 mm sand, set carefully,rolled into position by a light roller and madeflush with the finishedlevel of the pavement.

407.5. Surface Finish and Quality Control of Works

The surface finish of constructionshall conform to therequirementsof Clause902. Control on the quality of materials andworks shall beexercisedby the Engineer in accordance with Section 900.


Shoulder (earthen/hard/paved),islandandmedian constructionshallbe measuredas finished work in position as below:

(i) For excavation in cu. m.

(ii) For earthwork!granularfill in Cu. m,

(iii) For sub-base, base, surfacingcourserin units as for respective items.

(iv) For kerb in running metres.

(v) For surfing and tilelslab finish in sqm.

(vi) For brick/stone btock edging in sqm.

407.7. RateThe Contractunit ratefor shoulder (hard/paved/earthenwith brick

or stone block edging),island and medianconstructionshall bepaymentin full for carrying out the requiredoperationsincluding full compen-sation for all componentslisted in Clause401.8 (1) to (v) as applicable.The rate for brick/stoneblock edging shall include the cost of sandcushion.

408. CEMENT CONCRETE KERB AND KERB WITHCHANNEL

408.1. Scope

This work shall consistof constructingcementconcrete kerbsandkerbs with channel in the central median and/or along thefootpathsor separators in conformity with the lines, levels and dimensionsasspecified in the drawings.

408.2. Materials

Kerbs and kerb with channelshall be providedin cementconcreteof Grade M20 in accordancewith Section 1700of these Specifications.

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Sub-Bases, Bases (Non-Bituminous) and Shoukiers Section 400

408.3. Typeof ConstructionThese shall be cast-in-situconstructionwith suitable kerb casting

machinein all situationsexceptatlocations where continuouscastingwithequipmentisnot practicable. In thosesituations,precastconcreteblocksshallbeused.

408.4. EquipmentAcontinuouskerb casting equipmentofadequate capacityandcontrols,

capableof laying the kerbs in required cross-sectionsand producingawell-compactedmassof concretefreeof voidsand honeycombs, shall beused.


408.5.1.Kerbshall belaid on firm foundationof minimum 150 mmthicknessof cementconcreteof M1O gradecastin-situ oronextendedwidthof pavement.The foundationshall haveaprojectionof 50 mm beyondthekerbstone. Beforelaying the foundationof leanconcrete,thebaseshall belevelledandslightly wateredto makeit damp.

408.5.2.In themedianportionsin thestraightreaches,thekerbshall becast in contintiotis lengths.In theportionswherefootpathisprovidedand/orthe slopeof the carriagewayis towards median(asin caseof superelevatedportions), thereshall besufficientgap/recessleft in the kerb to facilitatedrainageopenings.

408.53. After laying the keibs andjust prior to hardeningof theconcrete,sawcut groovesshallbe providedat5 m intervalsor asspecifiedby theEngineer.

408.5.4.Kerbs on the drainageendssuchasalong the footpathor themedian insuperelevatedportions,shall becastwith monolithic concretechannels asindicatedin drawings.Theslopeof thechanneltowardsdrainagepipesshall beensuredforefficientdrainageof theroadsurface.

408.5.5. Verticalandhorizontaltoleranceswith respectto trueline andlevel shall be±6mm.


Cementconcretekerb/kerbwith channelshall be measuredin linearmetre for thecompleteitem of work.

131


Foundation of kerb, where separatelyprovided shall be measured

in linear metre for complete item of work.

408.7. Rates

The Contract unit ratesfor cementconcretekerb/kerb with channeland foundation for kerb shall be payment in full compensationforfurnishing all materials, labour, tools, equipmentfor constructionandother incidental cost necessaryto complete the work.

409. FOOTPATHS AND SEPARATORS

409.1. Scope

The work shall consist of cctistructing footpaths and/orseparatorsat locationsas specifiedin the drawingsor as directedby the Engineer.The lines,levelsanddimensionsshallbe asper thedrawings.The scopeof the work shall include provision of all drainagearrangementsas shown in the drawings or as directed.

409.2. Materials -

The footpathsand separatorsshall be constructedwith any of thefollçwing types

(a) Cast-in-situ cesnent concrete of Grade M20 as per Section 1700 of the Specifi-cations.

(b) Precast cementconcreteblocks/tiles of Grade M20 as per Section 1700 of thespecifications. The minimum thickness of the cement concrete block/tile shallbe 25 mm and minimum size shall be 300 mm x 300 mm.

(c) Natural stone slab cut and dressed from stone of good and sound quality, uniformin texture, free from defects and at least equal to a sample submitted by theContractor and approved by the Engineer. The minimum thickness of thenatural stone slab shall be 25 mm and minimum size shall be 300 mm x 300mm.


409.3.1. Drainage pipesbelow the footpath originating from thekerbs shall be first laid in the requiredslope and connectedto thedrains/sumps/stormwater drain/drainagechutesas per provisions ofthe drawings, or as specified.

409.3.2. Portion on back sideof kerbs shall be filled and compactedwith granular sub-basematerial asper Clause401 of the Specifleationsin specified thickness.

409.33. The baseshall be preparedand finished to the requiredlines, levels and dimensionsas indicated in the drawings with the

132

Sub-Bases, Bases (Non-Bituminous) and Shoulders Section 400

following

(a) Minimum 150 mm thick,compacted granular sub-base material as per Clause 401 ofthe Specifications.

(b) Minimum 25 mm thick cement concrete of Grade M 15.

Overthe preparedbase,precastconcrete blocks/tiles/naturalstone slabsand/oreast-in-situslabshallbe set/laidasdescribedin Clauses 409.3.4and409

4093.4.Precast cementconcrete blocks/tiles/natural stone slab:Theblocks/tiles/slabsshall beseton alayerofaverage12 mm thick cement-sandmortar(l:3)laid on preparedbasein suchaway that thereis norocking.The gapsbetweenthe blocks/tiles/slabsshallnot be more than 12 mm andshall hefilled with cement-sandmortar(1:3).

409.3.5.Cast-in-situcementconcrete:Theminimumthicknessof thecementconcreteshall be 25 mm and it shall he caston the prepared baseinpanels ofspecifiedsize in a staggeredmanner. Constructionjoints shall beprovidedasperSection 1700of theSpecifications.


Footpathsandseparatorsshall bemeasured insqmetrèbetweeninsideof kerbs,

409.5. Rates

Contractunit rates shall heinclusiveof full compensationof all labour,materials,tools,equipmentandincidentalstoconstructionof footpaths.Costof providing pipes and arrangementfor their dischargeinto appropriatedrainagechannelsshall beincidental totheconstructionof footpaths.

410. CRUSHER-RUNMACADAM BASE410.1. ScopeThis work shall consistof furnishing, placingandcompactingcrushed

stoneaggregatesub-baseandbasecoursesconstructedin accordancewith therequirementssetforth in thisSpecificationandin conformitywith thelines,grades, thicknessesandcross-sectionsshownon theplansor asdirected bytheEngine r.

410.2. MaterialsThe materialto be usedfor thework shallbe crushed rock,If crushed

gravel/shingleis used,not lessthan90percentbyweightofthegravel/shinglepiecesretainedon 4.75 mm sieveshall haveatleasttwo fracturedfaces. Itshall befree from any organicmatter andotherdeleterioussubstancesandshall beof suchnaturethatit can becompactedreadily underwateringand

133

Section 400 Sub-Bases,Bases (Non-Bituminous) and Shoulders

rolling to form afirm, stablebase.Theaggregateshallconformtothegradingandquality requirementsshownin Tables400-12and400-13.

At theoptionoftheContractor,thegradingforeither53 mm maximumsizeor 37.5 mm maximumsize shallbeused,exceptthatonceagradingisselected,it shall notbechangedwithout theEngineer’sapproval.

TABLE 400.12. AGGREGATEGRADING REQUIREMENTS

Sieve size Per cent passing by weight53mm max. size 37.5mm max. size

63 mm 10045 mm 87-lOG tOO22~4 mm 5O~85 90-tOO5.6 mm 25-45 35-55

710 micron 10-25 10-3090 micron 2-9 2-9

TABLE 400-13. PHYSICAL REQUIREMENTSOF COARSE AGGREGATES FOR

CRUSHER-RUN MACADAM BASE

Test_-~ Test Method Requirements4Los Angeles IS :2386 40 maximumAbrasion value (Part-4)or*Aggregate IS :2386 30rnaxirnumImpact value (Part.4) or

IS : 5640

2. CombinedFlakiness and IS :2386 30maximum***Elongation Indices (Total) (Pan-i)

3. **W~t~.absorption IS: 2386 2per cent(Part-3) Maximum

4, liquid Limitof IS : 2720 Not more thanmaterial passing 425 micron (Part-5) 25

5. Plasticity Index IS :2720 Not more thanof material passing 425 micron (Part-5) 6

* Aggregate may satisfy requirements of either of the two tests.~ If the waterabsorption is more than 2 per cent, soundness test shall be carried

out as per IS:2386 (Part-5).~ To determine this combined proportion, the flaky stone from a representative

sampleshould first be separated out. Flakiness index is weightof flaky stonemetal divided by weight of stone sample. Only the elongated particlesbeseparated out from the remaining (non-flaky) stone metal, Elongation index isweight of elongated particles divided by total non-flaky partides. The value offlakiness ~rsdexand elongation index so found are added up.

I

134

Sub-Bases,Bases (Non-Bituminous) andShoulders Section400


410.3.1.Preparationor subgrade: Any ruts, deformations or softyielding places which occur in the sub-baseor subgradeshall becorrected and compactedto the requireddensitybefore the aggregatebasecourse is placed thereon.

410.3.2, Spreading, watering, mixing and compaction: The ag-gregateshall be uniformly depositedon the approvedsubgradeby meansof the hauling vehiclewith or without spreadingdevices.Aggregatewillbe distributedover the surfaceto the depth specifiedon the plans oras directed by the Engineer.

After the base course material has been deposited, it shall bethoroughly blade-mixedto full depthof the layerby alternatelybladingthe entire layer to the centreand backto the edges of the road. Itshallthenbe spreadandfinishedto the required cross-sectionby meansof a motor grader.

Water shall be applied prior to and during all blading andprocessingoperations to moisten the material sufficiently to preventsegregation of the fine and coarse particles. Water shall be appliedin sufficient amountsduring constructionto assistin compaction.

Alternatively, mixing of the crusherrun materialand watermay bedone in a mixing plant as per Clause406.3.3.

Compaction shall commence immediately after the spreadingop-eration. If the thickness of single compacted layer doesnot exceed100mm, a smooth wheel roller of 80 tolOO kN weight may be used.Fora compacted single layerupto 200 mm the compactionshall be donewith the help of vibratory roller of minimum static weightof 80 to 100kN or equivalent capacity roller. The speedof the roller shall notexceed5 km/h. Eachlayerof material shall be compactedto riot lessthan 98 per cent of the maximum densityas determinedby IS: 2720(Part.8).


The surfacefinish of constructionshall conform to therequirementsof Clause902.

Control on the quality of materials and works shall beexercisedby the Engineer in accordancewith Section 900.

135



During the period of construction,arrangementof traffic shall bemaintainedin accordancewith Clause 112.


Crusher-runmacadambaseshall be measuredas finished work inposition in cubic metres.

410.7. Rate

The Contractunit rate for crusherrun macadambase shall bepayment in full for carrying out the required operations includingfull compensationfor items as in Clause401.8 (i) to (v).

136

Baseand Surface Courses(Bituminous)

500

Base and Surface Courses(Bituminous)

Baseand SurfaceCourses(Bituminous) Section500

Base and Surface Courses(Bituminous) Section 500

501, PREPARATION OF SURFACE

501.1. Scope

This work shall consistof preparingan existing granular or black-toppedsurfaceto specifiedlines, grades and cross-sectionsin advanceof laying a bituminouscourse.The work shall beperformed on suchwidths and lengths ~sshown in applicable drawing and consist ofscarifying andre-laying the granularbasecourse and/or scarifyingtheexisting surface,filling of potholes, sealingof cracks and/orapplicationof a profile corrective course (levelling course) as necessary.

501,2. Materials

501.2.1. For scarifying and re-laying the granular surfaceThematerialsusedshallbe coarse aggregatessalvagedfrom scarificationof the existinggranularbasecourse supplemented by fresh coarseaggregates and screenings so that aggregates and screenings thussupplemented correspondto Clause404: Water Bound MacadamorClause406: Wet Mix Macadam,as the casemay be.

501.2.2. For patching potholes and seating cracks: For patchingpotholes, approvedmaterial having samespecification as that ofprofile corrective courseshall be used.For sealing small cracksfiner than3 mm,a fog sealconformingto Section 3000shall beappliedwhile largercracks wider than3 mm shall betreatedwith an emulsionslurry seal, conforming to Clause 516.

501.2.3. For profile corrective course: A profile corrective course(levelling course)is essentiallya pavementbasematerialcourse for cor-recting the existing pavementprofile which haseither lost its shapeor has to be given a new shapeto meet the requirementof specifiedlines, grades andcross-sections.

It shall be differentiatedfrom the strengthening course or othertype of structural pavement courseneededfor upgrading as a remedialmeasure against inherently deficient and/or distressedpavement.It ismeant to removethe irregularity in the existing road profile only.

501.2.4. Profile corrective course and its application: The typeof material for profile correctivecourseshall beas shownon thedrawing. If it is to be laid as part of the overlay/strengtheningcourse,theprofile corrective coursematerialshall beof the same specificationas that of the overlay/strengtheningcourse. However, if provided as a

139

Section500 Base and SurfaceCourses(Bituminous)

separatelayer,it may be of thesame specificationas the layer over whichit is to be laid or intermediatebetweenunderlyingandoverlying layers,as shownon the Drawing.

(i) Wherever isolated highspotsprojecting over the pavementsurfacedo exist, thesame shalt becut by milling machine or any other approvedmethod, to minimisethe profile corrective courserequirensenLIf, in the proceas,thebottom layergetsdisturbed, the local area shall be cut and filled with profile corrective coursemateral

(ii) Wherethe maximum profile corrective course thickness works out to be not morethan 40 mm, it shall be doneas an integral partof the overlay course.In othercases, the profile corrective course shall be providedas a separatelayer a5ptingsuch construction proceduresand using such equipment as may beappropriateto the specified type of material and thicknessof the course to be provided.


501.3.1. Preparing existing granular surface : Where theexisting surface is granular,all looseand disintegrated materials shallbe removed and the surfacelightly wateredif the profile correctivecourse to be providedas a separatelayer is also granular. If,however, over the existinggranularsurface,a profile correctivecourseof bituminous materialis to be laid, the existing granularsurface shallbe primedas per Clause502.

501.3.2.Scarifying existing bituminous surface Where necessary,the existing bituminous layer in the specifiedwidth shall be removedwith care without causingunduedisturbanceto the underlying layerby suitablemethodapprovedby theEngineer.After removing it, all looseand disintegratedmaterialsof underlying layer which mighthave beendisturbed in the processof removal shall, before laying of theoverlay course, beresetproperlyby spreading/handpackingof aggregatesand compacting with suitable roller/heavy hand rammers/approvedmechanical tampei~so that thelevel of the top surfaceof suchscarifiedarea shall be evenandproperlygraded with respectto adjoiningsurface.~.Where applicable,the granular surface,after removal of the existingbituminous layer,shalt be primed as per Clause502 to receive abituminousprofile correctivecourse.Reusable materialsshall bestackedas directed by the Engineer withall lift and lead of 1000 m.

501.3.3. Patching of potholesand sealingof cracks : Before pro-viding profile correctivecourseon the existing pavement, potholes, ifany, shall be drainedof water, cut to regularshapewith sides verticalupto the affecteddepth and slightly beyondthe limits of affectedareaanddried. All looseanddisintegratedmaterialsfror~it shall be removed.The potholes shall then be filled with material as per Clause No.

140

BaseandSurfaceCourses(Bituminous) Section500

501.2.2 in layers not exceeding75 mm after painting the sides andbottom with a thin layerof hot straight-runbitumen/emulsion andeach layer shall be compacted with approvedmechanical tampers!small vibratory roller and the top layer shall be flush with the existingbituminoussurface. All looseand/or surplusmaterials on the surfaceafter making good the potholes, shall be removed.

The cracks in the old pavementsurfaceshall be sealedwith a fogseal if cracks are small (less than 3 mm width); fog seal shall consistof a spray of a bituminouscutbackor a slow-settingbitumen emulsiondiluted with an equalamountof water, the rate of spray being 0.5to 1.0 litre /sq.m dependingupon the textureand drynessof the existingbituminoussurface.The sprayis allowed to set to a firm condition andtraffic is allowed only thereafterso as to ensure that the material isnot picked up by traffic. For large cracks, the sealing shall be donewith emulsion slurry seal as per Clause516 of these Specifications.

501.3.4. Laying the profile correctivecourse

501.3.4.1. After preparingthe granularsurfaceas in Clauses 501.3.1and 501.3.2, the profile correctivecourse with material as per Clause501,2.3/501.2.4 shall be laid and compacted to the requirement ofparticular Specification clause. Where a bituminous profile corredtivecourse is to be laid over a primed granular surface,a tack coatconforming to Clause 503 shall be applied prior to laying profilecorrectivecourse.

501.3.4.2.An existingbituminoussurfaceshall be prepared as perClause 501.3.3. and after applying a tack coatconforming to Clause503, the bituminous profile correctivecourse shall be laid andcompactedto the requirementof particular Specjfication clause.

501,3.5. In specific situation of short sagsor depressionsin thepavement,it may becomenecessaryto provide correctivecourse in theform of flat wedges,Normally, layersin maximum thickness at anypoint more than’ 100 mm shall not be provided. In placing multiplelifts, the lift of shortest length (at the lowest portion of the sag!depression)should be provided first, with successivelifts extendingover and fully covering underneathlayer, precludingdevelopmentof a seriesof joints on the top surfaces,as illustrated in Fig.500-1.

For camber correction or correction of superelevation of theexistingcarriageway,methodas shown in the illustrative Fig. 500-2shallbe adopted dependingon the profile of the existing carriageway.

141

Section500 Baseand SurfaceCourses(Bituminous)

— 3-

LIFTS —

(A) C~tRECT METHOD

EXISTING LAYER

— 2~

EXISTING LAYER

(B) INCORRECT METHOD

Note Profilecorrectivecoursematenatsone rn accordancewith the tilt Inicieness

Fig. 500-LMethodsfor providingcorrectivecoursefor short sagsanddepressions

142

2—a

—aaU

CaB

°E

41

~CC

O

Ba

sea

nd

Su

rface

Co

urs

es(B

itum

ino

us)

Se

ction

50

0

&

0td)

—HaaaCl

a0C)

C)

a0U

Fig.

500-2.Correctiono

fCam

berorS

uper-Elevation

143

Section500 BaseandSurfaceCourses(13ituminous)

501.3.6. Covering the profile corrective course: Work ofProfile Corrective Course shall be so plannedthat it shall be coveredby the designedbase/wearingcourseat the earliest,before opening toregular traffic.

501.4. Surface Finish and Quality Control of WorkRelevantprovisionsof Section900shallbeexercisedby the Engineer.

501.5. Arrangementfor Traffic

During the constructionoperations,arrangementof traffic shall bedone to Clause 112.


501,6.1. The work of filling potholesshall be consideredincidental10 the constructionof Profile CorrectiveCourse/bituminouscourse forwhich the existing pavementsurface is prepared.

The work of filling cracksby applying fog seal or emulsion slurryseal shall be measuredin squaremetres, and paid separately.

501.6.2. Scarifying existingbituminoussurfaceshaU be measuredin squ~remetre.

501.6.3.ProfileCorrectiveCourse shall be measuredas voluniecom-pacted in position in cubic metres or in tonnageas specified in thecontract, The volume shall be worked out by plotting the exactprofileof Profile Corrective Courseas built up at site and superimposedonthe existing pavementprofile.

501.7. Rates

501.7.1. Contract unit rate for scarifying of existing bituminoussurfaceincluding repairing/resettingdisturbed underlyinglayerandalsoremoving and stackingreusable/unusablematerialsshall include cost ofall labour, supply of mater’alsneededfor repair/resetting,hire chargesof tools andplant and transportationof scarifiedmaterialswith ‘all liftsand upto a lead of 1000 m.

501.7.2. The contractunit rate for ProfileCorrectiye Course shallbe payment in full for carrying out the requiredoperations includingfull compensMionfor:

(i) Making arrangementsfor traffic to tlause 112;

(ii) Providing all materials to be incorporated in she work including any royalties,fees,rents (where applicable) and all leads and lins, unless the contractspecifically excludes any item of msteriai required for the work or providesfor separate payment in accordance with Clause 514;

144

BaseandSurface Courses(Bituminous) Section500

(iii) Preparationof theexposedsurface/existing surfaceincluding filling of pot holes,all cleaning operationsand applicationof tack coat;

(iv) All labour, tools,equipmentand incidentals necessary to complete the workto the Specifications; and

(v) Carrying out the work in part widths of road where directed by the Engineer.

501.7.3. The contractunit rate for sealing cracksby applying fogseal shall be inclusiveof providing all materialsand tools arid plantand carrying out the work. The contractunit rate for sealingcracksby providing emulsionslurry sealshall be as setforth in Clause 516.9.

502. PRIME COAT OVER GRANULAR BASE

502.1., Scope

This work shall consist of application of single coat of lowviscosity liquid bituminous material to an absorbentgranular surfacepreparatoryto any superimposedbitUminous treatmentor construction.

502.2. Materials

502,2.1.The choice of a bituminousprimer shall dependupon theporosity characteristicsof the surfaceto be primed as classifiedin IRC:16. These are

(i) Surfacesof low porosity; suchaswet mix macadam and water boundmacadam,

(ii) Surfacesof medium porosity; such as cementstabilized soil base,

(iii) Surfacesof high porosity; such as a gravel base.

502.2.2, The different rangesof viscosity requirements‘for theprimers to be used for the different types of surfacesto be primed,as classified in 502.2.1, are given in Table 500-1.

Type of surface

TABLE 500-I. VISCOSITY REQUIREMENT AND QUANTITY OFBITUMINOUS PRIMERKinematic Viscosityof Primer at 60~C

(Centistokes)

Quan10

(

tity persq.m.kg)

Low porosity 30-60 6 to 9Medium porosity 70.140 9 to 12High porosity 250-500 12 to 15

502.2.3.The bituminous primer shall be Medium Curing Cutback(MC) produced by fluxing, in an approvedmanner,bitumenof 80/100penetrationgradewith kerosene.The cutbackshall be free from waterand shall not show any signs of separationprior to use. Slow settingCationic emulsion as per IS: 8887 may also be used,but the particulargrade to be usedfor the work shall be got approvedby the Engineer.

145

Section500 BaseandSurfaceCourses(Bituminous)

Sampling and testing of bituminousprimer shall be as per IS:217.IS:454 and IS:8887.

502.3. Weatherand SeasonalLimitations

The bituminousprimer shall not be applied on a wet surface orduring dust storm or whenthe weatheris foggy, rainy or windy. Theprime coat for surfacetreatmentshouldnot be applied when thetemperaturein the shade is less than 10°C.

502.4. Construction

502.4,1. Equipment: The primer distributor shall be pneumatictyred self-propelledpressuredistributorequippedfor sprayingthe materialuniformly at the specifiedrates and temperatures.Spraying by manualmethods maybeallowedfor smallareasat thediscretionof the Engineer.Power broom and/or blowersmay be supplementedby hand broomsas directed by the Engineer.

51)2.4.2. Preparationof road surface: The surface to be primedshall be sweptclean,free from dustandshall be dry. It shall be shapedto the specifiedgradesand section.It shall also be free from ruts, anyother irregularities and segregatedmaterials. Minor depressionsandpotholes may be ignored until the surfaceis primed, after which theyshall be patchedwith a suitable premix material prior to the surfacetreatment.

502.43. Application of bituminous primer: The bituminous primershall be sprayed/distributeduniformly over the dry surface,preparedasperClause502A.2usingself-propelledsprayerequippedwith self-heatingarrangement,suitablepump, adequatecapacitycompressorand sprayingbar with nozzleshaving constantvolume or pressuresystemcapable ofsupplying primer at specifiedrates and temperatureso as to provideauniformly unbroken spreadof primer. If the surfaceto be primed is sodry or dusty as to causefreckling of bituminous material, it shall belightly anduniformly sprinkledwith water immediately prior to priming;however,the bituminousmaterial shall not be applied till such time asno surface water is visible. The primer shall be applied at the rate asspecified in Table 500-1.

Temperatureof application of aprimer needonly be high enoughto permit the primer to be effectively sprayed through the jets of thespray bar andto coverthegranularbasesurfaceuniformly in the desiredquantity.

146

BaseandSurfaceCourses(Bifliminous) Section500

The desirablerangeof temperaturesat the time of application ofMC-30, MC-70 and MC-250 grades shall be 30 to 55°C;50 to 800Cand 75 to 100°Crespectively.For a bituminous emulsion primer, therangeof spraying temperaturemay be 20 to 60°C.

Following the applicationof bituminousmaterial, the surfaceshallbe allowed to cure for at least24 hours or for any otherperiod so asto allow penetrationinto the basecourseandaerationof volatiles fromthe primer material.If it is not absorbedwithin 24 hoursafterapplication,sand shall be spreadover the surfaceto blot the excessprimer. Careshall be takento preventover-priming; any pools of excessprimer lefton any part of the surfaceshall be sweptout over the adjacentsurfacebefore spreadingsand.

The primer coat shall be applied only on the topmost waterboundmacadam or any granular layer, over which the bituminous basecourse/wearingcourse is to be laid.

502.4.4. Curing of primer andopeningto traffic: It shall alwaysbe ensuredthat while opening to anykind of traffic, the primed surfaceis fully cured and is not sticky to avoid being picked up by traffic.Normally, the primed surfaceshall be allowed to cure for not lessthan 24 hoursand during this period no traffic of any kind shall bepermitted.

592.4.5. Laying of bituminous course over primed surface: Bi-tuminous base course or wearingcourseshall be laid over the primedwater bound macadam,wet mix macadamor any other granularbasecourse, in the usual manneras per relevantSpecificationfor the sameincluding the requirementof tack coat as per Clause503.

502.5. Quality Control of Work

Control on the quality of materials and work shall be exercisedbythe Engineer in accordancewith Section 900.

502,6. Arrangement for Traffic

During the Constructionoperations,arrangementof traffic shall bedone as per Clause 112.


Prime coat shall be measur~din termsof surfaceareaof application

in squaremetres.

147


502.8. Rate

The contractunit rate for prime coat shall be paymentin full forcarryingout the requiredoperationsincluding full compensationfor allcomponents listed in Clause401.8 (i) to (v) and as applicableto the work specified in these Specifications.

503. TACK COAT

503.1. Scope

Thiswork shallconsistof applicationof asingle coatof low viscosityliquid bituminous material to an existing road surfacepreparatorytoanotherbituminousconstructionover it.

503.2, Materials

Binder: The binder used for tack coat shall b~a bituminousemulsionor cutback as specified in the Contract.

503.3. Construction Operation

503.3.1. Preparation of base: The surface on which the tack coatis to be applied shall be cleanedof dust and any extraneousmaterialbefore the application of the binder, by using a mechanical broomor any other approvedequipment/methodas specifiedby the Engineer.

503.3.2.Application of binder: Binder may be heated to thetemperature appropriateto the gradeof cutback used andapproved bythe Engineerand sprayed on the baseat the rate specified in Table500-2. The normal rangeof sprayingtemperature for a bituminousemulsionshall be 20°C-60°Cand for a cutback 50°C-80°Cif RC-70/MC-70 grade is used.It shall be the responsibility of the Contractorto carefully handle the inflammable bituminouscutback material so asto safeguardagainst any fire mishap.The binder shall be applieduniformly with theaid of either self-propelledor towed bitumen pressuresprayer with self-heatingarrangementand spraying bar with nozzleshavingconstantvolume or pressuresystem,capableof sprayingbitumenat specifiedratesand temperature soas to provide a uniformly unbrokenspreadof bitumen. Work shouldbe plannedso that no more than thenecessarytack coatfor the day’s operationis placedon the surface. Afterapplication and prior to succeedingconstructionallow the tack coat tocure, without being disturbed,until the water/cutter has completelyevaporated,as determinedby the Engineer.

148


TABLE 500.2. RATE OF APPLICATION OF TACK COAT

Type Surface Quantity of liquidbituminous mater1i~inkg per 10 sq. m. area

i) Normal bituminous surfaces 2.0 to 2.5ii) Dry and hungry bituminous 2.5 to 3.0

surfacesiii) Granular surfacestreatedwith 2.5 to 3.0

primeriv) Non bituminous surfaces

a) Granular base(not primed) 3.5 to 4.0b) Cementconcretepavement 3.0 to 3.5

Note : There is no need to applya tack coat on a freshly laid bituminous courseif the

subsequentbituminouscourseis overlaidthe samedaywithoutopeningit to traffic.


Control on the quality of materialsandworks shall be exercisedbythe Engineer in accordancewith Section 900.

503,5. Arrangements for Traffic

During the period of construction, the arrangementof traffic shallbe done to Clause112.

503.6. Measurement for Payment

Tack coat shall bemeasuredin termsof surface area of applicationin squaremetres.

503.7. Rate

The contractunit rate for tack coat shall be payment in full forcarrying out the requiredoperationsincludingfull compensationfor allcomponentslisted in Clause401.8 (i) to (v) as applicableto the workspecified in these Specificatiot~s.

504. BITUMINOUS MACADAM

504.1, Scope

The work shall consist of construction, in a single course, ofcompacted crushed aggregatespremixed with a bituminous binder,to serveas base/bindercourse,laid immediatelyafter mixing, on a baseprepared previously in accordancewith the requirementof theseSpecificationsand in conformity with the lines, gradesand cross-sectionsshown on the drawing or as directedby the Engineer.

504.2. Materials

504.2.1. Bitumen:Thebitumenshall bepaving bitumen of suitable

149

Section 400 Sub-Bases,Bases(Non-Bituminous)andS~ou~ders

penetrationgrade(30/40to 80/100)asper IS:73. Theactualgradeof bitumentobeusedshall be decidedby theEngineerappropriateto theregion,traffic,rainfall andotherenvironmentalconditions, Guidelineson selectionof thegradeof bitumen are given in Appendix-4.

504.2.2. Aggregates

504.2.2.1.The aggregatesshall consist of crushed stone,crushedgravel/shingleor otherstones.Theyshallbeclean,strong,durable,of fairlycubicalshapeandfree from disintegratedpieces,organicorotherdeleteriousmatterandadherentcoating. If crushedshingle/gravelisused,not lessthan90percentby weightof thegravel/shinglepiecesretainedon 4.75mmsieveshall haveat least two fracturedfaces. The aggregatesshall preferablybehydrophobicandof low porosity. If hydrophilic aggregatesare to beused,thebitumenshallpreferablybetreatedwith anti~strippingagentsof approvedquality in suitabledoseasperAppendix-5. Theaggregatesshall satisfy thephysicalrequirementssetforth in Table500.3.

TABLE 500.3. PHYSICAL REQUIREMENTS OF AGGREGATES FORIUTUMINOUS MACADAM

S,No, Test TestMethod Requirement1. Los Angeles AbrasionValue

5 IS:2386(Part..4) 40percent Maximum2. Aggregate Impact Value5 IS:2386 ~Part-4) 30percentMaximum3. Flakinessand Elongation55 IS:238$(Part-1) 30 per centMaximum

Indices(Total)4. Coatingand Strippingof

BitumenAggregateMixturesAASI ITO T 182 Minimum retained

coating95percent5. Soundness IS:2386 (Part-5)

(i) Loss with Sodium 12 per centMaximumSulphate 5 cycles

(ii) Losswith Magnesium IS percentMaximumSulphate5 cycles

6 Waterabsorptian - IS:2386(Patt-3) ZpercentMaximum* Aggregatesmay satisfy requIrements 01 eitfler at the two tests.~ To determinethis combined proportion, theflaky stonefrom a representative

sample should first be separated out. Flakiness index is weight of flaky stonemetal divided by weight of stone sample. Only the elongated particles beseparated out from the remaining (non-flaky) stone metal. Ebngaflon index isweight of elongated particles divided by total non-flaky particles. The value offlakiness index and elongation index so found are addedup.

Note: If crushed slag is used, Clause 404.2.3. shallapply.504.2.2.2.Theaggregateforbituminousmacadamshallconformto one

of thetwo gradingsin Table 500-4,dependingon the compactedthickness;theactualgradingshall beasspecifiedin theContract.

504.2.3.Proportioningof materials:The bitumen contentfor pre-mixing shall be 3 to 3.5 percent by weightof the total mix exceptwhenotherwisedirectedby theEngineer.

150


TABLE 500~2.RATE OF APPLICATION OF TACK COAT

Type Surface Quantity ef liquIdbItuminousmaterial Inkg per 10 sq. m. area

i) Normal bitsaninous surfaces 2.0 to 2.5ii) Dry and hungry bituminous 2.5 to 3.0

surfacesiii) Granularsurfacestreatedwith 2.5 to 3.0

primeriv) Non bituminous surfaces

a) Granular base(not primed) 3.5 to 4,0b) Cementconcretepavement 3.0 to 3.5

Note There is no need to apply a tack coat on a freshly laid bituminous course if thesubsequentbituminous courseis overlaid the sameday without openingit to traffic.


Control on the quality of materialsand works shallbe exercisedbythe Engineerin accordancewith Section 900.


During the period of construction,the arrangementof traffic shallbe done to Clause 112.

503.6. Measurement for Payment

Tack coat shall be measuredin terms of surfaceareaof applicationin squaremetres.

503.7, Rate

The contractunit rate for tack coat shall be payment in full forcarrying out therequiredoperationsincluding full compensationfor allcomponentslisted in Clause401.8 (i) to (v) as applicableto the workspecified in theseSpecifications.

504. BITUMINOUS MACADAM

504.1. Scope

The work shall consist of construction, in a single course, ofcompacted crushed aggregatespremixedwith a bituminous binder,to serve as base/bindercourse,laid immediatelyafter mixing,on a baseprepared previously in accordancewith the requirementof theseSpecificationsandin conformitywith the lines, gradesand cross-sectionsshown on the thawing or as directed by the Engineer.

504.2. Materials504.2.1. Bitumen: The bitumen shall be paving bitumen of suitable

149


TABLE 500.4. AGGREGATE GRADING FOR BITUMINOUS MACADAM

IS SieveDesIgnation Per cent by weight passing the sieve

Grading I GradIng 2

45.0 mm 100 —

26.5 mm 75.100 10022.4 mm ‘ 60-95 75.10011.2 mm 30.55 50-855.6 mm 15-35 20-402.8 mm 5.20 5-20

90.0 micron 0-5 0-5

The maximum compacted thickness of a layer shall be 100 mm.

The quantitiesof aggregatesto be usedshall be sufficient to yieldthe specified thicknessafter compaction.

504.2.4. Variatioii in proportioning of material: The Contractorshall havetheresponsibilityfor ensuringproperproportioningof materialsand producinga uniform mix. A variation in binder content±0.3 percent by weight of total mix shall, however,bepermissiblefor individualspecimenstaken for quality control tests vide Section 900,


504.3.1.Weather and seasonal limitations : The work of layingshall not be taken up during rainy or foggy weatheror when the basecourse is damp or wet, or during dust storm or when the atmospherictemperaturein shade is 10°Cor less.

504.3.2.Preparationof the base:The baseon which bituminousmacadamis to be laid shall be prepared,shaped and conditioned tothe specifiedlines, gradesand cross-sectionsin accordancewith Clause501, anda priming coat whereneededshall be applied in accordancewith Clause502 as directed by the Engineer.

504.3.3. Tack coat: A tack coatas per Clause503 shall be appliedover the base.

504,3.4.Preparation and transport of mix: Bituminous macadammix shall be preparedin ahot mix plantof adequatecapacityand capableof yielding a mix of properand uniform quality with thoroughly coatedaggregates.

Hot mix plant shall be of suitable capacity preferably of batch mixtype. Total system for crushing of stone aggregatesand feeding ofaggregate fractions in required proportionsto achieve the desiredmix, deployedby the Contractormust be capableof meeting the overall

151


Specificationrequirementsunder stringent quality control. The plant shallhave the following essentialfeatures:

A-General

(a) The plant shall have coordinated set or essential units capable of producingsxsifonn mix as per the job mix formula.

(b) cold aggregatefeed systemwith minimum 4 bins having belt conveyor arrange-ment for initial proportioning of aggregatesfrom each bin in the required quantities.In order to have free flow of fines from the bin, it is advisable to havevibrator fitted on bin to intenninently shake it,

(c) Belt convryers below each bin shoold have variable speeddrive motors. Thereshould be electronic load sensor on the main conveyerfor measuring the flowof aggregates.

(d) Dryer unit with burner capableof heating the aggregateto the required temperature.without any visible unbumt fuel or carbon residue on the aggregateand reducingthe moisture content of the aggregate to the seecified minimum.

(e) The plant shall be fitted with suitable type of thermometric instruments atappropriateplacesso as to indicate or record/registerthetemperatureof heatedaggregate,bitumen and mix.

(f) Bitumen supply unit capableof heating, measuring/meteringand spraying ofbitumen at specifiedtemperature with automaticsynchronisation of bitumenand aggregate feed in the required proportion.

(g) A filler system suitable to receive bagged or bulk supply of filler materialand its incorporationto the mix in the correct quantity wherever required.

(h) A suitablebuilt-in dustcontrol systemfor thedryerto contain/recyclepermissiblefines into the mix. It should be capable of preventing the exhaust of fine dustinto atmospherefor environmentalcontrolwherever so specifiedby theEngineer.

(i) The plant should have centralised control panel/cabincapable of presetting,controlling/synchronising all operations starting from feeding of cold aggregatesto the dischargeof the hot mix to ensureproper quality of mix. It should haveindicators for any malfunctioning in the operation.

(j) Every hot mix plant should be equipped with siren or horn so that the operatormay use the same before starting the plant every time in the interest of safetyof staff.

B - For Batch Type Plant

(i) Gradationcontrol unit having minimum four deck vibratory screensfor accuratesizingof hot aggregate and storing them in separate bins. This unit should befully covered to reduce the maintenance cost and for better environmentalcondition.

(ii) Proper arrangementfor accurate weighing of each size of hot aggregate fromthe control’ panel before mixing.

(iii) Paddlemixerunit shall becapableof prodlicinga homogeneousmix withuniformcoating of all particles of the mineral aggregate with binder.

152


C - For Continuous Type Plant

(i) Gradation control unit having vibratory screens for accurate sizing of hotaggregateandstoring them in separatebins. This unit shouldbe fully coveredto reduce themaintenancecost and for better environmentalcondition.

(ii) There should be appropriate arrangementfor regulating and volumetric controlof the flow of hotaggregatefrom eachbin to achievethe required proportioning.

(iii) Paddle mixer unit shall be capable of producing a homogeneousmix withuniform coating of all particles of the mineral aggregate with binder.

D . For Drum MIx Plant

(i) It is a prerequisitethat only properly screened andgraded materials arefed to the bins. If required, a vibratory screeningunit shall be installed at theplans site to ensure the same.

A primary 4-deckvibratory screeningunit shall be installed beforethemultiplebin cold feed system for screeningthe aggregatesand grading sbe same.

(ii) Belt conveyersbelow eachbin shouldhave variable speeddrive motors. Thereshould be electronicload sensor on the main conveyerfor measuringthe flowof aggregate.

(iii) There should be arrangementto measuremoisture contentof the aggregate(s)sothat moisture correction may be applied for working out requirements of binderand filler.

The temperatureof binder at the time of mixing shall be in therange of 15&C to 163°C and that of the aggregatein the rangeof 155°C- 163°C.provided that the differencein temperaturebetweenthe binder and aggregateat no time exceeds14°C.

Mixing shall be thorough to ensurethat a homogeneousmixture isobtained in which all particlesof theaggregatesarecoateduniformly,and the dischargetemperatureof mix shall be between130°C to 160°C.

The mixture shallbe trinsportedfrom the mixing plant to thepointof use in suitabletipper vehicles.The vehicles employed for transportshall be clean andbe coveredin transit if sodirected by the Engineer.Any tipper causing excessivesegregationof materials by its springsuspensionor other contributing factors or that which showsunduedelayshallbe removedfrom the work until suchconditionsarecorrected.

504.3.5. Spreading:The mix transferredfrom the tipper at site tothe paver shall be spread immediately by means of self-propelledme~hanicalpaver with suitable screedscapableof spreading, tamping,and finishing the mix true to the specified lines, grades and cross-sections. The paver finishershall have thefollowing essentialfeatures:

(a) Loading hoppers and suitable distributing mechanism.

153


(b) All drives having hydrostaticdrive/control.

(c) The machineshall have a hydraulically extendablescreedfor appropriatewidthrequirement.

(d) The screedshall have tamping and vibrating arrangement for initial compactionso the layeras it is spread without rutting or otherwisemarring the surface.It shall have adjustableamplitude and variable frequency.

(e) The pavershall beequippedwith necessarycontrolmechanismso as to ensurethat the finished surface is free from surface blemishes.

(I) The paver shall be fitted with an electronic sensing device for automatic levellingand profile control within the specified tolerances,

(g) The screed shall have the intemat heating arrangement.

(h) The paver shall be capable of laying either 2.5 to 4.0 m width or 4.0 to 7.0m width as stipulated in the Contract.

(i) l’he paver shall be so designedas so eliminate skidding/slippageof the tyresduring operation.

However, in restrictedlocations and in narrow widths where theavailableplant cannotbe operatedin the opinion of the Engineer, hemay permit manual laying of the mix.

The temperatureof the mix at the time of laying shall be in therangeof 120°Cto 160°C.In multi-layer construction,the longitudinaljoint in one layer shall offset that in the layer below by about 150mm, However, thejoint in the top-mostlayershall be atthe lane lineof the pavement.

Longitudinal joints and edges shall be constructedtrue to thedelineatingline parallel to the centre line of the road. All joints shallbe cut vertical to the full thicknessof the previously laid mix and thesurface painted with hot bitumen before placing fresh material.Longitudinal and transversejoints shall be offset by at least 250 mmfrom those in the loWer coursesandthe joint on the topmost layershall not be allowedto fall within the wheel path. All transvemejointsshall be cut vertically to the full thicknessof the previously laid mixwith asphaltcutter/pavementbreakerand surface painted with hotbitumen before placing fresh material. Longitudinal joints shall bepreferably hot joints. Cold longitudinal joints shall be properly heatedwith joint heater to attain a suitable temperatureof about 80°Cbeforelaying of adjacentmaterial.

504.3.6. Compaction: After the spreading of mix, rolling shall bedoneby 80 to 100 kN rollers or other approvedequipment. Rollingshall startas soonas possibleafter the materialhasbeenspreaddeployinga sct of rollers as the rolling is to be completedin limited time frame.

‘54


The roller shall move at a speed not more than 5 km/h. Rollingshall be done with careto avoid unduly rougheniitgof the pavementsurface.

Rolling of the longitudinal joints shall be done immediatelybehind thrpaving operation. After this, the rolling shall commenceatthe edges and progresstowardsthe centrelongitudinally except thaton ~uperelevatedand uni-directional cambered portions, it shallprogressfrom the lower to the upper edgeparallel to the centre lineof the pavement.

The initial or break.downrolling shall be done with 80 - 100 kNstatic weight smoothwheel roller (3 wheelsor tandem),as soon as itis possibleto roll the mix without crackingthe surface or having themix pick up on the roller wheels, The secondor intermediate rollingshall follow the break-downrolling with vibratory roller of 80 to 100kN static weight or pneumatic tyred roller of 150 to 250 kN weight,with minimum 7 wheelsandminimumtyre pressureof 0.7 MPaas closelyas possible to the paver and be done while the paving mix is still atatemperaturethatwill result in maximumdensity.The final rolling shallbe donewhile material is still workable enough for removalof rollermarks,with 60 - 80 kN tandemroller. During thefinal rolling, vibratorysystem shall be switched ofL The joints andedgesshall berolled witha 80 to 100 kN static roller.

When the roller has passedover the whole areaonce, any highspots or depressionswhich becomeapparentshall be corrected byremoving or addingmix material.The rolling shall thenbe continuedtill the entire surface hasbeenrolled to 95 per cent of the averagelaboratory density (obtainedfrom Marshall specimenscompacted asdefined in Table 500-10), there is no crushingof aggregatesand allroller marks have beeneliminated. Eachpassof the roller shalluniformly overlap not less than one-third of the track made in thepreceding pass.The roller wheel shall be kept dampif necessary toavoid bituminousmaterial from sticking to the wheelsandbeing pickedup. In no caseshall fuel, lubricating oil be used for this purpose,norexcessivewater poured on the wheels.

Rolling operationsshall be completedin every, respect before thetemperatureof the mix falls below 100°C.

Roller(s) shall not stand on newly laid material while there is arisk that surface will be deformed thereby. The edges along andtransverseof the bituminousmacadamlaid andcompactedearlier shall

155

— I-


be cut to their full depth so as to exposefresh surfacewhich shallbe paintedwith a thin surfacecoat of appropriatebinder before thenew mix is placedagainst it.

504.4. SurfaceFinbh and Quality Control of WorkThe surfacefinish of construction shall conform to therequirements

of Clause902, Control on the quality of materialsand works shall beexercisedby the Engineer in accordance with Section 900.

504.5. The bituminousmacadamshall be coveredwith either thenext pavement course or wearingcourse,as thecasemay be, withoutany delay. If there is to be any delay, the courseshall be coveredbya seal coat to the requirementof Clause513 before allowing any trafficover it. The seal coat in such casesshall be consideredincidental tothe work and shall not be paid for separately.

504.6. Arrangementsof TrafficDuring the period of construction,arrangementof traffic shall be

done to Clause 112.504.7. Measurementsfor PaymentThe work shall be measuredas finished work in cubic metres or

by weight in metric t9nnes as provided in the Contract.

504.8. Rate

The contractunit rate for the work shalt be paymentin full forcarrying out the required operationsincluding full compensation for:

(I) Makingarrangementsfor traffic to Clause112 exceçxfor initial treatmentto verge,shoulders and constructionof diversions;

(ii) Preparation of base except for laying of profile corrective course but includingfilling of potholes;

(iii) Providing all materialsto be incorporated in the work including arrangementfor stock yards, all royalties, fees,rents where necessaryandall leads and lifts;

(iv) All labour, tools, equipment, plant including installation of hot mix plant, powersupply units and all machineries, incidental to completethe work to theSpeci-fications;

(v) Carrying out the work in pan widths of the road wheredirected;

(vi) Carrying out all tests for control of quality; and

(vii) The rate shall cover the provision.ofbitumen at 3.25 per cent of weight oftotal mix, with the provision that the variation of quantity of bitumen will beasseasedand the payment adjusted as per the rate of bitumen quoted.

156

Base andSurfaceCourses(Bituminous) Section500

The roller shall move at a speed not more than 5 km/h. Rollingshall be done with care to avoid unduly roughenir~gof the pavementsurface.

Rolling of the longitudinal joints shall be done immediatelybehind thr paving operation. After this, the rolling shall commenceatthe edges and progresstowards the centrelongitudinally except thaton ~uperelevatedand uni-directional cambered portions, it shallprogressfrom the lower to the upper edgeparallel to the centre lineof the pavement.

The initial or break-downrolling shall be done with 80 - 100 kNstatic weight smooth wheel roller (3 wheels or tandem),as soonas itis possible to roll the mix without crackingthe surfaceor having themix pick up on the roller wheels.The secondor intermediate rollingshall follow the break-downrolling with vibratory roller of 80 to 100kM static weight or pneumatic tyred roller of 150to 250 kM weight,with minimum 7 wheelsandminimumtyre pressureof 0.7MPaascloselyas possible to the paver and be done while the paving mix is still ata temperaturethat will result in maximumdensity.The final rolling shallbe done while material is still workable enough for removalof rollermarks,with 60 - 80 kN tandemroller. During thefinal rolling, vibratorysystemshall be switchedoff. The joints and edgesshall berolled witha 80 to 100 kN static roller.

When the roller has passedover the whole area once, any highspots or depressions which becomeapparentshall be corrected byremoving or adding mix material. The rolling shall thenbe continuedtill the entire surface hasbeenrolled to 95 per cent of the averagelaboratory density ~obtainedfrom Marshall specimenscompacted asdefined in Table 500-10), there is no crushing of aggregatesand allroller marks have been eliminated.Eachpassof the roller shalluniformly overlap not less than one-third of the trackmade in thepreceding pass.The roller wheel shall be kept damp if necessary toavoid bituminousmaterial from sticking to the wheelsandbeing pickedup. In no caseshall fuel, lubricating oil be used for this purpose,norexcessivewater pouredon the wheels.

Rolling operationsshall be completedin every, respect before thetemperatureof the mix falls below 100°C,

Roller(s) shall not stand on newly laid material while there is arisk that surface will be deformed thereby. The edges along andtransverseof the bituminous macadamlaid andcompactedearlier shall

155

BaseandSurfaceCours’es(Bituminous) Section500

505. BITUMINOUS PENETRATION MACADAM505.1. Scope

The work shall consist of construction of one or more layers ofcompacted crushed coarseaggregattswith alternate applications ofbituminous binder andkey aggregatesin accordancewith the require-ments of theseSpecificationsto serve as base,thinder courseand inconformity with the lines, grades arid cross-sectionsshown on thedrawings or as directed by the Engineer. Thicknessof an individualcourse shall not exceed75 mm.

505.2. Materials

505.2.1. Bitumen: The binder shall be paving bitumen of suitablepenetration grade within the rangeof S-35 to 8-90 or A-35 to A-90 (30/40 to 80/I 00)as per Indian StandardsSpecificationsfor “PavingBitumen” IS ;73, or apprcWedcutbackssatisfyingthe requirements ofIS 73, 217 or 454. The actual gradeof bitumen or cut backs to beused shall be decidedby the Engineer,appropriate to the region,traffic, rainfall and other environmentalconditions. Guidance in thisregard may be obtainedfrom Appendix-4.

505.2.2.Aggregates

505.2.2.1.The aggregatesshall satisfy thephysical requirementssetforth in Clause504.2.2.1 and Table 500-3.

505.2.2.2. The coarse and key aggregatesshall conform to thegrading given in Table 500-5.

505.2.3.Quantitiesof materials:The quantitiesof materialsusedfor this work shall be as specifiedin Table 500-6.


505.3.1. Weather and seasonal limitations: Clause No. 504.3.1shall apply.

505.3.2. Preparation of the base: The ‘base on which thePenetrationmacadamcourseis to be laid shall be prepared,shapedandconditionedto the specified lines, gradesandsectionsto Clause 501or as directedby the Engineer.A priming coat whereneededshall beapplied over the basein accordancewith Clause502 or as directedby the Engineer. A tack coat as per Clause503 shall be applied.

157

Section 500 ~iaseandSurfaceCourses(Bituminous)

TABLE 500.5.GRADING REQUIREMENTS OF COARSE AGGREGATES AND KEYAGGREGATES FOR BITUMINOUS PENETRATION MACADAM

‘

IS SteveDesign.atlon

Per cent by weight passing the Steve

For 50 mm compactedthickness

for 75 mm compactedthickness

CoarseAggregate

KeyAggregate

CoarseAggregate

KeyAggregate

63 mm53 mm45 mm26.5 mm22.4 mm132 mm11.2 mm5.6mm2.8 mm

—~

—

10037-72

—

2-20—

—

0-5

—

—~

—

—

10050-75

—

5-250-5

100—

58-82—

5-27—

, —

—

0-5

—

—

—

10050-75

—

5-25—

0-5

TABLE 500.6.QUANTITIFS OF MATERIALS REQUIRED FOR 10 sq.m.OF ROADSURFACE FOR BITUMINOUS PENETRATION MACADAM BASFJBINDER COURSE

Compactedthickness‘

Binder

Straightrun bitumen

CoarseAggregate

KeyAggregate

50 mm75 mm

50 kg68 kg

0.60 cu.m.0.90 cu.m.

0.15 en. m.0.18 cc. m.

505.3.3..Spreading and compacting coarse aggregates: Thecoarseaggregatein a dry andclean form shall be spreaduniformly andevenly at the rate specified in Table 500-6 preferably with the helpof a self-propelled or tipper tail mountedaggregatespreader capableof spreadingaggregateuniformly at thespecifiedratesover the requiredwidths. The surface of the layer shall be carefully checked withcambertemplatesandall high and low spotsremediedby removing oradding aggregatesas may be required.Thespreading shall becarriedno further in advanceof the rolling and penetratingoperationsthancan be completedin one averageday’s work. Segregatedaggregatesoraggregatesmixed with earthor other foreign substancesshallberemovedand replacedwith gradedaggregates.

505.3.4. Compaction: After the spreadingof coarse aggregates,dry rolling shall bedone by 80 - 100kN smooth-wheeledsteel roller.Rolling shall start as soon as possible after the material has beenspread. The rolling shall commenceat the edges,parallel to the centreline of the road and progresstowardsthe centre longitudinally except

158


on superelevatedand uni-directionalcamberedportions, where it shallprogress from the lower to the upper edgeafter the edgeshave beenrolled. For superelevatedportions,the overlapping should be approxi-mately one-third of the width of the rear wheel on each trip.

After initial dry rolling, the surfaceshall becheckedwith a crowntemplateand a 3 metre straight-edge.The surfaceshall not vary morethan 10 mm from the templateor straight-edge. All surface irregularitiesexceeding the above lirnit shall be corrected by removing or addingaggregatesas required.

The rolling shall be done until the compacted coarse aggregatehas firm surfacetrue to the crosssection shown on the plans and thatit has a texture that will allow free and uniform penetration of thebituminous material.

505,3.5. Application of bituminous material: After the coarseaggregatehas beenrolled andchecked, the bituminousbinder shall beapplied at specifiedtemperaturesas directed by the Engineer. Therate of application shall be as specified in Table 500-6.

At the timeof applyingthebinder,the aggregatesshall be surfacedry for full depth of the layer.

The bituminous materialshallpreferably be applied by apressuredistributor uniformly over the surfaceat the specified rate. Over smallareas,where the use of a spray bar is impracticable, the bituminousmaterialshall be appliedby the nozzle attachment.Only when permitted,pouring pots may be usedaccordingtc~the directionsof the Engineer.

505.3.6. Application of key aggregates:Immediatelyafter the firstpenetration of bitumen, the key aggregatesin a clean and dry stateshall be spread uniformly over the surfaceby meansof an approvedmechanical spreader or by approved manual methods at the ratespecified in Table 500-6.

If necessary, the surfaceshall be broomed to ensure uniformapplication of the key aggregates.The entire surfaceshall then berolled with a 80 - 100 kN smooth steel wheel roller (along withvibratory roller if available) to the Specifications conforming to Clause505.3.4.

505.4. Surface Finish and Quality Control

The surface finish of constructionshall conform to therequirementsof Clause 902.

159


Controls on the quality of materials and works shall be exercisedby the Engineer in accordancewith Section 900.

505.5.The PenetrationMacadamshall be provided with final sur-facing (binderlwearing course) without any delay. If there is to beany delay, the courseshall be coveredby a sealcoatto the requirementsof Clause 513 before allowing any traffic over it. The seal coat insuch casesshall be considered incidental to the work and shall not bepaid for separately.


During the period of construction, arrangementsfor traffic shall bedone to Clause 112.


Penetration Macadam Base/BinderCourseshall be measured asfinished work in square metres.

505.8. Rate

The contract unit rate for PenetrationMacadamCourseshall bepayment in full for carrying out the required operations includingfull compensation for all components~istedin Clause504.8 (i) to(vi).

506. BUILT-UP SPRAY GROUT

506.1. Scope

This work shall consistof atwo-layercompositeconstructionof com-pactedcrushedcoarseaggregateswith applicationof bituminousbinderafter each layerand key aggregatesbn top for the second layer, ihaccordancewith the requirementsof theseSpecifications to serve asa basecourseandin conformity with the tines, gradesandcross-sectionsshown on the drawings or as directed by the Engineer. Thicknessofthe courseshall be 75 rum.

Built-up spray grout shall be used in a single course in a pavementstructure.

506,2. Materials

506.2.1. Bitumen: Clause 504.2.1 shall apply.

506.2.2.Aggregates: The coarseaggregateshall conform to Clause504.2.2.1.

Theaggregateshall satisfy thephysical requirementssetout in Table

160


500-3. The coarseand key aggregatesfor built-up spray grout shallconform to the grading given in Table 500-7.TABLE 500-7. GRADING REQUIREMENTS OF COARSE AND KEY GGREGATES

FOR BUILT-UP SPRAY GROUT

IS SieveDesignation

Per cent by weight passing the Sieve

CoarseAggregate Key Aggregate

53.0 mm26.5 mm22.4 mm13.2 mm5.6 mm2.8 mm

tOO40-75

—

0-20—

0-5

—

—

lOt)40-750-200-5


506.3.1. Weatherand seasonallimitations: Clause 504.3,1 shallapply.

506.3.2. Preparation of base: The base on which the b.uilt-upspraygrout courseis to belaid shallbe prepared,shapedand conditionedto the specified lines, gradesand cross-sectionsin accordance withClause501. A priming coat whereneededshall be applied in accordancewith Clause502 with suitable primer as directed by the Engineer.

506.3.3.Jack coat: A tack coat over the base shall be applied asper Clause 503.

506.3.4. Spreading and rolling coarseaggregates for the firstlayer: Immediately after the application of tack coat, the coarseaggregatesin a dry and clean form shall be spread uniformly andevenly preferably by mechanicalmeansat the rate of 0.5 cu.m. per10 sq.rr. area. The surface of the layershall be carefully checkedwith ten3plates and all high and low spots remediedby removing oradding aggregatesas may be required.

Immediately after spreading of the aggregates,the entire surfaceshall be rolled with a 80 - 100 kN smooth-wheeledroller. Rollingshall commenceat the edgesand progresstowards the centreexceptin superelevatedand uni-directional camberedportions where it shallproceedfrom the lower edgeto the higher edge.Eachpassof the rollershall uniformly overlap not less than one-third of the track made inthe precedingpass.

After initial rolling, the surface shall be checked transverselyandlongitudinally with templatesandany irregularitiescorrectedby loosening

161

Scction5(X) BaseandSurfaceCourses(Bituminous)

the surface, adding or removing necessaryamounts of aggregate,followed by rolling.

Rolling shall bestoppedbeforevoids in theaggregatelayerareclosedto suchan extent asto prevent free and uniform penetration of the binder.

506.3-5. Application of binder - first spray:The binder shall1* heatedto the temperatureappropriateto gradeof bitumen approvedby the Engineerand sprayedon aggregatelayer at the rate of 15 kg/10 sq. m. (in terms of straight-runbitumen) in a uniform mannerwiththe help of mechanical sprayerscapableof sprayingbitumen uniformlyatspecified ratesandtemperatures.Excessivedepositsof binder causedby stopping or starting of the sprayers or through leakage or anyother reason shall be corrected promptly.

506.3.6. Spreading and rolling of coarse aggregate for thesecondlayer: Immediately after the first applicationof the binder,thesecondlayerof coarseaggregatesshall be spreadandrolled to Clause506.3.4.

506.3.7. Application of’ binder-second spray: The secondaggregatelayer shall then be given a binder sprayat the rateof 15 kg!10 sq. m. (in terms of straight-run bitumen) to Clause506.3.5.

506.3.8. Application of key aggregate: Immediately aftersecondapplication of the binder, key aggregatesin a clean and drystate shall he spreaduniformly and evenly, preferably by mechanicalmeansat the rate of 0.13 cu.m./10sq. m. soas to cover the surfacecompletely. If necessary,‘the surfaceshall be broomedto ensureuniformapplicationof thekey aggregates.Theentire surface shallthen be rolledwith a 80-100 kN smooth-wheeled roller to Clause506.3.4. Whilerolling is in progress, additional key aggregates,whererequired,shallbe spreadby hand. Rolling shall continue until the entire course isthoroughly compactedand the key aggregates are firmly in position.


The surface finish of constructionshall conform to therequirementsof Clause902.

Control on the quality of materialsand works shall be exercisedbythe Engineerin accordancewith Section 900.

506.5.The built-up-spray-groutshall beprovidedwith final surfacingwithout any delay. If there is to be any delay, the course shall becovered by a seal coat to the requirement of Clause 513 before

162

BaseandSurfaceCourses(Bituminous) Section5(X)

allowing any traffic over it, The seal coat in such cases shall beconsidered incidental to the work and shall not be paid forseparately.


During the period of construction,atrangementof traffic shall bedone to Clause 112.


Built-up spraygrout shallbe measuredas finished work in squaremetres.

506.8. RateThe câutractunit rate for built-up spray grout shall be paymentin

full for cañyingout therequiredoperationsincluding full compensationfor all componentslisted in Clause504.8 (i) to (vi).

597. DENSE BITUMINOUS MACADAM

507.1. Scope

This work shall consistof constructionin a single course of 50to 100 mm thick base/bindercourseto the following Specificationsona previously preparedbase.

507.2. Materials

507.2.1.Bitumen:Thebitumenshallbepavingbitumenof PenetrationGrade S 65 or A 65 (60/70) as per Indian StandardSpecifications for“Paving Bitumen” IS: 73. In caseof non- availability of bitumen ofthis grade,S 90 (80/100)gradebitumenmay be usedwith the approvalof the Engineer. Guidanceto selection of the gradeof bitumen mayhe taken from Appendix-4.

507.2,2. Coarse aggregates: The coarseaggregatesshall consistof crushed stone,crushedgravel/shingleor otherstones.They shall beclean, strong, durable,of fairly cubicalshapeandfree from disintegratedpieces,organicor other deleteriousmatter and adherentcoating. Theaggregatesshall preferably be hydrophobic and of low porosity. Ifhydrophilic aggregatesare to be used,the bitumen shall be treatedwithantistrippingagentsof approvedquality in suitabledoses.Theaggregatesshall satisfy the physical requirementsset forth in Table 500-8.

If crushedgravel/shingleis used,not lessthan90 percentby weightol the gravel/shinglepiecesretainedon 4.75 mm sieve shall have atleast two fractured faces.The portionof the total aggregatepassing

163

Section 500 Base and SurfaceCourses (Bituminous)

4.75 mm sieveshall havea sand equivalent value of not lessthan 50 whentestedin accordancewith therequirementof IS: 2720(Part-37).

The plasticity index of the fractionpassingthe425 micron sieveshallnot exceed4.

TABLE 500.5. PHYSICAL REQITIREMENTS OF AGGREGATES FOR DENSEUtTUMINOUS MACADAM

S.No, Test TessMethod Requirement

I [AssAngetesAbrasionValuet 15~2386~Part’4) 40per centmaximum

2. AggregateImpactvaluet IS:2386(Pars-4) 30perceatMaximum

3. FlakinessandElongauontt

Indices(‘l’oial)15:2386(Pan-i) 30percentMaximum

4 (‘oaring andStrippingofBitumenAggregateMixtures

AASItTO T 182 Minimum retainedcoating95 percent

5, Scsindness(i) Inst with Sodium

Sulphate(ii) l,o.sswith Magncsium

Sulphate

IS:2386(Pan-5)S cycles

5 cycles

12 per centMaximum

18 per cent Maximum

5. Waterahsoption 15:2386(l5art-3) 2 per cent Maximum

* Aggregates may satisfy requirements of either of the two tests* * To determine this combined proportion, the flaky stone from a representative

sample should first be separated out, Flakiness index is weight of flaky stonemetal divided by weight of stone sample. Only the elongated particles beseparated out from the remaining (non-flaky) stone metal Elongation index isweight of elongated parlicles divided by total non-flaky particles. The value offlakiness index and elongation index so found are added up.

507.2.3.Fineaggregates:Fine aggregatesshallbe the Fractionpass-irtg 2.36mmsieveandretainedon 75 micronsieve,consistingof crusher-runscreening,gravel, sandor a mixture of both. Theseshall he clean,hard,durable,ttncoated,dry andfree from any injurious,soft or flaky piecesandorganicor otherdeleterioussuhstances.

507.2.4. Filler: Filler shall consisl of finely divided mineral mattersuchasrxk dust, hydraledlime orcementasapprovedby theEngineer.

The filler shallbegradedwithin the following limitstS Sieve Percentpassingby weight

601) micron 1003(X) micron 95-1(X)

75 micron 85-100

- The filler shall be free from organicimpuritiesandhavea PlasticityIndex not greaterthan4. ThePlasticityIndex requirementshall not apply iffiller is cement or lithe. When the coarse aggtregateis gravel,

164


2 per cent by mass of total aggregateof portlandcementor hydratedlime shall be added and the percentageof fine aggregate reducedaccordingly. Cement or hydratedlime is not required when thegravelis limestone.

507.2.5.Aggregategradation : The combinedcoarseand fine ag-gregatesand filler (when used) shall produce a mixture to conform tothe grading set forth in Table 500-9.

TABLE 500-9. AGGREGATE GRADATION FOR DENSEBITUMINOUS MACADAM

Sieve Designation Percentagepassingthe sieve by weight

37.5 mm 10026.5 mm 90-10013.2 mm 56-804,75 mm 29-592.36 mm 19-45

300 micron 5-1775 micron 1-7

The aggregatemix, as usedin work, shall not vaty from the low limit on onesieve to the high limit on the adjacentsieve but shall be well graded.

507.3. Mix Design

507.3.!. Requirement of mix: Apart from conformitywith gradingand quality requirementsof individual ingredients,the mix shall meetthe requirementsset out in Table 500-10.TABLE 500-10. REQUIREMENTS OF DENSE BITUMINOUS MACADAM MIX

S.No. Description Requirements

1. Marshall stability (ASTM Designaiion-D-l559) 820 kg (1800 Ib)determinedan Marshall specimenscompacted minimumby 75 conipactionblows on each end

2. Marshall flow (mm) 2-4

3. Per cent Air voids 3-5

4. Minimum voids in m.intral aggregates(VMA) 10 per cent - 12 per cent

5. Per cent voids in mineral aggregatesfilled by bitumen (VFB) 65-75

6. Binder contentper cent by weight of total mix Not less than 4.0 per cent

507.3.2. Binder content: The binder contentshall be so fixed asto achieve the requirementsof themix setout in Table 500-10. Marshallmethod for arriving at the binder content shall be adopted,replacing theaggregatesretained on 26.5 mm sieve by the aggregatespassing 265mm sieve and retained on 22.4 mm sieve.

165


507.3.3.Job mix formula : The Coffiractor shall intimate to theEngineer in writing, atleast20 days before the start of the work, thejob mix formula proposedto be used by him for the work and shallgive the following details:

(i) Sourceand location of all materials;

(ii) Proportions of all materiaLs expressedas follows where each is applicahle~:

(a) Binder, as percentageby weight of to4al mix;

(b) Coarse aggregatelFineaggregate/Mineralfiller as percentageby weightof total aggregateincluding mineral filler~

(iii) A single definite percentagepassingeachsieve for the mixed aggregate;

(iv) The results of testsenumeratedin Table 50010 asobtainedby theContractor;

(v) Test resultsof physical charaãeristicsof aggregatesto be used;

(vi) Mixing temperatureand compacting temperature.

While working out thejob mix formula, theContractorshall ensurethat it is based on a correct and truly representativesample of thematerialsthat will actually be used in the work and that the mix andits different ingredientssatisfythe physical and strengthrequirementsof these Specifications.

Approval of the job mix formula shall be based on independenttesting by the Engineer for which samples of all ingredients ofthe mix shall be furnished by the Contractor as required by theformer.

The approvedjob mix formula shall remain effective unless anduntil modified by the Engineer.Should a changein the source ofmaterials be proposed, a new job mix formula shall be establishedand got approved from the Engineer before actually using thematerials.

507.3,4. Permissiblevariation from job mix formula: It shallbe the responsibility of the Contractorto produce a uniform mixconforming to the approved job mix formula subject to thepermissible variations of the individual percentagesof the variousingredientsin theactual mix from the job mix formula to be used withinthe limits as specified in Table 500-Il. Thesevariationsare intendedto apply to individual specimenstaken for quality control tests videSection 900.

166


TABLE 500.11. PERMISSIBLE VARIATIONS FROM THE JOB MIX FORMULA

S.~4o, Description0f Ingredients Permissiblevariationby weight of totalmix-in per cent

Aggregatepassing 13.2 men sieve and larger sieves ±82. Aggregatepassing 112mm sieve and 5.6 mm sieve 73. Aggregatepassing2.80 mm sieveand 1.40 mm sieve 64. Aggregatepassing710 micron seive and 355 micron sieve ±S5. Aggregatepassing 180 micron sieve ±46. Aggregate passing 90 micron sieve ±27. Binder ±0.38, Mixing temperature ±10°C


507.4.1.Weather and seasonallimitations: Clause504.31. shallapply.

507.4.2.Preparationof base: The baseon which Dense BituminousMacadamis to be laid shall be prepared,shapedandconditionedto thespecified lines, gradesandcrosssectionsin accordancewith Clause501or as directed by the Engineer.The surface shall be thoroughly sweptclean free from dust and foreign matter using mechanical broom anddust removed or blown off by compressedair. In portions wheremechanical meanscannot reach,other approvedmethod shall be used.A priming coat whereneeded,shallbe appliedin accordancewith Clause502 or as directed by the Engineer.

507.4.3.Tack coat: A tack coat over the base shall be applied asper Clause 503.

507.4.4. Preparationof mix: Clause504.3.4 shall apply.

.507,4.5, Spreading: The mix transportedfrom the hot mix plantto the site shall be spreadby meansof a self-propelled paver withsuitable screedscapableof spreading,tarnping and finishing the mixto specified grade, lines andcross-section.PaverFinisher shall havethe essential featuresas spelt out in Clause504.3.5. However, inrestrictedlocationsand in narrow widths where the availableequipmentcannot be operated in the opinion of the Engineer, he may permitmanual laying of the mix. Similarly for smaller jobs, mechanical pavermay be used with the approvalof the Engineer.

The temperature of mix at the time of laying shall be in the rangeof 120°-160°C.

Mixes wit’h a temperatureof lessthan 120°Cshall not be put intopaver spreader.Longitudinaljoints and edges shall be constructed

167

Section500 Baseand Surface Courses(Bituminous)

true to the delineating lines parallel to the centre line of the road.Longitudinal and transversejoints shall be offset by at least 250 mmfrom those in the lower coursesand the joint on the top most layershall not be allowedto fall within the wheel path. All lransversejointsshall be cut vertically to the full thicknessof the previously laid mixwith asphalt cutter and the surface painted with hot bitumen beforeplacing freshmaterial.Longitudinal joints shall be preferably hot joints.Cold longitudinal joints shall he properly heatedwith joint heater toattain a suitable temperatureof about 80°Cbefore laying of adjacentmaterial. -

507.4.6.Rolling : After spreading the mix by paver, it shall be thor-oughly compacted by rolling with a set of rollers moving at a speednot more than 5 km/h, immediately following close to the paver.Generally the initial or breakdownrolling shall he done with 80-100kN static weight smooth-wheeledroller. The intermediaterolling shallbe done with 80 -100 kM static weight vibratory roller or with apneumatictyred roller of 150-250kM weight havinga tyre pressure ofat least0.7 MPa. The finish rolling shall be donewith 60 8OkN weightsmooth wheeled tandem roller. All the compaction operations, i.e.,breakdownroiling and intermediaterolling can be accomplishedby usingvibratory tandem roller of 80-100 kN static weight. During initialbreakdownrolling and finish rolling, no vibratory compactionshall beresorted to. The exact pattern of rolling shall be establishedaftertrial compactionas approvedby the Engineer.Any displacementoccurringas a result of reversingof the direction of a roller or from any othercauseshall be correctedat onceas specifiedand/or removed andmadegood.The rollers shall not be permitted to stand on pavement whichhasnot been fully compactedand wheretemperatureis still more than70°C.Necessary precautionsshall be taken to prevent droppingofoil, grease,petrol or other foreign matteron the pavementeitherwhenthe rollers are operatingor standing.

The wheels of roller shall be kept moist to prevent the mix fromadhering to them. But in no caseshall fuel/lubricating oil be usedfor this purposenor excessivewater pouredon the wheels, Rollingshall commence longitudinally from edges and proceedtowardsthecentre, except that on superelevated and unidirectional camberedportions, it shall progressfrom the lower to upper edge parallel tothe centreline of the pavement.The roller shall proceedon the freshmaterial with rear or fixed wheel leading so as to minimise the

168


pushing of the mix and each passof the roller shall overlap theprecedingone by half the width of the rear wheel.

Rolling shall be continued till the density achieved is at least 98per cent of that of laboratory Marshall specimen(compactedas definedin Table 500-10) and all roller marks are eliminated.Skin patchingofan area that hasbeen rolled, will not be permitted. Rolling operationsshall be completedin all respectsbefore the termperatureof the mixf~.illsbelow 100°C.

507.5. Opening to Traffic

Traffic may be allowedafter completionof the final rolling whenthe mix has cooled down to the surrounding temperature.The DenseBituminous Macadam shall be providedwith an appropriate wearingcourseas early as possibleprior to regularopeningto normal traffic and!or impending rain.



Control on the quality of materialsand works shall be exercisedbythe Engineerin accordancewith Section 900.


During the period of construction,arrangementsfor the traffic shallbe done to Clause 112,

507.8. Measurementsfor P~~~ne~t

Dense Bituminous Macadamshall be measuredas finished workin cubic metres or tonnes as directedby the Engineer.

507.9. Rate

The contract unit rate for DenseBituminous Macadam shall bepayment in full for carrying out the required operations includingfull compensation for all componentslisted in Clause504.8 (i) to(vi). The rate shall cover the provision of bitumen in the mix at 4,5per cent of the weight of the total mix, with the provision that thevariation of quantityof bitun~nwill be assessedandthepaymentadjustedas per the rate of bitumen quoted.

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508. SURFACE DRESSING508.1. Single and Two-Coat Surface Dressing using Bitumen

508.1.1.Description: This work shall consistof the application ofone coat or two coats of surfacedressing,each coat consistingof alayer of bituminous binder sprayed on base prepared previously,followed by a cover of stone chippingsproperly rolled to form awearing courseto the requirementsof these Specifications.

508.1.2. Materials

508.1.2.1.Binder : The binder shall be straight-run bitumen ofa suitable grade appropriateto the region, traffic, rainfall and otherenvironmentalconditionsas directed by the Engineer and conformingto IS: 73. Guidance in this regard may be obtainedfrom Appe,idix4.

508.1.2.2. Stone chippings : The stone chippings shallconform to Clause504.2.2.1. The StonePolishing Value as measuredby BS 812 (Part 114), shall not he lessthan55. The stone chippingsshall also conform to the quality requirements of Table 500-3except that water absorption shall be restricted to a maximum of Iper cent. The size of stone chippingsshall be in accordancewith Table500-12.

508.1.2.3. Quantities of materials: The quantities of materials usedtbr this wofk shall be as specified in Table 500-13.TABLE 500-12. SIZE REQUIREMENTS OF STONE CHIPPINGS FOR SURFACE

DRESSING USING BITUMEN

S.No.

Type of construction Normal size orstone chipplngs

Specifications

1. Single coat surface dressingor the first coat of two-coatsurface dressing

13.2 mm 100per centpassingthrough 22.4mmsieve & retained on 11.2 mm sieve.,

2. Secondcoat of two-coatsurface dressing(also usedas a renewal coat)

11.2 mm 100 per centpassingthrough13.2 mmsieve and retainedon 5.6 mm sieve,

TABLE 500-13. QUANTiTIES OF MATERIALS REQUIREDROAD SURFACE FOR SURFACE DRESSING

FOR 10 sq. ns.OFUSING BITUME~

S.No. Type or construction Binder Stonechlppings

1. Single coat surface dressing or the first coatof the two—coat surface dressing 18.0 kg 015 cu.m.

2. Second coat of the two-coat surface dressing(also used as a renewal coat) 10.0 kg 0.10 cu.m.

70


508,1.3. Construction operations

508.1.3.1. Weather and seasonal limitations: Clause 504.3.1shall apply.

508.1.3.2. Preparation of base : The baseon which the surfacedressing is to be laid shall be prepared,shapedand conditioned tothe specified lines, gradeand cross-sectionin accordancewith Clause501 andas directed by the Engineer.Priming coat, whereneeded,shallbe provided as per Clause502 andas directedby theEngineer. Wherethe existing surface shows signsof fatting up, thisshall be rectified.The bituminousprimedsurfaceto bedressedshallbe thoroughlycleanedeitherby usinga mechanicalbroom or any otherapprovedequipment/method as specified by the Engineer.

Dust removedin the processshall be blown off with the help ofcompressed air.

508.1.3.3. Application of binder: Bitumen shall be heated tol50~-.163°Cand sprayed on the dry surface in a uniform mannerwiththe help of self-propelled mechanical sprayershaving self-heatingarrangementand bitumen pressurepump and sprayingbar with nozzleshaving constant volume or pressure system capable of sprayingbitumen uniformly at the rates specified in Table 500-13 and abovementionedtemperature.Excessivedepositsof bindercausedby stoppingor starting of the sprayeror through leakagesor any other reason shallhe corrected by blotting with sand before the stone chippings arespread.

508.1.3.4. Application of stone chippings: Immediately afterthe applicationof binder,stonechippingsin a dry andclean state shallhe spread uniformly on the surfaceby meansof a self-propelled ortowed mechanicalgrit spreadercapableof spraying uniformly at ratesspecified in Table 500-13 so as to cover the surface completely. Ifnecessary,The surfaceshall be broomedto ensureuniform spread ofchippings.

508.1.3,5. RoIling: Immediatelyafter the applicationof the covermaterial, the entire surfaceshall be rolled with a 80-100 kN smoothwheeled steel roller, 80-100kN static weight vibratory roller, or otherapproved equipment.Rolling shallcommenceat the edges andprogresstowards the centre except in superelevatedand uni-directionalcamberedportionswhere it shall proceed from the lower edge to thehigher edge.Eachpassof the roller shalt uniformly overlap not less

171


than one-thirdof the trackmadein the precedingpass. While rollingis in progress,additional chippings shall be spread by hand innecessary quantities required to make up irregularities. Rolling shallcontinueuntil all aggregate particlesare firmly embedded in thebinder and present a uniform closed surface.

508.1.3.6. Application of second coat of surface dressingWhere surface dressingin two coatsis specified,the secondcoat shallhe applied immediately after laying of the first coat. The constructionoperations for the secondcoat shall be the same as described inClauses508.1.3.3 to 508.1.3.5.

508.1.4. Openingto traffic : Traffic shall not be permittedto runon any newly surfacedressedarea until the following day. in specialcircumstances,however, the Engineermay open the road to trafficimmediately after rolling, but in suchcasestraffic speed shall belimitedto 16 km per hour till the following clay.

508.1.5. Surfacefinish andquality controlof work: The surfacefinish of constructionshall conform to the requirementsof Clause902.

Control on the quality of materialsand works shall be exercisedbythe Engineer in accordancewith Section 900.

508.1.6. Arrangements for traffic : During the period ofconstruction,arrangementof traffic shall be done as per Clause 112.

508.1.7.Measurementsfor payment:Eachcoatof surfacedressingshall be measuredas finished work in squaremetres.

508.1.8. Rates: The contractunit rate for each coat of surfacedressing shall be paymentin full for carrying out the requiredoperations including full compensationfor all components listed it

Clause504.8 (i) to (vi).

508.2. Two—Coat Surface Dressing Using Cationic BitumenEmulsion

508.2.!, Scope

508.2.1.1. This work shall consistof two-coatsurfacedressing, eachcoat consistingof a layer of cationic bitumen emulsionbinder sprayedon a basepreparedpreviously, followed by acover of stoneaggregate,properly roiled to form a wearing courseto the requirements of theseSpecifications.

508.2.1.2. It shall, however,not be applicableto a single coatsurface dressingusing cationic bitumen emulsion.

172


508.2.2. Material

508.2.2.1. Binder: The binder shall be a Cationic type bitumenemulsion of Rapid Setting~RS)gradecomplying with 1.5. 8887 andhaving bitumen content 60 per cent minimum by weight.

508.2.2.2.Aggregate(A)~GeneralRequtrements:Clause508.1.2.2.shall apply exceptthe sizerequirement

which shall be as given in Table 500-14. Wet aggregatescan beusedfor surfacedressing with Cationic bitumen emulsionsandwhen aggregatesare dusty, theyshould be cleanedby washingor by sprinkling water copiously. If the roadsurface is thy, a light sprinkling with waler shall be done.

(B) Size: The aggregates shalt conform to the size given in Table 500-14,

TABLE 500.14. REQUIREMENTS OF STONE dIPPINGS FOR SURFACEDRESSING USING BITUMEN EMULSION

I. .For first coat-13.2 mm size Passing22.4 mm sieveandretained on 11.2 mm sieve.

2. I’or secondcoat-6.7 mm size Passing9.5 mm sieveand retainedon 2.36 mm sieve.

(C) QuantIties of Materials: The quantities of materials used for this work shaltbe as given in Table 500-15.

TABLE 50045. REQUIREMENTS OF MATERIALS USING BITUMENEMULSION

MaterIal For 10 sq. m. area For FIrst Coat For SecondCoat

Cationic Bitumen EmulsionAggregates

12 to0.10

14 kgso 0.12 cu.m,

16 to 18 kg0.06 to 0.08 cu.m.

508.2.3. Construction operations

508.2.3.!.Weatherlimitations: Cationic bitumenemulsionsshouldnot normally be stored below 0°C.However, surface dressing withCationic bitumen emulsion should be carriedout only when theatmospherictemperature is above 10°C.The work can be carried outwhenthe baseis damp. All standingwaterin depressionsshall, however,be removed.

508.2.3.2.Preparation of base: The existing baseon which surfacedressing is to be laid shall be prepared,shapedand corrected to auniform grade and camber in accordancewith Clause501.

The surfaceshall be cleanedto removeall loose particles, dust andloreign matter. It is preferableto spray water on the surface to settlethe loose dust and also to exposeclean surfaceof aggregatesin thecaseof granular base courses.

508.2.33.Preparation of binder: Before opening, the Cationic bi-tumen emulsion drums should be rolled at slow speed,to and fro,

173


for a distance of about 10 metres,5 to 6 times to mix the contentsproperly.

508.2.3.4. First Coat(A) Application of Binder: Cationic bitumen emulsionbinder can be applied on

wet road surface. If the road surface is dry, light sprinkling with water shallhe done. Cationic bitumen emulsion shall be sprayed uniformly on the preparedbase by mechanicalsprayers. In exceptionalcases spraying from a sprayingcan may he resorted to at directed by the Engineer.The spraying can shouldhave6 mm diameterholesspaced30 mm apart to prevent clogging. An emulsiontank of 30 litres capacitypressurizedby compressedair from a hand pump anda 12 mm flexible pipewith a spraynozzle is a simpleandefficient arrangementfor spraying.

(B) Application of aggregate:Immediately after spraying of Cationic emulsion,aggregate of 13.2 rum size shall be spread uniformly and evenly by mechanicalmeans to cover the surface completelyand evenly. Any oversize aggregate,if seen, shall be removed.

(C) Rolling : Immediately after the application of cover material, the surfaceshall be rolled with 80-100kN roller preferablyby smoothwheeled tandemtype.The rolling shall beginat the edgeand proceedtowards the centre, parallel sothe centre line except in superelevatedandunidirectional -.amberedporsionrwhere it shall proceedfrom the loweredgeto the higher edge. While rolling,aggregates shall be addedor removedso as to ensure a unifonnly coveredsurface. Each-pass of roller shall uniformly overlapnot less than one thirdol thetrack made in theprecedingpass.Rolling shall continue for just enoughtime to embed the aggregatesin the binder andpresent a uniform closedsurface. Excessiverolling, resulting in crushingof aggregatesshall be avoided.

508.2.3.5. Secondcoat(A) ‘rune interval : ‘The secondcoat of surface dressing shall be applied on the

same day asthe Isrst coat but at least not earlier than one hour after finishingthe rolling of the first coat.

(B) Application of emulsion:Traffic shall not be allowed on the first coat beforetheappi ication of second coat. If the aggregates of the first coat appear tobe loose and unbonded - in few spots, the same shall not be disturbed.

‘[he Caliortic bitumen emulsion for secoqdcoat shall besprayedby mechanicalsprayeror in exceptional cases by using pouring can with theapproval of theEngineer, taking care not to disturb the first layer while walking over it.

(C) Application of aggregate: Immediately after the application of emulsion, 6.7mm size aggregates shall be spread uniformly by mechanical means to coverthe whole surface evenly.

(II) Rolling: Rolling shall start soon after spreading the aggregates and alloperations carried out as per Clause 508.2.3.4(C) to achieve a uniform closedsurface.

(E) Finishing: After one pass of the roller, depressions shall be filled with6.7 mm size aggregate.If excessof aggregate is found in isolatedspots, thebigger sizeaggregates shall be removed to give a uniform surface. Finish

rolling on the next day helps to give a firm surface.

174


508.2.4. Opening to traffic: The road may be opened to traffic 4hoursafter completing rolling of the secondcoat, but preferably thenext day alter 24 hours.

Where theroad width is single lane, traffic can beallowed at slowspeed of not morethan10 km per hour making sure to add aggregatesand emulsion whereverthe surfacehas been picked up by traffic.

508.2.5. Surface finish and quality control of work : Thesurfacefinish of constructionshall conform to therequirementsof Clause902,

Control on the quality of materialsand works shall beexercisedbythe Engineerin accordancewith Section 900.

508.2.6. Arrangements for traffic : During the period ofconstruction,arrangementof traffic shall be done to Clause i 12.

508.2.7. Measurements for payment : Two coats of surfacedressingshall be measuredas a fmished work in squaremetres,

508.2.8. Rate: The contract unit rate for two coats of surfacedressing shall be payment in full for carrying out the requiredoperations including full compensationfor all components listed inClause504.8 (i) to (vi).

508.3. Surface Dressing with Precoated AggregateusingBitumen

508.3.1. Scope

508.3.1.1. The work shall consistof application of either a singlecoat or two coats of surface dressingover a previously preparedbase,each coat consistingof applicationof bituminousbinder sprayedon abase previously preparedfollowed by a coverof precoated materialsproperly rolled to form a wearing courseto the requirementsof theseSpecifications.

508.3.1.2.This Specificationmay be adoptedin lieu of the con-ventional surface dressingto Clause508.1, in situationswherebetteradhesionis requiredbetweenthe aggregatesandbinder during construc-tion and later in service. The technique is basically the same asconventionalsurfacedressingexceptthat a small quantity of binder isused for precoatingthe aggregates.However,.,it is quitedifferent frompremix construction.

175

Section500 BaseandSurface Courses(Bituminous)

508.3.2. Materials

508.3.2.1. Bind~r:The binder shall be straight run bitumen ofa suitablegradeappropriateto the region, traffic and otherenvironmentalconditions and as directed by the Engineer and conforming toIS:73.

508.3.2,2. Aggregates: The aggregaSshall conform to Clause504.2.2. They shall conforni to the quality requirementsof Table 5(X)-3 exceptthat the water absorptionshall be restrictedto maximum ofI per cent. The StonePolishingValue as measuredby BS 812 (Part-114) shall not be less than 55.

The size of the aggregatesshall be .in accordance with Table500-12.

508.3.2.3. Quantitiesof materials:The quantitiesof materials usedfor this work shall be as specified in Tables 500-12 and 500-13.

508.3.2.4. Precoating:The aggregatesshall be precoatedwith 0.75to 1.00 per cent of their weight with binder andshall not be precoatedsimultaneously with the surface dressing operation.The precoatedag-grcgatesshallbe allowedto curefor atleastoneweek sothatthey becomenon-stickyto facilitate easyspreadinglike normal uncoatedaggregates.The aggregates,free of dust or fine parlicles shall be preheated to160°Cfor pr~coatingand then mixed with bitumen binder (0.75 to1.00 per cent hy weight of aggreg~fte)heated to its applicationtemperature.The aggregatesand binder shall be thoroughly mixed ina mixer of approvedtype till the aggregatesare uniformly coated.


508.3.3.1 Weather and seasonal limitations: Clause 504.3.1shall apply.

508.3.3.2.Preparationof base: Clause 508.1.3.2 shall apply.

508.3.3.3.Applicationof binder: After deducfingthe binder quantityconsumedin precoating aggrega~e~[or:.‘first coat in terms of para508.3.2.4 from the quantitiesspn:sfiecl in Table 500-13, remainingbinder of first coat shall be heatedto 150°-165°Cand sprayedon theclean and dry surfacein a uniform mannerpreferably with the help ofmechanicalsprayershaving self-heatingarrangement,bitumen, pressurepump anti spray nozzle bar capableof spraying bitumen uniformly attha4xatesandtemperaturesspecifiedabove.Excessivedepositsof bindercaused by stoppageor starting of sprayeror through leakage or anyother reasonshall be correctedbefore stone chip~ingsare spread.

176


508.3.3.4. Application of aggregates : Immediately after theapplicationof binder,aggregatesin a dry andclean state shall bespreaduniformly on the surface preferably bymeans of a mechanicalgriLLercapableof spreadinguniformly at the rates specifiedin Table 500-14so as to cover thesurface completely.If necessary,the surface shallbe broomed mechanicallyor manuallyto ensure uniform spread ofaggregates.

508.3.3.5. RoIling: Clause508.1.3.5 shall apply.

508.3.3.6. Application of secondcoat of surface dressing : Thesecondcoat of surface dressing, where specified, shall be appliedimmediately after the first coat or soon after, depending upon theconditions at site and typeof binder used.The constructionoperationsfor the secondcoatshall be the sameas described in Clause508.3.3.3.to 508.3.3.5. exceptthat the rateof applicationof aggregatesandbinderfor secàndcoat shall be as specified in Table 500-13 afterdeductingbinder consumedfor precoating the aggregatesrequired forsecondcoatvide Clause508.3.2.4.

508.3.4.Opening to traffic : Clause508.1.4. shall apply.

508.3.5.Surfacefinish andquality controlof work: The surfacefinish of constructionshall conform to the requirementsof Clause902.Control on the quality of materials and works shall be exercisedbythe Engineerin accordancewith Section 900.

508.3.6.Arrangements for traffic : During the period of construc-tion, arrangementof traffic shall be done to Clause112,

508.3.7.Measurementsfor payment: Each coat of surface dressing.shall be measuredas finished work in squaremetres.

508.3.8. Rates: The contractunit rate for each coat of surfacedressing shall be paymentin full for carrying out the requiredoperations including full compensationfor all components listed inClause504.8 (i) to (vi).

509. OPEN-GRADED PREMIX CARPET

509.1. Open-graded Premix Carpet using Bitumen

509.1.1. Scope: This work shall Consistof laying andcompactingan open-gradedcarpetof 20 mm thickness in a singlecourse composedof suitablesmall-sized aggregatesprem’txed with a bituminous binderon a previously preparedbase,in accordancewith the requirementsof these Specifications,to serve as a wearing course.

177


509.1.2. Materials

509.1.2.1.Binder: The binder shallbe bitumenof a suitable gradeappropriate to the region, traffic, rainfall ançl other environmentalcon-ditions,as directed by the Engineerand satisfying the requirementsof IS 73, 217, 454 or otherapproved cuthack as applicable.Guidancein this regard may be taken from Appendix- 4.

509.1.2.2. Aggregates:The coarseaggregatesshall conform toClause 504.2.2.l.TheStone Polishing Value as measuredby BS:812-(Part 114) shall not be less than 55.

The aggregatesshall satisfy the quality requirementsset forth inTable 500-3 except that the water absorption shall be limited to amaximum of I per cent.

509.1.2.3. Proportioning of materials: The materials shall beproportioned as per quantitiesgiven in Table 500-16.TABLE 500.16. QUANTITIES OF MATERIAlS REQUIRED FOR 10 m

2 OF ROADSURFACE FOR 20 mm THICK OPEN-GRADED PREMIX CARPETUSING BITUMEN

Aggregatesfor Carpet

(a) Stone chippinga-13.2 mm size; passing22.4 mm 0.18m5steve and retained on 11.2 mm sieve

(b) Stone chippings-I1.2mmsize passing 13.2 mm 0.09s&sieve and retainedon 5.6 mm sieve

Total 0.27&

Binder for Prembdng(quantitiesin terms of straight run bitumen)

(a) For 018 m5 of 13.2 mm size stone chippmgs 9.5 kgat 52 kg per m’

(b) For 0.09 m3 of 11.2 mm size stone chippings 5.1 kgat 56 kg per m3

Total 14.6 kg.

509.13. Construction operations

509.13.1.Weatherandseasonallimitations: Clause504.3.1 shallapply.

509.1.3.2. Preparation of base: The underlying base on whichthe bituminous carpet is to be laid shall be prepared, shaped andconditioned to the specifiedlines,gradeandcross-sectionin accordancewith Clause 501. A prime coat where needed shall be applied inaccordancewith Clause502 as directed by the Engineer.

178


509.1,3.3.Tackcoat : A tack coatcomplying with Clause503, shallbe applied over the basepreparatoryto laying of the carpet.

509.1.3.4. Preparationof premix: Hot mix plant of appropriatecapacity and type shall be used for the preparationof mix material.The hot mix plant shall have separatedryer arrangementfor heatingaggregatesand pugmill for mixing aggregatesand binder.

The temperatureof binder at the time of mixing shall be in therangeof 150°C to 163°C and that of the aggregatesin the range of1550 C to 163°C providedthat the differencein temperature betweenthe binder and aggregatesat no time exceeds14°C. Mixing shall bethoroughto ensurethat a homogeneousmixture is obtainedin which allparticles of the aggregatesare coateduniformly and the dischargetemperatureof mix shall be between130°C and 160°C.

The mix shall be immediately transportedfrom the mixer to thepoint of use in suitablevehicles or wheel barrows. The vehiclesemployed for transportshall be clean andthe mix being transportedcovered in transit if so directed by the Engineer.

509.13.5. Spreading and rolling: The mixed material shall bespreadby suitable means. As soon as sufficient length of bituminousmaterial has been laid, rolling shall commencewith 80-100 kN rollers,preferably of smoothwheel tandemtype, or otherapproved equipment.Rolling shall begin at the edge and progress toward the centrelongitudinally, except that on the superelevatedand uni-directionalcambered portions, it shall progressfrom the lower to upper edgeparallel to the centre line of the pavement.

When the roller haspassedover the whole areaonce, any highspots or depressionswhich becomeapparentshall be corrected byremoving or addingpremixedmaterials.Rolling shall thenbecontinueduntil the entire surfacehas beenrolled to compactionandall the rollermarks eliminated. In eachpassof th~roller, preceding track shall beoverlappeduniformly by at least 1/3 width. The roller wheels shall bekept dampto preventthepremix from adheringto the wheelsandbeingpicked up. In no caseshall fuel/lubricatingoil be used for this purpose.Excessuseof water for this purposeshall be avoided.

Rollers shall not stand on newly laid materialwhile there is a riskthat it will bedeformedthereby. Rolling operationsshall be completedin every respectbefore the temperatureof the mix falls below l000C,

179


The edgesalong and transverse of the carpetlai,d and compactedearlier shall becut to their full depth so as to exposefresh surface whichshall be paintedwith a thin surface coat of appropriate binder beforethe new mix is placed against it.

509.1.3.6. Sealcoat: A seal coat conforming to Clause513 shallbe applied to the surfaceimmediately after laying the carpet.

509.1.4. Opening to traffic: No traffic shallbeallowedon the roadtilt the seal coat has been laid. After the seal coat is laid, the roadshall be openedto traffi~according to Clause 513.4.

509.1.5. Surface finish and quality control of work: The surfacefinish of constructionshall conform to the requirements of Clause902. Control on the quality of materialsand works shall be exercisedby the Engineerin accordancewith Section 900.

509.1.6. Arrangements for traffic: During the period of construc-lion, arrangementof traffic shall be done to Clause 112.

509.1.7. Measurementsfor payment:Opengradedpremix carpetshall be measuredas finished work in squaremetres.

509.1.8. Rate:The contractunit rate foropen-gradedpremix carpetshall be paymentin full for carrying out the required operationsincluding full compensationfor all componentslisted in Clause504.8.

509.2. 20mm Thick Premix Carpet using Cationic Bitumen Emul..sion

.509.2.1. Scope:This work shall consistof laying and compactinganolengradedpremixcarpetof 20mm thicknesswith Cationic bitumenemulsion placedon apreviouslypreparedbasein accordancewith therequirementsof these Specificationsto serve as a wearing course.

509.2.2. Materials

509,2.2.1.Binder: The binder shall be Cationicbitumen emulsionof Medium Setting (MS) gradecomplying with IS: 8887 and havingbitumen content 60 per cent minimum by weight. For liquid seal coatMS gradecan be used,but it is preferableto useRapid Setting (RS)grade of Cationic bitumenemulsion. However,for premix sealcoat StowSetting (SS) grade Cationic bitumen emulsion shall be used.

509.2.22.Coarseaggregates: C!ause 509.1.2.2. shall apply. Ag-gregatesshould becleanedby washing or by spriniding watercopiously.

The coarseaggregatesshall satisfy the quality requirementssetforth

180


in Table 500-3,except that the water absorptionvalueshall be limitedto a maximumof I per cent. Stripping value is not to be consideredunlessdirectedby the Engineer.Waterabsorptionup to 2 per cent maybe permitted in exceptionalcasesonly.

509.2.2.3. Fine aggreg~tes~Fine aggregatesfor seal coat shallbecrushed stone chips or coarsesand,clean,uncoatedand free fromclay, dust and other deleteriousmatter.

509.2.3. Quantities of materials required: The materials shallbe proportionedas per quantitiesgiven in Tables500-17 and 500-18.

TABLE 500.17. QUANTITIES OF AGGREGATES FOR 10 nsa AREA

(A) Prembi Carpet

(a) Coarseaggregate13.2 mm size; passing

Is 22.4 mm sieve and retainedon IS 11.2 mm sieve 0.18 m’(b) Coarseaggregate11.2 mm size; passing

Is 13.2 mm sieveand retained on IS 5.6 mm sieve 0.09 in’

(B) For SealCoat:

(a) Liquid seal coat:~

Crushed fine aggregates6.7 mm size; passingIS 9.5 mmsieve and retainedon Is 2.36 mm sieve 0.06 m

3

(b) Premix seal coat:

Coarse sand or stone grit passing 2.36 mmsieveand retainedon 180 micron sieve 0.06 rn~

TABLE 500.18. QUANTITIES OF BINDER

(A) For Tack Coat For 10m2 area

(i) Normal bituminous surfaces 2.0 to 2.5 kg

(ii) Dry and hungry bituminous surface 2.5 to 3.0 kg

(iii) Granular surfaces treatedwith primer 2.5 to 3.0 kg

(iv) Non bituminous surfaces:(a) Granularbase (not primed)

(b) Cementconcrete surface

3.5 to

2.5 to

4.0 kg

4.0 kg

(B) For Premix Carpet: 20 to 23 kg

(C) For Seal Coat:

(a) for liquid seal coat 12 to 14 kg

(b) for premix seal coat 10 to 12 kg

509.2.3,1. Aggregates


509.2.4.1.Weather limitations: Cationic bitumen emulsionsshall

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not normally be stored below 0°C.However, premix carpet workwith Cationic emulsion shall be carriedoutonly when the atmospherictemperatureis above 10°C.

509.2.4.2. Preparation of base:The underlyingbase on whichthe premix carpetis to be laid shall beprepared,shapedand conditionedto the specified lines,gradesand cross-sectionsin accordancewith Clause501. The cleanedsurfacecan befinally washedwith water, if it is readilyavailable.

509.2.4.3.Preparationof binder: Clause508.2.3.3 shall apply.

509.2.4.4.Tackcoat: Clause508.2,3.4(A) shall apply. Tack coatshall be applied not earlier than 10 minutes before spreading thepremix. On water bound macadamsurface,water shall be sprayed tomake the surface damp before applying tack coat.

509.2.4.5.Preparationof premix: Premixing of Cationic bitumenemulsion and aggregatescan be donein a suitablemixer such as coldmixing plant as per IS~5435 (Revised)or concretemixer or by shovelsin exceptionalcaseswith the approvalof the Engineer.However, forlarge works,continuousmixing operation canbe doneeither in batchor continuousmixer units suitable for. emulsion mixes.

When using concretemixer for preparingthe premix, 0.135 cu.m.(0.09 cu.m. of 13.2 mm size and 0.045 cu.m. of 11.2 mm size) ofaggregatesper batchmay be usedas this quantity will cover 5 sq.m.of road surfacewith 20 mm average thickness.

The aggregatesrequiredfor one batch should bekept ready nearthe mixer. The aggregatesshall becleanedfree from dust and dirt, ifany, by dipping or washing or copiously sprinkling water.

First the coarseaggregatesof 13.2 mm size shall be chargedintothe mixer followed by 5 to 6.5 kg of Cationic bitumen emulsion andthen 11,2 mm size aggregatesare added,followed by 5 to 6.5 kg ofCationic bitumen emulsion. After the materials have been mixedthoroughly, the mix shall be immediately transportedto the layingsite in suitable vehicles. Toomuch mixing shall be avoided as it mayresult in decoaiingof aggregates.

Because of ease of mixing, Cationic bitumen emulsion andaggregates can be mixed manuallyby shovels whenmechanical mixeris not availableor when the work is too small, with the approval ofthe Engineer. 0.06 cu. m. of aggregatescan be conveniently mixedin one heap,with appropriate quantityof emulsion. It is preferableto

182


make the aggregatesdamp before mixing as it reduces the effortrequiredfor mixing andalso helpsto get bettercoatingof aggregates.The 13.2 mm size aggregatesand emulsionaremixed first andthen the11.2mm size aggregatesandremainingquantity of emulsionare addedand mixed.Toomuchmixing shall beavoidedasit will resultin decoaiingof aggregates.

509.2.4.6. Spreading ofmix: Thepremixedcaiionic bitumen emul.sion and aggregatesshall bespreadwithin 10 minutesof applying thetack coat. The mix is easilyworkablefor about20 minutesaftermixingandhenceall levelling, raking,etc., shouldbe completedwithin this timefor easy workability.

The mix should be spreaduniformly to the desired thickness,grades and crossfall (camber) making due allowance for extra quantityrequired to fill up depressions,if any. The crossfall should bechecked by means of camberboards andinequalitiesevened out. Toomuch use of blades orrakes should beavoided.

509.2.4,7.Rolling: The rolling shall start immediately after layingthe premix. Smoothwheeledtandemroller of 80.100kN shall be usedpreferably, though threewheeledsteel roller of equivalentcapacitycan also be used.While rolling, wheelsof roller should beclean andkeptmoist to preventthe premix from adheringto the wheelsandbeingpicked up. In no caseshall fuel/lubricating oilbe usedfor this purpose.Excessiveuse of water for this purposeshall also be avoided.

Rolling shall commenceat the edgesandprogress towards thecentre longitudinallyexceptin caseof superelevated anduni-directionalcamberedsectionswhererolling shall be done fromlower edgetowardsthe higher edge parallel to the centreline of the road.

After one passof roller over the whole area, depressionsoruncoveredspotsshouldbe correctedby addingpremix material.Rollingshall becontinueduntil theentire surfacehasbeenrolled to compactionandall theroller marks eliminated.In eachpass of the roller, precedingtrack shallbe overlappeduniformly by at least 1/3 width, Roller(s) shallnot stand on newly laid material while there is a risk that it will bedeformedthereby.At joints, the edges along thetransverseof the carpetlaid and compactedearlier shall be cut to their full depth so asto expose freshsurface which shall bepainted with a thin surfacecoat of binder before the new mix is placed againstit.

509.2.4.8.Seal coat: A sealcoat, liquid or premix type, shall beapplied 4 to 6 hours after laying the premix carpet.

183


Liquid seal coat: Quantities of the materials required are givenin Tables500-17 and 500-18.

For application of binder Clause 508.2.3.4 (A) shall apply.

Immediately after sprayingemulsion,stonechips in a clean stateshall be spreaduniformly, preferablyby meansof a mechanicalgritter,otherwise manuallysoasto cover the surface completely.Startrollingwith 60-80 kN roller soon after spreading the chips. The rollingoperationshall be as indicated in 509.2.4.7as far as applicable.

Premix seal coat: The quantitiesof aggregateand binder to beusedshall be as given in Tables500-17 and 500-18.Grit or sand usedfor premix seal coat shouldbe madethoroughly wet with wat~rbeforemixing with emulsion of slow setting grade.

The mixing, spreadingand rolling etc. shall be carriedout as perClauses509.2.4.5 to 509.2.4.7except for the quantities and materialswhich shall be for premix sealcoat. Rolling shall be continuedtill thepremi~material completely seals the voids in the premix carpetandsmooth uniform surfaceis obtained.

509.2.5. Opening to traffic : Traffic should not be allowed overthe premix surface with or without seal coat, for 6 to 8 hours afterrolling. In caseof single lane roads,traffic may be allowed at slowspeednot exceeding10 km per hour. If any premix material getspickedtip by vehicle tyres, the spot shall be filled up by new mix. It ispreferableto open the road to traffic the next day after 24 hours.

509.2.6.Surface finish and quality control : The surface finishof constructionshall conform to the requirementsof Clause902.

The control on thequality of materialsand worksshall be exercisedby the Engineerin accordancewith Section 900,

509.2.7. Arrangementsfor traffic : During the period of construc-tion, arrangementof traffic shall be done to Clause 112.

509.2.8. Measurementsfor payment: The premix carpetand sealcoat shall be measuredas finished work in squaremetres.

509.2.9. Rates : The contract unit rate for premix carpetarid sealcoat shall be paymentin full for carryingout the required operationsincluding full compensationfor all componentslisted in Clause 504.8(i) to (vi).

184


510. MIX SEAL SURFACING

510,1. Scope

510.1.1.Thiswork shall consistof laying andcompacting mix sealsurfacing in a single coursecomposedof suitableaggregates premixedwith abituminousbinder on a previously preparedbase, in accordancewith the requirementsof theseSpecifications,to serve as a wearingcourse.

510.1.2.Mix sealsurfacingshallbe of Type A or TypeB asspecified.

510.2. Materials

510.2.1. Binder: Clause509.1.2.1 shall apply.

510.2.2. Coarse aggregates:Clause509.1.2.2shall apply.

510.2.3.Fine aggregates:The fine aggregatesshallconsistof crusherrun screening,natural gravel/sandor a mixture of both. These shallbe clean, hard, durable, uncoated,dry and free from injurious, softor flaky pieces and organic or deleterioussubstances.

510,2.4.Aggregatesgradation:Thecoarseandfine aggregatesshallbeso gradedor combinedas to conform to the gradingset forth in Table500-19.

TABLE 500.19. AGGREGATES GRADATION FOR MIX SEAL SURFACINGIS SieveDesignation

Per centby weightpasslngthesteve

For Type A MtxSeal Surfacing

For Type B MixSeal Surfacing

13.2 mm — 100

11.2 mm 100 88.100

5.6 mm 52-88 31-52

2.8 mm 14-38 5-25

90 micron 0.5 0.5

510.2.5. Proportioning of materials : The total quantity ofaggregatesused for Type A or B mix sealsurfacingshall be 0.27 cubicmetre per 10 square metres area. The quantity of binder used forpremixing in terms of straight-runbitumenshall be 22.0kg and 19.0kg per 10 square metres area for Type A and Type B surfacingrespectively.


Clause509.1.3.1 through 509.1.3.5 shall apply.

185



Traffic may beallowed aftercompletionof the final rolling whenthe mix has cooled down to the surroundingtemperature.


The surfacefinish of constructionshallconform to therequirementsof Clause 902.

Control on the quality of materialsandworks shall be exercisedbythe Engineer in accordance with Section 900.


During the period of construction,arrangementof traffic shall bedone to Clause 112.


Mix seal surfacing, Type A or 13 shall be measured as finishedwork in square metres.

510.8. Rate

The contractunit rate for mix seal surfacing, Type A or B shallbe paymentin full for carrying out the requiredoperations includingfull compensation for all componentslisted in Clause504.8 (i) to (vi),

511. SEMI-DENSE BITUMINOUS CONCRETE

511.1. Scope

This work shaltconsist of construction in a single course of semi-dense bituminous concrete binder/wearing course on a previouslypreparedbituminous base to the requirements of the Specifications.

511.2. Materials

511.2.1. Binder: Clause 504.2.1 shalt apply

511,2.2.Coarseaggregates:Clause504.2.2shall apply. The StonePolishing Value as measuredby BS 812 (Part—114) shall not beless than 55. The aggregatesshall satisfy the physical requirementsas given in Table 500-3exceptthat the maximum value of waterabsorption shall be I per cent. However, water absorption upto amaximum of 2 per cent may be permitted in exceptionalcasesonly.

511.2.3. Fine aggregates:Clause507.2.3 shalt apply

511.2.4. Filler: Clause507.2.4 shall apply.

511.2.5. Aggregates gradation: The mineral aggregatesincluding

186


filler shall be so gradedor combined as to conform to the grading setforth in Table 500-20.TABLE 500.20. AGGREGATES GRADATION FOR SEMI-i)ENSE B11’UMINOUS

CONCRETEIS SieveDesignation

Per cent by weight passing the IS sieve

Grading_1 Grading_2 Grading_3

22.4 mm .— 100 10013.2 mm 100 85-100 79-10011.2 mm 88-100 70-92 68-905,6 mm 42-64 42-64 33.552.8 mm 22-38 22-38 22-38

710 micron 11-24 11-24 6-22355 micron 7-18 7-18 4-14180 micron 5-13 5-13 2-990 micron 3-9 3-9 0-5

Note: Grading 1 shall be adopted for 25 mm compactedthickness and Grading 2/3 forhigher thicknesses.

511.3. Mix Design

511.3.1.Requirementsof mix: Semi-densebituminous concretemixshallhe properly designedso asto satisfy thecriteria laid down in Table500-21.

TABLE 500-21. REQUIREMENTS OF SEMI-DENSEBITUMINOUS CONCRETE MIX

1. Marshall Stability (ASTM Designation:D 1559) determinedon Marshall specimenscompactedwith 75 compactionblows on eachend

2. Marshall flow (mm)

3. Per cent air voids in mix 3-5

13.15(for 13.2 mm max size)

11-13(for 22.4 mm max size)

5. Per centagevoidt in mineralaggregatesfilled with bitumen (VFB) 65-75

6. Binder content,per cent by weight of mix

Notet : 1. Higher stability valuesconsistentwith otheras far as possible.

2. At bus stops,parkingareasand roundaboutsnear minimum flow value shouldbe adopted.

3. Attempt should be to have well gradedaggregatesand the per centvoids inthe mix closer t.o the lower limit.

4. Per cent air voids irs mineral aggregate(VMA) (Minimum)

820 kg (1800 lIss) Minimum

2-4

Not less than 4.0 per cent

requirementsshouldbe achieved

187


511.3.2. Binder content: The binder contentshall be so fixed asto achieve the requirements of the mix set forth in Table 500-2!. Marshall Method for arriving at the binder contentshall be adopted.

511.3.3. Job mix formula: Clause 507.3.3 shall apply.

511.3.4.Permissible variation from job mix formula: The Con-tractor shall have the responsibility‘of ensuring proper proportioningof materials in accordance with the approved job mix formulaandproducingauniform mix. Thepermissiblevariationsof the individualpercentagesof the various ingredientsin the ac.tual mix from the jobmix formula may be within the limits as specified in Table 500-22.Thesevariationsare intendedto apply to individual specimenstaken forquality control tests vide Section 900.

TA BLE 500-22. PERMISSIBLE VARIATIONS FROM JOB MiX FORMULAS,No. Description of ingredient PennSslble jariatlon by

weight ci total mix Inpercentage

I. Aggregate passing 13,2 mm sieve and larger sieves ±82. Aggregate passing 11.2 mm sieve and 5.6.mm sieve ±73. Aggregatepassing 2.8 nun sieve and 1.40 mm sieve ±64. Aggregatepassing710 micron sieve and 355 micron sieve ±55. Aggregate passing 180 micron sieve ±46. Aggregate passing90 micron sieve ±27. Bitumen ±0.38. Mixing Temperature ±10°C


511.4.1. Weather and seasonallimitations: Clause 504.3.1 shallapply.

511.4,2. Preparationof base : The baseon which semi-densebi-tuminousconcrete is to be laid.shall beprepared,shapedand conditionedto the specified lines, gradesandcross-sectionsin accordance withClause501 or as directedby the Engineer.

511.4.3. Tack coat : A tackcoat asper Clause503 shallbe appliedon the base.

511.4.4. Preparation of mix: Clause507.4.4 shall apply.511.4.5. Spreading of mix: Clause 507.4.5 shall apply.511.4.6. Itolling: Clause 507.4,6 shall apply.511.5. opening to TrafficTraffic may beallowedafter completionof the final rolling when

the mix has cooled down to the surrounding temperature.

188



The surfacefinish of constructionshall conformto therequirementsof Clause 902.

Control on the quality of materialsandworks shall be exercisedbythe Engineerin accordancewith Section 900.




Semi-dense bituminous concrete shall be measured as finishedwork in cubic metres or tonnesas directedby the Engineer.

511.9. Rate

The contractunit rate for semi-densebituminousconcrete shall bepaymentin full for carrying out the requiredoperationsincluding fullcompensation for aH componentslisted in Clause504.8 (i) to (vi).The rate shall cover the provisionof bitumen in the mix at 4.5 per centof the weight of the total mix, with the provision that the variationof quantity of bitumen will be assessedand the paymentadjustedasper the rate of bitumen coated.

512. BITUMINOUS CONCRETE

512.1. Scope

This work shall consistof constructingin asingle layer,bituminousconcrete (asptialtic concrete)of thickness25 - 100 mm on previouslyprepared bituminouscourseto therequirementsof theseSpecifications.

512,2. Materials

512.2.1. Bitumen: Clause507.2.1 shall apply.

512.2.2. Coarse aggregates: Clause 507.2.2 shall apply. TheStonepolishing Value as measuredby BS : 812 (Part 114) shall not~e les~thai 55. The aggregatesshall satisfy the physical requirementsas given i~ Table 50~-8except that the maximum value for thewater absorptionshould be I per cent

512.2.3. Fine aggregates: Clause 507.2.3 shall apply.

512.2.4. Filler : Clause507.2.4 shall apply.

512.2.5. Aggregatesgradation : The mineral aggregates, including

189


thineral filler shall be so gradedor combinedas to conform to thegrading set forth in Table 500-23.

TABLE 500-23. AGGREGATES GRADATiON FOR BITUMINOUS CONCRETE

15 SieveDesignation Per cent passing the sieve by weight

26.5 mm 10019 mm 90-1009.5 mm4.75 mm

56-8035-65

2.36 mm 23-49300 micron 5-1975 micron 2-8

512.3. Mix Design

512.3.1. Requirementof mix: Apart from conformity with thegrading andquality requirementsof in~1ividualingredients,the mix shallmeet the requirementsset forth in Table 500-24.

TABLE 500.24. REQUIREMENTS OF BITUMiNOUS CONCRETE MIXS,No. Description Requirements

L Marshall stability (ASTM Designation:D-1559) determinedon Marshall specimenscompactedby 75 compactionblowt on each end

820 kg (1800 Ib)Minimum

2. Marshall flow (mm) 2-4

3. Per cent air voids in mix ‘ 3-5

4. Per cent voids in mineral aggregate (VMA) Minimum 11-13 per cent5. Per cent voids in mineral aggregates

filled by bitumen (VFB) 65-75

6. Binder content,per cent by weight of total mix Minimum 4,5

7. Water Sensitivity (ASTM D1075) Loss ofstability on immersion in water at 60°C

Mm. 75 per centretainedstrength

8. Swell Test (Asphalt Instt, MS-2, No, 2) 1.5 per cent Max,

512.3.2. Binder content: The binder contentshall be so fixed asto achieve the requirementsof the mix set forth in Table 500-24.Marshall method for arriving at the binder content shall be adopted.

512.3.3.Job mix formula: Clause 507.3.3 shall apply except thatthe requirementof Bituminous Concretemix shall be as per Table 500-24.

512.3.4. Permissible variations from the job mix formula:The Contractorshall have the responsibilityof ensuringproper propor-tioning of materials in accordance with the approved job mix formulaand producinga uniform mix. The permissible variationsof individual

190


percentagesof various ingredientsin the actual mix from the job mixformula may be within the limits as specified in Table 5O0~l1. Thesevariationsare intendedto apply to individual specimenstakenfor qualitycontrol tests vide Section 900.


512.4.1. Weatherand seasonallimitations: Clause 504.3.1 shallapply.

512.4.2. Preparationof base: The base on which bituminousconcreteis to be laid shall be prepared,shapedand conditionedto thespecified levels, gradeandcrossfall (camber)in accordancewith Clause501 or as directed by the Engineer.

The surfaceshall be thoroughly swept clean free from dust andforeign matterusingmechanicalbroomanddustremovedby mechanicalmeans or blown off by compressedair. In portions where mechanicalmeanscannot reach, other approvedmethod shall be used.

512.4.3. Tack coat: A tack coat complying with Clause503 shallbe applied over the base.

512.4.4. Preparationof mix: Clause5074.4 shalt apply.512.4.5. Spreading:Clause507.4.5 shall apply.512,4.6. Rolling: Clause5074.6 shall apply.

512.5. Openingto TrafficTraffic may be allowed immediately after completion of the final

rolling when the mix has cooled down to the surroundingtemperature.

512.6. SurfaceFinish and Quality Control of WorkThe surface finish of construction shall conform to the

requirementsof Clause902.Control on the quality of materialsandworks shalt be exercisedby

the Engineer in accordancewith Section 900.

512,7. Arrangements for TrafficDuring the period of construction, arrangementof traffic shall be

done to Clause 112.

512.8. Measurements for PaymentBituminous concrete shall be measuredas finished work in cubic

metres or tonnes as provided in the Contract.

191

.__#--- .-. -. .- -

Section500 Baseand SurfaceCourses (Bituminous)

512.9. Rate

The contract unit rate for bituminousconcreteshall be paymentin full for carrying out the required operations including fullcompensation for all components listedin Clause504.8 (i) to (vi).The rate shall cover theprovision of bitumen in the mix at 5.0 percent of the weight of the total mix with the provision that variationof quantity of bitumen wilt be assessedand the paymentadjusted asper the rate of bitumen quoted.

513. SEAL COAT513.1. Scope513.1.1. This work shall consistof applicationof a seal coat for

sealing the voids in a bituminoussurface laid to the specifiedlevels,grade and cross fall (camber).

513.1.2. Sealcoat shall be of either of the two types as specifiedbelow:

(A) Liquid seal coatcomprising of an applicationof a layer ofbituminousbinder followed by a coverof stone chippings.

(B) Prernixedseal coatcomprising of a thin application of fine aggregatespremixed with bituminous binder.

513.2. Materials

513.2.1. Binder: Clause509.i.2.1 shalt apply.

The quantity of bitumenshall be9.8 kg and 6.8 kg per 10 squaremetres area for Type (A) and Type (B) seal coat respectively.

513.2.2. Stone chippings for type (A) seal coat : The stonechippingsshall consistof angular fragmentsof clean,hard, tough anddurable rock of uniform quality throughout. They should be free ofelongatedor flaky pieces, soft or disintegrated stone, organic orother deleterious matter. Stone chippings shalt be of 6.7 mm sizedefined as 100 per cent passing through 112 mm sieve andretained on 2.36 mm sieve. Thequantity used for ‘spreadingshallbe 0.09 cubic metre per 10 square metresarea. The chippingsshall satisfy the quality requirements speltout in Table 500-3except that the upperlimit for water absorptionvalue shall be 1 percent.

513.2.3. Aggregatesfor type (B) seal coat : The aggregatesshall be sandor grit and shall consist of clean, hard, durable,uncoated dry particles and shall be free from dust, soft or flaky/elongatedmaterial, organic matter or other deleterious substances.

192


The aggregate shall pass 2.36 mm sieve and be retained on 180micron sieve. The quantity usedfor preminingshall be 0.06 cubic metreper 10 squaremetre area.


513.3.1. Preparationof base: The seal coat shall be appliedimmediately after the laying of bituminouscoursewhich is requiredtobe sealed. Before application of seal coat materials, the surfaceshall be cleanedfree of any dust or other extraneousmatter.

513.3.2. Constructionof type (A) seal coat: The binder shall beheatedin boilers of suitable design, to the temperatureappropriatetothegrade of bitumenapprovedby the Engineer,andthe sealcoat appliedin accordancewith the constructionoperationsdescribed in Clauses508.1.3.3 through 508.1.3.5.

513.3.3.Constructionof type(B) sealcoat: Mixer of appropriatecapacity and type shall be used for preparationof mix material. Theplant shall have separatedryer arrangementfor heatingaggregateandpugmill for mixing aggregateand binder.

The binder shall be heatedin boilers of suitable design, to thetemperature appropriate to the gradeof bitumen approved by theEngineer. Also the aggregatesshall be dry and suitably heated to atemperaturedirectedby the Engineerbefore the sameareplaced in themixer. Mixing of binder with aggregatesto the specified proportionsshall be continued till the latter are thoroughly coated with theformer.

The mix shall be immediately transportedfrom the mixing plantto the point of use and spreaduniformly on the bituminous surface tobe sealed.

As soon as sufficient length has been covered with the premixedmaterial, the surfaceshall be rolled with 80-100 kN smooth-wheeledroller. Rolling shall be continued till thepremixedmaterialcompletelyseals the voids in the bituminouscourseand a smoothuniform surfaceis obtained.


In the caseof type (B) seal coat, traffic may be allowed soonafter final rolling when the premixed material hascooled down to thesurroundingtemperature.However,asregards type (A) sealcoat, Clause508.1.4 shall apply.

193




Control on the quality of materialsandworks shall be exercisedbythe Engineerin accordancewith Section 900.




Seal coat, Type (A) or (B) shall be measuredas finished work insquaremetres.

513.8. Rate

The contract unit rate for seal coat, Type (A) or (B) shall bepayment in full for carrying out the required operations includingfull compensation for all componentslisted in Clause504.8(i) to (vi).

514. SUPPLY OF MINERAL AGGREGATES FORPAVEMENT COURSES

514.!. Scope

These Specificationsshall apply to works where it is intendedonly to collect, transport and stack the mineral aggregates andmineral filler for use in pavementcourses.The actual work of layingthe coursesshall, however,be governedby the Specificationsfor thesame, given elsewherein theseSpecifications.The size and quantitiesof the aggregatesto be supplied shall be so selectedby the Engineerthat the grading requirementsset forth in these Specifications for thecoursesfor which the supply is intendedare satisfied.

All the materialsshall be procuredfrom approvedsourcesand shallconform to the physical requirements,specified in the respectiveSpecifications for the individual items given elsewhere in theseSpecifications.

514.2. Sizes of Mineral Aggregates

The mineral aggregatesshall be designatedby their standardsizesin theContractandshall conform to the requirementsset forth in Table500-25.

194

BaseandSurfaceCourses(Bituminous) Section 500

TABLE 500-25. SIZE REQUIREMENTS FOR MINERAL AGGREGATES

CoarseAggregate

S.No. Standard sizeof aggregates

Designationof sievethroughwhich theaggregatesshall

wholly pass

Designation ofsieve on whichthe aggregatesshall wholly be

retained

(i) 75 mm 106 mm 63 mm

(ii) 63mm 90mm 53mm

(iii) 45 mm 53 mm 26.5 mm

(iv) 26.5 mm 45 mm 22.4 mm

(v) 22.4 mm 26.5 mm 13.2 mm

(Vi) 13.2 mm 22.4 mm 11.2 mm

(vii) 11.2 mm 13.2 mm 6.7 mm

(viii) 6.7 mm 11.2 mm 2.8 mm

514.3. Stacking

1. CoarseAggregates

Only the aggregatessatisfyingthe Specification requirementsshallbe conveyed to the roadsideand stacked.Each size of aggregateshallbe stackedseparately.Likewise, materialsobtainedfrom differentquarrysourcesshall be stackedseparately.

2. Fine Aggregates: As given in relevantSpecifications.

The aggregatesshall be stackedentirely clear of the roadway oneven ground,or platform preparedin advancefor the purpose by theContractorat his own costand in a mannerthat permits of correct andready measurement.Materials shall not be stackedin locations liableto inundation or floods.

The dimensionsof the stacksandtheir location shall beasapprovedby theEngineer.Where thematerialis improperly stacked,theEngineershall have the right to order completere-stackingof the materials tospecificationsat the cost of the Contractor.-

Mineral filler shall be suppliedin dry statein bagsor othersuitablecontainersapproved by the Engineerand shall be protected fromweather dampness, etc., so as to prevent deterioration in quality.

514.4. Quality Conlrol of Materials

The Engineer shall exercisecontrol over the quality of the materials

195


so as to ascertaintheir conformity with the Specification requirements,by carrying out testsfor the specifiedproperties.

Testing shallbe to the following frequenciesandthe Engineershallhave the right to modify these according to the needs.

Coarseand fine One test for eachspecified property per 50 m3 of material.

aggregates

Mineral filler : One test for each specifiedproperty for every five tonnes,subjectto a minimum of one test for eachconsignman.

Materialsnot conforming to the Specificationrequirementsshall notbe brought to the work site.

514.5. Measurementsfor PaymentCoarseand fine aggregatessuppliedat site of works shall be paid

for in cubic metres.The actual volume of the aggregates to be paidfor shall be computedafter deductingthe specified percentagesfromthe volume computedby stack measurementsin Table 500-26.

TABLE 500.26. PER CENT REDUCTION IN VOLUME OF AGGREGATES

S.No. Standard sizeof aggregates

Percentagercomputedby

to arrive at the

eductionstack mvolume

In volumeeamrensentsto be paid for

1. 75 mm and 63 mm 123

2. 45 mm and 26.5 mm 10.0

3. 22.4 mm, 13.2 mm, 11.2 mm and 6.7 mm 5.0

4. Fine aggregate 5.0

Unlessotherwisedirected,measurementsshall not be takenuntil suf-ficient materials for useon the roadhave been collected andstacked.Immediatelyafter measurement,the stacksshall be marked by whitewash or other means as directed by the Engineer.

Mineral filler as deliveredat site of works shall be measuredintonnes.

514.6. RatesThe contract unit rates for different sizes of coarseaggregates,fine

aggregatesand mineral filler shall be paymentin full for collecting,conveying and stacking or storing• at site of works including fullcompensationfor

(i) all royalties, fees, rents where necessary;

(ii) all leads and lips; and

(iii) all labour, tooIs..equipi~ents and incidentals to complete the work to the Speci.fications.

196


515. BITUMEN MASTIC

515.1. Scope

515.1.1. This work shall consist of constructinga single layer of25 mm to 50 mm thick Bitumen Mastic wearing course for roadpavementsand bridge decks. The bitumen mastic shall be laid overa DenseBituminous Macadambase in case of road pavements andover a CementConcrete base in bridge decks.

515.1.2. The BitumenMastic is an intimate homogeneousmixtureof selectedwell-graded aggregatesandbitumen in such proportionsasto yield a plastic and voidless mass,which when applied hot canbe trowelled and floated to form a very dense impermeablesurfacing

515.2. Materials

515.2.1. Bitumen: The binder shall be straight-run bitumen ofa suitable grade satisfyingtherequirementsof IS:73 or industrial bitumenasper IS:702. It shallbe pavingbitumenof GradeS 35 (30/40penetrationgrade)or any otherappropriategradeas directed by theEngineer. Therequirementsof physical propertiesof bitumen are as given in Table500-27.TABLE 500.27. REQUIREMENTS OF PHYSICAL PROPERTIES OF BITUMEN

S.No. Characteristic Requirement Method of tests

1. Penetration at 25°C (in 1/100 cm) 20 to 40 IS; 1203

2. Softening point (Ring and Ball Method) 50°Cto 90°C IS; 1205

3. Ductility at 27°C(Minimum) 10 cm 15: 1208

4. Loss on heating(Maximum) 3 per cent IS: 1212

5. Solubility in CS2 (Minimum) 99 per cent IS; 1216

515.2.2.Coarse aggregates:The coarseaggregatesshall consistofhard, durable crushed stones, which shall be clean, strong, free ofdisintegratedpieces,organicand other deleteriousmatterandadherentcoatings.They shallbe hydrophobicandof low porosity andshall satisfythephysicalrequirementsgivenin Table 500-3 exceptthatthemaximumvalue of water absorptionshall be 1 per cent.

The percentage and grading of the coarse aggregatesto beincorporatedin the bitumenmastic dependingupon the thicknessof thefinished courseshall be as in Table 500-28.

197


TABLE 500.28. GRADING AND PERCENTAGE OF COARSE AGCREGATES

S.No. Type of work Thicknessof FinishedCourse(mm)

Percentageof CoarseAggregates

Grading ofAggregates

Coarse

Passingts. Sieve

Percen-tage

1. (a) 2.5-40 (a) 30-40Wearing course 19 mm 100for pavement 13.2 mm 88-96& bridge deck (b) 41.50 (b) 40-50 2.36 mm 0-5

515.2.3. Fine aggregates:The fine aggregatesshall be the fractionpassing2.36 mm andretainedon 75 micron sieveconsistingof crusherrun screening, natural sand or a mixture of both. These shall beclean, hard, durable,uncoated,dry and free from any injurious softor flaky piecesand organic or deleterious substances.

515.2.4. Filler: The filler shall be limestone powder passing75 micron sieve and shall have a calcium carbonatecontent of notless than 80 per cent by weight when determinedin accordancewithIS: 1195.

The grading of the fine aggregatesinclusive of filler shall be asgiven in Table 500-29.TABLE 500-29.GRADING OF FINE AGGREGATES (INCLUSIVE OF FILLER)

S.No. IS. SievePassing

IS. SeiveRetained

Percentageby Weight

1 2.36 mm 600 micron 0.25

2 600 micron 212 micron 5-35

3 212 micron 75 micron 10-20

4 75 micron

Bitumen Binder

— 30-50

14-17

515.3. Mix Design

515.3.1.Hardness number: The bitumen mastic shall have ahardnessnumberof 60 to 80 at 25°Cwithout coarseaggregatesand 10to 20 at 25°C after addingcoarse aggregates.The hardness numbershall be determinedin accordancewith the methodspecifiedin IS: 1195.

515.3.2. Binder content: The binder contentshall be so fixed asto achieve the requirementsof the mix set forth in Clause515.3.1. andshall be in the rangeof 14 to 17 per cent by weight of total mix asindicated in Table 500-29.

515.3.3. Job mix formula: The Contractor shall intimate the

198

Basear.u .~urfaceCourses(Bituminous) Section500

Engineerin writing at least 20 days before the start of the work, thejob mix formula proposedto be used by him for the work, indicatingthe sourceandlocationof all materials,proportionsof all materials suchas binder and aggregates,single definite percentagepassingeach sievefor the mixed aggregatesand resultsof the tests recommendedin various Tables and Clausesof this Specification.


515.4.1.Weather and seasonallimitations: Clause 504.3.1 shallapply.

515.4.2.Preparationof thebase:Thebaseon whichbitumenmasticis to be laid shall be prepared,shapedandconditionedto the specifiedlevels, gradeand crossfall (camber) in accordancewith Clause501 oras directedby the Engineer. In caseof a cementconcrete base, thesurface shall be thoroughly sweptand scrapedclean and free of dustand otherdeleteriousmatter. Under no circumstances shall bitumenmastic be spreadon a basecontaininga binder which will soften underhigh application temperatures.if any such spots or area are there,the sameshall be cut out and repairedbefore the bitumen mastic islaid.

515.4.3.Tackcoat : A tack coat as perClause503 shall be appliedon the base or as directed by— the Engineer:

515.4.4. Preparationof bitumen mastic : Preparationof bitumenmastic consistsof two stages.The first stageshall be mixing of fillerand fine aggregatesand then heating the mixture to a temperatureof170°Cto 200°C~Requiredquantity of bitumenshall be heatedto 170°Cto 180°C andaddedto the heatedaggregate.They shall be mixed andcookedin an approvedtype of mechanicallyagitatedmasticcookerforsome time till the materialsare thoroughly mixed. Initially the filleraloneis to be heatedin the cookerfor an hour andthenh~iJfthequantityof binder is added.After heatingand mixing for some time, the tineaggregatesand the balanceof binder are to be addedand furthercookedfor about one hour. The secondstage is incorporation of coarseaggregatesand cooking themixture for a total period of 3 hours.Duringcooking and mixing, care shall be taken to ensure that the contentsin the cooker are at no time heated to a temperatureexceeding200°C.

In casewhere the materialis not requiredfor immediateuse it shallbe cast into blocks with filler, fine aggregates and binder, weighingabout 25 kg each.Theseblocks when requiredto be used, have to

199

Section500 Baseand Surface Courses(B iturninous)

be reheated in the mechanically agitatedcooker to a temperatureof not less than170°Candnot more than200°C,thoroughlyincorporatedwith the requisite quantityof coarse aggregatesand mixedcontinuouslyfor not less than an hour. Mixing shall becontinueduntil layingoperationsare completedso asto maintain the coarse aggregates insuspension.At no stageduringtheprocessof mixing shall the temperatureexceed 200°C.

The bitumen mastic blocks (without coarseaggregates)shall showon analysis a composition within the limits as given in Table 500-30.

TABLE 500.30. COMPOSITION OF BITUMEN MASTIC -BLOCKS WITHOUTCOARSE AGGREGATES

I.SSievePassing

IS. SieveRetained

Percentageby weight.

Minimum Maximum

236 mm 600 micron 0 22600 micron 212 micron 4 30212 micron 75 micron 8 18

75 micron — 25 45

Bitumen Content 14 17

The mix shall be transportedto the laying site in a towed mixertransporter having arrangementfor stirring and keepingthe mix hotduring transportation.

515.4.5.Spreading:The bitumen masticshall bedepositeddirectlyon the prepared baseimmediately in front of the spreaderwhere itis spreaduniformly by meansof woodenfloats to the required thickness.The mix shall be laid in onemetre widthcOntainedbetweenangle ironof sizes suitable to retain the requiredthickness.The temperatureof themix at the time of laying shall be around170°C.In case blowing takesplace while laying the bitumen mastic,the bubbles shall be puncturedwhile it is hot and the surface treatedwell.

5 15.4.6. Joints: It shall beensured thatall constructionjoints areproperly and truly made. Thesejoints shall be madeby warmingexisting bitumen mastic by the applicationof excessquantity of thebitumen mastic mix which afterwardsshall be trimmed off to makeit flush with the surfaceson either side.

515.4.7. Surfacefinish: Thebitumen masticsurfacecan be slipperyafter floating; in order to provide resistanceto skidding, thebitumenmastic after spreading,while still hot, and in plastic condition shallbe coveredwith a layer of stone aggregates of9.5 mm size (passing

200


13.2 mm sieve and retained on6.7 mm sieve). Hard stone chipsofapproved qualityprecoatedwith bitumenat the rate of two per centof S-65 to S-90 penetrationgradesat 25°Cat the rateof 0.005 cu.m.per 10 sq.m. shall be rolled or otherwisepressedinto the surfaceof themastic layer when the temperatureof bitumen mastic is between80°Cand 100°C.


The traffic may be allowedafter completionof the work when thebitumen mastic has cooleddown to the surrounding temperature.

515.6 Quality Control of Work

The type and gradeof bitumen; the quality, gradeand percentageof coarseand fine aggregatesand tiller; the temperaturecontrol forheating the materials/mix, laying, floating and compacting, hardnessnumber of the bitumenmastic, etc.,should be strictly followed asindicated inthe various Clausesof this Specificationor as directed bythe Engineer.

The quality control tests for coarse andfine aggregatesshall beexercisedby the Engineerin accordancewith Section 900. For mineralfiller, onetest for eachpropertyfor every5 tonnes, subjectto aminimumof one testfor each consignmentshall be carriedout.

The surface of the bitumenmastic tested with a straight edge3.0 m long,placedparallel to the centreline of the carriagewayshallhaveno depressiongreaterthan 4 mm. The samelimit shall alsoapplyin case of transverse profilewhen tested with a cambertemplate.




Bitumen mastic shall be measuredas finished work in squaremetres or by weight in metric tonnesas provided in the Contract.

515.9. Rate

The contract unit rate for bitumen mastic shall he payment infull for carryingout the requiredoperationsincluding full compensationfor all componentslisted under Clause504.8 (i) to (vi).

201


516. SLURRY SEAL

516.1. Scope -

This work shall consistof mixing emulsified bitumen,well-gradedfine aggregates(with mineral filler) and water, spreading the mixtureand rolling on a pavementsurfacing as a surfacetreatment. -

516.2. Materials

The materials for slurry seal immediately prior to mixing shallconform to the following requirements:

516.2.1. Emulsified bitumen : The emulsified bitumen shallbe a Cationic rapid settingtype asapprovedby the Engineer,conformingto the requirementsas per IS: 8887. It shall be capableof producinga slurry as would developearly resistanceto traffic and rain and issufficiently stable to permit mixing with the specified aggregates,without breakingduring the mixing and laying processes.If approvedby the Engineer,a slow setting emulsion may be used.

516.2.2.Water: Watershall be of suchquality that the bitumen willnot separatefrom the emulsionbefore the slurry seal is in placeof work.

516.2.3. Aggregates: The aggregates shall be crushed igneousrock, limestoneor slagand may be blended, if required, with clean, sharp,naturally occurring sand free from silt, clay or other tine material toproduceagradingas given in Table 500-31.It shall meettherequirementsof the film stripping test (-IS: 6241) and suitable amount and type ofanti-stripping agent added, as may be i~eeded.

TABLE 500-31.AGGREGATES GRADING FOR SLURRY SEAL

Sievesize Percentage by masspassing

Finished thickness of sealing3mm 1.5mm

4.75 mm 100 —

3.35 mm 80-100 100

2.36 mm 75-100 95-100

1.18 mm 55-90 70-95

600 micron 35-70 55-75

300 micron 20-45 30-50

150 micron 10-25 10-30

75 micron 5-15 5-15

202

Base andSurface Courses(Bituminous) Section500

516.3. Proportioning

The mixed materialshallconsistof aggregates,waterandemulsified!bitumen (about 180-250litres per tonne of dry aggregates)and wherenecessary,Portlandcementasan additive. Theproportion of the additive(portland cement)shall not normally exceed2 per cent by weight ofdry aggregates.The preciseproportion of each constituentshould beselectedby laboratory testsand trials.

516.4. Mixing

The various constituentsshallbe weighedin the neededproportionsand mixed in amechanicalmixer so that all particlesof the aggregatesare uniformly coated and the slurry is of such consistencyas canbe satisfactorily laid. It shall be a semi-fluid, homogeneousmass withno emulsion run-off.

516.5. Site Preparation

The pavementsurfaceshall be suitably preparedby removing anyloose material, dust andvegetationafterpatchingup any potholes,de-pressionsetc. All manholecovers,inspectioncoversand gully gratingsshould be masked.

516.6. Laying

If required,a tack coat shall be applied. The rate of spreadof tackcoat shall dependon the surfaceto be treated: for bituminoussurfaces,at the rate of 0.15 to 0.30 litreWsq.m. and for concretesurfacesatthe rate of 0.4 to 0.6 litres/sq.m. Spreadingshall be carried out bymechanicalmeans.Spreadingshall not be undertakenwhen the groundtemperaturefalls below4°Cor wher thesurfacecontainsstanding water.The slurry shall be spreadat a rate such that the cover of aggregates(dry mass equivalent) is 4-6 kg! sq.m. for 3 mm thick work and 2-4 kg/sq.m. for 1.5 mm thick work.

The slurry shall be rolled by a pneumatictyred roller having an in-dividual wheel load between 7.5 and 15.0 kN making at least sixpasses or as may be directedby the Engineer.Rolling shall commenceas soon as the slurry has set sufficiently to ensurethat rutting orexcessive movementwill not occur. Adequatestepsshall be taken toavoid damage by traffic until such time that the mixture has curedsufficiently so that the slurry seal will not adhereto and be pickedup by the tyres of vehicles.

203



The surface finish of constructionshall conform to therequirementsof Clause902. Control on the quality of materials andworks shall beexercised by the Engineerin accordance with Section 900.


Slurry seal shall bemeasuredas finished work in squaremetres.

516.9. Rate

The contract unit rate for slurry seal shall be paymentin full forcarryingout the requiredoperationsincluding full compensationfor allcomponents listedin Clause 504.8 (1) to (vi).

517. RECYCLING OF BITUMINOUS PAVEMENT

517.1. Scope

This Specificationcoversthe recyclingof existing bituminouspave-ment materials towardsupgrading an old bituminous pavementwhichhas served its first-intended purpose.The work shall be performed onsuch widths and lengthsas may be directedby the Engineer and mayconsist of pavement removal,stockpiling of materialsfrom the oldpavement, addition of new bitumenand untreatedaggregatesin therequisiteproportions, mixing,spreading andcompaction of the blendedmaterials.

517.2. Materials

517.2.1.Materials forrecycledpavement:The recycled materialsshall be a blendof reclaimedandnew materialsproportionedto achievea paving mixture with specifiedengineeringproperties.The reclaimedmaterials shall betestedand evaluatedto find the optimum blendmeeting the mix requirements.Suchtesting andevaluation shall becarriedout on representativesamplesobtainedby the randomsamplingtechnique.

517.2.2.Extraction: ASTM DesignationD-2172 shall be adoptedto quantitatively separateaggregatesandbitumenfrom any representativesample of reclaimedbitumen pavement.

517.2.3. Aggregates evaluation : Mechanical sieve analysis(IS: 2386, Part 1) shall be performedon the aggregatesportionof thereclaimedbituminous pavement sample to determine the gradation.Any deficiencies shall be made up by suitably blending the neededsieve fractions of new and/or reclaimed aggregates withreclaimed

204


bituminouspavementaggregates.

517.2.4. Evaluation of bitumen: Basedon the relative weightsof extracted aggregates and bitumen in the reclaimed bituminouspavement,the bitumencontentshall bedeterminedat 60°Cto estimatethe required amountand grade of bitumen to be usedin the recycledmix design.

517.2.5.New bitumen: In order to increasethe bitumencontent tomeetthe recycled mix designrequirementsand also to blend with theagedbitumen in thereclaimedportionof themixture to yield a bitumencontent meetingthe design specifications,new low-viscosity bitumenshall be added.

The new bitumen used for this purposeare penetration grades80/100, 120/150 or 200/300 i.e. viscosity gradesAC-JO, AC-5, AC-2.5 (AR-4000, AR-2000, AR-bOO), as approved by the Engineer.

517.2.6. Recycling agents: These are organic materials withchemicaland physical characteristicsselectedto restore aged asphaltto desired specification of viscosity of combined aged asphalt andrecycling agent.

517.2.7.Untreatedaggregates:If necessary,fresh untreatedaggre-gates shall be added to the reclaimedbitumen pavementto produce amix with the desiredgradation.Reclaimedaggregatesmaterials, if any,or any aggregatesnormally used for the desiredbituminousmix or bothmay be used for this purpose.

517.2.8. Combinedaggregates:The blend of reclaimedand newaggregatesshall meetspecifiedgradationcriteria asapprovedby the En-gineer. The blend of aggregatesshall be checked for qualityrequirements,including resistanceto stripping as per Table 500-3.

517.3. Mix Design

The gradation requirementand bitumen,content in the final mixshall conform to Clause504, 507 or 512, dependingupon whether thefinal desiredbituminousmaterial is bituminousmacadam,densebitumi-nousmacadamor bituminousconcreterespectively.The mix designshallbe done as per the Marshall method,the requirements conforming tothe values as set out in the above Clauses.

517.4. Reclaiming Old Pavement Materials

The removal of pavementmaterials to the required depth shall be

205


accomplished either at ambienttemperature(cold process)or at anelevated temperature(hot process),as approvedby the Engineer.

517.4.1. Cold processof removal: In the cold process,the rippingand crushing operations shall be carried out using scarifiers, gridrollers, or rippers or by any other means as directed by the Engineer.The removedmaterialsshall be loadedand hauled for crushing to thesize as directed by theEngineer.Alternatively, cold milling or planingmachinescan be usedto reclaim asphaltpavementto controlleddepths.After the asphalt treated layers areremoved,any remaining aggregatematerialsthat are to be incorporatedin the recycled hot mix shall bescarifiedand removed.When thepavementmaterial removal is com-pleted, any drainagedeficienciesshall be corrected. Afterthat, thebase/sub-baseas the casemay be shall becut, graded andcompactedto proper grade, cross-section andprofile.

517.4.2. Hot processof removal: In this process,the road surfaceshall be heated, usuallyby LPG orany othersuitablemeans asapprovedby the Engineer,before scarification. A travelling plant shall be usedand a milling drum that follows the planer, removes the heated softbituminous layer.The depth,width andspeed of travel shall be adjustedto suit specific ~requirementsas directed by the Engineer.

517.4.3. Stockpiling: In the cold process,the reclaimed asphaltpavement material shall be stockpiled with the height of stockpilesnot exceeding 3 m. The reclaimeduntreated aggregatesbase/sub-basematerial shall be stockpiledin the samemanneras newaggregates.Thenumber and location of stockpilesshall be carefully planned forefficient operationof the hot-mix plant.

517.5. Mixing and Laying

517.5.!. Preparation of in ix: The mixing of recycled aggregates,~~ewaggregates and bitumen shall be donein a hot mix plant ofsuitable capacity whichshall be either batch type or drum-mix type,capable of meeting the overall Specification requirements understringent quality control.

The Plant shall have the featuresas given in Clause504.3.4.

The temperature of binder at the time of mixing shall be150-163°Candthat of aggregatein the rangeof 155-163°C. Providedalso thatat no time shall the difference in temperature betweentheaggregatesand binder exceed14 °C. The temperature of both theaggregatesandthe bitumenat the time of mixing shall be in accordance

206


with the job mix formula and strictly controlled. All overheatedandcarbonizedmixture, shall be rejected.

.Mixing shall be thoroughto ensurethat a homogeneousmixture isobtainedin which all particlesof the mineral aggregatesarecoateduni-formly.

Any tipper causingexcessivesegregationof materialsby its springsuspensionor other contributingfactorsor that showing unduedelaysshall be removedfrom the work until such conditions arecorrected.

517.5.2.Spreading:The mix transportedfrom the hot mix plant tothe site shall be spreadby means ofa self-propelled mechanical paverwith suitablescreeds capableof spreading,tampingandfinishing the mixto specifiedgrade, lines andcross—section.Paver Finishershall havetheessentialfeaturesas spelt out in Clause504.3.5.However,in restrictedlocations andin narrow width where the availableequipment cannotbeoperatedin the opinion of theEngineer, he may permit manual layingof the mix.

Mixes with a temperatureof less than 120 °Cshall not be put intopaver spreader.

Longitudinal jointsandedgesshall beconstructedtrue to the centreline of the road. Longitudinaland transversejoints shall beoffset byat least 250 mm from those in the lower courses and the joints onthe top most layer shall not be allowed to fall within the wheelpath.

All transversejoints shall becut vertically to the full thicknessof thepreviouslylaid mix with pneumaticcutter and thesurface paintedwith hot bitumen before placing fresh material.Longitudinal jointsshall bepreferably hotjoints. Cold longitudinal jointsshall beproperlyheatedwith joint heaterto attain a suitabletemperatureof about 80 °Cbefore laying of any adjacent material.

517.5.3. Compaction: Clause507.4.6 shall apply.

517.5.4. Opening totraffic: Traffic maybeallowedafter completionof the final rolling when the mix has cooleddown to the surroundingtemperature.


The surface finish of construction shall conform to the requirementsof Clause 902.

Control on the quality of materials and works shall be exercisedbythe Engineerin accordancewith Section 900.

207

BaseandSurfaceCourses(Bituminous)Section500

517.7. Arrangement for Traffic

During theperiod of construction,arrangementfor the traffic shallbe done to Clause 112.


The recycled pavementwork shall be measuredin cubic metres ortonnesof finished work as provided by the Contract.

517.9. Rate

The contract unit rate for recycledpavementshall be paymentinfull for carrying out therequiredoperationsincluding full compensationfor

(I) Making arrangementsfor traffic to Clause I 12,.

(ii) Providing all materials to be incorporatedin the work, including all royalties.fees, rents wherenecessaryand all leadsand hiss;

(iii) All labour, tools, equipment,plant and incidentals to complete the workto the Specification;

(iv) Cariying out the work in part width of the road where directed~and

(v) Carrying our tests to control the quality of the ‘work.

208

ConcretePavement

600

ConcretePavement

ConcretePavement Section600

601. DRY LEAN CEMENT CONCRETE

SUB-BASE

601.1. Scope

601.1.1. The work shall consistof constructionof dry lean ‘concretesubbasefor cementconcretepavement in accordancewith the require-mentsof theseSpecificationsandin conformitywith the lines,gradesandcross-sectionsshownon thedrawingsor as directedby theEngineer. Thework shall include furnishing of all plantandequipment,materials andlabour and performing all operations,in connectionwith the work, asapprovedby the Engineer.

601.1.2, The designparametersof dry lean concretesub-base,viz,,width, thickness,gradeof concrete,detailsof joints, if any, etc. shall beas stipulatedin the Contractdrawings.

601.2. Materials

601.2.1. Source of Materials:The Contractorshall indicate to theEngineer thesourceof all materialswith relevanttest data to be usedin the lean concretework sufficiently in advance and the approvalof the Engineerfor the sameshall be obtainedat least 45 days beforethe scheduledcommencementof the work. If the Contractorlater pro-poses to obtain the materialsfrom a different source, he shall notifythe Engineerfor hisapprovalat least45 days before suchmaterialsareto be used.

601.2.2.Cement: Any of the following typesof cementmay be usedwith prior approvalof the Engineer:

(i) OrdinaryPortlandCement IS 269(ii) PortlandSlag Cement IS : 455(iii) PortlandPo~zolanaCement IS 1489

If the subgradeis found to consist of.soluble suiphates in aconcentration more than 0.5 per cent, cementused shall be sulphateresistantand shall conform to IS: 6909.

Cement tobe usedmaypreferablybe obtainedin bulk form. It shallbe storedin accordancewith stipulationscontained in Clause1014 andshall be subjectedto acceptancetest prior to its immediateuse.

601.2.~.Aggregates:

601.2.3.1.Aggregatesfor leanconcreteshallbenatural materialcom-plying with IS: 383.Theaggregatesshall not be alkali reactive.~Thélimits

211

Section600~ ConcretePavement

of deleteriousmaterialsshall not exceedthe requirementsset out in IS:383. In casetheEngineerconsidersthattheaggregatesare not free fromdirt, the samemay be washedand drained for at least72 hours beforebatching, as directedby the~Engineer.

601.2.3.2.Coarseaggregate:Coarseaggregateshall consistof clean,hard, strong, dense,non-porous and durable piecesof crushed stoneorcrushed gravel andshall be devoid of piecesof disintegrated stone, soft,flaky, elongated,very angularor splinterypieces. The maximum size ofthe coarseaggregateshall be 25 mm. The coarseaggregateshallcomplywith Clause602.2.4.2.

601.2.3.3.Fine aggregate:The fine aggregateshall consistof clean,natural sand or crushedstonesandor a combinationof the two andshallconform to IS: 383.Fine aggregateshill befree from softparticles, clay,shale,loam,cementedparticles,mica, organic andother foreign matter,The fine aggregateshall comply with Clause602.2.4,3.

601.2.3.4.The coarseand fine aggregatesmay be obtainedin eitherof the following manner:

(i) In separate nominal sizes of coarse and fine aggregatesand mixed Logetherintimately beforeuse,

(ii) Separatelyas25 rem nominal single size,12.5 mm nominal sizegradedaggregatesand fine aggregateof crushed stonedust or sand or a combinationof thesetwo.

The material afterblendingshall conform to thegrading as indicatedin Table 600-I.

TABLE 600.1. AGGREGATE GRADATION FOR DRY LEAN CONCRETE

SieveDesignation Percentagepasssieve by welghh

Ing the~

26.50 mm 10019.00 mm 80-1009.50 mm 55.754.75 mm 35-60

600.00 micron 104575.00 micron 0-8

601.2.4.Water: Waterused for mixing andcuring of concreteshallbe clean and free from injurious amountsof oil, salt, acid, vegetablematteror other substancesharmful to the finished concrete.It shall meetthe requirements stipulatedin IS : 456.

601.2.5. Storage of materials: All materials shall be stored inaccordancewith theprovisionsof Clause1014 of these Specificationsand

‘1,,


other relevant IS Specifications.All efforts must be made to store thematerials in properplacesso as to prevent their deterioration or contami-nation by foreign matter and to ensure their satisfactory quality andfitnessfor use in the work. The storage place must also permit easyinspection,removal and stor~t~of materials. All suchmaterialseventhoughstoredin approvedgodo’~.ns must besubjectedto acceptancetestimmediatelyprior to their use.Therequirementof storageyard specifiedin Clause602.2.9shall alsobe applicable.

601.3. Proportioning of Materials for the Mix

601.3.1.The mix shall beproportionedwith a maximum aggregatecement ratio of 15 : 1. The w~aercontent shall be adjusted to theoptimumasperClause601.3.2for facilitatingcompactionby rolling. Thestrength and density requirementsof concrete shall be determinedinaccordancewith Clause601.6by making trial mixes,

601.3.2. Moisture content:Theright amountof water for the leanconcretein themain work shall bedecidedsoas to ensurefull compactionunderrolling andshall beassessedatthe time of rolling the trial length.Too muchwater will causethe leanconcr~t~iobe heavingup beforethewheelsandpickedup on thewheelsof the roller and too little willleadto inadequatecompaction,alow rn-situ strengthandan open-texturedsurface.

The optimum watercontentshall be determinedand demonstratedby rolling during trial length constructionand the optimum moisturecontent and degree of compactionshall be got approved from theEngineer.While laying in themain work, the lean concreteshall haveamoisturecontentbetweentheoptimumandoptimum+2 percent, keepingin view theeffectivenessof compactionachievedandto compensateforevaporationlosses.

6~I1.3.3.Cement content: The minimum cement content in thelean concrete shall not be lessthan 150kg/cu.ni. of concrete. If thi’~minimum cementcontent is not sufficient to produceconcreteof thtspecified strength, it shallbe increasedas necessarywithout additionalcostcompensationto the Contractor.

601,3.4. Concretestrength:The averagecompressivestrengthofeach consecutivegroup of 5 cubes made in accordance with Clause903.5.1.1 shall not be less than 10 MPa at 7 days. In addition, theminimum compressivestrengthof any individual cubeshall not be lessthan7.5 MPa at7 days.Thedesignmix complyingwith theaboveClauses

213

Section600 ConcretePavement

shall begot approvedfrom the Engineerand demonstratedin the triallengthconstruction.

601.4.Subgrade

The subgradeshallconform to thegrades andcross sectionsshownon the drawingsandshall beuniformly compactedto the designstrengthin accordancewith theseSpecifications and Specificationstipulated inthe Contract.The lean concretesubbaseshall not belaid on a subgradesoftenedby rain after its final preparation;surfacetrenchesand softspots, if any, must beproperly back-filled andcompactedto avoid anyweak or soft spot. As far as possible,the constructiontraffic shall beavoidedon the preparedsubgrade.A day beforeplacingof the sub-base,the subgrade surface shall begiven afine spray of waterandrolledwithoneor two passes ofa smoothwheeledroller after alapseof 2-3 hoursin order to stabilise loosesurface. If Engineer feelsit necessary,anotherfine spray of water may be appliedjust before placing sub-base.

6013. Construction

601.5.1.General:The paceandprogrammeof the leanconcretesub-baseconstruction shall be matching suitably with the programmeofconsi~ructionof the cementconcrete pavementOver it. The sub-baseshall be overlaidwith cementconcrete pavementonly after 7 days aftersub-baseconstruction.

601.5.2. Batchingandmixing: The batchingplant shall be capableof proportioning the materialsby weight,each type of material beingweighed separatelyin accordancewith Clause602.9.3.2. The cementfrom the bulk stockshall beweighedseparatelyfrom the aggregates.Thecapacityof batchingandmixing plantshall be atleast 25 percent higherthan the proposedcapacityfor the laying arrangements.The batchingand mixing shall be carriedout preferably in a forced action centralbatchingandmixing planthaving necessaryautomatic controlsto ensureaccurateproportioningand mixing. Othertypes of mixersshall be per-mitted subject to demonstrationof their satisfactoryperformance duringthe trial length.The type and capacity of theplant shallbegot approvedby theEngineerbeforecommencementof the trial length. The weighingbalancesshall becalibrated by weighing the aggregates,cement,waterand admixturesphysically either by weighing with large weighing ma-chine or in a weigh bridge. The accuracy of weighing scalesof thebatchingplant shall be within ±2 per cent in the caseof aggregatesand ±1per cent in the case of cement and water.

214


The design featuresof Batching Plant should be such that theshifting operations of theplant will not takevery long time whentheyare to be shifted from place to placewith the progress of the work.

601.5.3. Transporting:Plantmix leanconcreteshall be dischargedimmediatelyfrom the mixer, transporteddirectly to the point whereit isto be laid and protectedfrom the weather by covering the tippers!dumpers with tarpaulinduring transit. Theconcreteshall be transportedby tipping trucks,sufficient in number to ensure a continuoussupplyof material to feedthe layingequipmentto work ata uniform speedandin anuninterruptedmanner. The lead of thebatching plant to pavingsite shall besuch that the travel time availablefrom mixing to pavingas specifiedin Clause601.5.5.2 will be adheredto.

601.5.4. Placing:Leanconcreteshallbe laid/placedby apaver withelectronicsensor.The equipmentshallbe capableof laying the materialin one layer in an even manner without segregation,so that aftercompactionthe total thicknessis asspecified. Thepaving machine shallhavehigh amplitudetampingbarsto give good initial compactionto thesub-base.

The laying of the two-laneroad subbasemay be done either in fullwidth or laneby lane. Preferablythe lean cdncrete shall beplaced andcompacted across the full width of the road, by constructing itin one go or in two lanes running forward simultaneously.Transverseand longitudinal constructionjoints shall be staggered by500-1000mm and 200-400mm respectively from the correspondingjoints in the overlaying concreteslabs.

601.5.5. Compaction601.5.5.1. Thecompactionshall becarriedout immediatelyafter the

material is laid and levelled. In order to ensurethorough compactionwhich is essential,rolling shall be continuedon thefull width till thereis no further visible movementunder the roller and the surfaceis closed.The minimumdry densityobtainedshallbe 97 percent of that achievedduring the trial length construction vide Clause601.7. The densitiesachievedatthe edgesi.e 0.5 m from theedgeshall not beless than 95percentof that achievedduring the trial construction videClause601.7.

601.5.5.2. The spreading,compacting and finishing of the leanconcrete shall be carried outas rapidly as possible and theoperationshall be so arrangedas to ensure that the time betweenthe mixingof the first batchof concretein any transversesection of the layer and

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Section 600 ConcretePavement

the final finishing of the sameshall not exceed90 minutes when theconcrete temperatureis above25 and below 30 degree Celsiusand120 minutesif lessthan 25 degreeCelsius. Thisperiod maybe reviewedby the Engineerin the light of theresults of the trial run but in no caseshall it exceed2 hours. Work shall not proceed When the temperatureof the concreteexceeds30 degreeCelsius. If necessary,chilled wateror addition of ice may beresortedto for bringingdown thetemperature.It is desirableto stop concretingwhenthe ambient temperatureis above35°C.After compactionhasbeencompleted,roller shall not standon thecompacted surfacefor the durationof the curing period except duringcommencementof next day’s worknearthe location where work wasterminatedthe previousday.

601.5.5.3. Double drum smooth-wheeledvibratory rollers of mini-mum 80 to 100 kN static weightareconsideredto be suitablefor rollingdry leanconcrete.In caseany otherroller is proposed,the sameshall begot approvedfrom theEngineer, afterdemonstratingits performance,The numberof passesrequired to obtain maximum compactiondependson the thickness‘of the lean concrete,the compactibilityof the mix, andthe weight andtypeof theroller etc., andthe sameas well as the totalrequirementof rollers for thejob shall be determined during trial runby measuring the in-situ density and the scale of the work to beundertaken.

601.5.5.4.In addition to thenumberof passesrequiredfor compactionthereshall beapreliminary passwithout vibration to bed thelean concretedown and again a final passwithout vibration to removeroller marksand to smoothenthe surface.

Specialcareandattentionshall beexercised duringcompactionnearjoints, kerbs, channels,side forms and around gulliesandmanholes.In caseadequatecompactionis not achievedby the roller at these points,use of plate vibrator shall be made,if so directed by the Engineer.

601.5.5.5.The final lean concretesurfaceon completionof compac-tion and immediately beforeoverlaying,shallbe well closed, free frommovement under roller and free from ridg~s,low spots, cracks,loosematerial, pot holes, ruts or other defects. Thefinal surfaceshall beinspectedimmediately on completionand all loose,segregatedor defec-tive areas shall becorrectedby using fresh lean concretemateriallaid and compacted asper Specification. Forrepairinghoneycombedsurface, concrete with aggregatesof size 10 mm and below shall bespread andcompacted.It is necessaryto check thelevel of the rolled

216


surface for compliance.Any level/thicknessdeficiency should be cor-rectedafter applying concretewith aggregatesof size 10 mm and belowafter rougheningthesurface. Similarly the surfaceregularityalso shouldbe checked with 3m straight edge. The deficiency shouldbe madeup with concretewith aggregatesof size 10 mm andbelow.

601.5.5.6. Segregationof concretein thedumpersshall be controlledby premixing eachfraction of the aggregatesbeforeloading in the bin ofthe batching plant, by moving the dumperback and forth whiledischargingthe mix on it andother means.Even pavingoperationshallbe such that the mix does not segregate.

601,5.6.Joints: Contractionand longitudinal joints shallbe providedas per the drawing.

At longitudinalor transverseconstructionjoints, unlessvertical formsare used,the edgeof compactedmaterial shall be cut back to a verticalfacewherethe correctthicknessof the properly compactedmaterialhasbeenobtained.

601.5.7. Curing: As soonas thelean concretesurface is compacted,curing shall commence.One of the following two methods shall beadopted:

(a) The initial curing shaHbedoneby spraying with liquid curing compound. Thecuring compoundshall bewhite pigmentedor transparenttypewith water retentionindea of 90 per cent when testedin accordancewith BS 7542. Curing compoundshall be sprayedimmediately after rolling is complete. As soon as the curingcompoundhas loss its tackiness,the surfaceshall becoveredwith wethessianforthreedays.

(b) Curing shall be done by coveringthe surface by gunny bagslhessian,whichshall be keptcontinuouslymoist for 7 days by sprinkling waler.

601.6. Trial MixesThe Contractorshall make trial mixes of dry lean concrete with

moisturecontentslike 5.0, 5.5, 6.0, 6.5 and7.0percent using cementcontentspecifiedand the specified aggregate grading but withoutviolating therequirementof aggregate-cementratio specifiedin Clause601.3.1. Optimum moistureanddensityshallbe establishedby preparingcubeswith varying moisturecontents.Compactionof the mix shall bedone in three layers with vibratory hammer fitted with a square orrectangularfoot as describedin Clause 903.5.1.1.After establishingtheoptimummoisture,aset of six cubesshall be castatthat moisturefor thedeterminationof compressivestrength on the 3rd and the seventhday.Trial mixes shall be repeatedif the strengthis not satisfactoryeitherby

217


increasingcement contentor using higher grade of cement. After themix designis approved, the Contractorshall constructatrial Section inaccordancewith Clause601.7.

If during the constructionof the trial length, the optimummoisturecontentdeterminedas aboveis foundto be unsatisfactory,the Contrac-tor may make suitablechangesin the moisture content to achieve asatisfactory mix, The cubespecimensprepared withthe changed mois-ture contentshouldsatisfy the strength requirement.Before productionof the mix, natural moisture content of the aggregate shouldbedeterminedon aclay-to-daybasis so that the moisture contentcould beadjusted.The mix finally designedshould neither stickto the rollersnorbecometoo dry resulting in ravelling of surface.

601.7. Trial Length

601.7.1. The trial lengthshall be constructedat least 14 days inadvance ofthe proposeddate ofcommencementof work. At least30 daysprior to the constructionof the trial length, the Contractor shall submitfor theEngineer’sapprovala“Method Statement”giving detaileddescrip-tion of the proposedmaterials, plar~t,equipment, mix proportion, andprocedurefor batching,mixing, laying, compactionandother construc-tion procedures.The Engineershall also approve the location andlength of trial constructionwhich shall be aminimumof 60 m lengthandfor full width of the pavement.The trial lengthshallcontainthe construc-tion of at least one transverseconstruction joint involving hardenedconcreteand freshlylaid sub-base.The construction oftrial length willbe repeatedtill the Contractorproveshisability to satisfactorily constructthe subbase.

601.7.2. In order to determineanddemonstratethe optimum mois-ture content which results in the maximum dry density of the mixcompactedby the rolling equipmentandtheminimum cementcontentthat is necessaryto achievethe strengthstipulatedin the drawing, trialmixes shall bepreparedas per Clause601.6.

60 1.7.3. After the constructionof thetrial length,the in-situ densityof the freshly laid material shall be determinedby sandreplacementmethodwith 20 cm diadensitycone.Three density holesshall be madeatlocationsequallyspacedalong a diagonalthat bisectsthe trial length;average of these densitiesshall be determined.Thesemain densityholes shall not be madein the strip 50 cm irom the edges.The averagedensity obtainedfrom the threesamplescollected shall be thereferencedensity and is consideredas 100 per cent. The field densityof regular

218

Concrete Pavement Section600

work will be comparedwith this referencedensity in accordancewithClauses601.5.5.1 and 903.5.1.2. A few coresmay be cut as per theinstructionsof theEngineerto checksegregationor any other deficiency.

601.7.4. The hardenedconcrete shall be cut over 3 m width andreversedto inspectthebottom surfacefor any segregationtakingplace.The trial length shallbe constructedafter making necessarychanges inthe gradationof the mix to eliminatesegregationof the mix, The lowersurfaceshall not havehoney-combingandtheaggregatesshall not be heldloosely at the edges.

601.7.5. The trial lengthshall be outsidethe main works. The mainwork shall not start until the trial length has been approvedby theEngineer.After approvalhasbeengiven, the materials, mix proportions,moisture content, mixing, laying, compaction plant and constructionproceduresshall not be changedwithout the approval of the Engineer.

601.8. Tolerancesfor Surface Regularity, Level, Thickness,Density and Strength

The tolerancesfor surface regularity, level, thickness,density andstrengthshall conform to therequirementsgiven in Clause903.5.Controlof quality of materialsandworks shall be exercisedby the Engineerinaccordancewith Section900.

601.9. Traffic

No heavycommercialvehicleslike trucksandbusesshall be permit-ted on the leanconcretesub-baseafter its construction.Light vehicles ifunavoidablemay, however,be allowed after 7 days of its constructionwith prior approvalof the Engineer.

601.10. Measurement~for Payment

The unit of measurementfor dry leanconcretepavementshall bethecubic metre of concreteplaced,basedon the net plan areas for thespecified thickness shown on the drawings or as directed by theEngineer.

601,11. Rate

The Contractunit ratepayablefor dry lean concrete sub-baseshallbe paymentin full for carryingout the required operationsincludingfull compensationforall labour, materialsand equipment,mixing, trans-port, placing, compacting, finishing, curing, testing and incidentals tocompletethe work as per Specifications,all royalties, fees, storageandrents wherenecessaryand all leadsand lifts.

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602. CEMENT CONCRETE PAVEMENT

602.1.Scope

602.1.1.The work shall Consistof constructionof unreinforced,doweljointed, plain cement concrete pavement in accordancewith therequirementsof these Specificationsand in conformity with the lines,grades and cross sectionsshown on the drawings. The work shallinclude furnishing of all plant andequipment,materials and labour andperformingall operationsin connectionwith the work, asapprovedby theEngineer.

602.1.2. The designparameters,viz., thicknessof pavementslab,grade of concrete,joint detailsetc.shall beas stipulatedin the drawings.

602.2. Materials

602.2.1. Source of materials: The Contractor shall indicate to theEngineer the sourceof all materialsto be usedin theconcretework withrelevanttest data sufficiently in advance,andthe approvalof the Engi-neerfor thesameshall be obtainedat least45 daysbefore the scheduledcommencementof thework. If the Contractor later proposesto obtainmaterialsfrom a different source,he shall notify the Engineerfor hisapproval,at least 45 days belore such materials are to be used withrelevant test data.

602.2.2. Cement: Any of the following typesof cement capableof achieving the designstrengthmay be usedwith prior approvalof theEngineer,but the preferenceshould be to use at least the 43 Gradeorhigher.

(i) Ordinary Portland Cement,33 Grade, IS 269.

(ii) Ordinary Portland Cement,43 Grade IS 8112.

(iii) Ordinary Portland Cement, 53 Grade, IS 12269.

If the soil aroundhassolublesaltslike sulphatesin excessof 0.5 percent, the cementusedshall be sulphateresistant and shall conform to IS:12330.

Guidance may be taken from IS: SP: 23, Handbook for ConcreteMixes for ascertainingthe minimum 7 days strengthof cementrequiredto match with the designconcretestrength.Cement to be used maypreferably be obtained in bulk form. If cementin paper bags areproposed to be used, there shall be bag-splitters with the facility toseparatepiecesof paperbagsand disposethem of suitably. No paperpieces shall enter the concretemix. Bulk cementshall be stored in

220

Concrete Pavement Section600

accordancewith Clause 1014. The cementshall be subjectedtoacceptancetest just prior to its use.

602.23. Admixtures : Admixturesconforming to !S:6925 and IS:9103 shall be permitted to improve workability of the concrete orextensionof settingtime, on satisfactoryevidencethat they will not haveany adverseeffecton the propertiesof concretewith respectto strength,volume change,durabilityandhaveno deleteriouseffect on steelbars.The particularsof theadmixtureand the quantity to be used,must befurnishedto theEngineerin advanceto obtain his approvalbefore use.Satisfactory performanceof the admixtures should be provedboth onthe laboratory concretetrial mixes and in trial paving works. If airentrainingadmixtureis used,the total quantity of air in air-entrainedconcreteas a percentageof the volume of the mix shall be 5 ±1.5 percent for 25 mm nominal size aggregate.

602.2.4.Aggregates

602.2.4.1.Aggregatesfor pavementconcreteshallbe natural materialcomplying with IS : 383 but with a Los Angeles Abrasion Test resultnot more than 35 per cent. The limits of deleterious materials shall notexceedthe requirementsset out in IS : 383.

The aggregatesshall be free from chert,flint, chalcedony or othersilica in a form thatcan reactwith thealkaliesin the cement.In addition,the total chloridescontentexpressedas chloride ion contentshall notexceed0.06 per centby weight andthe total sulphatecontent expressedas sulphuricanhydride(SO3)shall not exceed 0.25 percent by weight.

602.2.4.2. Coarse aggregate:Coarse aggregateshall consist ofclean, hard, strong, dense, non-porousand durablepiecesof crushedstone or crushed graveland shall be devoid of piecesof disintegratedstone,soft, flaky, elongated,very angularor splinterypieces.The maximumsize of coarseaggregateshall not exceed25 mm for pavementconcrete.Continuouslygradedor gapgradedaggregatesmay be used,dependingonthe grading of the fine aggregate.No aggregate which has waterabsorption more than 2 per cent shall be usedin the concrete mix.Theaggregatesshallbe testedfor soundnessin accordancewith IS: 2386(Part-5). After 5 cyclesof testingthe loss shall not be more than 12 percent if sodium sulphatesolution is usedor 18 per cent if magnesiumsulphatesolution is used.

Dumpingand stacking of aggregatesshall be done in an afiprovedmanner. In casetheEngineerconsidersthatthe aggregatesare not free

221


from dirt, the samemay be washedand drained for at least 72 hoursbeforebatchingas directedby the Engineer.

602.2.4.3. Fine aggregate:The fine aggregateshall consistof cleannatural sand or crushedstone sand or a combinationof the two andshall conform to IS : 383. Fine aggregateshall be free from softparticles, clay, shale, loam, cementedparticles, mica and organic andother foreign matter. The fine aggregateshall not contain deleterioussubstancesmorethan the following

Clay lumps 4.0 per centCoal and lignite 1.0 per centMaterial passingIS SieveNo. 75 micron 4.0 per cent

602.2.5.Water: Water used for mixing andcuring of concreteshallbe clean and free from injurious amount of oil, salt, acid, vegetablematteror othersubstancesharmful to the finishedconcrete.It shall meetthe requirementsstipulatedin IS: 456,

602.2.6. Mild steel bars for dowels and tie bars : These shallconform to the requirementsof IS : 432, IS : 1139 and IS : 1786 asrelevant. The dowel barsstiall conform to GradeS 240 and tie barstoGradeS 415 of l.S.

602.2.7. Premoulded joint filler: Joint tiller board for expansionjoints which areproposedfor useonly at some abutting structureslikebridges andculvertsshall be of 20-25mm thicknesswithin a toleranceof ± 1.5 mm and of a firm compressiblematerial andcomplyingwith the requirementsof IS:1838,or BS SpecificationClauseNo. 2630or Specificationfor Highway Works, Vol. I Clause1015. It shall be 25mm less in depththan the thicknessof the slabwithin a tolerance of ±3 mm and provided to the full width between the side forms. It shallke in suitable lengthswhich shall not be less thanone lanewidth. Holesto accommodatedowelbarsshall be accuratelyboredor punchedout togive a sliding fit on the dowelbars.

602.2.8. Joint sealingcompound:The joint sealingcompoundshallbeof hot poured, elastomerictypeor cold polysulphide type havingflexibility, resistanceto agehardening and durability. If the sealantisof hot pouredtypeit shallconform to AASHTO M282 andcoldappliedsealantshall be in accordancewith BS 5212 (Part 2).

602.2.9.Storageof materials:All materials shall be stored inaccordancewith the provisionsof Clause1014of the SpecificationsandotherrelevantIS Specifications.All efforts must be made to store thematerials in properplaces so as to prevent their deterioration or

222


contaminationby foreign matterandto ensure their satisfactory qualityandfitnessfor the work. The platform whereaggregatesarestockpiledshall be levelledwith 15 cm of watered, mixed andcompactedgranularsub-basematerial.The area shall haveslopeanddrain to drain off rainwater. The storagespacemust also permit easy inspection, removaland storageof the materials.Aggregatesof differentsizesshallbe storedin partitioned stack-yards.All such materials even though stored inapprovedgodowns mustbe subjectedto acceptancetest as per Clause903 of these Specificationsimmediately prior to their use.

602.3. Proportioning of Concrete

602.3.1.After approvalby the Engineerof all the materials to beusedin the concrete,the Contractorshall submitthe mix designbasedonweighed proportionsof all ingredientsfor the approval of theEngineer.The mix designshall be submittedat least 30 daysprior to the pavingof trial length and the design shall be basedon laboratory trial mixesusing the approvedmaterials and methods as per IS:10262(Recom-mended Guidelinesfor Mix Design)or on thebasisof any other rationalmethod agreedto by the Engineer.Guidancein this regard can alsobeobtainedfrom IS:SP:23 Handbookon ConcreteMixes. The targetmeanstrength for the designmix shall be determined as indicatedin Clause903.5.2. The mix design shall be based on the flexural strength ofconcrete.

602.3.2. Cement content:Thecementcontent shall not be lessthan 350 kg percu.m.ofconcrete.If thisminimum cementcontent is notsufficient to producein the field, concrete of the strength specifiedin the ddiwings/design, it shall be increased as necessarywithoutadditional compensationunder the Contract. The cementcontent shall,however,not exceed425 kg per cu.m.of concrete.

602.3.3.Concretestrength

602.3.3.1.While designingthe mix in the laboratory, correlationbetween flexural and compressivestrengthsof concreteshall be estab-lished on the basis of at least thirty testson samples.However,qualitycontrol in the field shall beexercisedon the basis of flexural strength.It may, however, be ensuredthat the materials and mix proportionsremain substantially unaltered during the daily concrete production.Thewater contentshall be the minimum requiredto provide the agreedworkability for full compactionof the concreteto the requireddensityasdeterminedby the trial mixesor othermeansapprovedby the Engineerand the maximum free watercementratio shall be 0.50.

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602.3.3.2. The ratio betweenthe 7 and28 day strengthsshall beestablished for themix to be usedin the slabin advance,by testing pairsof beamsandcubesat eachstageon at least six batches of trial mix.The averagestrengthof the 7 day curedspecimensshall bedivided bythe average strengthof the28 day specimensfor eachbatch, and theratio ‘R’ shall be determined.Theratio ~R’shall be expressedto threedecimal places.

If during the constructionof the trial length or during normalworking, theaveragevalueof any four consecutive7 day testresults fallsbelow the required 7 day strength asderived from thevalue of ‘R’,then thecement contentof the concreteshall, without extrapayment,beincreased by 5 per cent by weight or by an amount agreedby theEngineer.The increasedcement contentshall be maintainedat leastuntilthe four corresponding28 day strengthshave been assessedfor itsconformity with the requirementsas per Clause602.3.1.Wheneverthecement contentis increased,theconcretemix shallbe adjustedto maintainthe requiredworkability.

602.3.4.Workability

602.3.4.1. The workability of the concreteat the point of placingshall be adequatefor the concreteto be fully compactedand finishedwithout undueflow. The optimum workability for the mix to suit thepaving plant being used shall bedeterminedby the Contractor andapprovedby theEngineer.The control of workability in the field shallbe exercisedby the slumptest as per IS :1199.

602.3.4.2. The workability requirementatthe Batching Plant andpaving siteshall beestablishedby slumptestscarried duringtrial paving.Theserequirementsshall beestablishedfrom seasonto seasonand alsowhenthe lead from Batchingplant site to the paving sitechanges.Theworkability shall beestablished for thetype of pavingequipment avail-able. A slump value in the rangeof 30±15 mm is reasonablefor pavingworksbut thismay be modifieddependingupon the site requirementandgot approvedby theEngineer. These testsshall be carried outon everytruck/dumperat Plant site and paving siteinitially when the workcommencesbut subsequentlythe frequency canbe reducedto alternatetrucksor as per the instructions of the Engineer.

602.3.5.Design mix

602.3.5.1.The Contractorshall carryout laboratory trialsof designmixes with the materialsfrom the approvedsourcesto be used. Trial

224


mixes shall be madein presenceof theEngineeror his representativeandthe designmix shall be subject to the approval of the Engineer.Theyshall be repeatedif necessaryuntil theproportions that will produce aconcrete which complies in all respectswith thisSpecification,andconforms to the requirementof the design/drawingshavebeen deter-mined.

602.3.5.2. Theproportionsdeterminedasa resultof the laboratorytrial mixesmay be adjustedif necessaryduring the constructionof thetrial length. Thereafter,neitherthe materials nor the mix proportionsshall be varied in any way except with the written approvalof theEngineer.

602.3.5.3. Any changein the sourceof materialsor mix propó~tionsproposedby theContractorduringthecourseof work shall be assessedbymaking laboratory trial mixes and the constructionof a further triallength unlessapprovalisgiven by the Engineer for minor adjustmentslike compensationfor moisturecontent in aggregatesor minor fluctua-tions in the grading of aggregate.

602.4. Sub-base

The cement concretepavementshall be laid over the sub-baseconstructed in accordancewith the relevant drawings andSpeèifica-lions contained in Clause601. If the sub-base is found damagedatsomeplacesor it hascrackswider than 10 mm it shall be t~epairedwithfine cementconcreteor bituminous concrete before laying separationlayer Pnorto laying of concrete it shall be ensuredthattheseparationmembraneasperClause602.5 is placedin position andthe sameis cleanof dirt or other extraneousmaterialsandfree from any daniage.

602.5. SeparationMembrane

A separationmembraneshallbeusedbetweenthe concrete stabandthe subbaseSeparationmembraneshall beimpermábleplasticsheeting125 micronsthick laid flat withoutcreasesBefore placing theseparationmembrane,the sub-baseshall be swept clean Of ~ll the extti~neóusmaterials using air compressor.Whereveroverlapof plastic sheetsisnecessary,the sameshall beat least300 mm andan~damagedsheetingshall be replacedat the Contractor’sexpense. Theseparationmembranemay be nailed to the lower layer with concretenails.

602.6.Joints602 6 1 The location and typeof Jointsshall be as shown in the

drawing. Joints shall be constructeddependingupon thèfr ‘ Thnctlonàl

225


requirement as detailedin thefollowing paragraphs.The locationof thejoints should be transferred accuratelyat the site andmechanical sawcuttingof joints doneas per stipulated dimensions.It shouldbeensuredthat the full required depth of cut is made from edgeto edgeof thepavement.Transverseand longitudinal joints in the pavementand sub-base shallbe staggeredso that they are not coincidentvertically andareat least I m and 0.3 m apartrespectively.Sawing of joints shall becarried out with diamondstudded blades soon after the concretehashardenedto take the load of the sawing machineandpersonnelwithoutdamagingthe texture of the pavement. Sawingoperationcould startas early as 6-8 hours dependingupon the season.

602,6.2.Transverse joints

602.6.2.1.Transversejoints shall becontractionand expansionjointsconstructedat the spacingdescribed inthe Drawings. Transversejointsshall b~straightwithin thefollowing tólerailces along the intendedlineof joints which is thestraight line transverseto the longitudinal axis ofthe carriagewayat the positionproposedby the Contractorandagreedtoby the Engineer, exceptat road junctions or roundaboutswhere theposition shall beas describedin the drawings:

(i) Deviationsof the filler boardin the caseof expansionjointsfrom the intendedlineof the joint shall not be greater than±10mm.

(ii) The best fit straight line through the joint grooves asconstructedshall henot more than25 mm from the intended line of the 3oInL

(iii) Deviationsof the joint groove from the bestfit straight line of the joint shallnot begreaterthan 10 miii

(iv) Transv~rsejoints on eachtide of the longitudinal joint shall be in line with eachother and of thesametype and width, Transversejoints shall have a sealinggroove whichshall be sealedin compliance withClause 602.11.

602.6.2.2. Contractionjoints: Contraction joints shall consistofa mechanical sawn Joint groove 3 to 5 mm wide and 1/4 to 1/3 depthof the stab±5 mm or asstipulated in the drawings anddowel barscomplying with Clause60265 andas detailed in the drawings

The conti~action:~::jointsshall be cut as soon as the concrete hasundergoneinitial hardening andis hardenoughto take the load of jointsawing machinewithout causing damageto the slab.

602.6.2.3.E~ :i~iói~joints: The expansionjoints shall consistof ajoint filler boardcomplying withClause602.2.7 anddowelbarscomply-ir~gwith Cl~use,6O~$.5,;andasdetailedin the drawings.Thefiller boardsha~lbe positioi~edvcrtieally with theprefabricatedjoint assembliesalong

226


the line of thejoint within the tolerancesgiven in Clause602,6.2.l~andat such depth below the surfaceas will not impedethe passageof thefinishing straightedgesor oscillatingbeams of thepavingmachines.Theadjacentslabsshall becompletelyseparatedfrom eachotherby providingjoint filler board. Spacearound the dowel bars,betweenthe sub-baseand the filler boardshall bepackedwith asuitablecompressiblematerialto block the flow of cementslurry.

602.63. Transverse construction joint: Transverse constructionjointsshallbe placedwheneverconcretingis completedafteraday’sworkor is suspendedfor morethan 30 minutes.Thesejointsshall be providedat theregular location of contractionjoints usingdowel bars. The jointshallbe madebutt type. At all constructionjoints, steel bulk heads shallbe usedto retaintheconcrete while the surface is finished. The surfaceof the concrete laid subsequentlyshall conform to the gradeand crosssectionsof thepreviouslylaid pavement.When positioning of bulk heaWstop-endis notpossible,concreting to an additional 1 or 2 m lengthmaybe carriedout to enablethe movementof joint cutting machineso thatjoint groovesmay be formedand the extra 1 or 2 rn length is cut outand removed subsequentlyafter concretehas hardened.

602.6.4.Longitudinal joint

602.6.4.1.The longitudinal joints shall be saw cut as per details ofthejoints shown in the drawing.Thegroovemaybe cut after the final setof theconcrete.Jointsshouldbe sawnto at least1/3 the depthof theslab±5 mm as indicatedin the drawing.

602.6.4.2. Tie bars shall be providedat the longitudtnai joints asperdimensionsandspacingshownin the drawing andin accordancewithClause602.6.6.

602.6.5.Dowel bars

602.6.5.1. Dowel barsshall bemild steelroundsin accordancewithClause602.2.6 with details/dimensionsas indicated in the drawing andfree from oil, dirt, loose rust or scale.They shall be straight, free ofirregularitiesandburring restrictingslippagein the concrete.Theslidingendsshall be sawn or croppedcleanly with no protrusionsoutside thenormal diameter of the bar.The dowel bar shall be supported oncradles/dowelchairs in pie-fabricatedjoint assembliespositioned priorto theconstructionof the slabs or mechanicallyinserted with vibrationinto the plasticconcreteby a method which ensurescorrectplacementof the barsbesidesfull re-compactionof the concretearoundthe dowelbars.

227

Section600 Concrete Pavement

602.6.5.2. Unless shown otherwiseon the drawings,dowel barsshall,be positionedat mid depth of the slab within a toleranceof ±20mm, and centeredequally aboutintendedlinesof the joint within atolerance of ±25 mm. Tey shall be aligned parallel to the finishedsurface of the slabandto the centreline of the carriageway and to eachotherwithin tolerancesgiven hereunder,the compliance of which shallbe checkedas per Clause602.10.7.

(i) For bars supportedon cradlesprior to the laying of theslab:

(a) All bars in ajount shall be within ±3mm per 300mm length of bar

(b) 2/3rd of the bars shall bewithin ±2 mm per 300 mm length of bar

(c) No bar shall differ in alignmentfrom an adjoining bar by more than 3mm per 300 mm length of bar in either thehorizontalor verticalplane

(d) Cradles supportingdowelbar shall not extendacross theline of joint i.e. nosteelbar of the cradleassembly shaH be continuousacrossthe joint.

(ii) For all bars inseried after laying of the slab:

(a) Twice the tolerancefor alignment as indicated in (I) above

602.6.5.3. Dowel bars, supportedon cradles in assemblies,whensubject to aload of 110N appliedateitherendandin either theverticalor horizontal direction (upwardsand downwards and both directionshorizontally) shall conform to be within the following limits:

(i) Two-thirds of thenumberof barsof any assembly testedshall not deflectmorethan2 mm per 300 mm length of bar

(ii) The remainder of thebars in that assembly shall not deflectmore than 3 mmper 300 mm length of bar.

602.6.5.4. The assemblyof dowel bars and supporting cradles,including the joint filler board in thecase of expansion joints, shallhave the following degreeof rigidity when fixed in position:-

(i) For expansionjoints, the deflectionof the top edgeof the fillet boardshall be notgreaterthan13 mm, when a load of 1.3 kN is appliedperpendicularto the verticalfaceof the joint filler board and disuibutedover a length of 600mm by meansof a bar or timber packing, at mid depth andmidway betweanindividual fixings,or 300 mm from eitherend of any length of filler board, if a continuous fixingis used.The residual deflectionafter removal of the loadshall be not more than3 mm.

(ii) The joint assemblyfixings to sub-baseshall not fail underthe l.3kN loadappliedfor testingthe rigidity of the assemblybut shallfail’be~oretheload reaches2.6kN.

(iii) The fixings for contraction joint shall not fail under 1.3 kN load and shall failbefore the load readies2~6kN when appliedover a length of 600mm meansof a bar or limber packing placedas near to the level of the line of fixings aspracticable.

228


(iv) Fixings shall bedeemedto fail when thereis displacementof the assembliesbymorethan3 mm with any foms of fixing, under the test load.The displacementshall be measuredat the nearestpart of the assembly to the centre of the bar ortimber packing.

602.6.5.5.Dowel barsshall be coveredby a thin plasticsheathfor atleast two-thirdsof the lengthfrom oneend for dowel bars in contractionjoinLs or half the length plus 50 mm for expansionjoints. The sheathshall be tough,durableandof an average thicknessnot greaterthan 1.25mm. The sheathedbar shall comply with the following pull-out tests:

(i) Four bars shall be taken at random from stockand withoutany special preparationshall be covered by sheaths as required in this Clause. The ends of the dowelbars which have beensheathedshall be cast centrally into concrete specimens150 x 150 a 600 mm, madeof the samemix proportionsto be used in thepavement, but with a maximum nominal aggregate size of 20 mm andcured inaccordancewith IS: 516. At 7 days a tensile load shall be applied to achieve amovement of the barof at least 0,25 trim. The average bond stressto achievethis movement shall not be greaterthan 014 MPa.

602.6.5.6.For expansionjoints,a closely fitting cap 100 mm longconsistingof waterproofedcardboardor an approvedsyntheticmateriallike PVC or (31 pipe shall be placedover the sheathedend of eachdowel bar. An expansionspaceat leastequalin length to the thicknessof the joint filler board shall be formedbetweenthe endof the cap andthe end of the dowel barby using compressiblesponge. To block theentry of cementslurry betweendowel andcap it may be taped.

602.6.6.Tie bars

602.6.6.1. Tie barsin longitudinaljoints shall be deformed steelbarsof strength415 MPa complying with IS:1786and in accordancewiththe requirements given below. The bars shall be free from oil,dirt,looserust and scale.

602.6.6.2.Tie barsprojecting acrossthe longitudinal joint shall beprotected from corrosion for 75mm on each side of the joint by aprotectivecoatingof bituminouspaintwith the approval of theEngineer.The coating shall be dry when the tie bars are used.

602.6.6.3.Tie bars in longitudinal joints shall be madeup into rigidassemblieswith adequatesupports and fixings to remain firmly inposition during the constructionof the slab. Alternatively, tie bars atlongitudinal joints may be mechanicallyor manually inserted into theplastic concretefrom aboveby vibration using a method which ensurescorrectplacementof thebarsand recompactionof theconcretearoundthetie bars.

229

Section600 CemcretePavement

602.6.6.4. Tie barsshall be positionedto remainwithin the middlethird of the slab depth as indicatedin the drawingsand approximatelyparallel to the surfaceandapproximatelyperpendicularto the line of thejoint, with thecentreof eachbaron the intended line of thejoints withina toleranceof ±50mm,andwith a minimum coverof 30 mm below thejoint groove.

602.7. Weatherand SeasonalLimitations

602.7.1. Concreting during monsoonmonths: When concrete isbeingplaced during monsoonmonths and when it may be expectedto rain, sufficient supply of tarpaulin or other water proof cloth shall beprovidedalong the line of the work, Any time whenit rains, all freshlylaid concrete whichhad notbeencoveredfor curing purposesshall beadequatelyprotected.Any concretedamagedby rain snail beremovedandreplaced.If the damageis limited to texture,it shall be retexturedinaccordancewith the directivesof the Engineer.

602.7.2. Concreting in hot weather: No concretingshall bedonewhen the concretetemperatureis above30 degreeCentigrade. Besides,in adverse conditions like high temperature, low relative humidity,excessivewind velocity, imminenceof rains etc., if so desiredby theEngineer, tentson mobile trussesmay be providedover the freshly laidconcrete for aminimum periodof 3 hours as directed by theEngineer.The temperatureof the concretemix on reachingthe paving site shallnot be more than 30°C. To bring down thetemperature, if necessary,chilled wateror ice flakes should be made use of.

No concreting shall be done when the concrete temperature isbelow 5 degreeCentigradeand the temperatureis descending.

602.8. Side Forms, Rails and Guidewires

602.8.1. Side forms and rails: All sideforms shall beof mild steelof depthequalto thethicknessof pavementor slightly less toaccommo~date the surfaceregularityof the sub-base.The forms can be placed onseriesof steelpackingplatesor shimsto take care of irregularity of sub-base.They shall be sufficiently robust andrigid to support the weightand pressurecausedby a paving equipment. Sideforms for use withwheeledpavingmachines shallincorporate metalrails firmly fixed at aconstantheightbelow the top of the forms. The forms andrails shallbe firmly securedin position by not lessthan 3 stakes/pinsper each 3m length so asto preventmovementin any direction.Formsandrailsshallbe straightwithin a toleranceof 3 mm in 3 m andwhen in placeshall

230


not settle in excessof 1.5 mm in 3 m while paving is being done.Forms shall be cleanedand oiled immediately before each use. Theforms shall be beddedon a continuousbedof low moisturecontentleancementmortar or concreteandset to the line and levels shown on thedrawings within tolerances±~10 mm and ±3 mm respectively.Thebeddingshall not extendunder the slab andthere shall be no verticalstepbetweenadjacentforms of more than 3 mm. The forms shall begot inspectedfrom the Engineer for his approval before 12 hoursontheday beforetheconstructionof theslabandshall not be removeduntilat least 12 hours afterwards.

602.8.2. At all times sufficient forms shall be used andset to therequiredalignmentfor at least200 m lengthof pavement immediatelyinadvanceof the pavingoperations,or the anticipated length of pavementto be laid within the next 24 hrs whicheveris more.

602.83.Use of guidewires

602.8.3.1. Whereslip form pavingis proposed,aguidewire shall beprovided along both sides of the slab. Eachguidewireshall be at aconstantheightabove and parallelto the requirededges of the slab asdescribedin thecontract/drawingwithin a vertical toleranceof±3mm.Additionally, one of the wires shall be kept at a constanthorizontaldistancefrom the requirededgeof the pavementas indicated in thecontract/drawingwithin a lateral toleranceof ±10 mm.

602.8.3.2. Theguidewiresshallbe supportedon stakesnot more than8 m apart by connectorscapableof fine horizontal and verticaladjust..ment. The guidewireshall be tensionedon thestakesso that a 500gramweight shall produce a deflection of not more than 20 mm whensuspendedat the mid point betweenany pair of stakes.The ends of theguidewires shall be anchoredto fixing point or winch and not on thestakes.

602.8.3.3. The stakes shall be positioned and the connectorsmaintainedat their correctheightandalignmentfrom 12 hourson thedaybefore concreting takes place until 12 hours after finishing of theconcrete. The guidewire shall be erected and tensioned on theconnectorsat any section for at least 2 hours before concreting thatsection.

602.8.3.4. The Contractor shall submitto the Engineer for hisapprovalof line and level, the stakesand connectorswhich are readyforuse in the lengthof road to be constructedby 12 hours on the working

231


day before the dayof constructionof slab. Any deficiencies notedby theEngineershall berectifiedby theContractorwho shall then re-apply forapprovalof theaffectedstakes.Work shallnot proceeduntil theEngineerhasgiven hisapproval.It shall be ensuredthat the stakesand guidewiresare not affected bythe constructionequipmentwhen concretingis inprogress.

602.9. Construction

602.9.1. General:A systemsapproachmay be adoptedfor construc-tion of the pavement,and the Method Statementfor carrying out thework, detailing all the activities including indication of time-cycle,equipment, personnel etc., shall begot approved from the Engineerbefore the commencementof the work.The above shall include the type,capacityand make of the batchingand mixing plant besidesthe haulingarrangement and pavingequipment.Thecapacityof paving equipment,batching plant as well asall the ancillary equipmentshall beadequatefor a paving rate of atleast300 m in one day.

602.9.2.Batching andmixing: Batchingandmixing of the concreteshall be done at a centralbatchingand mixing plant with automaticcontrols, located at asuitable placewhich takesinto accountsufficientspace for stockpilingof cement, aggregatesand stationary water tanks.This shall be, however, situtated at an approved distance, dulyconsidering thepropertiesof themix and the transporting arrangementsavailablewith the Contractor.

602.9.3.Equipment for proportioning of materials and paving

602.9.3.1. Proportioningof materialsshall be donein the batchingplant by weight,each typeof material beingweighed separately. Thecement from the bulk stock may be weighed separately from theaggregatesand watershall be measuredby volume. Wherever properlygraded aggregateof uniform quality cannotbe maintainedas envisagedin the mix design,the grading of aggregatesshall be controlled byappropriate blending techniques.The capacityof batchingand mixingplant shall beat least 25 per cent higher than theproposedcapacityofthe laying/pavingequipment.’

602.9.3.2.Batching plantand equipment:

(1) General- The batchingplantshall include minimum four bins,weighinghoppers,andscalesfor the fine aggregate andfor eachsize of coarseaggregate.If cementis used in bulk, a separatescalefor cement shallbe included. The weighing hoppersshall

232

oncretePavement Section600

beproperly sealedand vented to precludedust during operation.Approvedsafety devicesshall be provided andmaintainedforthe protection of all personnel engaged in plant operation,inspectionandtesting. The batchplantshall be equippedwith asuitablenon-resettablebatchcounterwhich will correctly indi-cate the numberof batchesproportioned.

(2) Bins andhoppers-Bins with minimumnumberof four adequateseparatecompartmentsshall beprovided in the batchingplant.

(3) Automatic weighing devices-Batchingplant shall be equippedto proportionaggregatesandbulk cementby meansof automaticweighing devicesusingload cells.

(4) Mixers- Mixers shall bepantype,reversibletype or anyothermixer capableof combining the aggregates,cement,and waterinto a thoroughly mixed anduniform mass within the specificmixing period,andof dischargingthemixture, without segrega-tion. Eachstationarymixer shallbe equippedwith an approvedtiming devicewhich will automaticallylock the dischargeleverwhen the drum has been charged and releaseit at the endof the mixing period. Thedeviceshall be equippedwith abellor other suitable warning device adjusted to give a clearlyaudiblesignal eachtime the lock is released.In caseof failureof the timing device,the mixer may be used for the balance ofthe day while it is being repaired,providedthat each batch ismixed 90 secondsor asper the manufacturer’srecommendation.The mixer shall be equippedwith a suitablenon-resettablebatchcounter which shall correctly indicate the numberof batchesmixed.

The mixers shall be cleanedat suitable intervals. The pickupand throw-overbladesin the drum or drumsshall be repairedorreplacedwhen they areworn down 20 mm or more. The Con-tractor shall (1) haveavailableat thejob site a copy of themanufacturer’sdesign,showingdimensions andarrangementsofblades in referenceto original height anddepth, or (2) providepermanentmarkson bladeto show points of 20 mm wear fromnew conditions.Drilled holes of 5 mm diameter near each endand at midpoint of each blade are recommended. BatchingPlant shall be calibrated in the beginning and thereafter atsuitableinterval not exceedingI month.

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(5) Control cabin - An air-conditioned centralised control cabinshall be providedfor automatic operationof the equipment.

602.9.33.Paving equipment : The concrete shall be placed withan approvedfixed form or slip from paverwith independentunitsdesignedto (i) spread,(ii)consolidate,screedandfloat-finish, (iii) textureandcurethe freshlyplacedconcretein onecomplete passof themachine in sucha mannerthata minimum of hand finishing will be necessaryandso asto providea denseand homogeneouspavement in conformity with theplans and Specifications.Thepaver shall be equipped with electroniccontrols to control/sensorline and gradefrom either or both sidesof themachine,

Vibrators shall operateat a frequencyof 8300 to 9600 impulsesperminute under load at a maximum spacing of 60 cm. The variablevibration setting shall be provided in the machine.

602.9.3.4. Concretesaw : The Contractor shall provide adequatenumberof concretesawswith sufficient numberof diamond-edgesawblades. The saw machineshall be either electric or petrol/dieseldriventype. A watertank with flexible hosesandpump shall bemadeavailablein this activity on priority basis. The Contractorshall haveat leastonestandbysaw in good working condition. The concretingwork shall notcommenceif the saws are not in working condition.

602.9.4.Hauling and placing of concrete

602.9.4.1. Freshly mixed concrete from the central batching andmixing plant shall be transported to the paver site by meansoftrucks/tippersof sufficient capacity and approved design in sufficientnumbers to ensurea constantsupply of concrete. Coversshall be usedfor protectionof concreteagainst the weather. The trucks/tippersshallbe capableof maintaining the mixed concrete in a homogeneous stateanddischargingthe samewithout segregationandloss of cementslurry.Thefeedingto thepaveris to beregulated in such a way thatthe pavingis done in an uninterruptedmannerwith a uniform speedthroughoutthedays work.

602.9.4.2.Placing of concrete

Concrete mixed in centralmixing plant shall be transported to theSite withoutdelayandthe concretewhich, in theopinion of the Engineer,has been mixed too long before laying will be rejected and shall beremovedfrom thesite. The total time takenfrom theaddition of the waterto,the mix, until the completion of the surfacefinishing and texturing

23.4


shallnot exceed120 minutes whenconcrete temperatureis lessthan25°Cand90 minuteswhenthe concrete temperatureis between25°Cto 30°C.Truck~ltippersdelivering concreteshall not run on plastic sheetingnorshall they run on completedslabs until after 28 days of placing theconcrete.ThePavershall becapableof pavingthe carriagewayas shownin the drawings, in a single passand lift.

602.9.4.3. Wherefixed form payersare to be used,forms shall befixed in advanceasper Clause602.8.of the Specifications. Before anypaving is done, thesite shallbeshownto theEngineer,in orderto verifythe arrangementfor pavingbesidesplacingof dowels, tie-barsetc., asperthe relevantClausesof this Specification.The mixing and placing ofconcreteshall progressonly at sucharateas to permit properfinishing,protecting andcuring of the pavement.

602.9.4.4. En all cases,the temperatureof the concrete shall bemeasuredat the point of dischargefrom the deliveryvehicle.

602.9.4.5. The addition of water to thesurfaceof the concrete tofacilitate the finishing operationswill not be permitted except with theapproval of the Engineerwhenit shall be appliedas a mist by meansof approvedequipment.

602.9.4.6. If considerednecessaryby the Engineer, the pavingmachines shall beprovidedwith approvedcoversto protect thesurfaceofthe slabunder constructionfrom direct sunlight andrain or hot wind.

602.9.4.7.While the concreteis still plastic, its surface shall bebrushtexturedin compliancewith Clause602.9.8 and the surface and edgesof the slabcuredby the applicationof asprayedliquid curing membranein compliancewith Clause602.9.9.After the surfacetexturing,but beforethe curing compoundis applied, the concreteslabshall bemarkedwiththe chainageat every 100 m interval.

602.9.4.8. As soonas the side forms areremoved,edgesof the slabsshall be correctedwhereverirregularities have occurredby using fineconcrete composedof onepart of cementto 3 partsof fine chips andfine aggregateunder the supervisionof theEngineer.

602.9.4.9.If the requirementof Clause902.4. for surface regularityfails to be achievedon two consecutiveworking days, then normalworking shall ceaseuntil the causeof the excessive irregularityhasbeenidentified and remedied.

602.9.5, Construction by fixed form paver602.9.5.1. The fixed form paving train shall consist of separate

235


powered machineswhich spread,compactand finish the concrete in’ acontinuousoperation.

602.9.5.2.The concreteshall bedischargedwithout segregation intoa hopperspreader whichis equippedwith meansfor controlling its rateof deposition on to thesubbase.Thespreadershall be operatedto strikeoff concreteuptq a level requiring a small amountof cutting down bythe distributorof the spreader. Thedistributorof spreadershall strike offthe concreteto the surcharge adequateto ensurethat the vibratorycompactorthoroughly compactsthe layer. If necessary,poker vibratorsshall be usedadjacentto the side forms and edges of the previouslyconstructedslab. The vibratory compactorshall be set to strike off thesurfaceslightly high so that it is cut down to the required level by theoscillatingbeam.The machineshallbe capableof being rapidly adjustedfor changesin averageanddifferential surchargenecessitatedby changesin slab thicknessor crossfall, The final finisher shall be able to finishthe surfaceto the requiredlevel andsmoothnessasspecified,carebeingtaken to avoid bringingup of excessivemortar to the surfaceby over-working.

602.9.6.Construction by slip form paver

602.9.6.1. The slip form pavingtrain shall consistof power machinewhich spreads, compactsand finishes the concrete in a continuousoperation.The slip form paving machineshall compactthe concrete byinternal vibration and shape it between the side forms with either aconforming plate or by vibrating and oscillatingfinishing beams. Theconcreteshall bedepositedwithoutsegregationin front of slip form paveracrossthewholewidth andto aheightwhichat all timesis in excessofthe requiredsurcharge.The deposited concrete shall be struck off tothe necessaryaverageand differential surchargeby meansof the strikeoff plateor a screw augerdeviceextendingacrossthe whole width ofthe slab.The equipment for striking-olf the concreteshall becapableof being rapidly adjustedfar changes ofthe average and differentialsurchargenecessitatedb’ change in slab thicknessor crossfall.

602.9.6.2.The level of the conforming plate andfinishing beamsshallbe controlled automaticallyfrom the guidewires installedas perClause602.8 by sensorsattachedat the four cornersof the slip form pavingmachine. The alignmentof the paver shall becontrolled automaticallyfrom the guidewireby at leastone set of sensorsattachedto the paver.The alignment andlevel of ancillary machinesfor finishing, texturingand curing of the concreteshall beautomatically controlledrelative

236


to the guidewire or to the surfaceandedgeof the slab.

602.9.6.3.Slip-form paving machinesshallhavevibratorsof variableoutput,with amaximumenergy outputof not less than2.5 KW permetrewidth of slabper 300 mm depthof slabfor a la~~ngspeedupto 1.5 mper minute or pro-ratafor higher speeds.The machinesshall be ofsufficient mass to provide adequatereaction during spreading andpaving operationson the traction units to maintain forward movementsduring the placing of concretein all situations.

602.9.6.4. If the edgesof the slip formedslab slumpto the extentthat the surfaceof the top edgeof the slabdoes not comply with therequirementsof Clause602.14, then specialmeasuresapprovedby theEngineer shall betakento support theedgesto the required levelsandwork shall bestoppeduntil suchtime as theContractor candemonstratehis ability to slip form the edgesto the requiredlevels.

602.9.7. Construction by hand-guided method:Areas in whichhand-guided methods of constructionbecomeindispensableshall begot approvedby the Engineerin writing in advance.Such work maybe permitted only in restrictedareasin small lengths.Work shall becarried out by skilled personnelas per methods approved by theEngineer. The acceptancecriteria regarding level, thickness, surfaceregularity, texture, finish, strengthof concreteand all other qualitycontrol measuresshall bethe sameas in thecaseof machine laid work.

602.9,8.Surface texture

602.9.8.1. After the final regulation of the slab and before theapplicationof the curing membrane, thesurfaceof concreteslabshallbebrush-texturedin adirection at rightanglesto the longitudinalaxisof thecarriageway.

602.9.8.2. The brushedsurfacetexture shall beappliedevenly acrossthe slabin one direction by the useof a wire brushnot less than 450mm wide but longer brushesarepreferred. The brush shall be madeof32 gauge tapewiresgroupedtogetherin tuftsspacedat 10 mm centres.The tufts shall containan averageof 14 wiresand initially be 100 mmlong. Thebrushshall havetwo rowsof tufts. The rows shall be 20 mmapartand the tufts in one row shall be opposite the centreof the gapbetweentufts in the. other row. The brush shall be replacedwhen theshortesttuft wears downto 90 mm long.

602.9.8.3. The texturedepthshallbedeterminedby the Sand PatchTest asdescribedin Clause602.12.This testShallbe performed at least

237


once for each day’s paving and whereverthe Engineer considersitnecessaryat times after constructionas under:

Five individual measurementsof the texture depthshall be takenat least 2 m apart anywherealonga diagonalline acrossa lane widthbetweenpoints 50 m apart along the pavement. No measurement shallbe taken within 300 mm of the longitudinal edgesof a concreteslabconstructedin onepass.

602.9.8.4.Texture depthsshall not be less than the minimum re-quired whenmeasurementsare takenasgiven in Table 600-2nor greaterthan a maximum averageof 1.25 mm.

TABLE 600.2.TextureDepth

Time of TestNumber ofMeasurements

RequiredTextureDepth(mm)Specified ToleranceValue

I Between 24 hours and 7 days afterthe constn.,of the slab or untililie stab is first usedby vehicles.

2. Not later than 6 weekt before theroad is openedto publictraffic. ,

An average of5 measurements

An averageof5 measurements

1.00

1.00

±025

÷0.25-035

602.9.8.5.After the applicationof thebrushedtexture,the surfaceofthe slab shall havea uniform appearance.

602.9.8.6.Where the texturedepthrequirementsare found to bedeficient,the Contractorshall make goodthe texture acrossthe full lanewidth overlength directedby theEngineer,by retexturing the hardenedconcretesurface in an approvedmanner.

602.9.9.Curing

602.9.9.1. Immediatelyafter the surfacetexturing, the surfaceandsidesof the slabshall becuredby the application of approved resin- basedaluminised reflective curingcompoundwhich hardensinto an impervi-ous film or membranewith the helpof a mechanicalsprayer.

Curing compoundsshallcontainsufficient flake aluminium in finelydivideddispersion to produceacompletecoverageof thesprayedsurfacewith ametallic finish. The compound shall becomestableandimpervi-otis to evaporationof water from the surfaceof the concrete within 60rninutes of applicationa~dshall beof approvedtype. The curing com-pot~~dsstall havea waterrelentionefficiency index of 90 per centin ac-cordaiv’e with BS SpecificationNo. 7542.

238


602.9.9.2. The curingcompoundshall not reactchemically with theconcreteandthe film or membraneshall not crack, peel or disintegratewithin threeweeksafter application.Immediatelyprior to use, the curingcompoundshall be thoroughly agitated in its containers.The rate ofspreadshallbe in accordancewith the manufacturer’sinstructionscheckedduring the constructionof the trial length and subsequentlywheneverrequired by the Engineer. The mechanical sprayershall incorporate anefficient mechanical devicefor continuousagitationandmixing of thecompoundduring spraying.

602.9.9.3. In addition to sprayingof curing compound, the freshconcrete surfaceshall be protectedfor at least 3 hoursby coveringthefinished concrete pavementwith tentsas described in Clause602.7.2,during adverseweatherconditions as directed by theEngineer. Afterthreehours,thepavementshall becoveredby moisthessianandthe sameshall then be kept damp for a minimum period of 14 daysafter whichtime the hessianmay be removed.The hessianshall be kept continuouslymoist. All damaged/tomhessianshall be removedand replacedby newhessianon a regularbasis.

602.9.9.4.The Contractorshall be liable athis expenseto replaceany concretedamagedas a resultof incompletecuring or crackedon aline other than that of a joint.

602.10. Trial Length

602.10.1.The trial lengthshall be constructedat leastonemonth inadvance of the proposedstart of concretepaving work. At least onemonth prior to the constructionof the trial length, the Contractorshallsubmit for the Engineer’sapprovala detailedmethod statementgivingdescription of theproposedmaterials,plant, equipmentandconstructionmethods. All the major equipments like paving train, batching plant,tippersetc., proposedin the constructionare to be approved by theEngineerbeforetheir procurement.No trials of new materials, plant,equipmentor constructionmethods,nor anydevelopmentof them shallbe permitted either during the constructionof trial length or in anysubsequentpaving work, unless they form part of further, approvedtrials. These trial lengthsshall be constructedaway from thecarriage-way but with at least a subbaselayer below it.

602.10.2. The Contractor shall demonstratethe materials, plant,equipment andmethodsof constructionthat areproposedfor concretepaving,by first constructinga trial lengthof slab, at least60 m but notmorethan 300m long for mechanisedconstructionandat least30 m long

239


for hand guided methods. If the first trial is unsatisfactory,theContractorshall haveto demonstrate his capability to satisfactorilyconstructthepavementin subsequenttrials.

602.10.3 The trial length shall be constructed in two parts over aperiod comprising at least part of two separateworking days,with aminimum of 30 m constructedeachday for mechanisedconstructionanda minimum of 15 m on eachday for hand guidedconstruction. The triallengthshall be constructed at a similar rate (speed,around lm/hr) to thatwhich is proposed for the main work.

602.10.4. Transversejoints andlongitudinal joints of each type thatare proposedfor dowel-jointed unreinforcedconcreteslabs in the mainwork shall be constructedandassessedin the trial length. If in the triallength the construction of expansion joint and longitudinal joint is notdemonstrated,the first 2 expansion joints and at least the first 150 mof longitudinal construction joint for mechanisedpaving in the mainwork, shall be consideredas the trial length for thesejoints.

602.10.5.The trial length shall comply with the Specification in allrespects,with the following additionsand exceptions:

602.10.5.1.Surface levelsand regularity(i) In checking for compliancewith Clause 903.5 the levelsshall be taken at intervals

at the locationsspecified in this Clause alongany line or lines parallel to thelongitudinal centre line of the trial length.

(ii) The maximum numberofpermittedirregularitiesof pavementsurfaceshall complywith the requireçsentsof Clause 902.4.Shorier trial lengths shall beassessedpro.rats based on valuesfor a 300 m length.

602.10.5.2. Joints(iii) Alignment,of dowel barsshallbeinspectedasdescribedin Clause602.10.7 in any

two consecutivetransversejoints. If the position or alignmentof the dowel barsat one of thesejoints doesnot comply with Clause602.6.5, ii that joint remainstheonly one that doesnot complyafter thenext 3 consecutivejoints of the sametype have beeninspected,then themethodof placing dowels shall bedeemedto be satisfactory.In order to check sufficient joints for dowel bar alignmentwithoutextendingthe trial length unduly,theContractormay, by agreementwiththe Engineer,construct joints at more frequentjoint intervals than the normalspacingrequiredin theContract.

(iv) If therearedeficienciesin the first expansionjoint that is constructedasa trial, thenextexpansionjoint shall be a trial joint. Shouldthis alsobedeficient, furthertziaiexpansionjoints shall bemadeasparsof the trial length which shall not form partof the permanentworks, unlessagreed by the Engineer.

240


602.10.53.Density(v) Density shall be assessedas described in Clause 602.3.3, from a! least3 cores

drilled from eachpart of the trial length.

602.10.5.4.Position of tie bars(vi) Compliance with Clause 602,6,6 for the position andalignment of tie bars

shall be checked by drilling additional cores from the slab unless they canbe determinedfrom cores taken for density.

602.10.6.Approval and acceptance602.10.6.1Approval of the materials, plant, equipment andconstruc-

tion methodsshall be given when a trial length complies with theSpecification. The Contractorshall not proceed with normal workinguntil the trial lengthhasbeenapprovedand any earlier defectivetriallengthshavefren removed,unlessthat can beremediedto the satisfac-tion of theEngineer,If theEngineerdoesnot notify theContractorof anydeficienciesin anytrial lengthwithin 10 daysafter thecompletionof thattrial length, the Contractormay assumethat the trial length, andthematerials, plant,equipmentandconstructionmethodsadoptedareaccept-able.

602.10.6.2.When approval hasbeen given, the materials, plant,equipment and construction methods shall not thereafterbe changed,except for normal adjustmentsand maintenanceof plant, without theapprovalof theEngineer.Any changesin materials,plant,equipment,andconstructionmethodsshall entitle theEngineerto require,the Contractorto lay afurther trial lengthasdescribedin thisClauseto demonstratethatthe changes will not adversely affect the permanentworks.

602.10.6.3.Trial lengths which do not comply with the Specification,with the exceptionof areaswhicharedeficient only in surfacetextureandwhich can be remediedin accordancewith Clau~e602.9.8.6 shall beremoved immediately upon notification of deficiencies~y the Engineerandthe Contractorshall construct a further trial length.

602.10.7.Inspection of dowel bars

602.10.7.1.Compliance with Clause602.6.5.for the position andalignmentof dowel bars at constructionand expansionjoints shall becheckedby measurementsrelative to the side forms or guidewires.

602.10.7.2. When the slabhasbeenconstructed,the position andalignment of dowel bars and any filler board shalT be measuredaftercarefully exposingthem in the plasticconcreteacrossthe whole width ofthe slab.When thejoint is anexpansionjoint, the top of the filler board

241


shall first be exposed sufficiently in the plastic concrete to permitmeasurementof any lateralor verticaldisplacementof the board. Duringthe courseof normal working, these measurementsshall be carried outin thepavementsectionattheendof day’s work by extending slablengthby 2 m. Alter sawing the transverse joint groove, the extended2 mslab shall be removedcarefully soon after concrete hasset to exposedowelsover half the length. These dowels can be testedfor tolerances.

64)2.10.7.3. If theposition andalignment of the bars in a singlejoint in the slab is unsatisfactorythen the next two joints shall beinspected. If only onejoint of the threeis defective,the rate Of checkingshall be increasedto onejoint perday until theEngineeris satisfied thatcomplianceis beingachieved.In the event of non-compliance in twoor more successivejoints, the Contractorshall revertto the constructionof fresh trial lengths and make any necessaryalteration to concretemix, pavingplant or methods until the dowelbar position andalignmentare satisfactory.

602.10.7.4.After the dowel barshavebeenexamined,the remainderof the concreteshall be removedover a width of 500 mm on each sideof the line of thejoint andreinstatedto the satisfactionof theEngineer.The dowelsshall be insertedon bothsidesof the 1 m wide slabby drillingholes and grouting with epoxy mortar. Plastic sheath as per Clause602.6.5.5‘shall be provided on dowels on one of thejoints. The jointgroove shall be widened and sealedas per Clause602.11.

602.11. Preparation and Sealing of Joint Grooves

602.11.1,General

All transversejoints in surfaceslabsshall be sealed using sealants~.lescrihedin Clause602.2.8.Jointsshall not be sealedbefore 14 daysafter construction.

602.11.2.Preparation of joint groovesfor sealing

602.11.2.1. Joint groovesusuallyare not constructedto provide theminimum width specified in the drawingswhen saw cut joints areadopted.They shall be widened subsequentlyby sawingbefore sealing.iicpth/w idth gauges shall be used to control the dimension of thegroove.

602.11.2.2.If rough arrisesdevelopwhen groovesare made,theyshall be ground to provide a chamfer approximately5 mm wide. If thegroove is at an angle upto 10 degreefrom the perpendicularto thesurface, the overhanging edge of the sealing groove shall be sawn

242

ConcretePavement Section 600

or ground perpendicular.If spallingoccurs orthe angleof theformer isgreaterthan 10 degrees, thejoint sealing groove shalt besawn widerand perpendicularto the surfaceto encompassthe defectsupto a maxi-mum widl.h, including anychamfer,of 35 mm for transversejoints and20 mm for longitudinaljoints. If the spallingcannotbeso eliminated thenthe arrisesshalt berepairedby an approved thin bondedarris repairusing cementitious materials.

602.11.2.3.All groovesshall becleanedof any dirt or loose materialby air blastingwith filtered, oil-free compressedair. If need arisestheEngineer may instruct cleaning by pressurised waterjets, Dependingupon the requirementof the sealantmanufacturer,the sidesof the groovesmay haveto be sandblastedto increase the bondage betweensealantandconcrete.

602.11.2.4. The groove shallbe cleanedanddried at the time ofpriming and sealing.

602.11.2.5. Before seating the temporaryseal provided for btockingthe ingress of dirt, soil etc., shall be removed. A highly compressible heatresistantpaper-backeddebonding strip asper drawing shall be insertedin the groove to serve the purposeof breaking the bond betweensealant and the bottom of the groove and to plug the joint groove sothat the sealant maynot leakthroughthe cracks. ‘The width of debondingstrip shalt bemore than the joint groove width so that it is held tightlyin the groove. In the case oflongitudinaljoints, heat resistanttapesmayhe inserted toblock the leakage through bottom of the joint.

602.11.3.Sealing with sealanis

602.11.3.1. When sealantsareapplied, an appropriateprimer shallalso be used if recommended by the manufacturer andit shall beapplied in accordancewith their recommendation.The sealantshall beapplied within the minimum andmaximumdrying times of the primerrecommendedby themanufacturer.Priming and sealing with appliedsealants shall not be carriedout when the naturally occurringtemperaturein thejoint groove to be sealed is below 7°C.

602.11.3.2.If hot applied sealant is used it shall be heatedandapplied from a thermostatically controlled,indirectly heatedpreferablywith oil jacketed melter and pourer having recirculating pump andextruder. For large road projects, sealant shall be appliedwith extruderhaving flexible hose and nozzle. The sealant shall not be heated to atemperaturehigher thanthe safe heating temperatureand notfor aperiod

243


longer thanthe safeheatingperiod,asspecifiedby the manufacturer.Thedispensershall he cleanedout at theend of each day in accordancewiththe manufacturer’s recommendationsandreheatedm4terial shall not beused.

602.11.3.3.Cold applied sealantswith chemical formulation likepolysulphide maybe used.Theseshall be mixed and applied within thetime limit specifiedby the manufacturer.If primers are recommendedthey shall be appLied neatly with an appropriate brush.The MovementAccommodationFactor (MAF) shall be more than 10 per cent.

602.11.3.4. The sealantsapplied at contractionphaseof the slabswould result in bulging of the sealantoverand above theslab.Therefore,the Contractorin consultationwith theEngineer,shallestablish the righttemperatureand time for applying the sealant.Thermometershall behung on a pole in the site for facilitating control during the sealingoperation.

602.11.3.5. Sealantshall be applied, slightly to a lower level thanthe slab with a toleranceof 5 ±2 mm.

602.11.3.6. During sealing operation,it shall be seenthat no airbubbles are introduced in the sealanteither by vapours or by thesealing process.

602.11.4. Testing of applied sea lants: Manufacturer’s certificateshall be producedby theContractorfor establishingthatthe sealantis notmore than six monthsold and statingthat the sealant complieswith therelevant standard as in Clause 602.2.8. The samples shall meet therequirementof AASHTO M 282for hot appliedsealantor BS 5212: (Part-2) for cold applied sealant.

602.12. Measurementof Texture Depth - Sand PatchMethod

602.12.!.The following apparatusshall be used:(i) A cylindrical containerof 25 ml internal capacity

(ii) A nat woodendisc64 mm diameter with a hard rubber disc, 1.5 mm thick, stuckto one face, the reverae face being provided with a handle

(iii) Dry natural sandwith a roundedparticleshapepassinga 300 micmn 15 sieveandnctainedon a 150 micron 15 sieve.

602.12.2. Method: The surfaceto be measuredshall be dried, anyextraneous mortar and loosematerial removed and the surface sweptclean using a wire brush both at right angles and parallel to thecarriageway. The cylindrical containershall be filled with the sand,tapping the base 3 timeson the surfaceto ensure compaction,and

244


striking off the sandlevel with the top of the cylinder. The sandshallbe poured into a heap on the surface to be treated. The sand shall bespreadover the surface,working the disc with its face kept flat in acircular motion so that thesand is spreadinto a circularpatch with thesurfacedepressionsfilled with sand to the level of peaks.

602.12.3. The diameterof thepatchshallbe measuredto the nearest5 mm. The texturedepth of concretesurfaceshall be calculated from3l000/(DxD) mm whereD is the diameterof the patchin mm.


No vehicular traffic shall beallowedto runon the finished surfaceof a concretepavementwithin aperiod of 28 days of its constructionanduntil the joints arepermanentlysealed.The road may be openedtoregular traffic after completion of the curingperiod of 2~days and afterscaling of joints is completed including the constructionof shoulder,with the written permission of the Engineer.

602.14. Tolerances for Surface Regularity, Level, Thicknessand Strength

The tolerances for surface regularity, level, thickness andstrengthshall conform to the requirements given in Clause 903.5. Control ofquality of materials and works shall be exercised by the Engineer inaccordance with Section 900.


602.15.1.Cement Concrete pavement shall be measured as a fin-ished work in squaremetreswith specified thickness.The volume to bepaidfor will becalculatedon thebasisof thicknessandplans shown onthe project drawingsand adjustedfor the deficiency in thickness. Noadditionalpaymentshallbe madefor extrathicknessof the slab. The fullpayment will be made to this item after 28 days strength of the concreteis found to be satisfactory.

The unit for measurementfor concretepavementshall be thecubicmetre of concreteplaced,basedon the net plan areas for the specifiedthicknessshown on the Drawingsor directedby the Engineer.The rateshall includeall provisionsof this Specification andshall include theprovisionof all materialsincludingpolythenefilm, concrete,stock piling,mixing, transport,placing,compacting,finishing,curing togetherwith allformwork, and including testingand submissionof testcertificatesandrecords. No deduction shall be made in measurementfor openingsprovided that the area of each is less than 0.5 sq. m. The unit rate

245

Section&00 ConcretePavement

as entered in the Bill of Quantities shall also include the full costsof contraction, expansion, construction, and longitudinal joints, It shallalso incLude joint filler, keys, caulking rod, deboñding strip, sealantprimer, joint sealant, dowel bar and tie rod.

602.15.2, Pavement thickness

All precautionsand care shall he taken to construct pavementhaving uniform thicknessas called for on the plans.

Thicknessof the cementconcretepavementshall be calculatedon thebasis of level dataof the cementconcretepavementand theunderlyingsub-basetaken on a grid of 5 m x 3.5 m or 6.25 m x 3.5 m, the formermeasurementbeing in longitudinal direction.

A day’s work is consideredas a ~lot’ for calculating the averagethicknessof the slab. In calculating the averagethickness, individualmeasurementswhicharein excessof the specifiedthicknessby more than10 mm shall be consideredas the specifiedthickness plus 10 mm.

Individual areasdeficientby more than 25 mm shall be verified bythe Engineer by orderingcorecutting andif in his opinion the deficientareaswarrantremoval,they shall be removed and replacedwith concreteof the thicknessshown on the plans.

When the average thicknessfor the lot is deficient by the extentshownin Table600.3, the Contractunit pricewill be adjustedasper thisTabLe,

TAIILE 600.3. PAYMENT ADJUSTMENT FOR DEFICIENCY IN THICKNFSS

Deficiency in the averagethicknessof day’s work

Per cent of Contractunit price payable

Upto5mm 1006.10mm 87

11-15mm 8116.20mm 7521-25mm 70

In the stretch where deficiency of average thickness is more than25 mm, the section whose thicknessis deficientby 26 mm or more isidentified with the help of cores.Such slabs shall be removed andreconstructedat the cost of the Contractor.During such rectificationwork, care shall be takento replacefull slab and to the full depth.

246

Concrete Pavement Seaion600

602.16. Rate

The Contract unit rate for the constructionof the cementconcreteshall be paymentin fuLl for carrying out the operationsrequired forthe different items of the work as per theseSpecificationsincludingfull compensationfor all labour, tools, plant, equipments,testing andincidentals to complete the work as per Specifications, providing allmaterials to be incorporated in the work including all royalties, fees,storage,rents wherenecessaryand all leadsandlifts.

603. ROLLED CEMENT CONCRETEBASE

603.1. Scope

603.1.1.The work shall consistof constructionof rolled concretebase course for cementconcretepavement in accordancewith therequirementsof these Specificationsand in conformity with the lines,gradesand cross sections shown on the drawingsor as directed by theEngineer. The work shall incLude furnishing of all plantandequipment,material and Labour and performing all operations in connectionwiththe work, as approved by the Engineer.

603.1.2.Thedesignparametersof rolledcementconcretebase courseviz,,width, thickness, grade of concrete,detailsof joints, if any,etc. shallbe as stipulatedin the contractdrawings.

603.2. Materials

603.2.1. Source of materials: The Contractor shall indicate to theEngineer thesourceof all materialsto be usedin the lean concreteworkwith relevant test data sufficiently in advance and the approval of theEngineer for the same shall be obtained at least 60 days before thescheduled commencement of the work. If the Contractor later proposesto obtain the materials from a different source, he shall notify theEngineer for his approval at least 60 days before such materials are tobe used.

‘t~03.2.2. Cement: Any of the following types of cement may be usedwith prior approval of the Engineer.

(i) Ordinary PortlandCement IS 269, 8112 or 12269

(ii) Portland SlagCement IS 455

(iii) Portland PozzolanaCement IS 1489

If the subgradeis found to consist of soltible sulphates in aconcentration more than 0.5 per cent, cementused shall be sulphateresistantand shall conform to IS 12230. Cement to be used may

247


preferablybe obtainedin bulk form. It shall bestoredin accordancewithstipulationscontainedin Clause1014 andshaLl be subjectedto acceptancetest prior to its immediateuse.

603.2.3.Aggregates

603.2.3.1. Aggregates for lean concreteshall be natural materialcomplying with IS: 383.Theaggregatesshall not be alkali reactive.Thelimits of deleteriousmaterialsshall not exceedthe requirementsset outin IS: 383. In casetheEngineerconsidersthatthe aggregatesare not freefrom dirt, the samemay be washedand drained for at least 72 hoursbefore batching as directedby theEngineer.

603.2.3.2. Coarse aggregate : Coarse aggregatesshall consistol’clean, hard, strong, dense, non-porous and durable pieces of crushedstone or crushed gravel and shall be devoid of pieces of disintegratedstone, soft, flaky, elongated,very angularor splinterypieces.The maxi-mum size of the coarseaggregate shall be 25 mm. The coarse aggregateshall comply with the Clause 602.2.4.2.

603.2.3.3. Fine aggregate : The fine aggregate shall consist ofclean natural sand or crushed stonesandor a combinationof the twoand shalL conform to IS:383. Fine aggregate shall be free from softparticles,clay, shale,Loam, cementedparticles, mica, organic and otherforeign matter. Thefine aggregateshallcomply with theClause602.2.4.3.

603.2.3.4.The coarseand fine aggregatesmay be obtainedin eitherof the following manner:-

(1) In separatenominal sizes of coarse and fine aggregates and mixed togetherintimately before use.

(ii) Separatelyas 25 mm nominalsinglesize, 12.5 mm nominalsizegraded aggregateand fine aggregate of crushed stone dust or sandor a combinationof thesetwo.

The material afterblendingshallconform to the gradingasindicatedin Table 600-4 below:

TABLE 600.4. AGGREGATE GRADATION FOR DRY LEAN CONCRETE

SieveDesignation PercentagePassingthesieveby weight

37.5 mm 10019.0 mm 80.1009.5 mm 55-804.75 mm 35-60

600 micron 10-3575 micron 0-8

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ConcretePavement Section 600

603.2.4. Water: Water used for mixing and curing of concreteshallbe clean and free from injurious amount of oil, salt, acid, vegetablematter or other substances harmful to the finished concrete. It shall meetthe requirements stipulated in IS: 456.

603.2.5. Storage of materials: All materials shall be stored inaccordancewith the provisionsof Clause1014 of theseSpecifications,andotherrelevantIS Specifications. All efforts must be made to storethe materialsin proper places so as to preventtheir deteriorationorcontaminationby foreignmatterand to ensuretheir satisfactory qualityand fitness for the work. The storageplace must also permit easyinspection, removal and storageof materials. All such materials eventhough stored in approved godowns must be subjected to acceptance testimmediately prior to their use. The requirement of storage yardspecifiedin £lause 602.2.9 shall be applicable.

603.3, Proportioning of Materials for the Mix

603.3.1.Themix shallbe proportioned with a maximum aggregate:cement ratio of 15.1. After the approvalof all thematerials to be usedin the concrete, the Contractor shall submit the mix design basedonweighed proportion of all ingredientsfor the approval of the Engineer.The mix designshall be submittedat least30 daysprior to the pavingof trial lengthanddesignshall be done based on the laboratory trialsusing approvedmaterialsand methods. The watercontent shall beadjusted to the optimumas perClause 603.3.2. for facilitating compac-tion by rolling. The target meanstrength for the designmix as well asacceptance Speciflcation of concrete shall be in accordancewith Clause903.5.2. The mix design shall be based on the flexural strength ofconcrete.

603.3.2. Moisture content: The right amount of waterfor the rolledconcretein themain work shall bedecidedfor ensuringfull compactionunder rolLing andshallbeassessedatthe time of rolling thetrial length.Too much water will cause the concreteto be picked up on thewheelsof the roller and too little will lead to inadequatecompaction,alow in-situ strength andan open textured surface. Theoptimum watercontent shall be determined in accordance with Clause 603.7. anddemonstratedby rolling duringtrial length construction;andtheoptimummoisturecontentand degreeof compactionshall be got approved bythe Engineer. While laying, in the main work, the rolled concrete shallhave a moisture content between the optimum and optimum + 2 per cent,

249


keepingin view theeffectivenessof compactionachievedandto compen-sate for evaporationlosses.

603.3.3. Cement content: The minimum cement content in therolled concreteshall not be less than 150 kg/cuff. of concrete. If thismininium cement contentis not suflicient to produce concrete of thespecifiedstrength, it shall be increasedas necessarywithout additionalcompensation under the Contract.

603.3.4.Concretestrength:The flexural strength asspecified shallbe the governingcriteriafor approvalof themix, While designingthe mixin the laboratory, correlationbetweenflexura! and compressivestrengthsof concreteshall beestablishedon thebasisof tests on samples for useat alater dateto verify the in situ flexural strengthof rolled concretethrough testingof cores.

At leastabatchof two beamandcubespecimens,oneeachfor 3 dayand 7 day strengthtesting shall becast for every 100cum or part thereofof concreteplacedduring construction.On each day’s work not Less thanfour beamsand four cubes shall be made.

A ratio between the3 and7 day strengths shall beestablishedforthe mix to be used.This will help in assessingthe fall in strength,if any in advanceso that correctiveaction can be taken for the futurework.

603.4. Subgrade

The subgrade shall conform to the grades and cross sections shownon the drawings andshall be uniformly compactedto the design strengthin accordance with these Specifications and the Specification stipulatedin the Contract. Therolled concretebaseshall not be laid on a subgradesoftened by rain after its final preparation;any surfacetrenches,soft spotsetc., must be properly back-filled and compactedto avoid any weak orsoft spot. As far as possible, theconstructiontraffic shall beavoidedonthe preparedsubgrade.A day beforeplacingof the sub-base,the subgradesurfaceshall be given a fine spray of waterand rolled with one or twopassesof a smoothwheeledroller aftera lapseof 2-3 hours in order tostabilise the loose surface.If the Engineerfeels it necessary,anotherfine sprayof watermay beappliedjust before placing the basecourse.

603.5.Construction

Clause601.5 shaLl apply.

250


603.6. Trial Mix

Using the specifiedcementcontentarid proportioned aggregates,theContractor shall maketrial mixes at water contents ranging from 5 percent to 7 per cent by weightof dry materials at 0.5 per centintervalsusing an aggregate/cement ratio of not greater than 15.0. Optimummoistureand density shall be established by preparing cubeswith varyingmoisturecontents.The compaction of mould shall be done in threelayersas explainedin Clause903.5.2.1.The optimum moisture content deter-mined normally gives an indication about the moisturecontent whichafter minor adjustment may provide satisfactory mix which could berolled.

After determiningthe moisturecontentfrom theabovetrial mix, a setof six beamsandcubesshall be preparedfor testingthemon 3rd and 7thday. if the flexural strengthachievedis lower than thedesired strength,the abovetrial shall be repeatedafter increasingthe cementcontentandadjusting the mix appropriately.

During the constructionof trial lengthasper Clause 603.7 minormodifications may haveto be carried Out to the moisture content ofthemix, But such modified mix shall haveto satisfy the flexural strengthrequirement. Flexural strength to be achieved shall be the governingcriteria for the design.of mix.

603.7. Trial Length

Clause601.7shall apply.

603.8. Traffic

No heavycommercialvehicleslike trucksandbusesshallbe permit-ted ontherolled concretebaseafter its construction.Light vehicles maybe, however,allowedafter7 daysof its constructionwith prior approvalof the Engineer.

603.9. Tolerances for Surface ReguIarity~ Level, Thicknessand Strength

The tolerances for surfaceregularity, level, thickness andstrengthshall conform to the requirements given in Clause 903.5. Control ofquality of materials and works shall be exercisedby the Engineerinaccordancewith Section 900.


The unit of measurement for concreteandrolledconcretepavementshall be the cubic metre of concreteplaced,basedon the net plan areas

251


for the specifiedthicknessshown on the drawings as directedby theEngineer.

603.11. Rate

The Contractunit ratepayablefor rolled cement concrete for basecourse shall bepaymentin full for carrying out the requiredoperationsincluding full compensation forall Labour, materials and equipment,mixing, transport, placing, compacting,finishing, curing, testing andincidentalsto completethe workas per Specifications,all royalties,fees,storageandrents where necessaryandall leadsand lifts.

252

Geosynthetics

700

Geosynthetics

Geosynthetics Section700

701. GEOSYNTHETICS IN ROAD AND BRIDGE WORKS

701.1 Scope

This specificationcoversthevarious applicationsof Geosyntheticma-terials in road and bridge works including supplying andlaying as perspecialprovisions.

“Geosynthetic is a general classification for all synthetic materialsused in geotechnical engineering application. It includes geotextiles,geogrids,geonets,geomembranesandgeocomposites.

(1) Geotextile : Any permeabletextilenaturalor Synthetic,usedwith fotmdation, soil,rock, earth,or any other geoteclasicalengineeringrelatedmaterial. In the presentchapter,ii is relatedto syntheticmaterialonly.

(ii) Geogrid: A deformedornon-deformed grid of polymericmaterial usedprimarilyfor reinforcementpurposeswith foundation,soil,suck, earth, or anyothergeotech-nical engineering relatedmaterial.

(iii) Geonets : These are net made of polymeric material used for drainageoffoundation,soil, rock, earthor any othergeotechnicalengineeringrelatedmaterial.

(iv) Geomembrane : An essentially impermeable membraneof polymeric materialusedwith foundation, soil, rock, earth or any othergeotechnicalengineeringrelatedmaterial,to control fluid migration.’

(v) Geocomposite A manufacturedmaterialusing geotextiles.geognds,geonetsancilor geomembranein laminatedor compositeform.”

701.2Material Testing and Acceptance

Unlessotherwisestated,theseGeosynthetic materialsshall conform tothe requirementsas under:

701.2.1.Geotextile : Geotextile shall be made of polyethylene orpolypropyleneor polyesteror similar fibres, either woven or nonwoven invariety, throughmachinemadeprocessof heatbondingor needlepunchingor weaving techniques.Thesefabricsare requiredto passwater throughbut retain the soil particles,which requirespecific cross-planepermeabil-ity or permittivity andapparantopening size or equivalent openingsizeor095. The above two requirements alongwith the requirement of strengthand durability denote general characteristics of geotextilesto be used.

The type of geotextile to be used in a particuLarapplication shall bedecidedon thebasis of design.

701.2.2. Geogrid : Geogrid shall be made from integralLy jointed,mono or bi-directionallyorientatedor stretchedmeshesmadefrom poly-ethylene or polypropyleneor polyesteror similar polymer, with high

255

Section700 Geosynthetics

secant modulus, in square, rectangular,hexagonal or oval mesh form.Their junction strength shall be high with high creep resistance,anddimensionalstability. Theiropenstructureshall permiteffectiveinterlock-ing with soil, aggregates,rock etc., theyshall be usedas atensilememberor reinforcement. Characteristics strength of suchGeogrids vanesfrom 40kN/m to 200kN/m peakstrengthat a maximum elongationof 15 per centin the direction of the length of the roll.

701.2.3. Geonet : Geonetshall be made from a single extrudedunoriented process from polyethylene or polypropylene or similarpolymer. It shall have square or rectangular net shapeaperturewhen usedfor protective works like gabions and mattresses. While in polygonalaperture it shall be used as a separator. It shall not be used as soilreinforcement due to its high creep characteristics, neither as a slopereinforcement or soil retaining wall or asphalticreinforcement. Geonetsused in protective works for highway structuresshall be atleast650 gm/sq.m. in unit weight. It shall be black in colour, available in roll form insuitable width.

701.2.4.Geomembrane : Geomembraneshall be made from PVC orpolyethelenesheetsof atleast0.8 mm thickness, duly protected from ultra -violet exposurewith 2.5 per cent carbon black, in black colour, suppliedin roll form with 3 m or abovewidth. The joints of these sheetsshall beheatbonded or seamed for effective permeation cut off, at site usingstandardequipment as part of the laying process. While fixing on to aslope, they shall not be punctured or stappled to impair their use.

701.2.5.Geocomposite: (leocompositesshall be made from combi-nation of geonets,geogrids or geomembranesof above description usingheat bonded,seamedstitched or wrap techniques.Their principal use shallbe to regulate drainage in cross-plane or in-plane directions. Minimumunit weight of such material shall conform to the specialprovisions or asper Contract drawing.

701.2.6.Testing and acceptance: Geosyntheticsshall be tested inaccordance with testsprescribedby BIS. In absenceof IS Codes, testsprescribed either by ASTM or British Standards or International StandardsOrganisation, shall be conducted.

701.3 Application Areas

Someof the application areas for geotextilesand related materials and

256


their functions are given below in table700-1.Table 700-1.ApplIcationsand Functionsof Geosynthetics

5. No. Application Area~

GeosynthetlcsInvolved

FunctionsforPerformance

I.2.3.4.5.6.7.

Embankments on soft soilsRetaining wallsDrainage and FiltrationDrainage-prefab, compositeErosionControlriprapSediment control-silt fenceAsphalt overlay

GT, GOGO, GTGTGC, ONCIT ‘

GTGT, GC

K SRF, SD, F, 5, BF,SB, It, SB, R, 5

Note GT = geotextileGG = geogridGC = geocompositeON = geonet

S = separationR = reinforcementF = filtrationD = drainageB = barrier

702. GEOTEXTILES IN SUB-SURFACE DRAINS702.1. ScopeThework coverstheuse of geotextilesin subsurfacedrains,suchas

fin drains or narrow. filter drains. The fin drain shall meana planargeocompositestructure designedto perform the samefunction as a narrowfilter drain. The work shall be carried out as per design drawings.

702.2.Materials702.2.1.The geotextile fabric shall be a woven or non-woven fabric

consisting of long-chain polymeric filaments or yarns such as polypro-pylene,polyethyleneor polyesteror any combination thereof, formed intoa stable network such that the filaments or yarns retain their relativeposition to each other.

702.2.2.The geosynthetic material of which the drain is made shallbe treated with carbon black sothat they areprotectedfrom the deleteriouseffectsof short term exposure to ultraviolet light, and shall be resistant todegradation by acid, alkalis, common chemicals, bacteria, fungi andmoulds occurring in soils and highway construction materials. In caseofexposure to ultraviolet light, the Engineer may requireevidencethat thegeosyntheticmaterial still complieswith the requirements of this Clause.Where necessary,the sideintended for entry of water and direction of in-plane flow shall be identified.

702.2.3.The geotextileshall(a) Sustain a load of not less than10 kN/m at breakandhavea minimum failure strain

257


of 10 per cent when determined in accordancewith BS:6906 (Part1) or shall havea grab tensilestrengthmore than0.4 kN/m andgrab elongation correspondingtothis limit in accordancewith ASTM D 4632.

(b) The Apparent opening size, shall satisfy the following

(i) Soil with 50 per centor lessparticles by weightpassingIS sieve75 microns,apparent openingsize less than0.6 mm.

(ii) Soil more than 50per centparticles by weight passing IS sieve75 microns,apparentopening sizeless than 0.927 mm.

The test should be as per TF 25 # 6

(c) allow water to flow through it at right angles to its principal plane, in eitherdirection at a rate of not less than10 litres/m2/sec. under a constanthead of waterof 100 mm, determinedin accordancewith BS:6906 (Part 3) or ASTM D 4491 oras stated in the designdrawing. The flow rate determinedin thetest shall becorrectedto that applicableto a temperature of 15°Cusing publisheddata onvariation in viscosityof water with temperawre.

(d) havea minimum puncture resistanceof 200 N whendeterminedin accordancewithBS:6906 (Part 4) or ASTM D 4833.

(e) have a minimum tear resistanceof ISO N when determined in accordancewithASTM Standard D 4533.

702.2.4.The compositedrain shall haveaflow ratethrougheachfaceof the drain of more than 75 percent of the valuespecifiedin sub-Clause702.2.3 (c), determined by direct measurementof the cOmposite drainusing BS:6906 (Part 3). The composite drain shall have values of long-term in-plane flow rates as stated in the design drawing.

702.3. InstaHation

702.3.1. The installation of fin drains shall be as per the designdrawings. Where fin drainsare assembledon site, the assemblyarea shallbe clean anddry and free of any wind-borne pollutants. No geotextileorcore material shall be exposedto daylight (or any sourceof ultravioletradiation) for a period exceedinga cumulative total of 50 hours.Whei~efin drains are laid in trench, the bottom of the trench shall be free ofirregularities and shall be brought to the required level. Rock and otherhard protrusionsshallbe removedandany excesscut in the trenchbottomfilled and compactedback to the required grade with suitable excavatedor imported material as directed by the Engineer. Fin drains shall becapable of being jointed longitudinally or laterally into pipe~systeinsorchambers for inflow and outflow purposes. Joints parallel to the directionof flow and any exposededgedshall be protected from the ingress of soilby a geotextile wrapping with a minimum overlap of 150 mm or othermeasuresas agreedby the Engineer.

702.4. Narrow filter drains consisting of a porous or perforated pipe

258

Gcosynthetics Section700

laid in anarrowtrenchsurroundedby a layer of geotext.ilefilter shall havethe samepropertiesof geotextileasspecifiedin Clause702.2.The spicingof lengths of geotextileandminimum overlap shall be as per the designdrawing or as approved by theEngineer. Such drains shall be installed asper the designdrawing to Clauses 702.3 and309.3.5.

702.5.Measurementsfor Payment

Measurement for fin drain/narrowfilter drainsshall be per runningmetre length of the drain. Disposal of surplus material beyond 1000 mshall be measuredin cu.m.

702.6,Rates

The Contract unit rates for subsurfacedrainsshall be payment in fullfor all itemssuchas excavation,dressingthe sidesand bottom, providinggeotextile composites, laying and jointing pipes etc. including fullcompensationfor all materials, labour, tools, equipmentincidental tocompletethe work as shown on drawings with all leadsand lifts exceptfor removal of unsuitablematerial for which the lead shall be 1000 m.Provisionof inlets, outletpipes,beddingetc., wherever requiredshall beincidental to construction of drain. The Contract unit for disposalofsurplusandunsuitablematerialbeyondtheinitial 1000m lead shall be inaccordancewith Clause301.3.11.

703. REINFORCED EARTH

703.1. Scope

The work covers the construction of reinforced earth structures,togetherwith the construction of earthwork in layers, assemblyanderection of reinforcing elementsand placementof facing panels and allassociatedcomponents.

703.2. Reinforcing Element

703.2.1.The reinforcing elementshall be of Oeotextile, aluminiumalloy strip, copper strip, carbon steel strip, mats of metal or syntheticgrids, or any other proprietary material which may be approved by theEngineer andindicatedon the drawings.

703.2.2. Geotextile The material shall conform to Clause701.2.6.

703.2.3.Aluminium ahoy strip shall comply with BS:1470 quality5454 in the H 24 condition.

703.2.4.Copper strip shall comply with BS:2870quality C 101 or C102 in the 1f2 H condition andshall have 0.2 per cent proofstress of notlessthan 180 N/mm2.

259


703.2.5. Carbonsteel strip which shall be galvanizedshall complywith BS:l449 (Part 1), either quality KHR 34/20 P or quality 50/35 P,eachhavinga silicon contentof not lessthan0.25 per cent andnot morethan 0.40 per cent. The fabricated element shall be galvanized inaccordance with BS:729, and the average zinc coating weight for anyindividual test area shall not be less than 1000 gm/sq.m.

703.2.6.Stainless steel strip shall comply with BS:1449 (Part 2)quality 316 S 31 or 3/6 S 33 except~thatthematerialshallbe cold rolledto provide a 0.2 per cent proof stressof not lessthan400 N/sq. mm andthe tensile strength shall not be less than 540 N/sq. m.

703.2.7,All metallic componentsburiedin soil shallbe of electrolyti-cally compatible materials.

703.2.8.Geogrids : The supply of geogridsshall carry a certificationof BIS or ISO 9002 for all works. While the reinforcingelementfor wallor slopeportion shall be with mono oriented Geogrid,the reinforcementfor the foundation of a reinforced earth wall or slope shall be with bi-directionallyorientedGeogrid.For mono orientedGeogrid,the character-istic designtensile strength at a strain not exceeding10 per cent in 100years shall be at least 40 kM/rn when measuredas per GR1:GG3. Thestrengt~.for bi-directionafly oriented Geogrid in the longitudinal directionshall be at least 40 kN/m at a maximum elongationof 15 per cent. TheGeogrid shall be inert to all naturally occurringchemicals,mineralsandsalts found in soil.

703.3. Earth FillThe fill material for reinforcedearthstructuresshall havean angleof

interface friction between the compacted fill and the reinforcingelementof not lessthan 25°C,measuredin accordancewith IS : 13326(Part 1).The soil shouldbe predominantlycoarsegrained; not more than 10 percent of the particles shall pass75 micron sieve. The soil should havepropertiessuch that the salts in the soil should not react chemically orelectrically with the reinforcing elementsin an adversemanner.

703.4. Facia Material

703.4.1.The facing shall comprise of one of following(1) Reinforcedconcrete(Cast in situ or precast)stabs

(ii) Plain cementconcreteform fill hollow block (Precast)

(iii) Masonry constn1ction,Rubble facia

(iv) Otherproprietary andpatentedproven system

260


The facingshall be sufficiently flexible to withstand any deformationof the fill.

703.4.2.Faciaunit joint filler should be durable,resistantto the effectof air pollution and water/saline water.

703.4.3.Bedding material shall consistof either cementmortar or adurablegasketseatingsuch as resin bonded cork strip.

703.4.4. Connection between the facia and the reinforcingelementshall be by using polyethylene strips/rods, fibre glass dowelsorany othermaterialshownin the drawing.Any other material used shall betested to provide 100 per cent joint strength as of parent element incontinuity.

Overlapping in principal reinforcement or in the joint shallensure load transfer through joints, perpendicular to the direction oflaying.

703.5.Construction Details

703.5.1. The plan area of the reinforced earth structure shall beexcavated to provide a nominally level basewhich may be steppedat thebackas requiredto receivethe horizontal reinforcing elementgrid.

The depth of the foundationbelow the finished ground level at thefoot of the slope or wall shall not be lessthan 1000 mm.

Additional strip footing, troughguide made of concreteor anchorkeypadshallbe providedat founding level to receivethe facia or the bottommost reinforcementconnection. This shall have adequatesoil coveragainst erosion and scourin particular cases.

703.5.2.Orientation : The reinforcing elementsshall be placed atright anglesto the face of the wall, with greatercrosssectionaldimensionin the horizontal plane.The placementof the elementsincluding theirvertical/horizontal spacing and length shall be as in the drawing.

703.5.3.Facing batter: It may be necessaryto set facing unit at anadditionalbatter thanas provided in the drawingas thereis atendencyforinitially positioned units of facia to lean outward as the fill material isplaced and compacted. Care and caution shall be taken to rectify thisphenomenon.

703.5.4.Drainage : Drainageshall beprovidedasper drawing givenin detail.The retainedfill shall have a suitably designeddrainage bay toallow free draining of the reinforced fill.

261


703.5$, Laying and compacting : The reinforcing elementsshallbe laid free from all kinks, damage and displacement duringdeposition,speading,levelling andcompactionof thefill. The programmeof filling shall be such that no constructionplant runs directly on thereinforcement.

All constructionplanthavingamassexceeding1000Kg shall be keptat least 1 .5 m away from the face of slopeor wall. In this area(upto 1.5m from the face of slope or wall), following compactionplant shall beused

(I) Vibratory roller having a weightper metre width of roll not exceeding 13(X) kg.with total weight not exceeding 10,000kg.

(ii) Vibratory plate compactor of maximum weight 1000 kg.

(iii) Vibro tamperhaving a weight not exceeding75 kg.

Compactionby any other method like using dozer or back bladecompactionby dozer or excavatorbucket shall be permittedwith dueapproval from the Engineer after ascertainingthe level of compaction soachieved.

During constructionof reinforced fill, the retained material beyondthe reinforcementat the rear or the structureshall be maintainedat thesame level as reinforced fill,

The compactedlayer shall not be more than 200 ram, to achievecompaction of 95 per cent of maximum laboratory density wheremeasured as per IS : 2720 (Part 8). Temporaryformworkshall be usedtosupport the construction as per specifieddetails given in the drawing.Theforms, scaffolding andpropsshall be sufficient in numbers to allow takingup of a sectoralconstructionschedulespecifiedin the design.


Measurementfor reinforcing elementsshall be in linear metre foranchor strips or in sq.m. for geogrid/geotextileetc.

The measurementfor facia shall be in sq. metres.The measurementfor foundation for facia and capping beam shall be in linear metres.Measurementfor compacted earthfill shall be in cubic metres forcompactedsoil.

703.7. Rates

Rate shall include cost of labour, plant hire, material storage andhandling expenses,for completing the works.

Rate for providing reinforcing elementsshall include material cost, all

262


transportationcostsandstorageof the sameasper specialprovisions.Therateshall alsoincludecostof laying of the reinforcingelementsincludingall overlaps, jointing or stitching, heat bonding or extension.

Rate for facia fixing shall include cost of joints, all necessarytemporaryformwork, scaffoldingandall lifts andleads,if any, asshownin the drawing, unless otherwise specified to the treatedseparately alongwith foundation or slope/wall kerb at thetop of slopeor wall. Rate for bedblock and cappingbeamshall includeall items of excavation,concrete,reinforcingsteel, formwork, labour andequipment.

Ratefor soil fill shall includecompactionas desiredin requisitelayersthrough mechanical means, cost of hire or labour for plant operations,dressing and levelling slopes, including special measuresfor edgereinforcementsas shownin the drawing.

704. GEOSYNTHETICSFOR HIGHWAY PAVEMENTS

704.1. Scope

This work shall consistof laying geosyntheticmaterialsover existingbiuturninous surface, including preparation of surface and joining,stitching or overlappingof geosyntheticfabric etc., as part of highwaypavementstrengtheningin layers as shown on drawings.

704.2. Paving Fabrics704.2.1. Description : This work shall consist of furnishing and

placing as asphalt/bitumenoverlay textile (paving fabric) beneath apavementoverlayor betweenpavementlayersto providea waterresistantmembrane andcrackretardinglayer.

704.3.Material Requirements

704.3.1.Paving rabric: The paving fabric will be a nonwovenheatset material consisting of at least 85 per cent by weight polyolefins,polyestersor polyarnides.The paving fabric shall be resistantto chemicalattack, rot and mildew and shall have no tears or defects which willadversely alter its physical properties.The fabric shall be specificallydesignedfor pavementapplicationsandbe heat bonded only on one sideto reducebleed-throughof tack coat during installation. The fabric shallmeetthephysicalrequirementsof Table 704-2.Heavyduty paving fabricsshould be used in areasexperiencingunusually high impact forces orheavy loadssuchas airportrunwaysand taxiways:

263


Table 704.2. PhysIcalRequirements.PavlngFabrics

36.3

50

10

150

I-lest bondedonone side only

2. All numerical values representminimum averageroll values (averageof testresultsfrom anysampledroll in a lot shall meetor exceedthe minimumvalues) inweaker principal direction, Lot shall be sampled according to ASTM D 4354,“Practicefor Samplingof Geosyntheticsfor Testing”.

3. Conformanceof paving fabrics to specificationproperty requirementsshall bedeterminedas per ASTM 1) 4759, “Practice for Determining the SpecificationConformanceof Geosynthetics”.

704.3.2.TackCoat: The tackcoat usedto impregnatethefabric andbond the fabric to the pavementshall be a paving gradeBitumenof 80-100 penetration.A cationicor anionicemulsionmay be usedas approvedby the engineer.The useof cutbacksor emulsionswhichcontainsolventsshall not be used.

704.4. Construction and Installation Requirements

704.4.1.Shipment and storage’: The paving fabric shall be kept dryand wrapped such that it is protectedfrom the elementsduringshippingandstorage.At no time shall the pavingfabric be exposedto ultravioletlight for a period exceedingfourteen days.Paving fabric rolls shall bestored in a manner which protects them from the elements. If storedoutdoors, they shall be elevatedand protected with a waterproof cover~.The paving fabric shall be labeled as per ASTM D 4873, “Guide foridentification, storage,and handlingof geotextiles”.

704.4.2.Weather limitations: Minimum air andpavementtempera-ture shall be at least 10°Candrising for placementof bitumenand shallbe at least 15°Cand rising for placementbitumen emulsion. Neitherbitumen tack coat nor paving fabric shall be placed when weatherconditions,in the opinion of the engineer,are not suitable.

TensileStrength

Elongation

Asphalt Retention

Melting Point

SurfaceTexture

ASTM D 4632

ASTM D 4632

Texas DOT 3099

ASTM D 276

Visual Inspection

Notes1. Certification of conformancefrom paving fabric manufacturermay be required.

264


704.43. Surfacepreparation : The pavementsurface shall bethoroughly cleanedof all dirt, water, andoil to the satisfactionof theengineer. Cracks 3 mm wide or greater shall be cleaned and filled withsuitablebituminous materialor by a method approvedby the engineer.Crack filling material shall be allowed to cure prior to paving fabricplacement.Potholesandother pavementdistressshallberepaired.Repairsshall beperformedas directedby the engineer.

704.4.4.Tack coatapplication : The tack coat shall be spreadbymeans ofa calibrated distributor spray bar. Hand spraying and brushapplicationmay be usedir~!ocatiOnsof fabric overlap.Every effort shallbe madeto keep handsprayingto a minimum. The tack coatshall beapplied,uniformly to theprepareddry pavementsurfaceat the rate of 1kg/sq.m. or as recommendedby the paving fabric manufacturer andapprovedby the engineer.When using emulsions,the application ratemust be increasedas directedby the engineerto offset thewatercontentof the emulsion. Within streetintersections, on steepgrades,or in otherzones where vehicle speed changesare common place, thenormalapplicationrateshall bereducedby a~out20 percent asdirectedby theengineer.The tack coatapplication ratemustbe sufficient to saturatethefabric andto bond the fabric to the existing pavement surface.

The temperatureof thetack coatshall be sufficientlyhigh to permita uniform spray pattern.For bitumen, theminimum temperatureshall be140°C.To avoid damageto the fabric, distributor tank temperaturesshaltnot exceed160°C.For bitumen emulsions,the distributor tank tempera-tures shall be maintained between 55°Cand70°C.

The targetwidth of tack coat application shall be equal to the pavingfabric width plus 150 mm. The tack coatshall beapplied only as far inadvanceof pavingfabric installationas is appropriateto ensurea tackysurfaceatthetime of pavingfabricplacement.Traffic shallnot beallowedon the tack coat. Excesstack coat shall becleanedfrom the pavement.

704.4.5.Paving fabric placement : Thepavingfabric shallbeplacedonto the tack coat using mechanicalor manual laydown equipmentcapableof providing a smooth installationwith a minimum amount ofwrinkling or folding. The pavingfabric shall beplacedprior to the tackcoat cooling andlosing tackiness.Pavingfabric shall not be installedinareaswhere theoverlay asphalttapersto a thicknessof lessthan40 mm.Excess pavingfabricwhichextendsbeyondthe edgeof existingpavementor areasof tack coat applicationshall be trimmed and removed.Whenbitumen emulsions are used, the emulsion shalt be allowed to cure

265


properly such that essentially no water moisture remainsprior to placingthe paving fabric. Wrinklesor folds in excessof 25 mm shall beslit andlaid flat. All transverse joints and slit folds or wrinkLesshall be shingle.lapped in the direction of the paving operation, Brooming and/orpneumaticrolling will be requiredto maximizepavingfabric, contactwiththe pavement surface. Additional hand-placedtack coatmay be requiredat laps and repairsas detcrm~n~dby the engineerto satisfy bitumenretentionof thelapped pavingfabric. Alt areaswith paving fabricsplacedwill be~pavedthe same day. No traffic exceptnecessaryconstructionequipmentwill be allowedto drive on the paving fabric.

Turning of the paver and other vehiclesshall be donegradually andkeptto aminimum to avoidmovementanddamageto the pavingfabric.Abrupt starts and stopsshall also be avoided. Damaged fabric shall beremovedand replacedwith the same type of fabric. Overlapsshall beshingled-lapped in the directionof paving. Additional tackcoat shall beplacedbetweentheoverlapto satisfysaturationrequirementsof the fabric.Overlapshallbe sufficientto ensurefull closureof thejoint but not exceed150 mm.

704.4.6.Overlay placement: Bituminousoverlayconstructionshallcloselyfollow fabric placement.All areasin which pavingfabrichasbeenplaced will be paved during the sameday. Excess tack coat which bleedsthrough the paving fabric shall be removed.Excesstack coat can beremovedby broadcasting hotmix or sandon the paving fabric.

705. PROTECTION WORKS WITH GEOSYNTHETICS

705.1. Scope

This work shallconsistof layingboulderGabions/Mattressesin wrapsof Geosyntheticsin the form of bolsters, on slopesof embankments or inapron. Gabionsor Mattressesare alsoused for stonespurs. Geotextiles areused for prevention of migration of fine soil particles.

705.2. Gabions/Mattresseswith Geogrids and Geonets

Mattressesconstructedwith Geogridsor Geonetsshall be used forthickness of 300 mmor aboveas shownin the drawings.While adoptinga particular size for gabionsor mattresseswidth of the roll of geogrid/geonetmay be kept in view to minimise wastageof the geosyntheticincutting off pieces.The mesh opening may very dependingon functionalrequirementbut shalt haveaperture between35 mm and tOO mm. The

266

c;eosynthetics Section700

mesh/net shall have following characteristicsAperture Rectangular, squareor oval shaped (and not in diamond, round or.

polygonal shape).

Colour BLack

Mechanical : 1~akstrengthia~iless than 10 kN/m at maximumelongationofProperties 15 per cent.Notmorethan5 percentelongationat half peak load.

Stands/Fabric Integral joints with junction strengthof 100 per cent of plainForm strandsas measuredby GRI-003 standards.Material shall have

ISO 9002 ce~1ification.

Life : Aileast B years in caseof continuousexposureand 5 years forburned~plications (drflnedas capableof retainingatleast75percentof its original strengthafter the life spanawed.

7053.Construction705,3.1. Assembly: Gabion andmattressboxesshall be assembled in

situ, on a level surface. After fabrication is done in situ they shall becorrectly filled in layers in densepackedstate.

The bottom,sidesandendpanelsshall be erectedafter removal of allkinks, keptin an uprightpositionto form rectangularboxesby joining thesideswith connectorsof 40 mm x 6 mm size,or by ring staples.The topcornersshallbe tie tensionedfrom sidesto keepit erectfor filling. Forgabionsof 600 mm or moreheight, suitablecrossinternal ties shall beplacedin layersof 300mm connectingoppositesidesin lateralbracestiedwith polymer braids of ultra-violet stabilisedvariety so as to ensureprotection againstbulging of the gabions during filling with stones.

705.3.2.Constructionand installation : The filling of the gabion/mattressshalt be done by hand in layers so as to minimise viods andachieve specified density. The stonesin contact with the surfaceof thegeogrids/geonetsshall be placed in sucha way thattheir sharpedgesarekeptturnedinsideso thattheydo not damagethe material of the geogrids/geonets.The oppositepanelsof the boxesshall be firmly securedwithlateral tiesto withstandthedesignforces.Thebottom of thegabionmeshshall be securedin a key typeexcavationfor preventingslide. The spacebetween the gabion and earthen sides shall be filled with sand and thefilling compacted,In most of thecasesdesignshall besupplementedwitha Layer of geotextile under the gabion/mattress to prevent migration offines.

705.3.3.Laying boulder apron in crates : Mattressesof minimumheight 300 mm shaltbeused.Thetypical size of a single continuousunitshall be I m x 5 m size with bafflesat 1 mcentres. The size of bouldersshall be atleast100 mm or double the size of the aperturewhicheveris

267


larger.The densityof boulderfilling shall be asstatedin the drawing andthe specific gravity of stonesnot lessthan 2.65. Methodologyof layingboulders shall be as peg Clause2503.3. Gabionsif placedin the apronshallbe of size1 m x 5 m in planwith height at least600mm, with bafflesin 1 m centres.

Gabionsor mattressesmade with polymer geogrids/geonetsshallalways be laid in situ andshall not be performed, filled andtransportedto be droppedin deep waters. Wheredepthof water is low or dry bedisavailable, theboxesshallbefilled in situ. In streamsor water bodyhavingrunning boulders in the bed, the gsbions/mattressesshallbe armouredwithplacement of loose largebouldersalongside the gabion wall to protectagainst impacthit of stray boulders.

Stakesor keying shall always be provided in the founding recess,where the gabionbe located,especiallyin casethe ground is assessedtobe sloping or yielding type.

705,3.4.Groynes or spurswith crates : Groynesor spurs of gravityretaining variety shallbe constructedusinggeogrid/geonetgabionsplacedin a stableconfigurationone over the other to form a well. They shall befilled in situ on a shallow depth of water or dry bed with firm foundingandlevel strata.The provisionof alayerof geotextile/geocompositeshallbe made while placing the structure if resting over a bed of fine soil toprevent passageof fines and sinking.

705.3.5. Measurements for payment : The fabric of geotextile/geocompositeshall be measuredin sq. metres,,of plan areaof actual use(as per drawing).

The connecting rodsor polymer braids shall be measuredin metres.Ring staplesshall be measuredin number provided per linear metre.

The boulder fill shall be measuredin cubic metres.

The excavationfor keyingof gabionsin thegroundtrenchesshall bemeasuredin cubic metres.

The backfilling in side trenches shall be deemed part of theexcavationwork.

705.3.6.Rate : The cost of Geosyntheticmaterial for fabrication of(iabions(Mattressesshall be all inclusive of supply, transportationandstorage.

The contract rate percubicmetreof crate fill shall Consistof cost ofbouldersandtheir transportation.

268


The contract rate for excavation and backfilling of trenches, seatingtrenchupto 15 cm (includedin rate),shall include cost of labour, tools andplant for completionof the work.

The cost of making a crate shall include preparation of box ofgeogrid/geonet,tensioning and staking arrangements,tying, internalcrossbraids,etc., for foi’ming of the cratesin an engineeredmanneraridfilling the crate by laying boulders. The east shall include transportationof material from storeto site.

Wherevercompositesystemusing Geosyntheticswith natural mater-rial like stone revetrnentetc. shall be used,the provisionof measurementand rate as per Clauses2509 and 2510 areapplicable.

ztt

Traffic Signs,Markings and

Other Road Appurtenances

800

Traffic Signs,Markingsand Other RoadAppurtenances

Traffic Signs, Markingsand Section 800Other Road Appurtenances

801. TRAFFIC SIGNS

801.1. General

801.1.1. The colour, configuration, size and location of all trafficsignsforhighwaysother thanExpresswaysshall be in accordancewith theCodeof Practice for Road Signs,IRC: 67 or asshownon the drawings.For Expressways,the size of the signs, letters and their placementshallbe as specified in the Contractdrawingsand relevant Specifications. Inthe absence of any details or for any missing details, the signs shall beprovidedas directed bythe Engineer,

801.1.2.Thesignsshall beeitherreflectorisedor non-refiectorisedasshown on the drawings or as directed by theEngineer.When they areof reflectorised type, they shall beof retro-reflectorisedtype andmadeof encapsulatedlens type reflective sheetingvide Clause801.3, fixedover aluminium sheetingas per these Specifications.

801.1.3.In general, cautionary andmandatory signsshall be fabri-cated through processof screen printing. In regardto informatory signswith inscriptions, either the message could be printed over the reflectivesheeting, or cut lettersof non-reflectiveblacksheeting used for thepurpose which must bebonded well on the basesheetingas directed bythe Engineer.

801.2. Materials

The various materials and fabrication of the traffic signs shallconform to the following requirements:

801.2.1, Concrete : Concrete shall be of the grade shown on theContractdrawingsor otherwiseas directed bythe Engineer.

801.2.2,Reinforcing steel : Reinforcing steel shall conform to

the requirementof IS:l786 unless otherwiseshown on the drawing.801.23.Bolts, nuts,washers: High strength boltsshall conform to

IS : 1367 whereasprecisionbolts, nuts, etc., shahconform to IS: 1364.801.2.4. Platesand supports: Plates andsupportsections for the

sign posts shall conform to IS: 226 andIS: 2062or any ot!~errelevantIS Specifications.

801.2.5. Aluminium: Aluminium sheetsusedfor sign boards shallbe of smooth, hardandcorrosionresistantaluminium alloy conformingto IS 736-Material designation24345 or 1900.

273

Section800 Traffic Signs and Appurtenances

801.2.6. Signs with, a maximum side dimensionnot exceeding600mm shall not be less than 1.5 mm thick, All others shall be at least 2mm thick. Thethickness of thesheetshallbe relatedto the sizeof thesign and its support and shall be suchthatit doesnot bend or deformunder the prevailing wind and other loads.

801.2.7.In respectof sign sizesnot coveredby IRC:67, the structuraldetails (thickness,etc.) shall be as per the approveddrawings.

801.3. Traffic Signs Having Retro-reflective Sheeting

801.3.1. Generalrequirements:The retro-reflectivesheetingusedon the sign shall consistof the white or colouredsheeting having asmooth outersurfacewhich has the property of retro-reflectionover itsentire surface. It shall be weather-resistantand show colour fastness. Itshall be new andunusedandshallshow no evidenceof cracking, scaling,pitting, blistering, edge lifting or curling and shall have negligibleshrinkage or expansion. A certificate of having testedthe sheetingforthesepropertiesin an unprotectedoutdoorexposurefacing the sun fortwo years and its having passedthesetestsshall be obtainedfrom areputed laboratory, by the manufacturerof the sheeting.The reflectivesheetingshall be either of EngineeringGrade materialwith enclosedlensor of High Intensity Grade with encapsulatedlens. The type of thesheetingto be used would dependupon thetype,functionalhierarchyandimportanceof the road.

801.3.2. High intensity grade sheeting: This sheeting shall beof encapsulatedlens type consisting of spherical glass lens, elementsadheredto a syntheticresin andencapsulatedby a flexible, transparentwater-proof plastichaving a smoothsurfacerTheretro-reflectivesurfaceaftercleaning with soapand waterandin dry conditionshall have theminimum co-efficient of retro-reflection (determined in accordancewith ASTM Standard E : 810) as indicated in Table 800-1.

TABLE KOO-1. ACCEPTABLE MiNIMUM COEFFICIENT OF RETRO.REFLECTION FOR HIGH INTENSITY GRADE SHEETING(CANDELAS PER LUX PER SQUARE METRE)

Observationangle(in degrees)

EntranceAngle(In degrees)

White Yellow Orange Green/Red

Blue•

0.2 -4 250 170 100 45 200.2 ÷30 150 100 60 25 110.5 -4 95 62 30 15 7.50.5 +30 65 45 25 10 5,0

274

Traffic SignsandAppurtenances Section800

When totally wet, the sheetingshall not show lessthan 90 percentof the values of retro-reflectance indicated in Table 800.-I. At the endof 7 years, thesheetingshall retain at least 75percent ofits originalretro-reftectance.

801.3.3. Engineering grade sheeting: This sheeting shallbe ofenclosedlens type consistingof microscOpic lens elements embeddedbeneath thesurfaceof asmooth,flexible, transparent,water-proofplastic,resulting in a non-exposed lensopticalreflecting system. Theretro-reflective surfaceaftercleaningwith soapandwaterandin dry conditionshall havethe minimum coefficient of retro-reflection (determinedinaccordance with ASTM Standard:E-810) as indicated in Table 800-2.

TABLE 800-2. ACCEPTABLE MINIMUM COEFFICIENT OF RETRO-REFLECTION FOR ENGINEERING GRADE SHEETING(CANDELAS PER LUX PER SQUARE METRE)

Observationangle Indegree

Entranceangle Indegree

White Yellow Orange Green Red Blue

0.2 -4 70 50 25 9.0 14.5 4.0O~2 +30 31) 22 7.0 3.5 6.0 1.70.5 .4 30 25 13.5 4.5 7.5 2.00.5 ÷30 15 13 4.0 2.2 3.0 0.8

When totally wet, the sheetingshall not show less than90 percentof the values, of retro-reflection indicated in Table 800-2.At the endof 5 years, the sheeting shall retain at least50 per cent of its originalretro-reflectance.

801.3.4.Messages/borders:Themessages (legends,letters,numeralsetc.) and bordersshall either be screen-printed or of cut-outs. Screenprinting shall beprocessedand finished with materials andin a mannerspecified by the sheeting manufacturer. Cut-outsshall be of materials asspecified by the sheeting manufacturer and shall be bonded with thesheeting in the manner specifiedby the manufacturer.

801.3.S.For screen-printed transparentcolouredareas on white sheet-ing, the co-efficient’ of retro-reflectionshallnot beless than50 percentof the values of corresponding colour in Tables 800-I and 800-2, asapplicable.

801.3.6. Cut-out messagesandborders,wherever used,shall bemadeout of retro-reflective sheeting(as per Clause801.3.2or 801.3.3as appli-cable),exceptthose in blackwhich shall beof non-reflectivesheeting.

275

Section800 Traffic SignsandAppurtenances

801.3,7. Colour: Unless otherwise specified, the general colourschemeshall be as stipulated in IS : 5 “Colour for Ready Mixed Paints”,viz.

Blue - IS Colour No. 166: French Blue

Red - IS Colour No. 537: Signal Red

Green - IS Colour No. 284: India Green

Orange - IS Colour No. 591: DeepOrange.

The Colours shall be durable and uniform in acceptable hue whenviewed in day light or under normal headlights at night.

801.3.8. Adhesives : The sheeting shall either have a pressure-sensitive adhesive of the aggressive-tack type requiringno heat, solventor otherpreparationfor adhesion to a smooth cleansurface,or a tack freeadhesiveactivated by heat, applied in a heat-vacuumapplicator, ina mannerrecommendedby the sheetingmanufacturer.Theadhesiveshallbe protected by an easily removable liner (removable by peeling Withoutsoaking in water or othersolvent) andshall be suitablefor the type ofmaterial of the baseplate used for the sign. The adhesiveshall form adurablebond to smooth,corrosion and weatherresistantsurfaceof thebaseplate such thatit shall not be possibleto remove the sheeting fromthe sign basein onepiece by use of sharp instrument.In caseofpressure-sensitiveadhesivesheeting, the sheeting shall be applied inaccordancewith the manufacturer’sSpecifications,Sheetingwith adhe-sivesrequiring use of solvents or otherpreparationfor adhesiveshallbe applied strictly in accordancewith the manufacturer’sinstructions.

801.3.9.Refurbishment:Where existing signs are specified forrefurbishment,the sheetingshall havea semi-rigid aluminium backingpre-coatedwith aggressive-tacktype pressuresensitive adhesive. Theadhesiveshall be suitablefor the typeof material usedfor the sign andshould thoroughly bond with that material.

801,3.10.Fabrication801.3.10.1. Surfaceto be reflectorisedshall be effectively prepared

to receive the retro-refleetivesheeting. The aluminium sheeting shallbe de-greasedeither by acid or hot alkaline etching and all scale/dustremoved to obtain a smooth plain surface before the application of retro-reflective sheeting. If the surfaceis rough,approvedsurfaceprimer maybe used. After cleaning, metal shall not be handled, exceptby suitablede~’ice or clean canvas gloves,between all cleaning and preparation

~276

Traffic Signs andAppurtenances Section800

operation andapplication of reflective sheeting/primer.Thereshall beno opportunity for metal to comein contactwith grease,oil or othercontaminants prior to theapplicationof retro-reflectivesheeting.

801.3.10.2. Complete sheetsof the materialshallbe used on thesignsexceptwhere it is unavoidable;at splices, sheetingwith pressuresensitiveadhesives shall beoverlappednot less than5 mm. Sheetingwithheat-activatedadhesivesmay be splicedwith an overlapnot less than5mm or butted with a gapnot exceeding0.75 mm.Where screen printingwith transparentcolours is proposed,only butt jointing shall be used.The materialshall cover the sign surfaceevenly and shall be free fromtwists, cracks andfolds.Cut-outsto producelegendsandbordersshall bebondedwith the sheetingin the manner sjecifiedby the manufacturer.

801.3.11. Warranty and durability The Contractor shall obtainfrom the manufacturer a seven-year warranty for satisfactory fieldperformanceincluding stipulatedretro-reflectance of the retro-reflectivesheetingof high intensitygradeanda five yearwarranty for the adhesivesheeting of engineering gradeand submit the sameto the Engineer. Inaddition, a seven yearanda five year warranty for satisfactory in-fieldperformanceof the fmished sign with retro-reflectivesheetingof highintensitygradeandengineering graderespectively,inclusive of the screenprintedor cut out Ieuer~legendsandtheir bondingto the retro.-reflectivesheetingshall be obtained from theContractor/supplier and passedonto the Engineer. The Contractor/suppliershall also furnish a certificationthat the signsandmaterialssuppliedagainstthe assignedwork meets allthe stipulated requirementsand carry the stipulated warranty.

Processedandappliedin accordancewith recommendedprocedures,thereflective material shall beweather resistantand,following cleaning,shall show no appreciablediscolouration,cracking,blistering or dimen.sional change andshall nothave less than50 per cent of thespecifiedminimum reflective intensity values (Tables 800-I and 800-2) whensubjectedto acceleratedweatheringfor 1000hours,usingtype E or EliWëatherometer(AASI3TO DesignationM 268).

801.4.Installation

801.4.1.Sign posts, their foundations andsign mountings shall beso constructedasto hold thesein aproperandpermanentposition againstthe normal storm wind loadsor displacementby vandalism.Normally,signswith an areaupto 0.9 sq. m. shall be mounted on a single post,andfor greater area two or moresupportsshall be provided.Sign supportsmay be of mild steel, reinforcedconcreteor galvanisediron (0.1). Post-

277


end(s)shall be firmly fixed to thegroundby meansof properly designedfoundation. The work of foundation shall conform to relevant Specifica-tions as specified,

801.4.2. All componentsof signs and supports, other than thereflective portion and 0.1. postsshall be thoroughly descaled,cleaned,primed and painted with two coatsof epoxypaint.Any part of mild steel(M.S.) post below ground shall be painted with threecoatsof red leadpaint.

801.4.3. The signs shall be fixed to the postsby welding in the caseof steel posts and by bolts and washers suitablesize in the caseof reinforcedconcreteor 0.1. posts.After the nuts havebeentightened,the tails of the bolts shall be furred over with a hammer to preventremoval.

801.5.Measurements for Payment

The measurement of standardcautionary,mandatory and informa-tion signs shall be in numbersof differenttypes of signs supplied andfixed, while~for direction and place identification signs, theseshall bemeasuredby area in squaremetres,

801.6.Rate

The Contract unit rateshall be paymentin full for the cost ofmaking the roadsign, including all materials, installing it at the site andincidentalsto completethe work in accordancewith the Specifications.

802. OVERHEAD SIGNS’802,1. General

802.1.1. Overheadsigns maybe used in lieu of, or as an adjunctto, ground signs wherethe situationsowarrantsfor proper informationand guidanceof the road user.Thefollowing conditionsmay be consideredwhile deciding about the provision of overheadsigns:

(1) Traffic vohame at or nearcapacity

(2) Complex interchangedesign(3) Threeor more lanesin eachdirection

(4) Restrictedsight distance

(5) Closely spacedinterchanges

(6) Multi-Sic exits(7) Largepercentageof commercialvehicles

(8) High speedtraffic

278


(9) Consistency of sign message location through a series of interchanges

(10) Insufficientspace for groundmounted signs

(11) Backgroundof streetlighting

(12) Distances of important places enroute highways at suitableintervals,

802.1.2. From safetyandaestheticstandpoints,overheadsigns shallbe mounted on overheadbridge structureswhereverpossible.Wherethese are requiredto be provided at someother locations,the supportsystem should be properly designed based on sound engineering prin-ciples, to safely sustain the dead load, live load andwind load on thecompleted sign system. For this purpose, the overhead signs shall bedesignedto withstanda wind loading of 150 kg/rn2normal to theface ofthe sign and 30 kg/rn2 transverse to the face of the sign. In addition tothe deadload of thestructure,walkway loading of 250 kg concentratedlive load shall also be consideredfor the designof the overheadsignstructure.

802.2. Height

Overhead signsshall provide a vertical clearanceof not less than5.5m over the entire width of the pavementand shoulders except where alesser vertical clearanceis used for the design of other structures. Thevertical clearanceto overhead sign structuresor supports need not begreater than 300 mm in excessof the minimum design clearance ofotherstructures.

802.3. Lateral Clearance

802.3.1.The minimum clearanceoutside the usableroadway shoul-der for expressway signs mountedat the road sideor for overhead signsupports either to the right or left side of the roadway shall be 1.80 m.This minimum clearanceof 1.80 m shall also apply outside of anunmountable kerb. Where practicable, a sign should not be less than3 mfrom the edgeof the nearest traffic lane. Large guide signs should befarther removedpreferably 9 m or more from the nearesttraffic lane,unless otherwisespecified. Lesserclearances,but not generally lessthan1.80 m, may be usedon connectingroadwaysor ramps at inter-changes.

802.3.2. Where a median is 3.6 m or less in width, considerLzionshould be given to spanning over both roadways without a centralsupport. Where overhead sign supportscannot be placed at a safedistance away from the line of traffic or in an otherwiseprotectedsite,they should either be so designed as to minimise the impact forcesorprotectmotorists adequatelyby a physical barrieror guardrail of suitabledesign.

279


802.4. Number of Signs at an Overhead Installation

In no caseshouldtherebe more than three signsdisplayedatany oneLocation, including regulatoryor warningsigns, eitheron the overheadstructureor on its support.

802.5. Materials for Overhead Sign and Support Structures

802.5.1. Aluminium alloy or galvanized steel to be usedas trussdesign supportsshall conform to relevant IS. These shall beof sectiçnsand type asper structural design requirements as shown on the plans.

802.5.2. After steel trusseshave been fabricated and all requiredholespunched ordrilled on both the horizontaltrussunits and the verticaland support units, they shall be galvanized in accordancewith ISSpecifications.

802.5.3. Where aluminium sheets areusedfor roadsigns,they shallbe of smooth, hardandcorrosionresistantaluminium alloy conformingto IS 736- Material Designation24345 or 1900. Tbethicknessof sheetshall be related to the size of the sign with minimum thicknessof sheetas 1.5 mm.

802.5,4. High strength bolts shall conform to IS: 1367 whereasprecision bolts,nuts etc. shall conformto IS: 1364.

802.5.5. Platesand support sectionsfor sign postsshall conform toIS: 226 and IS: 2062,

802.5.6. Theoverheadsigns shallbereflectorisedwith high intensityretro-reflectivesheetingpreferably of encapsulatedlenstype.

802.6. Size, Locations,etc. of Signs

802.6.1. The sizeof the signs, lettersand their placementshall beas specifiedin the ContractdrawingsandSpecifications.

802.6.2. In the absenceof detailsor for any missing details inthe Contract documents, thesigns shall be providedas directed bythe Engineer.

802.7. Installation

802.7.1.The supportingstructureand signs shall be fabricated anderectedas per detailsgiven in the plans.

802.7.2.Sign posts, their foundations andsign mountingsshall beso constructed as to hold signs in a proper and permanent positionto adequately resist swaying in the wind or displacementby vandalism.

280


802.7.3. The work of construction of foundation for sign supportsincluding excavation and backfill, forms, steel reinforcement,concreteand its placement shall conform to therelevant Specifications givenin theseSpecifications.

802.7.4. The structuresshall be erectedwith thespecifiedcamberandin sucha mannerasto preventexcessivestresses,injury anddefacement.

802.7.5. Brackets shall be provided for mounting signsof the typeto be supported by the structure. For better visibility, they shall beadjustableto permit mounting the sign faces at any anglebetweenatruly vertical position and threedegreefrom vertical. This angleshallbe obtained by rotating the front lower edge of the sign forward. Allbrackets shall be of a length equal to the heightsof the signs beingsupported.

802.7.6.Before erectingsupportstructures,the bottom of each baseplate shall be protectedwith an approvedmaterial which will adequatelypreventany harmful reactionbetweenthe plate and the concrete.

802.7.7. The end supportsshall be plumbed by the use of levellingnuts and the space betweenthe foundation and base plate shall becompletely filled with an anti-shrinkgrout.

802.7.8. Anchor bolts for sign supportsshall be set to properlocations and elevation with templates and carefully checked afterconstruction of the sign foundationandbefore the concretehas set.

802.7.9. Al! nuts on aluminium trusses,exceptthose used on theflanges,shall be tightenedonly until they are snug.This includesthenutson the anchor bolts. A thread lubricant shall be usedwith eachaluminiumnut.

802.7.10.All nuts on galvanizedsteel trusses,with the exceptionofhigh strengthbolt connections,shallbe tightenedonly to a snug condition.

802.7.11.Field welding sh~1lnot be permitted.

802.7.12. After installation of signsis complete, thesign shall beinspectedby the Engineer.If specularreflection is apparenton any sign,its positioning shall be adjustedby the Contractor to eliminate orminimize this condition.


802.8.!.Aluminium or steeloverheadsign structurewill be measuredfor paymentby the specific unit (each)complete in place or for each

281


component of the overheadsign structureas indicated in the Bill ofQuantities and the detaileddrawing(s).

802.8.2. Flat sheet aluminium signs with retro-reflectivesheetingthereonshall be measured for paymentby the square metre for eachthickness,cqmpletein place.

802.9. Rate

802.9.1. The structural steel part of the overhead sign shall bemeasuredin tonneswhile thesignhoardshall be measuredin sq. in. Otheritems like excavation for foundationandconcrete in foundation to bemeasured and paid in Cu. m. separately. The Contract unit rate foroverhead sign structure shall be payment in full compensationforfurnishingall labour,materials, tools,equipment,excavation,fabricationandinstallation and all other incidental costs necessaryto completethe work to the Specifications.

802.9.2. The Contract unit rate for aluminium sheet signs shallinclude thecost of making the sign including all materialsandfixing thesame in position andall other incidentalcostsnecessaryto completethework to the Specifications.

803. ROAD MARKINGS

803.1. General

Thecolour, width andlayoutof roadmarkingsshall bein accordancewith the Codeof Practicefor RoadMarkings with paints,IRC : 35, and

as specifiedin the drawingsor as directed by the Engineer.

803.2. Materials

Road markingsshall be of ordinary road markingpaint, hot appliedthermoplasticcompound,or reflectorisedpaint asspecifiedin the item andthe material shall meetthe requirementsas specifiedbelow.

803.3. Ordinary Road Marking Paint

803.3.1. Ordinarypaintusedfor road markingshall conform to GradeI as per IS: 164.

803.3.2. The road marking shall preferablybe laid with appropriateroad marking machinery.

803.3.3.Laying thicknessof road markingpaint shall be as specifiedby the Engineer.

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803.4. Hot Applied Thermoplastic Road Marking

803.4.1. General(i) The work underthissectionconsistsof marking traffic stripesusinga thennopiattic

compoundmeetingthe requirements specifiedherein.

(ii) The thermoplasticcompoundshall bescreeded/extnidedon to thepavementsurfacein amolten stateby suitablemachinecapable of controlled preparationandlayingwith surfaceapplication of glass beadsat a specificrate.Uponcooling to ambientpavementtemperature, it ~hatlproduceanadherentpavementmarking of specifiedthickness and width and capableof resistingdeformationby traffic.

(iii) The colour of the compoundshall be white or yellow (IS colour No, 356) asspecified in the drawings or as directed by theEngineer

(iv) Where the compound is to be applied to cement concrete pavement,a sealingprimer as recommendedby the manufacturer,shall be applied to the pavementin advance of placing of the stripes to ensureproperbonding of the compound.On newconcrete surfaceany laitance and/or curing compoundshall be removedbefore the markings are applied.

893.4.2.Thermoplastic Material,

803.4.2.1.General : The thermoplastic material shall be homo-geneouslycomposedof aggregate,pigment,resinsandglassreflectorizingbeads,

803.4.2.2.Requirements(i) CompositIon : The pigment, beads,and aggregateshall be uniformly dispersed

in the resin, The material shall be free from all skins, dirt and foreign objectsand shall comply with requirementsindicated in Table 800-3.

TABLE 800.3. PROPORTIONS OF CONSTITUENTSOP MARKING MATERIAL(Percentageby weight)

Component White Yellow

Binder 18.0 mm. 1811mm.Glass Beads 30-40 30-40Titanium Dioxide 10.0 miii. —

Calcium CarbonateandInert Fillers 42.0 max. SeeYellow Pigments — Note

Note : Amount of yellow pigment, calcium carbonateand inert fillers shall be at theoption of the manufacturer, providedall otherrequirementsof this Specificationaremet.

(ii) Propertles The propertiesof thermoplastic material, when tested in accordancewith ASTM D36i’BS.3262.(PartI), shall be asbelow:

(a) Luminance

White : Daylight luminanceat 45 degrees-65per cent miii, as per AASHTOM 249

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Section800 Traffic Signsand Appurtenances

Yellow : Daylight luminance at 45 degrees-45per cent mm. as perAASHTOM 249

(b) Drying tIme : When appliedat a temperature specifiedby the manufacturerand so the required thickness, the materialshall set to bear traffic in notmore than 15 minutes.

(c) Skid resistance: not less than 45 as per BS 6044.

(d) Crackingresistanceat low temperature:The materialshall showno crackson application to concreteblocks.

(e) Softeningpoint: 102.5 ±9.5 C aspetASTM D 36.

(f) Flow resistance:Not more than 25 percent as per AASIITO M 249.

(g) YellownessIndex (for white thermoplasticpaint): not more than 0.12 asper AASHTO M 249

(iii) Storagelife : The material shall meetthe requirements of theseSpecifications fora period of one year. The themsoplasticmaterialmust also melt uniformly withno evidenceof skins or unmeltedparticlesfor the oneyear storage period. Anymaterial not meeting the above requirementsshall be replaced by the manufac~turer/ supplier/Contraiior,

(Iv) Reflectorlsation : Shall be achievedby incorporationof beads, the grading andother propertiesof the beadsshall be as specified ~unClause 803.4.3.

(v) Marking : Each containerof the thermoplastic material shall be clearly andindelibly marked with the following information:

1. The name, trade mark or oilier meansof identification of manufacturer

2. Batch number

3. Date of manufacture

4. Colour (white or yellow)

S. Maximum application temperature and maximum safe heating temperature.

(vi) Sampling and testIng: The thermoplastic material shall be sampled and tested inaccordance with the appropriateASTM/BS method. The Contractor shall furnishto the Employer a copy of certified test reports from the manufacturers of thethermoplastic material showing results of all tests specifiedherein and shallcertify that thematerial meetsall requirements of this Specification.

803.4.3.Reflectorising glass beads

803.4.3.1. General : This Specificationcoverstwo types of glassbeadsto be used for the productionof reflectorisedpavementmarkings.

Type 1 beads are those which area constituent of the basicthermoplastic compoundvideTable 800-3andType 2 beadsare thosewhich are to be sprayedon the surfacevide Clause803.6.3.

803.4.3.2. Theglass beadsshall be transparent,colourlessand freefrom milkiness,dark particlesandexcessiveair inclusions.

284


These shall conform to the requirements spelt out in Clause803.4.3.3.

803.4.3.3.Specific requirementsA. Gradation: The glass beads shall meet the gradation require-

ments for the two types as given in Table 800-4.TABLE 800.4. GRADATION REQUIREMENTS FOR GLASS BEADS

SievesizePercant retaIned

Type 1 Type 2

1.18mm Oto3 -

850 micron 5 to 20 Oto5600 -do- - 5to20425 -do- 65 to 95 -

300 -do- - 30 to 75180 -do- 0 to 10 10 to 30below 180micron - 0 to 15

B. Roundness:The glassbeadsshall haveaminimumof 70 per centtrue spheres.

C. Refractive index: The glass beadsshall have a minimum re-fractive index of 1.50.

D. Free flowing properties : The glassbeadsshall be free of hardlumpsand clusters and shall dispense readily under anyconditions suitable for paint striping. They shall passthe freeflow-test.

803.4.3.4. Test methods: The specific requirements shall be testedwith the following methods:

(i) Free-flow test: Spread100 gramsof beads evenly in a 100 mm diameterglassdish. Placethedish in a 250mminside diameterdesiccatorwhich is filled within25 mm of the top of a desiccator plate with sulphuricacid watersolutionspecific gravity L10). Cover the desiccatorand let it stand for 4 hours at 2Oto 29degreeC. Removesample from desiccator, transferbeads to a pan and inspectfor lumpsor clusters, Then pour beadsinto a clean,dry glassfunnel having a 100mm stem and 6 mm orifice. If necessary,initiate flow by lightly tapping thefunnel. The glass spheresshall be essentially free of lumps and clustersand shallflow freely through the funnel.

(ii) The requirementsof gradation,roundnessand refractiveindex of glass beadsandtheamountof glassbeads in thecompoundshall be testedasper BS 6088 and BS3262 (PartI).

(iii) The Contractor shall furnish to theEmployer a copyof certifiedtest reports fromthe manufacturer of glass beads obtained from a reputed laboratory showing

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Section800 Traffic Signsand Appurtenances

resultsof all tests specifiedherein and shall certify that the material meetsall requirementsof this Specification.Flowever, if so required, thesetests maybe carried out as directedby theEngineer.

803.4.4.Application properties of thermoplastic material

803.4.4.1. The thermoplasticmaterial shall readily get screeded/extrudeda1 temperaturesspecifiedby the manufxturersfor respectivemethod of application to produce a line of specified thickness whichshall be continuousand uniform in shapehavingclearand sharpedges.

803.4.4.2. The material upon heating to application temperatures,shall not exude fumes, which are toxic, obnoxious or injurious topersons or property.

803.4.5.Preparation:~i) ‘The material shall bemeltedin accordancewith the manufacturer’sinstructionsin

a heater fitted with a mechanicalstirrer to give a smooth consistency to thethermoplastic material to avoid local overheating. The temperatureof the massshall be within the rangespecified by the manufacturer,and shall on no accountbe allowedto exceedthe maximumtemperaturestatedby the manufacturer. Themolten material should be usedas expeditiously as possible and for thermoplasticmaterial which hasnatural bindersor is otherwisesensitive to prolonged healing,the material thall not be maintained t:n amoltencondition for morethan4 hours.

(ii) After transfer to the laying equipment,the material shall be maintained withinthe temperaturerange specified by themanufacturerfor achievingthedesiredconsistencyfor laying.

803.4.6. Properties of finished road marking(a) ‘I’he stripe shall not be slippery when wet.

(b) The marking shall not lift from thepavement in freezing weather.

(c) After application and proper drying, the stripe shall show no appreciabledeformation or discolouration under traffic and under road temperatures upto60~C.

(d) Themarkingshall not deteriorate by contact with sodiumchloride, calciumchlorideor oil drippings from traffic.

(e) l’he stripe or marking shalt maintain its original dimensions and position, Coldductility of thematerialshall besuchasto permitnormalmovementwith the roadsurface without chopping or cracking.

(I) ‘I’he colour of yellowmarking shall conform to IS Colour No. 356 as given in lS:164.

803.5. Reflectorised Paint

Reflectorised paint, if used,shallconformto theSpecification by themanufacturersandapprovedby the Engineer.Reflectorisingglass beadsfor reflectorisingpaintswhereusedshall conform to the requirement ofClause803.4.3.

286


803.6.Application

803.6.1. Marking shall be doneby machine. For locations wherepainting cannotbedoneby machine,approvedmanualmethodsshall beused with prior approval of the Engineer.TheContractor shall maintaincontrol over traffic while painting operationsare in progressso as tocause minimum inconvenienceto traffic compatiblewith protecting theworkmen.

803.6.2. The thermoplastic material shall be applied hot eitherby screeding or extrusion process. After transferto the laying apparatus,the material shall be laid at a temperaturewithin the rangespecifiedbythe manufacturer for the particularmethod of laying being used. Thepaint shall he applied usinga screedor extrusionmachine.

803.6.3. The pavementtemperatureshall not be less than 10°Cduring application.All surfacestobe markedshall be thoroughly cleanedof all dust, dirt, grease,oil and all other foreign matter beforeapplication of the paint.

The material,whenformedinto traffic stripes,mustbe readily renew-able by placing an overlayof new materialdirectly over an old line ofcompatiblematerial.Suchnew materialshall sobonditself to the old linethat no splitting or separationtakesplace.

Thermoplastic paint shall be applied in intermittent or continuouslines of uniform thicknessof at least2.5mm unlessspecified otherwise.Where arrowsor lettersare to be provided, thermoplastic compound maybe hand~sprayed.In addition to the beads includedin the material, afurtherquatnity of glass beads of Type 2, conforming to the abovenoted Specification shall be sprayeduniformly into a mono-layeron tothe hot paint line in quicksuccessionof thepaintsprayingoperation.Theglassbeadsshall beappliedatthe rateof 250gramsper squaremetrearea.

803.6.4. The minimum thicknessspecified is exclusiveof surfaceappliedglass beads,The methodof thicknessmeasurementshall be inaccordancewith AppendicesB and C of BS - 3262 (Part 3).

803.6.5.Thefinishedlinesshall be free from ruggednesson sidesandendsand be parallelto the generalalignmentof the carriageway. Theuppersurfaceof the lines shall be level, uniform and free from streaks.

803.7. Measurementsfof Payment

803.7.1.The paintedmarkings shall be measuredin sq. metres ofactualarea marked(excluding the gaps, if any).

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Section800 Traffic Signs and Appurtenances

803.7.2.In respectof markingslike directional arrowsand lettering,

etc., the measurementshall be by numbers.

803.8. Rate

The Contract unit rate for roadmarkingsshallbe payment in fullcompensationfor furnishing all labour, materials, tools, equipment,including all incidental costsnecessaryfor carryingout thework at thesite conforming to theseSpecificationscomplete as per the approveddrawing(s) or as directedby the Engineerandall other incidental costsnecessaryto completethe work to theseSpecifications.

804. HECTOMETRE/KILOMETRE STONES

804.1. General

The ‘work covers thesupply,painting,letteringandfixing of distancemeasurementstonesand shall include:

(i) Flectometre stones

(ii) Kilometre stones

(iii) 5th Kilometre stones

804.2. The dimengionsof the stonesandthe size,colour, arrange~ment of letters and script shall be as per IRC : 26 “Type Designsfor200 Metre Stones” and 1RC: 8 “Type Designsfor Highway KilometreStones”.

804.3. The hectometre/kilometrestones may be made of localstones,concrete or any othermaterialavailablelocally and approvedby theEngineer. The stones shall be bedded into the ground withadequatefoundations as indicated in the drawings or in the relevantI.R.C. Specificationsor as directedby the Engineer.The orientationandlocation of the stonesshall be as indicatedin the drawingsor in therelevant I .R.C. Specificationsor as directedby the Engineer.


The measurementwill be in numbersof 200 metre,kilometre and5th kilometre stonesfixed at site.

804.5.Rate

The Contractunit rate for hectometre/kilometre/5thkilometre stonesshall be paymentin full compensationfor furnishing all labour,materials,tools, equipmentand making thestones,painting andletteringand fixingat site andall other incidentalcostsnecessaryto completethe work totheseSpecifications.

288


805. ROAD DELINEATORS

805.1. General

The work covers supplyingandfixing roadway indicators, hazardmarkersandobjectmarkers.

805.2. The design, materialsto be usedand the location of theroad delineators shall conform to RecommendedPracticefor RoadDelineators,IRC: 79, andto relevantdrawingsor as otherwisedirectedbythe Engineer.


The measurementshall be madein numbersof delineators fixedat site.

805.4.Rate

The Contractunit rate for RoadDelineatorsshall be paymentin fullcompensationfor furnishing all labour,materials,tools, equipment forpreparing, supplying and fixing at site andall other incidental costsnecessaryto completethe work to theseSpecifications.

806. BOUNDARY STONES

806.1. General

The work comprisesof supplyingandfixing boundarystonr~as perdesignsandSpecificationsgiven in IRC: 25 “Type Designs fo BdtrndaryStones”and atlocationsindicated.iii the drawingsor~asdirec~&iby theEngineer.

806.2.Measi~rernentsfor PaymentThemeasurementshall be madein numbersof bouridary,stonesfixed

at site.

806.3. RateThe Contractunit rate for boundarystonesshall be paymëntin full

compensationfor furnishingall labour, materials,tools, equipment forpreparing, supplying andfixing andall other incidentalcosts necessaryto complete the work to theseSpecifications.

807. FENCING

807.1. General

The work comprisesof fixing Mild Steel(M.S.)pusts and providingbarbed wire fencingincluding necess~rystaysand entrygatesasshownin the drawing (s) and as directed by the Engineer.

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Section 800 Traffic SignsandAppurtenances

807.2. The M.S. postsshall conform to IS:226 andshall be of angleiron of size indicated in thedrawings.Theangleiron shall be embeddedin concrete to a sufficient depth below ground as indicated in thedrawings.The steel shall befabricatedandpaintedto conform to Section1900 of these‘Specifications.

807.3.The barbedwire shall beof galvanisediron andshall conformto IS:278.

807.4,Entry gate(s)shall be madeof M.S. rodsor othermetal asperthe design shown in the drawing(s).


The measurementshallbein running metreof fencing including theentry gates.

807.6, RateThe Contract unit rate for fencingshall be payment in full com-

pensation for furnishing all labour, materials, tools, equipment forfabrication and fixing at site andall other incidental costsnecessary tocompletethe work to theseSpecifications.

808. TUBULAR STEEL RAILING

808.1. General

The work shallconsistof supplying,fixing anderectingtubular steelrailings as shown on the drawingsandas directedby the Engineer.

808.2. The railings shall be of tubular steel in conformancetoIS:1239. The fabrication andpainting exceptfor the final coat shall becompletedbefore despatchto the site. Prior to the painting, all surfacesshall be grit blastedto thesatisfactionof theEngineerandpickled. Thepriming coatof paint shall be appliedas soon as the steelhas dried.

808.3. The posts shall be vertical and of the type as shown in thedrawing with a tolerancenot exceeding6mm in alength of 3 m. Therailing shall be erectedtrue to line and grade.


Therailing shallbe measuredin linear metre from endto end alongthe face of the railing, including end and intermediate posts, withno deductionsfor gaps as shown on the drawings.

808.5. Rate

The Contractunit rate for Tubular SteelRailing shall be payment

290


in full compensationfor furnishingall labour;materials, tools, equipmentand plant requiredfor fabrication, connection,oiling, painting,temporaryerection, inspection, test and final erectionat site and all otherincidentalcosts necessaryto completethe work to theseSpecifications.

809. CONCRETECRASH BARRIER

809.1, General

809.1.1.This work shall consist of construction,provision andinstallationof concretecrashbarrierat the edgesof the road and medianat locationsandof dimensionsas shownon the drawingsor as directedby the Engineer.

809.1.2. Concretebarrier shallgenerallybe located on approachesto bridge structures,at locationswhere the embankmentheight is morethan 3 metresand at horizontal curves.

809.2. Materials809.2.1.All materials shall conform to Section lOGO-Materialsfor

Structuresasapplicable,andrelevantClausesin Section 1600shall governthe steel reinforcement.The concretebarriersshall be constructed eitherby the “cast-in-placewith fixed forms” methodor the “extrusion or slipform” method or a combination thereofat the Contractor’soption withthe approval of the Engineer.Where“extrusion or slip form” methodisadopted,full detailsof the methodand literatureshall be furnished.

809.2.2. Concrete barriers shall be constructed with M ‘20 gradeconcreteand with High Yield Strengthdeformedreinforcementconform-ing to IRC: 21.

809.23. An expansionjoint with pre-mouldedasphalt filler boardshall be providedat thejunction of crashbatheron structureandcrashbarrier on the fill. The crashbarrier on the fill shall be constructedinpieces of length not exceeding20 m, with pre-mouldedasphthfillerboard joints.

8093.Construction Operations809.3.1. The location of crashbarrier shall be strictly adhered to

as shown on the drawing and as directed by the Engineer. Concretecrash bathers shall present a smooth, uniform appearance in theirfinal position, conforming to thehorizontalandverticallines shown ontheplans or .asorderedby the Engineerand shall be free o1f lumps, sagsor other irregularities. The top and exposedfacesof the bathersshallconform to the specifiedtolerances,asdefinedin Clause R()9.4, whent~stedwith 3 m straightedge,laid on the surface.

291


809.3.2.When concretebarriersare to be constructedon recentlycompleted bridges, the height of the barriers shall be adjusted tocompensatefor the camberand dead load deflectionof the superstruc-ture. The amount of adjustment shall be determinedby theEngineerandshall be ordered before the concreteis placed. Such barriersshall beplaced after form work has been released and as long after thesuperstructureconstructionas possiblewithout hampering the progressofthe work.

809.3.3. Backfilling to the concretebarriersshall be compactedinlayersto the compactionof the surroundingearthwork.

809.4.Tolerance The overall horizontalalignmentof rails shall notdepart from the road alignment by more than±30 mm,nor deviate inany two successivelengths from straight by more than 6 mm and thefices shall not vary more than 12 mm from the edgeot~a3 rn straightedge.Rarriers shall be at the specified height as shownin the plansabovethe edge of the nearestadjacentcarriagewayor shoulder,withina toleranceof ±30 mm.

8093.Measurements for Payment

All barriers will be measuredby linear metres of completed andaccepted length in place,correspondingendto end along the face ofconcretebarriersincluding approachanddepartureends.

809.6. Rate

The Contract unit rate shall include full compensationfor furnishingall labour,materials,tools, equipmentand incidentalcostsnecessaryfordoing all thework involvedin constructingtheconcretebarrier completein place in all respectsas per theseSpecifications.

810. METAL BEAM CRASH BARRIER

810.1. General

810.1.1. This work shall consistof furnishing and erectionof metalbeamcrashbarrier of dimensionsandatlocationsasshownon the drawing(s) or as directed by the Engineer.

810.1.2.Metal beamcrashbarrier shall generallybe locatedon ap-proachesto bridge structures,at locationswhere theembankmentheightis more than 3 metresandat horizontalcurves.

810.2. Materials

810.2.1. Metal beam rail shall be corrugatedsheetsteel beams of

292

Traffic Signsand Appurtenances Section800

theclass, type,sectionand thickness indicatedon theplans.Railing postsshall be madeof steelof thesection,weight and lengthas shown on theplans. All complete steelrail elements,terminal sections, posts, bolts,nuts, hardwareandothersteel fittings shall begalvanised.All elementsof the railing shall befree from abrasions,roughor sharpedgesandshallnot be kinked, twisted or bent.

810.2.2. Steel beamelementsand terminal sections shall begalvanised(zinc coated, O.55 kg per squaremetre, minimum singlespot) unlessotherwisespecified.The galvanisingon all othersteel partsshall conform to the relevantIS Specifications.All fittings (bolts, nuts,washers)shall conform to the IS 1367 and IS 1364.All galvanizingshall be done after fabrication.

810.2.3.Concretefor beddingand anchorassemblyshall conform toSection 1700 of theseSpecifications.


810.3.!. The lineandgradeof railing shall betrue to that shownonthe plans.The railing shall be carefullyadjustedprior to fixing in place,to ensureproper matchingat abutting joints and correct alignment andcamberthroughouttheir length.Holesfor field connectionsshall bedrilledwith the railing in placein the structureat proper gradeand alignment.

810.3,2. Unless otherwisespecified on the drawing, railing steelpostsshall begiven one shop coat of paint (primer) and threecoatsofpaint on structural steel aftererection,if the sectionsare not galvanised.Any part of assemblybelowground shall bepaintedwith three coatsofred lead paint.

810.3,3. Splices and endconnectionsshall be of the type anddesignsspecifiedor shown on the plansand shall beof suchstrengthasto developfull designstrengthof the rail elements.

810,4. Installation of Posts

810.4.1.Holes shall be dug or drilled to the depthindicatedon theplans or posts may be driven by approved methods and equipment,provided theseareerectedin properpositionandare freetromdistortionandburring or any other damage.

810.4.2. All post holes that are dug or drilled shall be of such sizeas will permit proper setting of the postsand allow sufficient roomfor backfilling and tapping.

810.4.3. Holes shall be backfilled with selected earth or stable

293


materials in layers not exceeding100mm thicknessandeachlayer shallbe thoroughly tamped and rammed.When backfihling and tamping arecompleted,the postsor anchors~shall be held securely in place.

810.4,4. Post holes that are drilled in rock and holes for anchorpostsshall be backfilled with concrete.

810.4.5.Postsfor metalbeamguardrailson bridgesshall bebolted tothe structureas detailedon the plans.The anchorbolts shall be set toproper location and elevationwith templatesandcarefully checked.

810.5. Erection

810.5.1. All guardrailanchorsshall be set and attachments madeandplacedas indicatedon the plans or as directed by the Engineer.

810.5.2. All boltsor clips usedfor fasteningtheguardrailor fittingsto the postsshall be drawnup tightly. Eachbolt shall have sufficientlength to extendatleast6 mm throughand beyondthe full nut, exceptwhere such extensionsmight interfere with or endangertraffic in whichcase the bolts shall be cul off flush with the nut.

810.5.3. All railings shall be erected,drawnand adjusted so thatthe longitudinal tensionwill be uniform throughoutthe entire length ofthe rail.

810.6. Tolerance

The posts shall be verticalwith a tolerancenot exceeding6 mm ina length of 3 metre.The railing barrier shall be erectedtrue to line andgrade.

810.?. Measurementsfor Payment

810.7.1. Metal beam railing barriers will be measuredby linearmetre of completed lengthasperplansandacceptedin place.Terminalsfanchors of various types shall be paid for by numbers.

810.7.2.No measurementforpaymentshallbe made for projectionsor anchorsbeyondthe endpostsexceptas noted above,Furnishingandplacing anchor bolts and/or devicesfor guardrail posts on bridgesshall be considered incidentalto the constructionand the coststhereofshall be includedin the price for other items of construction.

810.7.3. No measurementforpaymentwill be madefor excavationor backlilhing performedin connectionwith this construction.

810.8.Rate

The Contractunit rate shall include full compensationfor furnishing

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of labour, materials,tools, equipmentsandincidentalcostsnecessaryfordoingall thework involvedin constructingthemetalbeamrailing barriercompletein placein all respectsas per theseSpecifications.

811. ROAD TRAFFIC SIGNALS

811.1. General

The traffic signal, its configuration,size and location shall be inaccordancewith IRC: 93 and IS: 7537andas shown in thedrawings orasdirectedby theEngineer.Prior to installationof signals,the Contractorshall submitto theEngineer,for approval,detailedproposalsshowing thesignal type, sizes, paint and structuraldetails of the signal postsincluding control system.

811.2. Thetralfic signalsshall haveacompleteelectronicmechanismfor controlling the operation of traffic with an auxiliary manualcontroller.The time plan of signalsshall be as per drawingandshall bemodified as directedby the Engineer.

811.3. Materials

The various materials and fabrication thereof shall conform tothe following:

8113.1. Signal foundation: The signal foundationsshall be con-structed as per Specifications given in Clause13 of IRC: 93 or asshown in the drawings.

811.3.2. Constructionalrequirements:The constructionalrequire-ments for post, signal headassembly,signalhead,optical system,lampand holder, visor, post, supports for overheadmounted signals,equipmenthousing,locks,inter-connectingcables,earthing,mains termi-nation, controllerelectrical components,etc., shall conform to IS: 7537unless otherwisestated in IRC: 93. The post shall be painted andprotectedas per Clause3.7. of IS: 7537.

8113.3. Optical requirements:Theshapeof all signal lensesshallbe circular and shall be of specifiedcolour andsizeand as shown inthedrawing. Quality of lenses,arrangementof lenses, illuminations,visibility and shielding of signalsshall be as per relevant Clauses ofIRC : 93 and IS:7537.

811.4. Tests

Tests shall be carried out on all components of traffic signalincluding tests on completesystemfor its performanceas per relevantClausesof IRC : 93 and IS: 7537.

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Section 800 Traffic Signs and Appurtenances

811.5. Maintenanceof Traffic Signals

It shall be the responsibility of the Contractor to provide formaintenanceof the signal section system throughout the warrantyperiod for at least five (5) years after installationandas per Clause18of IRC : 93.


The measurementfor traffic signalisationsystemshall be by unit forcompletework asspecifiedandas perdrawing for completeroadjunction.

811.7.Rate

The Contract unit rate for the traffic signalisationsystemas awholeshall be paymentin full compensationfor furnishing all labour,materials,toots, equipment for preparing,supplying, fixing at site, testing andmaintenancethroughout~warrantyperiod and all other incidental costsnecessaryto completeand maintain the work to theseSpecifications.

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Quality Control forRoad Works

900

Quality Control forRoad Works

Quality Control for RoadWorks Section900

901. GENERAL901.1. All materials to be used,all methodsadopted and all works

performed shall be strictly in accordancewith the requirements of theseSpecifications.TheContractorshall set up a field laboratory at locationsapprovedby theEngineerandequipthesamewith adequateequipmentandpersonnelin orderto carryout all requiredtestsandQuality Control workasperSpecificationsand/orasdirectedby theEngineer.The internallayoutof the laboratoryshallbeasperClause121 and/or asdirectedby theEngineer.Thelist of equipmentand thefacilities to beprovidedshallbegotapprovedfrom the Engineer in advance.

901.2. The Contractor’slaboratoryshould be mannedby a qualifiedMaterialsEngineer/CivilEngineerassistedby experiencedtechnicians,andtheset-upshouldbegotapprovedby theEngineer.

901.3. The Contractorshall carry out quality control tests on thematerials andwork to the frequency stipulated in subsequentparagraphs.In the absenceof clear indicationsaboutmethodand or frequency of testsfor any item, the instructions of the Engineershallbe followed.

901.4.For satisfyinghimselfaboutthequalityofthematerials andwork,quality control testswill alsobe conductedby theEngineer (by himself,byhis Quality Control Unitsor by any other agenciesdeemedfit by him),generally to the frequency set forth hereinunder.Additional testsmay alsobeconductedwhere,in theopinion of theEngineer,needfor suchtestsexists.

901.5.The Contractor shall provide necessary co-operation andassistancein obtaining thesamplesfor testsandcarrying out the field testsasrequired by the Engineerfrom time to time. This may include provisionof labour, attendants,assistancein packing anddespatching andany otherassistanceconsidered necessary in connectionwith the tests.

901.6.For thework of embankment,subgradean&pavement,construc-tion ofsubsequentlayerofsameor othermaterialoverthefinished layershallbe doneafter obtaiiiing permissionfrom the Engineer. Similar permissionfrom theEngineershall be obtainedin respectof all otheritems of worksprior to proceeding with the next stage of construction.

901.7. TheContractor shallcarry out modificationsin the procedureofwork, if found necessary,asdirected by the Engineerduring inspection,Works falling short of quality shall be rectified/redone by the Contractor athisown cost,anddefectivework shall alsobe removedfrom thesiteofworksby theContractor at his own cost.

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Section900 Quality Control for Road Works

901.8. The costof laboratorybuilding including services, essentialsupplies like water, electricity, sanitary servicesand their maintenanceandcostof all equipment, tools,materials,labour andincidentalsto performtestsandotheroperationsof quality control accordingto theSpecificationrequirementsshall be deemed to be incidental to the work andno extrapaymentshall be made for thesame.If, however,thereis aseparateitemin theBill of Quantitiesfor settingup of alaboratory and installingtestingequipment, suchwork shall bepaidfor separately.

901.9:Fortestingof samplesof soils/soil mixes,granularmaterials,andmixes, bituminousmaterials andmixes,aggregates,cores etc.,samplesinthe required quantityand form shall besupplied to the Engineerby theContractorathisown cost.

901.10. For cement,bitumen,mild steel,and similarother materialswhere essentialtestsareto be carriedout at the manufacturer’splantsoratlaboratoriesotherthanthesite laboratory,thecost of samples,sampling,testingandfurnishingof testcertificatesshallbe borne by the Contractor.He shall also furnish the testcertificatesto theEngineer.

901.11. For testing of cementconcreteat site during construction,arrangements forsupplyof samples,sampling,testingand supply of testresultsshall bemadeby ttte Contractorasper thefrequencyandnumberoftests specifiedin the Handbookof Quality Control for ConstructionofRoadsand Runways(IRC: SP:11)andrelevantIS Codesor relevantclausesof theseSpecifications, thecostof whichshall beborneby theContractor.

901.12, Themethodof sampling andtesting of materials shall beasrequiredby the “HandbookofQuality ControlforConstructionof Roads andRunways”(IRC SP: 11), and theseMOSTSpecifitations.Wheretheyarecontradicting, theprovision in these Specifications shall be followed.Where they are silent, soundengineeringpracticesshall beadopted.Thesampling and testingprocedureto be used shall beaS approvedby theEngineer and his decisionshall be finalandbindingon the Contractor.

901.13. The materials for embankment constructionshall be gotapprovedfrom theEngineer.Theresponsibilityfor arrangingandobtainingthe landforborrowingor exploitationin any otherway shall rest with theContractorwho shall ensuresmooth anduninterruptedsupplyofmaterialsin the required quantityduringtheconstructionperiod.

Similarly, the supplyof aggregatesfor.constructionof madpavementshall be from quarries approved by the Engineer.Responsibility forarranginguniterruptedsupplyof materialsfrom thesourceshall bethatof theContractor.

300


901.14.DefectiveMaterials

All materialswhich the Engineer/hisrepresentativehasdeterminedas not conforming to the requirementsof the Contractshall be rejectedwhetherin placeornot; theyshallberemovedimmediatelyfrom thesiteasdirected.Materials,which have been subsequentlycorrected,shall not beusedin the work unlessapprovalis accordedin writing by the Engineer.Upon failureof theContractorto complywith anyorderof theEngineer/hisrepresentative,given under thisClause,theEngineer/hisrepresentativeshallhaveauthorityto causethe removal of rejectedmaterialandto deducttheremoval costthereoffrom anypaymentsdueto theContractor,

901.15.ImportedMaterials

At the time of submissionof tenders,the Contractor shallfurnish alist of materials/finishedproductsmanufactured, producedor fabricatedoutsideIndiawhichheproposesto usein thework. TheContractorshall notbeentitledtoextensionof time for acts or eventsoccurring outsideIndiaandit shall be the Contractor’sresponsibility to maketimely delivery tothejob siteof all suchmaterialsobtainedfrom outsideIndia.

The materialsimportedfrom outsideIndiashallconform to therelevantSpecificationsof theContract.In casewherematerials!finished productsare not coveredby the Specifications in the Contract, the details ofSpecificationsproposedto be followed andthe testingprocedureas well aslaboratories! establishmentswheretests are to be carriedout shall bespecifically brought out andagreedto in theContract.

The Contractorshallfurnish totheEngineera certificateof complianceofthetestscarriedout.Inaddition,certifiedmill testreportsclearlyidentifiedto thelot ofmaterialsshallbe furnishedatthe Contractor’scost.

902. CONTROL OF ALIGNMENT, LEVEL AND SURFACEREGULARITY

9011.General

All worksperformedshallconform to thelines, grades,crosssectionsanddimensionsshownon the drawingsor as directed by the Engineer,subjectto thepermittedtolerancesdescribedherein-after.

902.2.HorizontalAlignment

Horizontal alignmentsshallbereckonedwith respectto thecentrelineof thecarriagewayasshownon thedrawings.Theedgesof thecarriagewayasconstructedshallbecorrectwithin atoleranceof±10 mm therefrom.The

301


correspondingtolerance for edges of the roadway andlower layersofpavementshallbe ±25 mm.

902.3.SurfaceLevels

The levels of the subgradeand different pavement courses asconstructed, shall not vary from thosecalculatedwith reference to thelongitudinal andcross-profileof the roadshown on the drawingsor asdirectedby theEngineerbeyondthe tolerancesmentionedin Table 900-i.

TABLE 900.1.TOLERANCES IN SURFACELEVELS

I. Subgrade +20mm-25 mm

2. Sub-base + 10mm(a) Flexible pavement - 20mm(b) Concretepavement + 6 mm

IDry lean concreteor Rolled concretel - 10mm

3. Base-coursefor flexible pavement(a) Bituminous course +6mm

- 6mm(1,) Other thanbituminous + 10mm

(i) Machinelaid .10mm+ l5rnxn

(ii) Manually laid - 15mm

4. Wearingcoursefor flexible pavement(a) Machinelaid +6mm

-6mm(I,) Manuallylaid + 10mm

- 10mm

5. Cementconcretepavement +5 mm-6mm ~

~ Thit maynot ex,,ceed-8mm at 0. 30cmfrom the edges.

Provided, however, that the negative tolerance for wearingcourseshall not be permittedin conjunctionwith the positivetoleranceforbasecourse,if thethicknessof theformeris therebyreducedby morethan6 mmfor flexible pavementsand5 mm for concretepavements.

For checkingcompliancewith theaboverequirementforsubgrade,sub-baseandbasecourses,measurementsof thesurfacelevelsshallbetakenonagridof pointsplacedat 6.25m longitudinallyand3.5 m transversely.Forany 10 consecutivemeasurementstakenlongitudinally or transversly, notmore than onemeasurementshallbe permitted toexceedthe toleranceasabove, this one measurement being not in excessof 5 mm above the

302


permittedtolerance.

For checking the compliance with the above requirement forbituminous wearingcoursesandconcretepavements,measurementsof thesurface levels shallbe takenon agrid of point~spacedat 6.25 m alongthelength andat 0.5m from theedgesandatthe ceèureof thepavement.In anylengthof pavement,complianceshall bedeemedto bemet for thefinal roadsurface, only if the tolerancegiven above is satisfied for anypoint on thesurface.

902.4.SurfaceRegularityof Pavemer’ Courses

The longitudinalprofileshallbecheckedwith a 3 metre long straightedge/movingstraight-edgeasdesiredby theEngineerat themiddle of eachtraffic lane along a line parallel to the centre line of the road.

Themaximum permittednumberof surfaceirregularities shall beasperTable900-2.

TABLE 900.2. MAXIMUM PERMIITEI) NUMBEROFSURFACEIRREGULARITIES

Surfacesofcarriagewaysandpavedshoulders

Surfacesoflaybys, serviceareasandall bitumInousbasecourses~

1rre~’isrity 4mm 7mm 4mm 7mm

Length(m) 300 75 300 75 300 75 300 75

NationalHighways/Expressways’ 20 9 2 1 40 18 4 2

Roadsof lowercategory’ 40 18 4 2 60 27 6 3

‘Category of each sectionof road as describedin theContract

The maxirnurn allowable difference between the road surface andundersideof a 3 mstraight-edgewhenplacedparallelwith, or at right anglesto thecentre line of the road at pointsdecidedby the Engineershallbe:

for pavementsi1tface (bituminous andcementconcrete) 3 mm

forbituminous basecourses 6 mm

for granularsub-base/basecourses 8 mm

for sub-basesunderconcretepavements 10 mm

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I - -

Section900 Quality Control for RoadWorks

902.5.Rectification

Where the surfaceregularityof subgradeandthe various pavementcoursesfall outsidethespecifiedtolerances,the Contractorshall beliableto rectify thesein the mannerdescribedbelow and to thesatisfacionofthe Engineer.

(I) SubgradetWhere thesurfaceis high,it shall be trimmed andsuitablycompacted.Wherethesameis low, thedeficiency shallbecorrectedby scarifyingthelower layerand adding freshmaterialandrecompacsingto therequireddensity÷Thedegreeofcompactionand the typeof material to beused shall conformto the requirementsof Clause305.

(ii) GranularSub-base:Sameasat (i)above,exceptthat thedegreeof compactionandthetypeofmaterialto be usedshallconform to therequirementsof Clause401.

(iii) Lime/Cement Stabilized Soil Subbase:For lime/cementtreatedmaterialswherethe surfaceis high, the sameshall be suitably trimmedwhile takingcarethat thematerialbelow is notdisturbeddueto this operation. However,where the surfaceis low, thesameshall be correctedasdescribedhereinbelow.

Forcementtreatedmaterial• whenthetime elapsedbetweendetectionof irregularityandthetimeof mixing of thematerial is less than 2 hours,the surface shall bescarified to a depthof 50mm supplementedwith freshly mixed materials asnecessaryand recompactedto therelevantspecification.When this timeis morethan 2 hours,thefull depthof thelayershallbe removedfromthe pavement andreplacedwith fresh material toSpecification This shall alan apply to lime treatedmaterial exceptthat the time criterionshall be 3 hoursinsteadof 2 hours.

(lv) Water Bound Macadam/WetMIx Macadam Sub.baseiBase:Wherethe surfaceis high or low, the top 75 mm shall be scarified, reshapedwith addedmaterial asnecessaryand recompactedto Clause404.This shall also apply to wetmix macadamto Clause 406.

(v) Bituminous Constructions: Forbituminous constructionother than wearing course,where the surface is low, thedeficiency shall be correctedby adding fyeshmaterialover a suitable tack coat if needed and recompacting to specifications.Where thesurface ishigh, the full depthof the layer shall beremovedand replaced with freshmaterial and compactedto specifications.

For wearingcourse,wherethesurface is high or low, the full depth of the layer shallbe removed andreplaced with fresh material andcompactedto specifications. In allcases where the removal andreplacementof a bituminous layer is involved, the areatreated shall not be less than5 m in length andnot less thari 35 m in width

(vi) Dry Lean ConcreteSub.base/RolledCementConcrete:The defective length ofthe courseshall be removed to full depthand replacedwith material conforming toClauses 601 or 603,as applicable. ‘the areatreated shallbe at least3mlong,not lessthan I lane wide and extend tothe full depth. Beforerelaying thecourse,thedisturbedsubgradeor layer below shall be corrected by levelling, watering and compacting.

(vll) Cement concrete pavement: The defective areas having surfaceirregularityexceeding3 mm but not greaterthan 6 mm may be. rectified by bump cutting orscrabbling or grinding using approvedequipment.When required by the Engineerareas which havebeen reducedin level by the above operation(s) shall be retextured

304

Quality Contml for RoadWorks Section900

in an approved mannereitherby cutting groove~( 5 mm deep)or rougheningthesurfaceby hackingthe surface.If high areasin excess 6mmor low areas in excessof 3 mm occur,exceedingthepermittednumbersand if theContractorcarusotrectify,theslab shall be demolishedand reconstructed at theContractor’sexpense andinnocasethearearemovedshalibe less than thefullwidthofthe lane in ~iiich theirregularity occursand full length of the slab

If deemed necessaryby theEngineer, anysectionof theslab which deviatesfromthe specified levels asd tolerancesshall be demolishedandreconstructed ax theContractor’s expense,

903, QUALITY CONTROL TESTS DURING CONSTRUCTION

903.1,General

The materialssuppliedand the workscarried Out by theContractorshall conform to the specificationsprescribedin theprecedingClauses.

For ensuringthe requisitequality of construction, thematerialsandworksshallbe subjectedto quality control tests,asdescribedhereinafter.The testingfrequencies setforth are thedesirable minimum and theEngineershall havethe full authority to carry out additional tests asfrequently ashe may deemnecessary,to satisfy himself that the materialsand works comply with theappropriatespecifications. However,thenumberof tests recommendedin Tables900-3and900-4maybereducedatthe discretion of theEngineerif it is felt that consistencyin thequalityof materialscan still be maintained with the reducednumber of tests.

Test proceduresfor thevarious quality control testsareindicated intherespectiveSections oftheseSpecificationsor forcertaintestswithin thisSection.Whereno specifictestingprocedureis mentioned, thetestsshall becarried out as per the prevalentaccepted engineeringpracticeto thedirectionsof theEngineer.

903.2. Testson Earthwork for Embankment, Subgrade Construc-tion andCut Formation

903.2.1, Borrow material Grid theborrow areaat 25 m c/c (orcloser,if thevariability ishigh) to full depthofproposedworking. These.pitsshouldbeloggedand plotted for proper identification of suitable sourcesofmaterial. The following testson representativesamplesshallbe carriedout:

(a) SandContent[IS: 2720 (Part-4)J: 2 tests per 3000 cubic metresof soil.

(b) PlasticityTestuS:2720 (Part’5)J:Eachtypeto betested,2testsper3000cub. metresof soil.

(c) Density Test[IS:2720 (Part S)l: Each soil type to be tested,2 tests per3000 cubicmetresof soil.

(d) DeleteriousContent Test [IS:2720 (Part—27)): As and when requiredby theEngineer.

305


(e) Moisture Content Test(IS :2720 (Pa*2)l: Onetest for every 250cubicmetresofsoil.

(I) CBRTeston materialsto be incorporated In thesub~radeon soaked/unsoakedsamplesuS : 2720(Part.16)]: oneCBR testfor every 3000 cu. m. atleastor closeras andwhenrequired by the Engineer.

903.2.2.CompactionControl: Controlshallbeexercisedoneachlayerby taking at leastonemeasurementofdensityfor each 1000 squaremetresofcompactedarea,or closerasrequiredto yield theminimumnumberof testresultsfor evaluatinga day’s work on statisticalbasis. Thedeterminationof densityshallbein accordancewith IS: 2720(Part-28).Testlocationsshallbe chosenonly throughrandomsampling techniques.Control shall not bebasedon theresultof anyone test but on the meanvalue of a set of5-10 densitydeterminations.Thenumberoftestsin onesetof measurementsshallbe 6 (if non-destructivetestsarecarriedout,thenumberof testsshallbedoubled)aslong asit is felt thatsufficientcontrol overborrow materialandthemethodof compactionis being exercised.If considerablevariationsare observedbetweenindividual densityresults, theminimum numberoftestsin onesetof measurementshall be increasedto 10. Theacceptancecriteriashallbe subjectto theconditionthatthemeandensityis notlessthanthe specifieddensityplus:

[ 1.65 111.65— times thestandard deviation.[ (No. of samples)°~jHowever, for earthwork in shoulders(earthen)and in thesubgrade,

atleastonedensitymeasuz~ementshallbetaken for every500 squaremetresfor thecompactedareaprovidedfurther that thenumberoftestsin eachsetofmeasurementsshallbeatleast 10. In other respects,the control shallbesimilar to that describedearlier.

903.2,3. Cut formation : Testsfor thedensityrequirementsof cut

formationshall be carriedout in accordancewith Clause903.2.2.

903.3. Tests on Sub-basesand Bases(excluding bitumen boundbases)

The testsandtheir frequenciesfor thedifferenttypesofbasesand sub-basesshallbeasgivenin Table900-3.Theevaluationof density results andacceptancecriteria for compactioncontrolshallbeonlinessimilar to thosesetout in Clause903.2.2.

903.3.1.Acceptancecriteria: Theacceptancecriteria for testson thestrengthof cement/limestabilisedsoil anddistribution of stabiliser contentshall be subjectto the condition that the meanvalue is not lessthan the

306


2. Lime/CementStabilisedSoil Sub-base

(i) Gradation(ii) Atterberglimits(iii) Moisturecontent

prior to compaction(iv) Densityof

compactedlayer(v) Deleterious

constituents(vi) C.B.R.

(i) Quality of Iime/cement

One testper200 m3

Onetestper 200m’Onetestper 250m2

Onetestper 500m2

As required

As required

Onetestfor eachconsignmentsubjectto aminimum of onetestper 5 sonnes

(ii) Lime/Cementcontent

(iii) Degreeofpuiverisation

Regularly, throughprocedural checks

Periodicallyasconsiderednecessarj

(iv) CBRorUnconfinedCompressiveStrengthtestonasetof3specimens

As required

3. Water BoundMacadam

Moisturecontentpriorto compactionDensityof compactedlayerDeleteriousconstituents

(i) AggregateImpactValue

(ii) Grading(iii) FlakinessIndex

andElongationIndex

(iv) Atterberglimitsof bindingmaterial

Onetestper 250sq. m.

Onetestper500in2

As required

Onetestper 200 in1 ofaggregateOnetestper 100m2Onetestper 200m’ofaggregate

Onetestper 25 in5 ofbindingmaterial

specifiedvalueplus:1.65

1.65— I timesthestandarddeviation.(No. of samples)°~j

TABLE 900.3. CONTROL TESTS AM) THEIR MINIMUM FREQUENCYFOR SUB.BASESAND BASES(EXCLUDING BITUMEN BOUND BASES)

I Granular

SI. Type of Test Frequency(mm.)No. Construction

(v)

(vi)

(vii)

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Section900 Quality Control far RoadWorks

SI.No.

Type ofConstruction

Test Frequency(miss.)

(v) Auerberglimitsof Onelesiperportionof aggregate 100cubicmetrepassing425micron of aggregatesieve

4. Wet Mix Macadam (1) AggregateimpactValue

Onetestper 200m’of aggregate

(ii)

(iii)

(iv)

(v)

Grading

FlakinessandElongationIndexAtterberglimits ofportion of aggregatepassing425micronsieveDthsity of compactedlayer,

One testper 100m’of aggregateOne test per 200m

3of aggregateOne testper 100m3of aggregate

One testper 500 m2.

903,4.Testson Bituminous Constructions

903.4.!.Thetestsandtheir minimumfrequenciesfor thedifferenttypesof bituminousworksshallbe asgiven in Table900-4.

903.4.2. Acceptancecriteria : The acceptancecriteria for testsondensityandMarshall stability shallbesubjectto the condition that themeanvalueis not lessthan thespecifiedvalueplus:

r 1.65 11.65 -- timesthestandarddeviation.

(No. of samples)°~jTABLE 900-4. CONTROL TESTSAND THEIR MINIMUM FREQUENCY FOR

BITUMINOUS WORKS

S. Type of Construction Test Frequency(minimum)No.

I. Prime Coat/TackCoat (i) Quality of binder

(ii) Binder temperaturefor application

(iii) Rateof spreadofBinder

Two samplesper lot to besubjectedtoall or sometestsasdirected by theEngineerAt regularcloseintervals

Two testsper day

2. SealCoat/SurfaceDressing

(I) Quality of binder Two samplesper lot Dress-ingto be subjected to all or

308

Quality Control for Road Works Section900

S. Type ofConstruction Test Frequency(Minimum)No.

(ii) AggregateImpactValue *

(iii) FlakinessIndexandElongation Index

(iv) Stripping valueofaggregates

(v) Watcrabsorptionofaggregates

(vi) Gradingof aggregates

(vii) Stonepolishingvalue(viii) Temperatureof

binderasapplication(jx) Rateof spreadof

materials

some tests as directed bythe EngineerOne testper 50 m

5 ofaggregate-do-

Initially onesetof 3representative specimensfor eachsourceof supply.Subsequently when war-ranted by changes‘in thequalityof aggregates-do-

Onetestper25m’oIaggre-gateAs requiredAt regular closeintervals

Onetestper 500m2ofwork

3. Open-gradedPremixCarpet/Mix-SealSurfacing

(i) Quality of binder

(ii) Aggregate ImpactValue

(iii) flakinessIndex andElongationIndexofaggregates

(iv) Strippingvalue

(v) Water absosplionofaggregates

(vi) Gradingofaggregates

(vii) Stonepolishingvalue(viii) Temperatureof

binderatapplication(ix) Bindercontent(x) Rateof spreadof

mixedmaterial

Two samplesperlot to besubjectedto all or sometealsasdirected by EngineerOne test perSOm’ ofaggregate-do-

Same as mentionedunderSerialNo.2Sameas mentionedunderSerialNo.2 -

Onetestper25 m5 of aggre-gatesAs requiredAt regular closeintervals

Two tests perdayRegular control throughchecks on materials andlayer thickness

BituminousMacadam (I) Quality of binder Two samplesper lot to besubjectedto all or sometestsas directedby theEngineer

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S. Type of Construction Test Frespsency(Minimum)No.

(ii) AggregateImpactValue

(iii) FlakinessindexandElongationindexofaggregates

(iv) Strippingvalue

(v) Gradingof aggregates

(vi) Water absorptionofaggregates

(vii) Bindercontent

(viii) Control oftemperatureofbinder andaggregatefor mixing and ofthemix at the timeoflayingandrolling

(ix) Rateof spreadofmixedmaterial

Onetestper 50 m3 of

aggregate-do--

Same as mentioned underSerialNo. 2teats per day per plantboth on the individuai con-stituents and mixed aggre-gates from thedryerSameasin SerialNo. 2

Periodic, subject to mini-mumoftwo testsperday perplantAt regular closeintervals

Regular control throughchecksof layer thickness

5. BituminousPenetrationMacadarn/Built-up Spray-Grout

(i) Quality ofbinder

(ii) Aggregate Impact Value

(iii) FlakinessIndex andElongationIndex

(iv) Strippingvalue

(v) Water absorptionofaggregates

(vi) Aggregategrading

(vii) Temperatureof binderat application

(viii) Rateofipreadofbinder

Two samplesper lot to besubjectedto all orsometestsasdirectedby the Engineer.

One testper ZOOm’ ofaggregate—do-

Sameas mentionedunderSerialNo 2Sameas in SerialNo.2

OnetestperlOOm’ ofaggre-gateAt regularclose intervals

Onetestper500m’ of area

6. DenseBituminousMacadam/SemiDenseBituminousConcrete!Bituminous Concrete

(i) Quality ofbinder

(ii) AggregateImpact Value

Two samplesperlot to besubjectedto all or sometestsasdirectedby theEngineerOne testper50 m’ ofaggregate

310


S. Typeof Construction Test Frequency(Minimum)No,

(iii) FlakinessIndex andElongation Index ofaggregates

(iv) StrippingValue(v) Waterabsorptionof

aggregates(vi) Sandequivalenttest

(vii) StonePolishingValue

(viii) Mix grading

(a) Watersensitivity ofmix (i~etentionofMarshallStability)

(xi) Swelltell on themix(xli) Controloftemperature

ofbinderin boiler,aggregatein thedryerandmix at the timeoflayingandrolling

(xiii) Control ofbindercontentandgradationin themix

(xiv) Rateof spreadofmixedmaterial

(xv) Densityof compactedlayer

As in SerialNo.2Asin SerialNo. 2

AsrequiredAsrequired,for SemiDenseBituminous Concrete/Bitu-minous Concrete

Oneset of tests on individ-ual constituentsand mixedaggregatefromthedryerforeach 400 tonnes of mixsubject to a minimum oftwo testsper plantper dayForeach400 tonnesofmixpeoduced,asetof 3 Marshallspecimensto be preparedandtessedforstability, flowvalue, density and voidcontentsubject to a mini-mum oftwosetsbeingtestedperplantperday

Asrequiredfor BituminousConcrete

- do.At regular close intervals

Onetestfor each400tonnesof mix subject to aminimum of two tests perday perplant

Regular controlandthrough checks on theweight of mixed materialand layer thickness

One testper250m~area

—do-

(ix) StabilityofMix

311


903.5. Quality Control Testsfor ConcreteRoad Construction

903.5.1. Dry leanconcretesub-base:

903.5.1.1. Sampling and testing of cubes: Samples of dry leanconcretefor making cubes shall be laken from the uncompactedmaterialfrom different locationsimmediatelybefore compactionat the rate of 3samplesfor each1000sq.m. or part thereoflaid each day. Thesamplingof mix shall be donefrom thepavingsite.

Test cubesof 150mmsize shall bemadeimmediately from eachmixsample.

Cubesshallbemadein accordancewith themethodsdescribedin 15:516exceptthat the cubesshallbe compactedby meansof avibratoryhammerwith themotildsplacedon alevel andrigidbase.The vibrating hammershallbeelectricorpneumatictypefitted with asquareor rectangularfoothavinganareaofbetween7500 to 14000sq.mm.Thecompactionshallbeuniformlyappliedfor 60±5 secondswith a downwardforceofbetween300Nand400Nonto each of thethreelayersof theleanconcretematerialplacedinto themould. Thesurfaceof eachcompactedlayershall be scarifiedbefore thenext layer is addedto givekey for thenext layer.The final layer shall befinishedflush with the top of the cube mould.

The dry leanconcretecubesshallbecuredin accordancewith IS:516.

903.5.1.2.In-situdensity:Thedry densityof thelaid materialshallbedeterminedfrom threedensityholesatlocations equally spacedalong adiagonalthatbisectseach2000squaremetreor part thereoflaid each dayandshallcomplywith therequirementsas per Clause601.5.5.1.Thisrateoftestingmaybe increasedatthediscretionof theEngineerin caseofdoubtorto determinetheextentof defectivearea in theeventof non-compliance.Density holesatrandom may bemadetocheckthedensityatedges.

903.5.13.Thickness:The averagethicknessof the subbase layer ascomputedby thelevel dataofsub-baseandsubgradeor lower sub-baseshallbeasper thethicknessspecifiedin thecontractdrawings. The thicknessatanysinglelocationshallnotbe10mm lessthanthespecifiedthickness.Suchareasshallbecorrectedasstatedin Clause601.5.5.5.Areaswhichcannotberepairedshouldbe replacedover full width. The extentof deficientareashouldbedecidedbasedon cores.

903.5.1.4. Frequencyof quality controltests: The frequency ofqualitycontrol testsfor levels,alignmentandmaterialsshall be asin Table900-6.

312


903.5.2.Pavementconcrete

903.5.2.1.Samplingand testing ofbeam andcubespecimens:At leasttwo beamandtwo cubespecimens,oneeachfor7 day and 28 daystrengthtesting shall be cast for ever 150 cu.m (or part thereof) of concreteplacedduring construction.On eachday’swork, not lessthanthreepairsof beamsandcubesshallbemadefor eachtypeofmix from the concretedelivered tothepaving plant. Eachpair shall be from adifferentdeliveryofconcreteandtestedataplaceto he designatedby theEngineerin accordancewith thetestingprocedureas outlinedin Clause602.3.3.Groupsof four consecutiveresults from single specimenstestedat28 daysshallbe usedfor assessingthe strengthfor compliancewith thestrengthrequirements.Thespecimensshall be transportedin an approvedmannerto preventsudden impactcausingfracturesordamagetothespecimen.The flexuralstrengthtestresultsshall prevailovercompressivestrengthtestsforcompliance.

A quality control chartindicating the strength valuesof individualspecimensshall be maintained forcontinuousqualityassurance.Wherethe requirementsare not metwith, or where thequality of the concreteor itscompactionis suspect,the actualstrengthof theconcretein the slabshall beascertainedby carryingOut testson corescut from thehardenedconcreteatsuch locations.The coresshallbecut atthe rateof 2 coresforevery150cu. m. of concrete.Theresultsof crushingstrengthtestson thesecoresshall not belessthan0.8timesthecorrespondingcrushingstrengthofcubes,wheretheheighttodiameterratio of thecoreis twO. Where height todiameterratio is varied, thenthe necessarycorrectionsshall be madeincalculatingthecrushingstrengthof cubes in the following manner.

The crushing strengthsof cylinderswith height to diameterratiosbetween1 and2 may becorrectedto correspondto a standardcylinder ofheight to diameterratio of 2 by multiplying with the correctionfactorobtainedfrom thefollowing equation:

f= 0.lln+0.78

where f = correction factor and

n = heightto diameterratio

Thecorrectedtestresultsshallbeanalysedforconformitywith thespeci-ficationrequirementsforcubesamples.Wherethecoretestsaresatisfactory,theyshallhaveprecedencefor assessingconcretequality overtheresultsofmouldedspecimens.Thediameterof coresshallnot be lessthan150mm.

If, however,the testson coresalso confirm that the concrete is notsatisfying the strength requirements,then the concretecorrespondingto

313


theareafrom whichthecoreswere cut should bereplaced,i.e., atleastoveran areaextendingbetweentwo transversejoints wherethedefectscouldbeisolated or overlarger areas, if necessary,asassessedby additionalcoresand their test results.Theequivalent flexural strength at 28 days shall beestimatedin accordancewith Clause602.3.3.2,

In order to ensurethatthespecifiedminimum strengthat 28 days isattained in 99percent of all test beams,the mix shall beproportionedto givean averagestrengthat28 days exceedingthespecifiedstrengthby2.33timesthestandarddeviationcalculatedfirst from the flexural strengthsof testbeamsmadefrom thetrial mix andsubsequentlyfrom the accumu-lating result of flexural strengthsof job control testbeams.

The standard deviationshall bere-calculatedfrom the testresultsobtainedafter any change in the sourceor quality of materials andthemix shallbeadjustedasnecessaryto comply with therequirements.

An individual28dayteststrengthbelowthespecifiedstrengthshall notbeevidencefor condemnationof theconcreteconcernedif the average28day strengthof this beamplus the preceding 5 andsucceeding4 beamsexceedsthe specifiedstrengthby 2.33 times thestandard deviation andprovided that there is no other evidence that theconcretemix concernedissubstandard.

Beamsshalibemadeeachdayinpairsat intervals, eachpairbeingfromadifferentbatchof concrete.At thestartof the work, and until such timeasthe Engineermay order a reduction in the number of beamsrequired,atleastsix pairsof beamsandcubesshall be made each day, oneof eachpairfor testing at 28 days for determination of ifle minimum permissibleflexural strengthand theother for testing atanearlyagefor theEngineerto assessthe qualityofthemix. When the firstthirty numberof28-dayresultsareavailable,and for solongastheEngineer is satisfiedwith thequalityof the mix, he may reducethe number of beams and cubesrequired.

During the course~f construction,when the sourceof anymaterialis to be changed,or if thereis any variation in the quality of thematerialsfurnished,additional testsandnecessaryadjustmentsin themix shall be madeasrequiredto obtaIn thespecifiedstrength.

The flexuralstrengthsobtainedonbeamstestedbefore28 daysshall beusedin conjunction with acorrelation betweenthem andth~28 day flexuralstrengths to detectany deterioration in the quality of the concretebeingproduced.Any such deterioration shall beremediedwithout awaiting the28 day strengthsbut the earlier strengthsshailnotconstitutesoleevidence

314

Quality Control for ReadWorks Section900

of non-complianceof theconcretefrom which they weretaken.

Concrete shall not comply with the Specificationwhen more thanonetestbeamin abatch hasa28 daystrength lessthanthespecifiedstrengthandtheaverage28 dayflex ural strength of the batch of beamsis lessthanthespecifiedstrengthplus2.33timesthestandarddeviationof the batch.

Should the c~ncretefail to pass the Specificationfor strengthasdescribed above,the Contractor may, all at his ownexpense,electto cutcoresfrom the suspectconcreteas the Engineershall direct. From therelationbetweencubestrengthandflexural strength, the core strength shallbeconverted to flexural strength.

The equivalent flexural strength at 28 days shall be theestimatedinsitu strength multiplied by 100and divided by the age-strengthrelationobtained from Table 900-5.

Any concrete that fails to meet the strengthspecification shall beremovedand replacedat Contractor’s expense.

TABLE 900.5.AGE- STREr’~GTHRELATION OF CONCRETE(RELATED TO 100 PER (TENT AT 28 DAYS)

DAYS 0 2 4 6 8

0 . 41.0 60.0 71.0 77.510 81.5 85.0 87.5 90.0 92.0

20 94.0 96.0 97.5 98.5 100.030 101.0 102.0 103.5 1043 105.540 106.5 107.0 108.0 1093 110.050 110.5 111.0 112.0 1125 113.0

60 114.0 1143 115.0 115.5 116.0

70 116.5 117,0 1173 118.0 118.580 119.0 1193 1193 120.0 120.590 121,0 121.5 122.0 122.0 122.5

100 123.5 1233 123.5 124.0 124.5110 125.0 125.0 1253 1253 126.0

120 126.0 1263 127.0 127.0 1273130 127.5 128.0 128.5 1283 129.0

140 129.0 1293 1293 130.0 130.0150 130.5 1303 131.0 131.0 131.5

160 131.5 1313 132.0 132.0 132.5170 1323 132$ 133.0 133.0 1333180 1333 134.0 134.0 1343 134.5190 135.0 135.0 135.0 135.5 135,5200 135.5 1353 136.0 136.0 136.5

315

I-a-a----—.

Section900 Quality Controlfor RoadWorks

210 136.5 136.5 137.0 137.0 137.0

220 137.0 1373 137.5 1373 138.0230 138.0 138$ 138.5 138.5 138.5

240 139.0 139.0 139.0 139.5 139.5250 139.5 140.0 140.0 140.0 140.0

260 140.5 1403 140.5 140.5 141.0270 141.0 141.0 141.5 141$ 141.5

280 142.0 142.0 142.0 142.0 142.0

290 142.5 142.5 142.5 142.5 142.53(X) 143.0 143.0 143.0 !43.0 143.5310 143.5 1433 144.0 144.0 144.0320 144.0 144.5 144.5 144.5 144.5

330 144.5 145.0 145.0 145.0 145.0340 145.0 1453 145.5 145.5 145.5

350 146.0 146.0 146.0 146.0 146.0360 146.0 146.0 146.5 146.5 146.5

903.5.2.2.In-situ density The density of the compactedconcreteshallbe such that thetotal air voidsarenot more than 3 per cent.Theairvoids shall be derived from the difference betweenthe theoreticalmaximumdry densityof theconcretecalculatedfrom the specificgravitiesof theconstituentsofthe concretemix andtheaveragevalueof threedirectdensitymeasurementsmadeon coresatleast150mmdiameter.Threecoresshallbe takenfrom trial lengthsandin first two km lengthof thepavement,whilethe slabisbeingconstructedduringnormal working.The proportionsof themix andthevibratoryeffortimpartedi.e thefrequencyandmagnitudeof vibrationshallbeadjustedto achieve themaximumdensity.

All cores takenfordensitymeasurementin the trial sectionshall alsobecheckedfor thickness.Thesamecoresshallbemadeuseof for determin-ing in-situ strength.In caseof doubt,ftdditionalcoresmaybeorderedby theEngineerand taken at locationsdecidedby him to checkthe densityofconcreteslabor the position of doweljtiebars without any compensationbeingpaidfor thesame.

In calculating thedensity,allowanceshall be made for any steel incores.

Coresremovedfrom themaincarriagewayshallbereinstatedwithcom-pactedconcretewith mix proportionsof 1 partof portlandcement: 2 partsof fine aggregate: 2 partsof 10 mm nominal size single sized coarseaggregateby weight.Beforefilling the fine mix, thesides shallbehackedandcleanedwith water.Thereaftercement-sandslurry shall be applied tothesidesjust prior to filling theconcretemix.

316


903.5.23.Thickness:Thicknessshallbecontrolledby takinglevelsasindicated in Clause902.3.Thicknessof theslab at anypoint checkedasmentionedaboveshall be within atoleranceof -5 mm to + 25 mm of thespecifiedthicknessasperDrawing. Thicknessdeficiencymorethan5 mmmay beacceptedandpaidfor atareducedrategiven in Clause602,15.2.Inno case,however,thicknessdeficiencyshallbe morethan25 mm.

903.5.2.4.Summaryof controltests: Table900-6givesasummaryoffrequencyof testingof pavementqualityconcrete.

TABLE 900.6 . FREQUENCY OF QUALITY CONTROL TESTSFORPAVING QUALITY CONCRETE

1. Levels,alIgnmentand texture

(i) Level tolerance

(ii) Width of pavementandpositionofpavingedges

(iii) Pavementthickness(iv) Alignmentofjoints, widths,

depthsof dowel grooves

(v) Surfaceregularitybothtransverselyandlongitudinally

(vi) Alignmentof dowel bars andtheiraccuracy~tiebars

(vii) Texturedepth

2. Quality ofMaterialsandConcrete

Clause902.3Clause 902.2.

Clauses 902.3and 903,5.2.3To be checkedc~tone Jointper 400m length or a day’swork whicheveris more.

Once a dayor one day’swork, without disturbingthe curingoperation.

To be checkedin trial lengthas perClause64)2.10.5.2andonceon every 2 km.

Clause602.9,8

Control testsfor materialsandconcrete shall be as under:

Cement Physicalandchemicaltests

(ii) Deleteriousconstituents

Once for eachsourceofsupplyandoccasionallywhencalledfor in case~oftongiirnproperstorage.B~sides,theContractoralsowill submitdaily testdataoncement released by theManufactwer.

IS: 2386 One zestfor everyday’s(Pt1) work of each fractionof

coarseaggregateand fineaggregate.initially; may berelaxed laterat the discre-tionof the engineer.

IS: 2386 -do-(Pt. 2)

IS: 269IS: 455IS : 1489IS : 8112IS : 12269

2. Coarseand (i) GradationFineaggregates

317


3. Coarse (i) Los Angeles AbrasionAggregate valueor Aggregate

Impact test(ii) Soundness

(iii) Alkali aggregatereactivity

4. Water ChemicalTests

5. Concrete (i) Strengthofconcrete

(ii) Corestrength onhardenedconcrete

(iii) Workability of freshconcrete.SlumpTest

(iv) Thicknessdetermination

(v) Thicknessmeasurementfor trial length

(vi) Verification of level ofstringline in the caseofslip form paving andsteelforms in thecase of fixedform paving

IS:2386 Regularly asrequired(Pt. 3) subjectto aminimum of one

zesta dayfor coarseaggre.gale & two testsa day forfrne aggregate.This datashall beusedfor correctingthewaterdemandofthemixon daily basis.

Oncefor eachsourceofsupplyandsubsequentlyon monthlybasis.Beforeapprovingtheaggregatesandeverymonthsubsequently-do-

Once for approvalof sourceof supply,subsequently onlyin caseof doubt.

lS:516 2cubesand2beamsper150 in’ or part thereof (oneforlday tnd other for 28 daystrength) or minimum 6cubesand6beamsperday’sworkwhicheveris more.

IS:5l6 As per therequirementoftheEngtheer~only in caseofdoubt,

One teat per eachdumperloadat both Batching plantsite andpaving site initiallywheat work starts. Subte-quendy sampling may bedonefromalternatedumper.

From the level dataof con~cretepavementsurfaceandsub-baseat grid pointsof 5/6.25mx33m

3 cores per triallength.

String line or steelformsshallbecheckedfor level atan interval of 5.0m or6.25m. The level toleranceallowedshall be ±2~nm.Theseshallbcgotapproved1.2 hours before the corn-meatcementof the concret~ing activity.

(iii) Waterabsoiption

IS:2 386(Pt.4)

lS:2386(Pt5)

IS:2386(Pt.7)

lS:456

IS:1199

318


903.5.3. Rolled ConcreteBase

903.5.3.1.Samplingand testingofbeamsandcubes:Clause9O3.5.2,1shall apply

903.5.3.2. Thickness Thicknessshallbecontrolledby taking levelsas indicated in Clause903.5.1.3.

903.5.3.3.In-situdensity : The dry densityof the laid materialshallbedetermined from threedensityholesat locationsequally spacedalong adiagonalthatbisectseach2000squaremetreor partthereof laideachdayandshallcomply with therequirementsasperClause601.5.5.1.This rate oftestingmaybeincreasedatthediscretionof the Engineerin caseof doubt orto determinethe extentof defectiveareain theevent of non compliance.Density holesatrandommay bemadetocheckthe densityatedges.

903.5.3.4.Summaryof controltests : Table900-6givesthesummaryof testsfor levels,alignmentandmaterials.

903.5.4.Summary of rate of samplingand testing:(i) Strength 3 beamsand3 cubesfor each 100sq. in. or panthereoflaid eachday.

(ii) Density 3 densityholesfor each2000 sq.m. or past thereoflaid eachday.

(iii) Cores : Only whenEngineerinstructs. They shallnotbecut on regular basis.

A, relationbetweenflexural strengthandcompressivestrengthmay bedevelopedby regressionanalysisusing the available data. This may beupdatedfrom time to time.

319

Materials for Structures

1000

Materials for Structures

Materials for Structures Section 1000

100L GENERAL

Materials to be used in the work shall conform to thespecifications mentionedon the drawings, the requirements laid downin this section and specificationsfor relevant items of work coveredunder these specifications.

If any material,not coveredin these specifications,is required tobe used in the work, it shall conform to relevant Indian Standards,if there are any, or to the requirementsspecified by the Engineer.

1002. SOURCES OF MATERIALThe Contractor shall notify the~Engineer of his proposed sources

of materials prior to delivery. If it is found after trial that sourcesof supply previouslyapproveddo not produceuniform andsatisfactoryproducts,or if theproductfrom any other sourceproves unacceptableat any time, the Contractor shall furnish acceptablematerial from othersourcesat his own expense.

1003. BRICKS

Burnt clay bricks shall conform to the requirementsof IS:l077,except that theminimum compressivestrengthwhen tested flat shallnot be lessthan 8.4 MPafor individual bricks and10.5 MPafor averageof 5 specimens.They shall be free from.cracks and flaws and nodulesof free lime. The brick shall have smooth rectangular faces withsharpcornersandemit a clear ringing sound when struck. The sizemay be according to local practice with a toleranceof ±~ per cent.

1004. STONESStones shall be of the type specified. It shall be hard, sound, free

from cracks, decay and weathering and shall be freshly quarriedfrom an approvedquarry. Stonewith round surface shall not be used.

The stones,when immersedin water for 24 hours, shall not absorbwater by more than 5 per cent of their dry weight when testedin accordancewith IS:1124.

The length of stones shall not exceed3 times its height norshall they be less than twice its height plus one joint. No Stone shallbe less in width than the height and width on the baseshall notbe greater.than three-fourth of the thickness of the wall nor less than150 mm.

323

Section1000 Materialsfor Stnictures

1005. CAST IRONCast iron shall conform to IS:210. The grade number of the

material shall not be less than 14,

1006. CEMENT

Cement to be used in the works shall be any of the following

types with the prior approval of the Engineera) Ordinary Portland Cement,33 Grade, conforming to IS~269.

b) Rapid HardeningPortland Cement,confonning to IS:8041.

c) Ordinary Portland Cement,43 Grade,conforming to lS:81 12.

d) Ordinary Portland Cement,53 Grade,confonningto IS:12269.

e) Sulphate Resistant Portland Cerneni,confomting to lS:12330.

Cement conforming to IS:269 shall be used only after ensuringthat the minimum required design strength can be achieved withoutexceedingthe maximumpermissiblecementcontent of 540 kg/cu.m. ofconcrete.

Cementconforming to IS:8112and IS:12269may be usedprovidedthe minimum cement content mentioned elsewhere from durabilityconsiderationsis notreduced.From strengthconsiderations,thesecementsshall be used with a certain cautionashigh early strengths of cementin the 1 to 28-dayrangecanbe achieved by finer grinding andhigherconstituentratio of C3S/C2S,where C3S is Tricalcium Silicate and C2Sis Dicalcium Silicate. In suchcements,the further growth of strengthbeyondsay4 weeksmay be much lower than that traditionally expected.Therefore, further strengthtestsshall be carried out for 56 and 90 daysto fine tune the mix design from strength considerations.

Cementconformingto IS:12330shall be usedwhen sodium sulphateand magnesiumsulphateare presentin large enoughconcentrationtobe aggressiveto concrete.The recommendedthresholdvalues as perIS:456aresulphateconcentrationin excessof 0.2 per cent in soil sub-strataor 300 ppm (0.O3percent) in ground water. Tests to confirm actualvalues of sulphateconcentration are essential when the structure islocatednearthe sea coast, chemical factories,agricultural land usingchemicalfertilizers andsites wherethereareeffluentdischargesor wheresolublesulphate bearingground waterlevel is high. Cementconformingto IS: 12330 shall be carefully selectedfrom strength considerationstoensurethat the minimum requireddesignstrengthcan be achievedwithout exceedingthe maximum permissiblecementcontentof 540 kg/cu.m. of concrete.

324

Materialsfor Stmctures Section1000

Cement conforming to IS:8041 shall be usedonly for precastconcreteproductsafter specific approvalof the Engineer.

Total chloride content in cementshall in no caseexceed0.05 percentby massof cement.Also, total sulphur contentcalculatedassulphuricanhydride(SO3) shall in no caseexceed2.5 per cent and 3.0 per centwhen tn-calcium aluminateper cent by massis upto 5 or greaterthan5 respectively.

1007. COARSE AGGREGATES

For plain and reinforcedcementconcrete (PCC and RCC)or prestressedconcrete(PSC)works, coarse aggregateshall consistofclean, hard, strong, dense,non-porousand durablepieces of crushedstone,crushed gravel, naturalgravel or a suitable combinationthereofor otherapprovedinert material.They shall not consist pieces ofdisintegrated stones, soft, flaky, elongated particles, salt, alkali,vegetable matter or other deleterious materials in such quantitiesas to reduce the strength and durabilityof the concrete,or to attackthe steel reinforcement. Coarse aggregate havingpositive alkali-silica reaction shall not be used.All coarseaggregatesshall conformto IS:383 and tests for conformityshall becarried out as per IS:2386,Parts I to VIII.

The contractor shall submit for the approvalof the Engineer, theentire information indicated in Appendix A of IS:383.

Maximum nominal size of coarseaggregatefor variousstructuralcomponents in FCC, RCC or PSC, shall conform to Section 1700.

The maximum valuefor flakinessindex for coarse aggregateshallnot exceed35 percent. Thecoarse aggregateshall satisfythe followingrequirementsof grading

TABLE 1000-1 REQUIREMENTSOF COARSE AGGREGATE

IS SieveSize Perrent by Weight Passing the Steve

40mm 20mm 12.5mm

63mm40mm20 mm12.5mm10 mm4.75mm

10095-10030.70—

10-350-5

—

10095.100—

25.550-10

—

—

10090-10040.850-10

325

Section1000 Materials for Structures

1008. SANDIFINE AGGREGATESFor masonrywork, sand shall conform to the requirements of

IS:2116.

For plain and reinforced cement concrete (FCC and RCC)or prestressedconcrete(PSC)works, fine aggregateshallconsistof clean,hard, strong and durablepiecesof crushedstone, crushed gravel, ora suitablecombinationof natural sand,crushed stoneor gravel. Theyshall not contain dust, lumps, soft or flaky, materials, mica or otherdeleteriousmaterials in such quantitiesas to reducethe strengthanddurability of the concrete,or to attack the embeddedsteel.Motorisedsandwashingmachinesshould be usedto removeimpurities from sand,Fine aggregate having positive alkali-silica reaction shall not beused. All fine aggregatesshallconform to IS:383 and testsfor conformityshall be carried out as per IS:2386,(PansI to VIII). The Contractorshallsubmit to theEngineerthe entire informationindicated in AppendixA of lS:383. The finenessmodulus of fine aggregateshall neitherbe less than 2.0 nor greaterthan 3.5.

Sand/fineaggregatefor structuralcOncreteshall conform to the fol-lowing grading requirements

TABLE 1000-2

IS SieveSize Percent by Weight Passingthe Sieve

Zone Zone II Zone Ill

10mm4.75 mm2.36 mm1.18 mm600 uderon300 micron150 micron

10090-10060-9530.7015-345-200-10

10090-10075-10055-9035.598-300-10

10090-10085-10075-10060.7912.400-10

1009. STEEL1009.1. Cast Steel

The use of cast steel shall be limited to bearingsandother similarparts. Steel for castings shall conform to Grade280-520Nof IS: 1030.In case where subsequentwelding is unavoidable in the relevant caststeel components,the letter N at the end of the grade designationofthe steelcasting shall be replacedby letter W. 0.3 per cent to 0.5 percentcoppermay be added to increasethecorrosionresistanceproperties.

326

Materialsfor Stmctures Section1000

1009.2. Steel for Prestressing

The prestressingsteel shall conform to either of the following(a) Plain hard drawn seelwire conformingto IS:1785 (Part I) and 1S~1785(Part II).

(b) Cold drawn indentedwire conformingto 1S:~O03

(c) High tensile steel bar conforming to lS:2090

(d) (Jncoated stressrelieved strandsconforming to 1S:600t

10093. Reinforcement I Untensioned SteelFor plain and reinforced cement concrete (FCC and RCC) or

prestressedconcrete(PSC) works, the reinforcement/ untensioned steelas the casemay be shall consistof the following gradesof reinforcingbars.

TABLE 1008-3GradeDesignation

liar Type conformingto governing ISSpecification

CharacteristicStrength i’y MPa

ElasticModulus GPa

S 240

S 415

lS:432 Part 1Mild Steel Bar

IS:1786High YieldStrength DeformedBars (HYSD)

240

415

~

200

200

Other gradesof bars conforming to IS:432 and IS: 1786 shall nothe permitted.

All steelshallbeprocuredfrom original producers,no re-rolledsteelshall be incorporatedin the worL

Only new steel shall be deliveredto the site. Every bar shall beinspectedbefore assemblingon the work and defective,brittle or burntbar Shall be discarded.Crackedendsof bars shall be discarded.

Fusion-bondedepoxycoatedreinforcingbars shall meetthe require-mentsof IS: 13620.Additional requirementsfor the useof suchreinforce-ment bars have been given below

(a) Patch up materialsshall beprocuredin sealedcontainerswith certi(icatesfromthe agency who hassupplied the fusion bondedepoxy bars.

(b) PVC costed0.1. binding wires of 180 shall catiy be used in conjtutction withfusion bondedepoxy bars.

(c) (lairs for supportingthe reinforcementshall also be of fusion bonded epoxycoated bars.

(d) The cut endsand damagedponictes shall be touchedup with repair patch upmaterial.

327

Section 1000 Materialsfor Structures

(e) The bars shall be cut by saw-cutting rather than flame cutting.

(I) While bendingthe bars, the pins of work benches shall be provided with PVCor plastic sleeves.

(g) The coated steel shall not be directly exposed to sun rays or rains and shallbe protected with opaquepolyethelenesheetsor such other approvedmaterials

(Ii) While concreting, the woTkmen or trolleys shall not directly move on coated barsbut can move on wooden planks placed on the bars.

When specified in the contract, protective coating prescribedbyCECRI shalt be provided in conformanceto specificationsgiven inAppendix/000/!, The CECRI coating processshall be allowed to beimplementedatthe siteof worksprovideda representativeof theInstituteis presentthroughoutthedurationof the coatingprocesswho shall certifythat the materialsand worimanship are in accordancewith prescribedspecificationsdevelopedby the Institute.

1009.4. Grey Iron Castings

Grey Iron castings to be used for bearings shall havethe followingminimum properties

(i) Minimum ultimate tensile strength 370 MPa(ii) Modulus of Elasticity 147000 Ml’s(iii) Brinell Hardness 230 Ml’s(iv) Shear Strength 370 Ml’s(v) CompressiveStrength 1370 Ml’s

The testing shall be as specified in IS:210.

1009.5. Steel Forgings

Forged steel pins shall comply with clause3, 3A or 4 of IS: 1875andsteel forgings shall comply with clause3, 3A or 4 of IS:2004.Rawmaterials of the forging will be taken as per IS:1875 with minimumreduction ratio of 1.8:1. Alter atively, if forging is madefrom ingot,a minimum reductionratio betweenthe ingot and forging will be 4:1.Forging shall be normalised.

1009.6. Structural Steel

Unless otherwisepermitted herein, all structuralsteel shall beforefabrication comply with the requirements of the following IndianStandards:

IS:226 StructuralSteel (StandardQuality)

1S~961 StructuralSteel (High Tensile)

IS:2062 Weldable StructuralSteel

IS:8500 Weldable Structural Steel (medium & high strength qualities)

328

Materials for Structures Section1000

IS 1148 : Hot rolled rivet bars (0110 40mm dia) for structuralpurposes

IS:1 149 High tensile rivet bars for structural purposes

IS: 1161 Steel tubes for structural purposes

IS:4923 : Ilollow Steel sectionsfor structural use

lS:1 1587 : Structuralweather resistantsteel

IS:808 Specifications, for Rolled Steel Beam, Channel and Angle Sections

IS:1239 : Mild Steel Tubes

IS:1730 : Dimension for Steel Plate, sheetand strip for structural and generalengineering purposes

IS: 1731 : Dimensionfor Steelflats for structuralandgeneralengineeringpurposes

IS: 1732 : Dimension for roundand squaresteel bars for structural and generalengineeringpurposes

IS:1852 : Rolling and cutting tolerancesfor hot rolled steel products

The useof structuralsteelnot coveredby the abovestandardsmaybe permittedwith the specific approval of the authority.Referto Section1900 for further details.

1009.7. StalnlessSteel

Stainlesssteel shall be austeniticchromium-nickelsteel,possessingrust, acidandheatresistantpropertiesconformingto IS:6603andIS:6911.Mechanicalproperties/gradefor such stainlesssteel shall be as specifiedby the accepting authority, but in no casebe inferior to mild steel.Generally,stainlesssteel is availableas perAISI grades.AISI 304 whichis equivalentto gradeO4Crl8Ni110of IS:6911 satisfiesthe requirementsof mechanicalpropertiesof structuralsteel.Othergradesof stainlesssteelfor specific purposesmay beprovided as per specific requirements.Forapplication in adverse/corrosive environment, stainless steel shallconform to AISI 316L or 02G17 Ni Mo2 of IS:6911.

1010. WATER

Water used for mixing and curing shall be clean and free frominjurious amountsof oils, acids, alkalis, salts, sugar, organic materialsor othersubstancesthat may be deleteriousto concreteor steel.Potablewater is generally consideredsatisfactoryfor mixing concrete.Mixingandcuring with seawatershallnot bepermitted.As aguide, thefollowingconcentrationsrepresentthe maximum permissiblevalues

(a) To ncuüalise200 ml sampleof water, using phenolpthaleinas an indicator, itshould not requiremore than 2 ml of 0.1 normal NsOH.

(b) To neutralise 200 ml sampleof water, using methyl orangeas art indicator, itshould not require more than 10 ml of 0.1 normal H~.

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-.-—-;-

Section1000 Materialsfor Structures

(c) The permissible limits for solids shall be as follows when tested in accordancewith lS:3025

PermissibleLimits (max)

Organic 200 mg/litInorganic 3000 mg/litSulphatcs (SO

4) 500 mg/litChlorides (Cl) 500 mg/lit *

Suspendedmatter 2000 mg/lit

~ In case of structures of lengths 30m and below, the permissible limit of chloridesmay be increased upto 1000 mg/lit.

All samplesof water (including potablewater) shall be testedand suitable measurestakenwhere necessaryto ensureconformity of the water so the requirements statedberein.

(d) The pH value shall not be less than 6

1011. TIMBER

The timber used for structural purposesshall conform to IS:883,

1012. CONCRETEADMIXTURES

1012.1. General

Admixtures are materials added to the concretebefore or duringmixing with a view to modify one or more of the propertiesof concretein the plastic or hardenedstate.

Concreteadmixturesareproprietaryitems of manufactureand shallbc obtainedonly from establishedmanufacturerswith proventrackrecord,qttality assuranceandfull fledgedlaboratoryfacilities for themanufactureand testing of concrete.

The contractor shall provide the following information concerningeach admixture after obtaining the same from the manufacturer

(a) Norsnal dosageanddetrimentaleffects, if any, of underdosageandover dosage.

(b) The chemical namesof the main ingredients in the admixtures.

(c) The chloride content, if any, expressedas a percentageby the weight of theadsnixture.

(d) Values of dry material content,ashcontentand relative density of the admixturewhich can be used for Uniformity Tests.

(e) Whetheror not the admixtureleads to theentertainmentof air when usedas perthe manufacturer’srecommendeddosage, and if so to what extent.

(Q Where two’ or more admixturea are proposed to be used in any one mix,confirmation as to their compatibility.

(g) There would be no increasein risk of corrosion of the reinforcementor otherembedmentsas a result of using the admixture.

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1012.2. Physical and Chemical Requirements

Admixturesshall conform to the requirementsof IS:9103.In addition,the following conditions shall be satisfied

(a) “Plasticisers” and “Super-Plasticisers”shall meet the requirements indicated for“Water reducing Admixture”.

(h) Except where resistanceto freezing and thawing and to disru11iveaction of de.icing salts is necessary,the air contentof freshly mixed concrete in accordancewith the pressure method given in lS:1199 shall not be more than 2 per centhigher than that of the corresponding control mix and in any casenot morethan3 per cent of the test mix.

(c) The chloride contentof the admixtureshall not exceed0.2 per cent when testedin accordancewith IS:6925.In addition,the maximumpermissiblelimit of chloridecontent of all the constituentsas indicated in Section1700 shall alsobeobserved

(d) Uniformity testson the admixtures are essentialto comparequalitatively the com-

position of different samples taken from batch to batch or from the same batchat different times.

The tests that shall be performed along with permissiblevariationsin the sameare indicated below

- Dry Material Content to be within 3 per cent and5 per centof liquid andsolid admixtures respectively of the value stated by the manufacturer

- Ash content to be within 1 per cent of the value statedby the manufac-turer.

Relative Density (for liquid admixtures) to be within 2 per cent of the valuestatedby the manufacturer.

(e) All tests relating to the concretesadmixturesshall be conducted periodically atan independent laboratory andcomparedwith the data given by themanufacturer

1013, REINFORCED CONCRETE PIPES

Reinforcedconcretepipes for highway structuresshall be of NP4type conforming to the requirementsof IS:458.

1014. STORAGE OF MATERIALS

1014.1. General

All materials maybe storedat properplacesso as to prevent theirdeteriorationor intrusionby foreignmatterandto ensuretheir satisfactoryquality andfitnessfor the work. The storagespacemust alsopermiteasyinspection, removal and restorageof the materials.All such materialseven though stored in approved godawns/places,must be subjectedtoacceptancetest prior to their immediate use.

1014.2. Brick

Bricks shall not be dumpedat site. They shall be stackedin regular

Section1000 Materialsfor Structures

tiers as they are unloaded,to minimisebreakageand defacement.Thesupply of bricks shall be availableat site at any time. Bricks selectedfor use in different situations shall be stacked separately.

1014.3. Aggregates

Aggregatestockpiles may be madeon ground that is denudedofvegetation,is hard and well drained.If necessary,the ground shall becovered with 50 mm plank.

Coarse aggregates,unless otherwise agreed by the Engineer inwriting, shall be delivered to the site in separatesizes (2 sizes whennominal size is 25 mm or less and 3 sizes when the nominal size is32 mm or more). Aggregatesplaced directly on the ground shall notbe removedf~omthe stockpile within 30 cm of the ground until thefinal cleaning up of the work, and then only the clean aggregatewillhe petmitted to be used.

Jn the caseof fine aggregates,theseshall be depositedat the mixingsite not less than 8 hours before use and shall havebeen tested andapprovedby the Engineer.

1014.4. Cement

Cementshall be transported,handledand storedon the site in sucha manneras to avoid deteriorationor contamination.Cement shall bestoredaboveground level in perfectly dry andwater.tightshedsandshallbe stacked not more than eight bags high. Wherever bulk storagecontainersare used their capacity should be sufficient to cater to therequirementat site and should be cleanedat least once every 3 to 4months.

Eachconsignmentshall be storedseparatelyso that it maybereadilyidentified and inspectedand cementshall be used in the sequenceinwhich it is deliveredat site. Any consignmentor part of a consignmentof cementwhich had deterioratedin any way, during storage,shall notbe usedin theworksand shallberemovedfrom thesiteby the Contractorwithout chargeto the Employer.

The Contractorshall prepareandmaintainproperrecords on site inrespectof delivery,handling,storageanduseof cementandtheserecordsshall be availablefor inspection by the Engineerat all times.

The Contractorshall makea monthly return to the Engineeron thedate correspondingto the interim certificatedate,showingthe quantitiesof cementreceivedand issuedduring the month and in stockat the endof the month.

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1014.5. Reinforcement /Untensioned SteelThe reinforcementbars, whendeliveredon the job, shall be stored

abovethe surfaceof the groundupon platforms,skids,or othersupports,andshall be protectedfrom mechanicalinjury and from deteriorationbyexposure.

1014.6. PrestressingMaterials

All prestressingsteel,sheathing,anchoragesand sleevesor couplingmust be protectedduring transportation,handling and storage. Theprestressingsteel,sheathingand other accessoriesmust be stored undercover from rain or thmp ground and protected from the ambientatmosphereif it is likely to be aggressive.Storageat site must be keptto the absoluteminimum.

(a) Tendon:Wire, strandandbar from which tendonsare to be fabricatedshall bestored about300mm above the ground in a suitably covered and closedspaceso as to avoid direct climatic influencesand to protect them from splashesfromany other materials and from the cutting operation of an oxy-acetylene torch orarcwelding processin the vicinity. Underno circumstances,tendonmaterial shallbe subjectedtd any welding operationoron site heattreatmentor metalliccoatingsuch as galvanising. Storage facilities and the procedures for transporting materialinto or out of store, shall be such that the material doesnot becomekinked ornotched.Wire or strand shall be stored in large diameter coils which enablethetendons to be laid out straight. As a guide, foe wires above 5mm dia, coils ofabout 2sn dia without breaksor joints shall be obtainedfrom manufacturerandstored.Protective wrapping for tendonsshall be chemically neutral, All prestressingsteelmust be provided with temporaryprotectionduring storage.

(5) Anchorage Components : The handling and storing procedures shall maintainthe anchoragecomponentsin a condition in which theycan subsequentlyperformtheir function to an adequatedegree.Componentsshall be handledand storedso that mechanical damageand detrimentalcorrosion are prevented. The corrosionof the gripping and securing system shall be prevented.The use of correctlyformulated oils and greasesor of other corrosion preventing material is recom-mendedwhere prolonged storageis required. Such protective material shall beguaranteedby the producer to be non.aggressiveand non-degrading.

Prestressingsteelshall be storedin a closedstorehavingsingle doorwith double locking arrangementsand no windows. Also the air insidethe store shall be kept dry as far as possibleby using various meansto the satisfactionof the Engineer.Also instrument measuringthe airhumidity shall be installed inside the store. This is with a view toeliminating the possibility of initial rusting of prestressingsteel duringstorage.The prestressingsteelshall be coatedwith watersolvabletrease.The prestressingsteel shouldbe absolutelyclean and without any signsof rust.

333

Section 1000 MaterialsforStructures

All prestressingsteel shall be storedat least30 cm above groundlevel and it shall be invariably wrappedby protectivecoverof tarpaperor polytheneor any other approvedmaterial.

The Contractor should seethat prestressingsteelshall be usedwithin3 monthsof its manufacture. He should chalk out his programme in thisrespect precisely, so as to avoid initial corrosion before placing inposition.

1014.7. later

Watershall be storedin containers/tankscoveredat top andcleanedat regular intervals in order to prevent intrusion by foreign matter orgrowth of organicmatter.Waterfrom shallow, muddyor marshysurfaceshall not be permitted.The intakepipe shall be enclosedto exclude silt,mud, grassandothersolid materialsandthereshall be a minimum depthof 0.60 m of water below the intake at all times.

1015. TESTS AND STANDARD OF ACCEPTANCE

All materials,even though storedin an approvedmannershall besubjectedto an acceptancetest prior to their immediate use.

independenttesting of cementfor everyconsignmentshall be doneby theContractoratSite in thelaboratoryapprovedby the Engineerbeforeuse. Any cementwith lower quality than thoseshown in manufacturer’scertificateshall be debarredfrom use.In caseof imported cement,thesame seriesof tests shall be carried out before acceptance.

1015.1. Testing and Approval of Material

The Contractorshall furnish test certificatesfrom the manufacturer/supplier of materialsalong with each batch of material(s)delivered tosite.

The Contractor shall set up a field laboratory with necessaryequipment for testing of all materials, finished products used in theconstructionas per requirementsof conditions of contractandtherelevantspecifications.The testing of all the materials shall be carried out bythe Engineeror his representativefor which the Contractorshall makeall the necessaryarrangementsand bear the entire cost.

Testswhich cannot be carried out in the field laboratory have tobe got doneat theContractor’scostatany recognisedlaboratory/ testingestablishmentsapprovedby the Engineer.

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1015.2. Sampling of Materials

Samples provided to the Engineer or his representativefor theirretention are to be in labelled boxes suitable for storage.

Samplesrequiredfor approval and testing must be suppliedwell inadvanceby at least48 hours or minimum period requiredfor carryingout relevantteststo allow for testingandapproval.Delay to works arisingfrom the late submissionof sampleswill not be acceptableas a reasonfor delay in the completion of the works.

If materialsare brought from abroad,the cost of sampling/testingwhether in India or abroadshall be borne by the Contractor.

1015.3. Rejection of Materials not Conforming to the Specifi-cations

Any stack or batch of material(s) of which sample(s)does notconform to the prescribedtests and quality shall be rejectedby theEngineeror his representativeand such materialsshall be removedfromsite by the Contractorat his own cost. Such rejectedmaterialsshall notbe made.acceptableby any modifications.

1015,4. Testing and Approval of Plant and Equipment

All plants andequipmentusedfor preparing,testing and productionof materials for incorporation into the permanentworks shall be inaccordancewith manufacturer’sspecificationsandshall be got approvedby the Engineerbefore use.

335

Pile Foundations

1100

Pile Foundations

Pile Foundations Section 1100

1101. DESCRIPTION

1101,.!. This work shall consistof constructionof all types of pilesfor structures in accordancewith the details shown on the drawingsand conforming to the requirementsof thesespecifications.

1101.2.The constructionof pile foundationsrequiresa carefulchoiceof the piling system dependingupon sub-soil conditions and loadingcharacteristicsand type of structure.The permissiblelimits of total anddifferential settlements,unsupportedlength of pile underscour,impactlentanglementof floating bodiesand any otherspecial requirementsofproject are also equally important criteria for selection of thepiling system. The method of installing the piles, including detailsof the equipment shall be submitted by the Contractor and gotapproved from . the Engineer.

1101.3. The work shall be done as per IS:291l exceptas modifiedherein.

1102. SUB-SURFACEINVESTIGATION

1102.1.The complete sub-surfaceinvestigationof stratain whichpile foundations are proposedshall be carried out in advanceand byin-situ pile tests. For details of geotechnicalsub-surfaceexplorationsreferencemay be madeto Section 2400, At least one bore-hole forevery foundationof thebridge shall be executed.Borings should becarried upto sufficient depths so as to ascertain the natureof strataarottnd thepile shaft and below the pile tip. However, depthof boringshall not be less than

i) 1.5 timesestimatedlength of pile in soil but not less than 15 m beyondthe probablelength of pile

ii) 15 timesdiameter of pile in weak/jointedrock but minimum 15 m in suchrock

iii) 4 times diameterof pile in sound, hard rock but min[mum 3 m in such rock

1102.2.The sub-surfaceinvestigationshall define adequatelystrati-fication of sub-strataincluding thenatureandtypeof strata, its variationand extent and specific propertiesof the same. The investigationshallbe adequatefor the purposeof selectionof appropriate piling systemand for estimatingdesign capacitiesfor different diametersand lengthof piles.

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Section1100 Pile Foundations

1102.3.Pressuremeter testsmay be used in the caseof rock, gravelor soil for direct evaluation of strength and compressibility charac-teristics. Though thesetests are of specialised naturethey are mostappropriate for difficult/uncertain sub-strata especially for importantprojects,

1102.4. For piles socketedinto rocks, it is necessaryto determinethe uniaxial compressivestrengthof the rock and its quality.

The investigationshall also include locationof ground water tableandotherparametersincludingresultsof chemical testsshowing sulphateandchloridecontentand any other deleteriouschemical content in soiland/or ground water, likely to affect durability.

1103. TYPE OF PILES

The piles may be of reinforced concrete, prestressedconcrete,steel or timber. The piles may be of solid or hollow sections or steelcased piles filled with concrete.Concretepiles may be driven cast-in-situ or precastor bored cast-in-situor precastpiles. driven intopreformedbores.The shapeof piles may be circular, square,hexagonal,octagonal,“H” or “I” Section.

1104. MATERIALS

1104.1.The basic materialsshall conform to the specifications formaterialsgiven in Section 1000. The specificationsfor steel reinforce-ment, structural concrete, prestressedconcrete and structural steelto be used in pile foundationsshall be as given in the relevantsections.

1104.2. Concrete in Piles

Grade of concreteto be used in cast-in-situpiles shall not be lessthan M 20 and the cement content shall not be less than 400 kg percubic meterof concrete.Gradesof concrete for precastreinforcedandprestressedconcretepiles shall not be less than M 25 and M 35respectively.Maximum water cementratio shall be 0.5 for cast-in-situpiles and 0.45 for precastpiles.

The minimum slump of concretefor driven cast-in-situpiles shallbe 1,00 mm to 150 mm and that of bored cast-in-situpiles 150 mmto 200 mm. The slump should not exceed200 mm in any case.

Concrete mix should have homogeneousmixture with requiredworkability for the systemof piling adopted. Suitableand approvedadmixturesmay be used in concretemix where necessary.

340

Pile Foundations Section1100

Where piles areexposedto actiân of harmful chemicals or severeconditions of exposuredue to presenceof sulphate, chloride etc.it may be preferableto opt for higher gradesof concrete restrictingwatercement ratio to 0.45. Specialtypesof cement,such as sulphateresistantcementmay” be used where consideredappropriate.

1105. TEST PILES

1105.1. Test piles which are shown on the drawingsor specifiedin the contract or installedby the Contractoron his own to determinethe lengths of piles to be furnished shall conform to therequirementsfor piling asindicatedin thesespecifications,if theyareto be incorporatedin the completed structure.

Test piles that are to becomea part of the completed structureshall be installed with the sametype of equipment that is pro-posedto be used for piling in the actual structure.

Test piles which are not to be incorporated in the completedstructure shall be removed to at least 600 mm below the proposedsoffit level of pile capand the remaining hole shall be backfilledwith earthor other suitable material.

The piles shall be load testedin accordancewith provisionslaid downin this section.

1106. PRECAST\CONCRETE PILES

1106.1. General

Precastconcretepiles shall be of the size and shapeas shown inthe approved drawings. if a squaresection is employed, the cornersshall be chamfered at least 25 mm unless otherwisespecifiedon the drawings.The lengthof pile shall not normally exceed25 metres.However, wherespecialequipmentsfor handlingand installation areavailable to the satisfaction of the Engineer,longer length couldbe permitted.

Piles shall be castwith a driving point and for hard driving, shallbe shod with a metal shoe approvedby the Engineer.

1106.2. Stacking, Storing and Handling

Care shall be taken that at all stagesof transporting, lifting andhandling,piles arenot damagedor cracked.During transportandstackingof piles, they shall be supportedat the samepoints as those providedfor lifting purposes.If the piles areput down temporarilyduring handling,they shall be placedon trestles or blocks located at the same points.

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Piles shall be stored at least 300 mm above tim level groundwhich is not liable to ui ~ual subsidenceor settlementunder theweightof the stackof piles. They shall be placed on timber supports whichare level andspacedsoas to avoid bending. The supportsshall be vertically one above the other. Spacesshall be left round the piles toenable them to be lifted without difficulty. The order of stackingshall be suchthat the older piles can be withdrawn without disturbingnewer piles. Separatestacks shall be provided for different lengths ofpiles. Wherepiles are stacked in layers,the numberof layers shallnot exceed three. Whanever curing is needed during storage,arrangementsshall be made to enable the piles to be watered. Fordetailed precautions with regard to curing operationsspecificationsfor structural concretegiven in Section 1700 shall apply.

Before the operation of handling and driving the piles, theminimum periodscountedfrom the time of castingshall be allowed foras indicatedin Table 1100-1. Prestressedpiles shall not be lifted orhandled until fully stressed.

TABLE 1100.1 TIME FOR CURING PRECAST PILES

Type of cementused in castingthe pile

Minimum periods from time of casting

Strike side.shutters(hours)

End ofwet curing

(days)

Lift fromcastIng

bed (days)

Drive(days)

Ordinary Portland

Rapid hardeningPortland

24

12

7

7

10

7

. 28

10*

1106,3. Lengtheningof Piles

Where a pile is to have another length cast on it during driving,the longitudinal reinforcementshall preferably be joined by full pene-tration butt welding. The concreteat the top of the original pile shallbe cut down to exposenot lessthan200 mm of the barsto avoidspallingof the concreteby heat.The added bars have to be held accuratelyandrigidly in positionduring welding. Wherefacilitieson siteare insufficientto make proper butt welding practicable, the joint may be madebylapping. The reinforcementat the headof pile will needto be exposedfor full anchoragelengthor 600 mm whichever is greaterandthe newbars over-lapped for this distance. Unless otherwise specified, theextension of the pile shall be formed to the samecross-sectionalprofileand wiLh concreteof at leastthe samestrength as that specified for theoriginal pile. The stirrup spacingshall in no case be greater than

342


150 mm. Not more than one extensionshall be permitted. In casemore than oneextensionis permitted by the Engineer,only approvedmechanicalcouplers shall be used.

Driving shall not be resumed until(i) The strength of the concretein the extension is at least equal to the specified

characteristic strength of concrete in pile, and

(ii) The approval of the Engineer has been obtained.

1106.4. Removal of Surplus Length

Any length of pile surplusto that requiredfor incorporation in thestructure shall be cut off neatly and removed. During the processof cutting off, it shall be ensured that projecting reinforcementtobe anchored into the pile cap and the prestressing strands/wiresare not damaged.When stripping prestressedconcrete piles, shockrelease of tendons shall be avoided. Referencemay also be madeto clause7.7.1. of IS:2911 (Part I Section 3) in this connection.

1106.5. Risen Piles

Level reading should be taken on each pile after driving andagain after all the piles are driven. Piles which are found to haverisen due to ground heaveor as a resultof driving adjacentpiles, shallbe re-drivento the original depth or resistanceunless re-driving testson adjacentpiles haveshown this to be unnecessary.

1106.6, Manufacture

The pile should be cast in one continuous operation from end toend of eachpile. Manufactureof precastconcrete piles shall conformto the guidelinescontainedin clauseNos. 7.1,7.2 and 7.3 of IS:2911(Part I, Section 3).

Pile shall be provided with suitable shoe for protecting the pointof the pile during driving in hard ground.

Piles shall not be movedfrom castingbed until the concrete hashardened sufficiently.

Piles shall not be driven in lessthan28 days aftercasting or unlesstheir strengthat the time of driving is at least that specified for 28days.

1106.7. PrestressedConcrete Piles

Additional specificationsfor precastprestressedconcrete piles shallconform to those containedin clause8 of IS:2911 (Part I Section 3).

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1107. CAST-IN-SITU CONCRETE PILES

Cast-in-situ concretepiles may be either installed by making abore into the groundby removalof materialor by driving a metal casingwith a shoe at the tip and displacing the material laterally.Thetwo types of piles are termed as “bored piles” and “driven piles”respectively.Cast-in-situconcretepiles may be cast in metal shellswhich may remain permanently in place. However,other types ofcast-in-situconcrete piles, plain or reinforced, casedor uncased,maybe used if in the opinion of the Engineerthe soil conditionspermittheir use and if their designandthe methodsof placingare satisfactory.

The metalcasingshall be of sufficient thicknessandstrengthto holdits original form andshow no harmful distortion after it and adjacentcasings have been driven and the driving core, ~f any, has beenwithdrawn.

Cast-in-situ concretedriven pilesshall be installed using aproperlydesigneddetachableshoe at the bottom of the casing.Certain specificrequirementsof cast-in-situdriven piles shall be as per Clauses1110and 1111.

Any liner or bore-hole which is improperly located or showspartial collapsethat would affect the load carryingcapacity of the pile,shall be rejectedor repaired as directed by the Engineerat thecost of the Contractor.

Wherever practicable,concreteshould be placedin a clean dryhole. Where concrete is placedin dry and there is casing pre-sent,the top 3 m of the pile shall be compactedusing internalvibrators.The concreteshould invariably be poured through a tremie with afunnel so that the flow is directed and concretecan be depositedinthe hole without segregation.

Where the casing is withdrawn from cohesive soils for theformation of cast-in-situ pile, the concreting should be done withnecessaryprecautionsto minimise the softeningof the soil by excesswater.Where mud flow conditionsexist, the casing of cast-in-situpilesshall not be allowed to be withdrawn.

Care shall be takenduring concreting to prevent as far aspossiblethesegregationof the ingredients.Thedisplacementor distortionof reinforcementduring concreting and also while extractingthe tubeshall be avoided.

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If the concrete is placed inside precast concrete tubes orconsistsof precast sections, theseshall be free from cracks or otherdamagebefore being installed.

The concrete shall be properly graded,shall be self-compactingand shall not get mixed with soil, excess water, or otherextra-neousmatter. Special care shall be taken in silty claysand other soilswith the tendencyto squeezeinto the newly depositedconcrete andcausenecking. Sufficient headof green concreteshall be maintainedto prevent inflow of soil or water into the concrete.

The placing of concreteshall be a continuousprocess from thetoe level to the top of the pile. To preventsegregation,a tubeor tremiepipe as appropriateshall be used to place concrete in all piles.

To ensurecompactionby hydraulic static heads,rate of placingconcrete in the pile shaft shall not be less than 6 m (length of pile)per hour.

Bored cast-in-situpiles in soils which are stable, may often beinstalled with only a small casing length at the top. A minimum of2.0 m length of top of bore shall invariably be provided with casingto ensureagainstloose soil falling into the bore. In cases in whichthe side soil can fall into the hole, it is necessary to stabilisethe side of the bore hole with drilling mud, or a suitable steelcasing.The casing may be left in position permanently speciallyin cases where~the aggressiveaction of the ground water is to beavoided, or in the cases of piles built in water or in caseswheresignificant length of piles coWd be exposeddue to scour.

For boredcast-in-situpiles,casing/linershall be driven openendedwith a pile driving hammercapableof achievingpenetrationof the linerto the length shown on the drawing or as approvedby the Engineer.Materialsinside the casingshall be removed progressively by air lift,grab or percussionequipment or other approvedmeans.

Where bored cast-in-situpiles are usedin soils liable to flow, thebottom of the casing shall be kept enough in advanceof the boringtool to preventthe entry of soil into the casing, thus preventing theformation of cavities and settlements in the adjoining ground.Thewater level in the casingshould generallybe maintainedatthe naturalground water level for the samereasons. The joints of the casingshall be made as tight as possibleto minimise inflow of water orleakageof slurry during concreting.

345

Section1100 PileFoundations

Boring shall be carried out using rotary or percussion typeequipment. Unless otherwiseapprovedby the Engineer, thediameterof the bore-holesshall be not more than the inside diameterof theliner.

Prior to the lowering of the reinforcementcage into the pileshaft, the shalt shall be cleaned of all loose materials. Cover toreinforcing steel shall be maintainedby suitable spacers.

The diameterof the finished pile shallnot belessthan thatspecifiedanda continuousrecordshall be kept by the Engineeras to the volumeof concreteplaced in relation to the pile length cast.

Before concreting under water, the bottom of the hole shall becleaned of drilling mud andall soft or loose material very carefully.in casea hole is bored with use of drilling mud, concreting shouldnot be taken up whenthe specific gravity of bouom slurry is morethan 1.2. The drilling mud should be maintainedat 1.5m above the.ground water level.

Concreting under water for cast-in-situconcretepilesmay be doneeither with the use of tremie method or by the use of an approvedmethod specially designedto permit underwaterplacementof concrete.

General requirementsand precautions for concretingunder waterare as follows

(a) The concretingof a pile must be completed in one continuous operation.Also,for bored holes, the finishing of the bore, cleaning of the bore, lowering ofreinforcementcageand concretingof pile for full height must be accomplishedin one continuous operation without any stoppage.

Q,) The concrete should be coherent,rich in cement with high slump andrestrictedwater cement ratio.

(c) The tremie pipe wilt have to be large enoughwith due regard to the size ofaggregate. For 20 mm aggregate the tremie pipeshould be of diameternot lessthan 150 mm and for larger aggregate,larger diameter tremie pipes may benecessary.

(11) The first chargeof concrete should be placed with a sliding plug pusheddownthe tube aheadof it to prevent mixing of water and concrete.

(e) The tremiepipe should alwayspenetratewell into the concretewith anadequatemargin of safety against accidental withdrawal if thepipe is surged to dischargethe concrete.

(f) The pile should be concretedwholly by tremieand themethodof depoaitinnshouldnot bechangedpart way up the pile to preventthe taitance from beingentrappedwithin the pile.

(g) All tremie tubes should be scn3pulouslycleanedafter use.

346

Pile Foundations Section 1100

The minimum embedmentof cast-in-situconcretepiles into pilecap shall be 150 mm. Any defectiveconcreteat the head of thecompletedpile shall be cut away and made good with new concrete.The clear cover betweenthe bottomreinforcementin pile cap from thetop of the pile shall be not less than 25 mm. The reinforcement inthe pile shall be exposedfor full anchoragelength to permit it to beadequatelybondedinto the pile cap. Exposing such length shall bedone carefully to avoid damagingthe restof the pile, in caseswherethe pile cap is to be laid on ground,a levelling courseof M 15 nominalmix concrete100 mm thick shall be provided. Defectivepiles shall beremoved or left in place as judged convenientwithout affecting theperformanceof adjacentpiles or pile cap. Additional piles shall beprovided to replacethe defectivepiles.

1108. STEEL PILES

Steel piles shall be “H” or “I” sectionsas shown on the drawingsand shall be of structural steel conforming to the specificationsgivenin Section 1000.

Steel piles shall be protected by suitable anti-corrosivepaint-ing as specifiedon the drawing. Piles shall be storedabove the groundusing protectivepacking to minimise damageto surfacecoating. Eachpile shall be supplied preferably in one piece without splices.

At the option of the Contractor,steel piling consistingof structuralsteel platesweldedtogethermay be substituted for the rolled sectionsspecified,provided that the depth, width and average thicknesses areat leastequal to those of the rolled sections, the steelplatesconformto specification given in Section 1000, the flangesare welded tothe web with continuous fillet welds on either side of the web, andthe welding conformsto Clause 1904.8 of these specifications.

The length of the steel pile may be built up in sections eitherbefore or during driving operations.The sectionsshall be of identicalcross-section. Pile splicesshall be made with full penetration buttwelds over the whole cross-section.Pile splices shall develop at leastthe yield strength of pile.

The connections shall be made by butt-welding the entire cross-section in accordancewith the provisions in Clause 1904.8 of thesespecifications. Care shall be taken to properly align the sectionsconnectedso that the axis of the pile will be straight. The numberof weldedconnectionsin the lengthof pile shall be as few as possible.

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Section1100 PileFoundations

1109. TIMBER PILES

The Engineershall stamp each pile on the butt with a stampwhichshall make an impression that is readily legible. Treated timber pileswill be inspectedby the Engineerafter treatment,

- Untreatedtimber may be used as test piles.

Untreated timber piles andtreatedtimberpiles shall beof approvedquality.

Treated timber piles shall be driven within 6 monthsafter treat-ment.

Timber piles shall be fumishedwith tip protection and shall beprotectedby theuseof steelstrapsas hereinafterspecified.Tip protectionshall be suitablefor useon timber piling of thesize to be driven.Detailsof tip protection shall be furnished to the Engineer for review andapprovalbeforedriving piles. Not less than 2 separatesteelstrapsshallbe placedwithin 600 mm of the butt of eachpile after the pile is squarecut, Not lessthan 2 separatesteel strapsshall be placedwithin 300 mmof the tip of each pile. Additional intermediatesteel strapsshall beplacedat not more than 3 metrescentremeasuredalong the length ofthe pile.

Timber piles which are to be cappedshall be separatelycut offso that true bearing is obtained on every pile. Piles inaccuratelycut off shallbereplaced.Splicingof timber pilesshall not be permittedexceptby written permission of the Engineer.

1110. DRIVING EQUIPMENT

Piles or their casingsmaybe driven with any typeof drophammer,diesel hammer or single-actingsteam or compressed air hammer,provided they penetrateto the prescribeddepthor attain the designedresistancewithoutbeing damaged.The weight or powerof the hammershould be sufficient to ensurea penetrationof at least 5 mm per blow,unless rock has been reached.It is always preferableto employ theheaviesthammerpracticableandto limit the stroke,so as not to damagethe pile. The minimum weight of the haniiper shall be 2.5t. In thecase of precastconcrete piles the massof the hammershall be notless than 30 times the mass of 300 mm length of pile.

Steamor air hammersshall be furnishedalong with boiler or aircompressorof capacityat leastequalto that specifiedby themanufacturerof the hammers.The boiler or air compressorshall be equipped with

348


an accuratepressuregauge at all times. The valve mechanismandother partsof steam,air or diesel hammersshall be maintainedin firstclass condition so that the length of stroke and numberof blows perminute for which the hammer is designed,will be obtained.Inefficientsteam, air or diesel hammers shall be removed from the work.

1111. DRIVING

1111.1. General ProcedureDetails of theequipmentand the method proposed for driving the

piles shall be submitted with the tender for scrutiny andapprovalof the Engineer.Piles shall be installed from firm ground or fromtemporarysupportsor from fixed platform.Thearrangementshallprovidesufficient rigidity to ensure accuracyof pile driving underall conditionsof tide, stream flow or hammer drop.

During driving the top of pile shall be protectedby a suitablehelmet of substantial steel constru~tion.The helmet shall provideuniformbearingacrossthetop of thepile andshallhold the pile centrallyunder the hammer.No pile shall be driven unless inspectedandapprovedby the Engineer.

Piles shall be driven from a fixed frame of sufficient rigidity toensureaccuracyof driving within specifiedtolerances.Forcesproducingunduebendingor torsionalstressesin piles shall not be applied duringdriving. The force of the hammer shall be directedcentrallyandaxiallyduring driving.

The strokeof a single acting or drop hammer shall be limited to1.2 m unless otherwisepermittedby the Engineer.A shorterstrokemay be necessary when there is danger of damagingthe pile.

Piles shall not bebentor sprunginto positionbut shall beeffectivelyguided and held on-line during the initial stages of driving. Attemptsto correctany tendencyfor the pile to run off-line by the applicationof significant horizontalrestraintwill not be permitted.Shortly after thecommencementof driving andatregularintervalsthroughout the drivingoperation,checksshall be made to ensurethat the pile framedoesnotexert any undue lateral force on the pile due to restraint withinthe helmet.~

If the indications arethat a pile will finish outside the specifiedtolerances,driving operationson that pile will cease.The pile shallbe withdrawn,the hole filled and the pile re-driven at no extra cost.

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Section 1100 PileFoundations

To avoid the possibility of premature“set-up” pile driving shall becontinuousin the later stages,without any deliberate stops. (Delays ofan hour or less may leadto significant “set-up” in piles i.e. resistanceto further driving increasesafter driving is stopped).

If any pile is damagedin any way during driving, it shall berepaired or replacedas directedby the Engineer,at no extra cost.If during driving, the head of a pile is damaged to the extentthatfurther driving is not possible, theheadshall be cut off and drivingcontinued.The costof cutting off shall be bomeby the Contractorandwhere,as a result of such cutting off the head, the pile is too short,the Contractor,shall, at his own cost, supply andsplice on sufficientlength of pile to restore the pile to its correct length.

Piles should bedriven to the minimum acceptable penetrationshown on the drawings. This may require preboringand/or jetting asindicated in thesespecificationswith the full approval of the Engineer.

Piles shall bedriven to nominal refusal or the required ultimatedynamic capacity nominated on the drawings or until the top of thepile is at the level required and specifiedon the drawing whichevergives the lowesttoe elevation.TheEngineer’sdecision in these mattersshall be final. Nominal refusal shall be takenas equivalentto 25 mmtotal penetrationfor the final 20 blows using a hammerof drivingenergy as specified and shall be usedas the criterion for acceptancefor piles founded on rock. Severedriving which results in an averageset per blow less than 0.5 mm will not be permitted.

Where hard drilling is encountered becauseof dense strata orobstructions locatedabove the predeterminedpile tip level, nominalrefusal shall not be considered to have been achievedunless theEngineeris satisfiedthatthetotal numberof blows, asthe averagedrivingresistancespecified for nominal refusal, indicates that further drivingwill not advance thepile through dense strataor obstructions,

The pile shall be driven as accurately as possibleto the verticalor to specifiedbatter. Strainingthe pile into position can damage itand the driving equipmentshould be adjusted as much as possibleto follow the position of the pile. Any deviation from the properalignment shall be noted and promptly reported to the Engineer. Ifthe deviationis to such an extentthat the resulting eccentricitycannotbe taken care of by strengthening the pile cap or pile ties, such apile shall, at the discretion of the Engineer, be replaced or supplementedby an additional pile. Unless otherwise specified,the permissible

350


positionaldeviationfor pilesshall be limited to thoseindicated in Clause1116.

Careshall be taken not to damage the pile by over-driving. Anysudden changein the rateof penetration which cannot be ascribedto the natureof the groundshall be noted and its causeascertained,ifpossible,before driving is continued.

When employing a tubewhich is subsequentlywithdrawn for theformation of cast-in-situ pile, consideration shall be given to thepossibility of doing harm to a pile recently formed by driving thetubenearbybefore the concretehassufficiently set. The danger of doingharm is greaterin compactsoils than loose soils. No pile shall bebored or driven within 3 in of a newly castpile until at least24 hoursafter completion of its installation.

Driving piles in loose sand tendsto compact the sand which inturn increasesthe skin friction. Therefore,driving a number of frictionpiles in a group shall proceedoutward from the centre as otherwiseit will be difficult to drive the innerpiles to the samedepth as the others.

In the caseof stiff clay also, the driving for a groupof piles shallproceed outward from the centre.However, in caseof very soft soil,the driving may proceed from outside to inside, so that the soil isrestrainedfrom flowing out during driving operations.

If there is a major variation betweenthe depth at which adjacentfoundationpiles in agroupmeetrefusal,a boring shall be madenearbyto ascertainthe causeof this difference. If the boring shows that thesoil contains pockets of highly compressive material below thelevel of the shorter pile, it will be necessaryto enforcepenetrationof all the piles to a level below the bottom of the zonewhich showssuch pockets.

1111.2. Preboring and Jetting

Driving of the piles may be assistedby preboringholes or by theuse of jets or both subject to the approval of the Engineer.Thesemay be usedessentiallyto achievethe minimum penetrationshown onthe drawings where such penetration is not reached under normalconditions of driving indicated in Clause 1111.1.

The diameterof the hole shall not be greaterthan the diagonaldimensionof the pile less 100 mm.

The maximum depth of the preboring shall be such that the

351


specified set (or less) is obtained when the toe of the pile is atfounding level. Preboring shall be as approvedby the Engineerandshall not extend below one metre abovethe founding level and thepile shall be driven to at least one metre belowthe prebored hole.Toensure that the pile is properly supportedlaterally in the hole, anyspaceremaining aroundthe pile at the ground level after driving isfinished shall be backfilled with approved granular material.

When water jetting is used,at least two jets shall be attachedtothe pile symmetricallywhen this type of technique is used.The volumeand pressure of water at the outlet nozzlesshall be sufficient to freelyerodematerial adjacent to the toe of the pile. The maximum depthof jetting shall be such that the specified set (or less) is obtainedwhen the toe of the pile is at founding level. Jetting shall ceaseasdirectedby the Engineer and shall not proceedbelow onemetreabovethe founding level andthe pile shall be driven atleastone metre belowthe pre..boredhole.

To avoid very hard driving and vibration in materials such assand,jetting of piles by means of water may be carried out only byexpresspermissionof the Engineer andin sucha manneras hot to impairthe bearing capacity of piles already in place, the stability of thesoil or the safetyof any adjoining buildings.Details of the arrangementfor jetting shall be got approved from the Engineer in advance.

If, for jetting, large quantities of water are used,it may be necessaryto makeprovision for collection of waterwhen it comes to the groundsurface, so that the stability of the piling plant is not endangeredbythe softeningof the ground.

Jetting shall bestoppedbefore completing the driving whichshall always be finished by ordinary methods.Jetting shall be stoppedif there is any tendency for the pile tips to be drawn towards thepile alreadydriven owing to the disturbanceto the ground.

1112. RAKER (INCLINED) PILES

The maximum rake to be permitted in piles shall not exceed thefollowing

I) I m S for large diametercast-in-situ pilesviz 0.75 m diameter and above

ii) I in 5 for smaller diameter casI-’m-situ piles

iii) I in 4 for precastdriven piles

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Pile Foundations Secilon 1100

1113. PILE TESTS

1113.1. General

The bearing capacityof a single pile may be determinedfrom testloading a pile. The load test on a con~retepile may not be carriedout earlier than 28 days from the time of casting of the pile.

There shall be two categoriesof tests on piles, namely, initial testsand routine tests. Initial tests should be carried out on test piles whicharenot to be incorporatedin the work, Routine tests shall be carriedOut as a checkon working piles. Thenumber of initial and routinetests on piles shall be as determined by the Engineer dependingupon the number of foundations, spanlength, type of superstructureand uncertaintiesof founding strata.In any case,the initial load testsshall not be less than2 in number, while theroutine load tests shallnot be less than 2 per cent of the total number of piles in the structurenor less than 2 in number.

The above stipulations hold good for both vertical as well aslateral load tests on pile foundations.

However, both initial and routine tests may be suitably increasedfor important structuresor caseswith large variation in the sub-surface strata.

The methodology of carrying out load testsand of arriving atsale load on piles shall conform to IS:2911 (Part IV).

In caseof any doubt of workmanship or load carrying capacity ofworking piles not subjectedto routine tests, or when ordered.by theEngineer, or when provided in the contract, load tests on workingpiles may be supplementedby non-destructive testing.Such testsmay include “integrity Testing” of ~oncretein the installed pile andutitisation of “Pile Driving Analyser” which gives an indication ofpile capacity in end bearing and side friction.

1114. PILE CAP

Pile Caps shall be of reinforced concrete. A minimum offset of150 mm shall be provided beyondthe outer facesof the outer mostpiles in the group. If thepile cap is in contactwith earth at thebottom,a levelling courseof minimum 100 mm thicknessof M 15 nominal mixconcrete shall be provided.

The attachment of the pile headto the cap shall be adequateforthe transmission of loads and forces. A portion of pile top may be

353


strippedof concreteandthereinforcementanchored into the cap. Manualchipping may be permitted after three days of pile casting, whilepneumatic tools for chipping shall not be usedbefore seven daysafter pile casting.The top of pile alter stripping shall projectat least150 mm into the pile cap. A layer of surfacereinforcementmay beprovidedwith a coverof 25 mm to retain the integrity of concretebelowthe main cap reinforcementwhich is to be laid 25 mm above the piletop.

Concreting of the pile cap shall be carriedout in dry conditions.The bottom of the pile cap shall be laid preferablyas low as possibletaking account of the water level prevalentat the time of casting.

The top of concretein a pile shall be brought above cut-offlevel to permit removal of all laitance and weak concrete before pilecap is laid. This will ensuregood concrete at the cut-off level.

1115. IMPORTANT CONSIDERATIONS, INSPECTION/PRECAUTIONS FOR DIFFERENT TYPES OF PILES

1115.1. Driven Cast-in-Situ Piles

1115.1.1, Specialist literature and the guidelines from the pileconstructionindustry shall be consultedregardingthe method of instal-lation, equipment and accessoriesfor pile driving and recordingof data.

1115.1.2.During installation of piles the final “set” of penetrationof pile per blow of hammershall be checked taking an average oflast 10 blows.

1115.1.3.The pile shoeswhich may be of either cast iron conicaltype or mild steel flat type shall have double reams for proper seatingof the removable casing tube inside the spacebetweenthe reams.

1115.1.4.Before commencementof pouring of concrete, it shall beensured that there is no ingressof water in the casing tube fromthe bottom. Further adequatecontrol during withdrawal of the casingtube is essentialso as to maintain sufficient head of concreteinsidethe casing tube at all stages of withdrawal.

1115.1.5. Concrete in piles shall be cast upto a minimum heightof 600 mm above the designed~toplevel of pile, which shall be strippedoff at the time of constructionof pile cap.

354


1115.2. Bored Cast-lu-Situ Piles

1115.2.1.While concreting uncased piles, voids in concreteshall be avoided and sufficient headof concreteis to be maintainedto prevent inflow of soil or water into the concrete. It is alsonecessaryto take precautions during concreting to minimise the softening of thesoil by excesswater.Uncasedcast-in-situpiles shall not be allowedwheremudflow conditions exist.

1115.2.2.The drilling mud such as bentonitesuspensionshall bemaintainedat a level sufficiently above the surrounding ground waterlevel to ensurethe stability of the stratawhich is being penetratedthroughout the boring processuntil the pile has been concreted.

1115.2.3. Where bentonite suspensionis used to maintain thestability of the bore-hole, it is essentialthat the properties ofthe material be carefully controlled at stagesof mixing, supply to thebore-hole and immediately before concrete is placed. It is usual tolimit

i) Tht~density of benton~tesuspensionto 1.05 gjcc

ii) The marsh cone viscosity between30 and 40

~i) The p11 value between 9.5 and 12

iv) The silt content less than I per cent

v) The liquid limit of bentonitenot less than 400 per cent

These aspects shall act as controlling factors for preventingcon-tamination of bentoniteslurry for clay and silt.

1115.2.4.The boresshall be washedby bentoniteflushing to ensureclean bottom at two stagesviz, after completion of boring and prior Ioconcreting alter placing of reinforcementcage. Flushing of bentoniteshall bedonecontinuouslywith freshbentoniteslurry till the consistencyof inflowing and out-flowing slurry is similar.

1115.2.5.Tremieof 150 mm to 200 mm diametershall be used forconcreting. The tremie should have uniform and smoothcross-sectioninside, and shall be withdrawn slowly ensuring adequate heightof concrete outside the tremie pipe at all stages of withdrawal.Other recommendationsfor tremie concreting are

(i) The sides of the bose-holehave to be stablethroughout.

(ii) The tremie shall be water-tight throughout its length and have a hopperattachedat its headby a water-tight connection

355

Section 1100 Pile Foundations

(iii) The tremie pipe shalt be large enough in relation to the sizeof aggregates.For20 mm aggregatethe tremiepipe shall be of diameter not less than 150 mmandfor larger size aggregate tremie pipe of larger diameteris required.

(iv) The tremiepipe shall be lowered to the bottom of the bore-hole,allowing wateror dotting mud to rise inside it before pouring concrete.

(v) The tremie pipe shall always be kept full of concrete and shall penetrate wellinto the concretein thebore-holewith adequatemargin of safetyagainstaccidentalwithdrawal if the pipe is surged to dischargethe concrete.

1115.2.6.For very long or large diameter piles, use of retardingplasticiser in concrete is desirable.

1115.2.7.For large diameterpiles, it may be essential to conductnon-destructivepile integrity tests to evaluateintegrity of the pile.

1115.2.8. Where possible, it may be desirableto grout the baseof pile with cementslurry under suitable pressureafter concretein thepile attains the desiredstrength.For this purpose,conduit pipes witheasily removableplugsat the bottom end should be placedin the borealongwith reinforcementcage before concreting.

1116. TOLERANCES

1116.1. PermissibleTolerancesfor Pilei) PrecastConcretePiles

a) Variation in cross-sectionaldimensions ±5 mm

h) Variation in length ±25 mm

c) Surface irregularitiesmeasuredwith 3 m straight edge 5 mm

d) Row for length in mm Pile Lengthin mm1000

ii) Driven Piles

a) Variation in cross-sectionaldimensions ÷50mm, -10 mm

b) Variation from vertical or specified rake 1 in 50

c) Variation in the final positionof the head in plan 75 mm

d) Variation of level of top of piles : ±25 men

iii) Bored Piles

a) Variation in cross-sectionaldimensions + 50 mm, -10 mm

b) Variation from vertical or specified rake I in 50

c) Variation in the final position : 50 menof the head in plan

d) Variation of level of top of piles ±25 mm

356


1116.2. Permissible Tolerances for Pile Caps(a) Variation in dimensions : ÷50mm- 10 mm

(b) Misplacement from specified position in plan : 15 mm

(c) Surfaceirregularitiesmeasuredwith 3 mstraight edge 5 mm

(d) Variation of levels at the top : ±25 mm

1117. TESTS AND STANDARDS OF ACCEPTANCE

The materials shall be tested in accordancewith theseSpecifica-Lions and shall meet the prescribedcriteria.

The work shall conform to theseSpecificationsand shall meet theprescribedstandardsof acceptance.

1118. MEASUREMENTS FOR PAYMENT

For supply of precastconcrete, timber or steel piles of speci-fied cross-section,the measurementshall be in metres of the lengthof piles orderedin writing by the Engineer measuredfrom the headto the butt of the shoeor the tapered point. Reinforcement in precastconcretepiles shall not be measuredfor payment.

For cast-in-situ drivenandboredconcretepiles of specifiedcross-section, the measurement shall be the length in metres of the acceptedpile that remainsin the finished structurecompletein place.Reinforce-ment in cast-in-situdriven and bored concretepiles shall be measuredfor paymentas per Section 1600.

Routine and Initial Pile Load Tests shall not be measured forpayment.

For installation of the pile, i.e. by driving in the case of precastconcrete, timber, steel and cast-in.~situdriven piles, and by boringin the caseof cast-in-situ bored piles the measurement shall bethe length in metresthat remains in the finished structurecompletein place, limited to that shown on drawings or ordered by the Engineer.No distinction shallbe madefor penetrationthrough hard strataor rockand socketing into rock.

For steel 1iner~fcasingshown on the drawings to be permanentlyleft in place,the measurementshallbe by weight in tonnes that remainsin the finished structurecomplete in place, limited to that shown ondrawings or orderedby the Engineer.

For the pile cap, the quantity of concreteshall be measured incubic metres as per Section 1700. While reinforcement in pile cap

357

Section 1100 Pile Foundations

shall be measured in tonnes asper Section 1600,

1119. RATE

The contract unit rate for supplying precast concrete, timber orsteelpiles shall include costof all labour,materials,toolsandequipment,and other work involved in making or fabricating the pile completeas shown on the drawing, and where required its loading, transport,delivery to site unloading and stacking it at the place indicated by theEngineer. The cost of reinforcement as per Seciton 1600 in precastconcretepiles shall be deemedto be included in the quoted rate for supplyof piles.

The contractunit rate for cast-in-situdriven and bored piles shallinclude the cost of concrete and all other items as per Section 1700.The contract unit rate shall also include costs of all labour, materials,equipments and all other incidentals involved in conducting routineand initial pile load tests including installation of piles for initial loadtests.

The contract unit rate for reinforcement in cast-in-situdriven andbored piles shall be as per Section 1600.

The contract unit rate for installation of piles shall include full com-pensation for furnishing all labour, materials, tools and equipment,andincidentals for doing all the works involved in driving timber, precastconcrete and steel piles, driving or making bores for cast-in-situdriven and bored concrete piles, cutting off pile heads,all completeinplace to the specified penetration of piles. Providing temporaryliner/casing and its withdrawal and placing reinforcementin positionshall alsobe deemedto be included in the rate for installationof pilesand no additional payment shall be made for the same.

The contract unit rate for permanentsteel liners shall incude costof all labour,fabricationandplacing the steel liner to the requireddepthas shown on the drawings and as orderedby the Engineer.

The contract unit rate for concrete in pile cap shall cover all costsof labour, materials, tools, plant and equipment,formwork and stagingincluding placing in position, sampling and testing and supervision,allas per Section 1700. Reinforcement in the pile cap shall be paid forseparatelyas per Section 1600.

358

Well Foundations

1200

Well Foundations

Well Foundations Section 1200.

1201. DESCRIPTION

This work consistsof construction of well foundation,taking it downto the founding level through all kinds of ~ub-sLrata,plugging the

bottom, filling the inside of the well, plugging the top and providinga well cap in accordancewith the details shown on the drawing -andas per thesespecifications,or as directed by the Engineer.

In case of well foundations of size- larger than 12 m diameter,supplementalconstructionspecificationswill be necessary.

1202. GENERAL

1202.1,Wells may have acircular, rectangular,or D-shapein planandmay consistof one, two or more comprirtmentsin plan.The outer

wall of the well isknown as -well stein~gwhich may be cellular.

The process of taking down the web • the founding level isknown as well sinking. Aftu reachingthe fot~ndinglevel, the hollowinside the well, (“dredgehole”) is pluggedat the bottom by concrete

(“bottom plug”). The dredge hole is then filled with approvedfillingupto the level indicatedon the drawings and provided with a concrete

plug (“top plug”).

To facilitate sinking of well, steel cutting edge is fabricatedandconnected to a concrete well curb of requiredshape.On top of the

well curb, adequate height of well steining is cast and the processof sinking is carried out. After a portion of the well has beensunk,

another height of well staining is cast on top of the previous sectionand further sinking carriedout. Thisprocessis continuedtill the bottomlevel of the well reachesthe founding level.

At the top of the well steining, an adequatelydesigned “well cap”is laid which transmitsthe loadsandforcesfrom the sub-structure(piers

‘or abutments)to the foundations.

1202.2. At least one bore-holemust be available/carriedout in ac-cordance with thesespecificationsat each well foundation location,prior to commencementof work, The depthof bore-holesshould extendupto a depth equal to one and a half times the outerdiameter/leastdimensionof thewell belowthe anticipatedfounding level. The resultsof soil exploration should be presented in accordance with clause7.4 of IRC:78. In casethe well foundation is to reston a rocky strata,it may be necessaryto undertakeadditional borings/probingsprior tocommencementof work to ascertainthe actual profile andthe quality

361

Section 1200 Well Foundations

of the rocky strata,at the level at which the well has to be seated,etc.

12023,Blasting may have to be resorted to in order to facilitatesinking through difficult strata,such as bouldersand rocks etc. In caseblasting is anticipated,protective/strengthening measuresspecified inclause710.6 (IV) of IRC:78 shall be taken. The gradeof concrete inbottom 3 metresof steining shall not be leanerthan M 20 or as shownon the drawings.

1202.4, In casethe bore hole data shows thepresenceof steeplydipping rock, chiselling may have to be resorted to so as to obtain

proper seatingof the fouodation. For this purpose,the well may requireto be,dewatered completely under high air pressure inside the well. Thisprocessis known aspneumatic sinking. Pneumatic sinking may alsohaveto be resorted to in caseswhere obstacles such as tree trunks, largesizedbouldersor hard strataetc. cannot be removedby open dredging.The necessity of adop4ng pneumatic sinking shall be decided by theEngineeP.

Thecurb and steininghave to be specifically designed for speciailoading* ~Thenpneumatic sinking is adopted.

1203, SETTING OUT AND PREPARATIONS FOR SINKING

120~1.Necessaryreference points shall be fixed, away from thezoneof blow-ups or possiblesettlementsresulting from well sinkingoperations. Such reference points shall be connected to the perma-nent theodolite stations with the baseline on the banks. The centreof the individual wells shall be marked with referenceto thesestations.The distance, wherever practicable, shall be checkedwith the help ofaccuratetapes and precision distomat.

Reference points shall also be fixed to mark X-X axis (usuallytraffic direction) and Y-Y axis (normal to X-~Caxis) accurately.

A temporary bench mark shall also be establishednear the wellfoundation, away from the zonesof blow-ups or possiblesettlement.The bench mark shall be checked regularly with respect to the

permanentbench mark establishedat the bridge site.

1203.2. For wells which are to be pitched in water, an earthen orsandisland shall be constructed.Sand islands are practicable for water

depths of about 5 metresunder stable bed soil conditions.For greaterdepths or in fast flowing rivers or for locations where soil is too weakto sustain sand island, floating caissonsmay have to be adopted.

362

Well Foundations Section1200

The plan dimensions of sand islands shall be such as to have aworking spaceof atleast2metresall aroundthesteining. The dimensionof the sand islandsshall howeverbe not less than twice the dimension

in planof thewell or caisson.Sand islandsshallbe maintainedto performtheir functions, until the well is sunk to a depth below the bed levelat least equal to the depth of water.

Sand island shall be protected against scourand the top level shallbe sufficiently above the prevailing water level to be decidedby the

Engineer so that it is safe against wave action.

While sandislandsareconstructedat well location, floating caissonsare generally fabricated at or nearthe banks on dry land or dry docks.floating caissonsare towed into position in floating condition.

Floating caissonsmay be of steel,reinforced concrete or a com-bination of the two. They should have at least 1.5 m free boardabovewater level andincreased,if considerednecessary,in case thereis a possibility of caissonssinking suddenlyowing to reasonssuch asscour likely to result from the lowering of caissons,effect of waves,sinking in very soft strata etc.

Stability of floating caissonssh~flbe ensured against overturi~-ing and capsizing while being towed and during sinking for the actionof water current, wave pressure,wind etc.

For floating caissons,a detailed method statementfor fabrication,floating and sinking of caissonsshall be preparedand furnishedto

the Engineer. Such statementshallinclude the total tonnage of steelinvolved, fabrication and welding specifications,list of materialsand

plant and a description of operationsand manpower required for thework. The caisson shall be testedfor leakagesbefore being towed tosite.

12033. Equipment

Equipment shall be deployedfor constructionof well foundationas required and as directedby the Engineer. Generally, the followingequipments may be requiredfor the work:

(a) Cranewith grab buckets- capacity0.5 to 2.0 cern.

(b) Submersible pimps

(c) Air compressors,air locksandotheraccessorieswhere pneumaticsinkingof wellis anticipated.

(ci) Chiselsof apprepristesizes

363

Section1200 Well Foundations

(e) Aqua-headerfor cutting rocky strata

(I) Diving helmetsand accessories

(g) Equipment for concrete production, transportation planing and compaction.

1204. CUTTING EDGE

1204.1. The mild steelcutting edgeshall be madefrom structuralsteelsections, The cutting edgeshall weigh not lessthan 40 kg per

metre length and be properly anchoredinto the well curb, as shownin the drawing.

When there are two or more compartmentsin a well, the bottomendof the cutting edgeof the inner walls of such wells shall be keptat about 300 mm above that of outer walls.

1204.2. The parts of cutting edge shall be erectedon level firmground. Temporary supportsshall be provided to facilitate erection andmaintaining the assemblyin true shape.The fabrication may be carriedout in the shop or at site. Steelsectionsshall not be heated and forcedinto shape.However,“V’t cutsmay be made in the horizontal portion,uniformly throughout the length, to facilitate cold bending. Afterbending,such“V” cuts should be closedby welding. Joints in the lengthsof structural sections,unless otherwisespecifiedshall be fillet weldedusing singlecover plate toensurethe requisitestrength of theoriginalsection,

12043. The cutting edge shall be laid about 300 mm aboveprevalentwater level.

1205. WELL CURB1205.1.Thewell curbmay be precastor cast-in-situ.Steel formwork for

well curb shall be fabricated strictly in conformity with the drawing.The outer face of the curb shall be vertical, Steel reinforcements shallbe assembledas shown on the drawings. The bottom ends of verticalbond rods of steining shall be fixed securely to thei cutting edge withcheck nuts or by welds.

The formwork on outer face of curb may be removed within 24 hoursafter concreting. The formwork ott inner face shall be removed after72 hours.

1205.2. All concreting in the well curb shall be done in onecontinuous operation.

364

Well Foundations Section 1200

1206. WELL STEINING

1206.1. The dimensions,shape,concrete strength and reinforce-mentsof the well shall strictly conform to thoseshownon the drawings.The fomtwork shall preferablybeof M.S. sheetsshapedandstiffenedsuitably. In casetimber formsareused,they shall be lined with plywoodor M.S. sheets.

1206.2. Steining built in the first lift above the well curb shall notbe more than 2 metresand in subsequentlifts it shall not exceedthediameter of the well or the depth of well sunk below the adjoiningbed level at arty time. For stability, the first lift of steining shall becast only after sinking the curb at least partially for stability.

ConcNting of steining may be carried out in subsequentlifts of about2 to 2.5 metres.Attempts shouldbe made to minimise the number ofconstructionjoints. The concreting layers shall be limited to about450mm restrictingthe free fall of concreteto not morethan 1.5 m. Laitanceformed at the top surfaceof a lift shall be removed to exposecoarseaggregates before setting of concreteat the proposedconstructionjoint. As far as possible,constructionjoints shall not be kept at thelocation of laps in the vertical steiningbars.

1106.3. The steining of the well shall be built in one straight linefrom bottom to top such that if the well is tilted, the next lift ofsteining will be aligned in the direction of th~tilt. The work will bechecked carefully with the aid of straight edges of lengthsapprovedby the Engineer. Plumb bob or spirit level shall not be used foralignment.After sinking of astageis complete,damagedportions if any,of steining at top of the previous stage shall be properly repairedbefore constructingthe next stage.

1206.4.The heightof steiningshall becalibratedby making at least4 gauges(preferablyin traffic direction andin adirectionnormalto trafficdirection)distributed equally on the outer peripheryof the well eachin the form of a 100 mm wide strip painted on the well, with everymetre mark shown in black paint. The ,,~gaugesshall startwith zero atthe bottom of the cutting edge. Marking of the gauges shall be donecarefully with a steel tape.

1206.5.After reaching the founding level, the well steining shallbe inspected to check for any damageor cracks.The Engineer willdirect and the Contractorshall executethe remedial measuresbeforeacceptanceof the well staining. In casethe well cannotbe~accepted

even with any remedial measures,then the well shall stand rejected.

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1207. WELL SINKING

1207.1. General

The well shall as far as possiblebe sunk true and vertical throughall types of strata.

Sinking or loading of the well with kentledgeshall be commencedonly after the steininghasbeencuredfor atleast48 hours or asspecifiedin the drawings.

No well shall be permitted to be placed in a pre-dredgedhole.

Thewell shall be sunk by excavating material uniformly frominsidethe dredge hole. Use of water jetting, explosives and diversmay be adoptedfor sinking of wells through difficult stratawith priorapproval of the Engineer.

Normally dewateringof well should not be permittedas a meansfor sinking the well. It also shall never be resorted to if there is *anydangerof sand blowing underthe well. Dewatering sl~ailhoweverbedone when well is to be founded into rock. Pneumaticsinking mayhave to be resortedto whereobstaclessuch as tree trunks, large sizeboulders,etc. aremet at the bottom or when thereis hardstratawhichcannotbe removed by open dredging, The necessityfor pneumaticsinking shall be decided by the Engineer.

Sinking history of well shall be maintainedin the format givenin Appendix 1200/I.

1207,2, Use of Kentledge as Sinking Load

Kentledge shall be placedin an orderly and safe manner on theloading platform and in such a way that it does not interfere withthe excavationof the material from inside the dredge holeandalsodoesnot in any way damagethe steining of the well.

Where tilts are presentor there is a dangerof well developinga tilt, the position of the load shall be regulated in such a manneras to provide greater sinking effort on the higher side of the well.

1207.3. Use of Water Jetting

Waterjetting may be employedfor well sinking whereverneces-sary.

1207A, Use of Explosives

Mild explosive chargesmay be used as an aid for sinking of thewell only with prior permission of the Engineer. Blasting of any sort

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shall only be done in the presenceof the Engineerand not before theconcrete in the steining has hardenedsufficiently and is more than 7daysold. When likelihood of blasting is predictedin advance,protectionof thebottom portionof thewell shall bedone asper thesespecifications.After blastingoperationsarecompleted,the well curbandsteiningshouldbe examinedfor any cracks and remedial measurestaken.

If blasting has been used after the well has reached the designfoundation level, normally 24 hoursshall be allowed to Lapse beforethe bottom plug is laid.

The chargesshall be exploded well below the cutting edge bymaking a sump so as to avoid chancesof any damageto the curb orto the steiningof the well. A minimum-sumpof I metre depthshouldbe madebefore resorting to blasting. Use of largecharges,0.7 kgor above,may not be allowedexceptunder expertdirection and withthe permissionfrom the Engineer. Suitable pattern of charges maybe arrangedwith delay detonators to reduce the numberof chargesfired at a time. The burden of the charge may be limited to 1 metreand the spacing of holes may normally be kept as 0.5 to 0.6 metres.

All prevalentlaws concerninghandling,storing and using of ex-plosives shall be ~strictlyfollowed.

All safety precautionsshall be taken as per IS:4081 “Safety Codefor B lasting and relatedDrilling Operations”, to the extentapplicable,whenever blasting is resorted to.

There shoulçl be no equipmentinside the well nor shall there beanylabour in the close vicinity of the well at the time of explodingthe charges.

If rock blasting is to be done for seating of the well, thedamagecausedby flying debris should be minimised by coveringblasting holes by nibber mats before blasting.

1207.5, Use of Divers

Use of divers may be made both for sinking purposelike removalof obstructions, rock blasting and for inspection. All safetyprecautionsshall be takenas per any acceptablesafetycode for sii~kingwith diversor any statutoryregulationsin force.

Only personstrained for the diving operationshall be employedand shall be certified to be fit for diving by an approveddoctor.

They shall work under expert supervision.The diving and other

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equipmentsshall beof acceptablestandardand certified to this effectby an approvedindependentagency. It shall be well maintainedforsafe use.

Arrangement for amplesupply of low pressureclean cool air shallbe ensured through an armoured flexible hose pipe. Standbycompressorplant shall be providedin caseof breakdown.

Separate high pressure connectionfor use of pneumatic toolsshall be made. Electric lights whereprovided shall be at 50 volts(maximum).The raising of the diver from the bottom of wells shallbe controlled so that decompressionrate conforms to the rate as laiddown in appropriateregulations.

1207.6. Use of Pneumatic Sinking

1207.6.1. General

The Engineershall familiarise himself with particular referencetocaisson diseases and working of the medical air-lock. A doctorcompetentto deal with casesof “Caisson Diseases” or othercompli-cations arising as a result of working under high pressure,shall bestationed at the construction site when pneumaticsinking is underprogress.

The contractor shall provide complete facilities including theissuing of ordersto ensure strict enforcementof the requirementsoutlined in these specifications.

Safety provisions as contained in IS:4138 and in thesespeci.fications shall be strictly followed.

Pneumatic sinkingshall be restrictedto a depth of 30.0 m.

1207.6.2.Man-Locks and Shafts

Locks, reducers,and shaft usedin connection with caissonsshallbe of riveted construction throughout. The material used in theirmanufacture shall be steelplate with thickness not less than 6 mm.

Shafts shall be subjected to hydrostatic or air pressuretest of atleast0.5 MPa, at which pressurethey shall be tight. The pressure atwhich testing hasbeen done shall be clearly andvisibly displayed.

Shafts shall beprovided,with a safe,properand suitable staircasefor its entire length includinglanding platformswhich arenot morethan6 metres apart. Where this is impracticable dueto space constraint,suitable laddersalong with landing platforms shall be installed. These

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Well Foundations Section 1200

shall be kept clear and in good condition at all times and shall beconstructed, inspectedand maintainedto the entire satisfactionof theEngineer.

A 1.0 m wide platform with 1.0 m high railing shall be providedall round the caissonair locks.

Where15 or more men areemployed,caissonsshall have two locks,one of which shall be usedas a man lock.

Locks shall be locatedso that the lowest part of the bottom doorshall not be less than 1 metre abovehigh water level.

The supply of fresh air to the working chambershall at all timesbe sufficient topermitwork tobe done without any dangeror excessivediscomfort. All air supply lines shall besuppliedwith check valves andcarried as near to the face as practicable.

A man-lock shall be usedsolely for the compression or de-compression of persons, and not for the passage of plant andmaterialandshall bemaintainedin a reasonablyclein andsufficientlywarm state. However, any hand tool or hand instrumentsused forthe purposeof the work may be carried into the man-lock.

Where it is not reasonablypracticableto provide a separateman-lock for use by personsonly, the lock when it is in actual use forcompressionor decompressionof a personor personsshall not be put,simultaneously,to any otheruse andshall be in a reasonablycleanandsufficiently warm stale.

1207.6.3.ValvesExhaustvalves shall be provided, having risers extendingto the

upperpart of the chamber. These shall be operated, whenevernecessaryspecially after a blast. Precautionsshall be takenthat menare not allowed to resumework after a blastuntil the gas andsmokeare cleared.

1207.6.4.Medical supervision andcertification

Every employeeabsentfrom work for 10 or more consecutivedaysdue to illness or any other disability shall be requiredto passthe regularphysical examinationby the doctor before being permitted to returnto work.

After a person hasbeenemployedcontinuouslyin compressedairfor a period of 2 months, he shall be re-examinedby the doctor and

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shall not be permitted to work until such re-examination hasbeenmadeand the report is satisfactory.

No person known to be addicted to the excessive use ofintoxicants shall be permitted to work in compressedair.

The doctor shall, at all times, keep a complete and full record ofexaminationsmadeby him, which shall contain datesof examinations,aclear and full description of the personexamined, his age andphysical condition at the time of examination and a statement asto the period such a person has been engaged in such employment.Records shall be kept at the place where the work is in progressand shall be subject to inspection by authorisedofficers.

Every man lock shall alwayshavea doctor or a responsiblepersonin attendance.In casethe person in charge is not a doctor he musthavepositivemeansof promptly communicating with andsecuringtheservicesof a competentdoctor in caseof emergency,Sucharrangementsshall invariably be subject to the approval of the Engineer.

if the air pressure exceeds0.2 MPa gaugeor if 50 or more menare employed, it is obligatory for the person in charge of medicallock to be a doctor experiencedin this type of work.

All casesof compressed-air illness shall be reportedand copies ofall such reports shall be kept on file at the place of work.

1207.6.5. Lighting

All lighting in compressedair chambersshall be operatedonly byelectricity. Two independentelectric lighting systemswith independ-ent sourcesof supply shall be used.Theseshall be so arranged thatthe emergencysourceshall become automaticallyoperativein caseoffailure of the regularly used source.

The minimum intensity of light on any walkway ladder, stairway,or lower working level shall be one-quarter(1/4) candlepower. In allwork places, the lighting shall always be such as to enableworkmento seetheir way aboutclearly.All externalpartsof lighting fixtures andelectrical equipment lying within 2.5 metres above the floor shall beconstructed of non-combustible,non-absorbinginsulating materials. Ifmetal is usedit mustbe effectivelyearthed.Portable lamp shall havenon-combustible, non-absorbing insulating sockets, approved handles,basket guards and approved cables. The use of worn or defectiveportable and pendant conductors, shall be prohibited.

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1207.6.6. Safety against fire hazard

No oil, gasoline,or other combustible material shall be stored within30 metres of any shaft, caisson, or tunnel opening. However, oilmay be storedin suitable tatiksin isolated fireproof buildings, providedsuch buildings are not less than 15 metres from any shaft, caisson, ortunnel opening or any building directly connected thereto.

Positive means shall be taken to prevent leaking flammableliquids from flowing into areasspecificallymentioned in the precedingparagraph.

Where feasible,a fire hoseconnectedto asuitable source of watershall he providedat the top of every caisson.Where lire mains arenot accessible,a supply of water shall be stored in tanks near thetop of every caisson,provided fire pails or suitable pumps are keptavailable. Approved fire extinguishersshall also be provided.

1207.6.7. Sanitation

Properly heated, lightedand ventilateddressingrooms shall beprovided for all employeesengagedin compressedair work. Such roomsshall contain lockers and benchesandbe openand accessibleto menduring intermissionbetween shifts.Adequatetoilet accomodationof onefor every twenty five employees shall be provided.

Care shall betaken to keepall parts of the caissonsand otherworking compartments,including lockerrooms,dry rooms, restrooms,and otherequipmentin a good sanitarycondition and free from refuse,decaying, ‘or other objectionable matter.

No nuisanceshall be tolerated in the air chamber. Smoking shallbe strictly prohibited and all matches and smoking materials shall beleft out of the locker rooms.

A separate dry-room shall be provided where working clothes maybe dried within reasonable time.

1207.6.8. Protection against gases

In all caseswhere gas is expectedincluding alluvium impregnatedwith decayedvegetablematter the use of Davy Safety Lamp shall becompulsory.

1207,6.9. Additional safety provisionsa) The weight of the pneumatic platform and that of steining and kentledge,if

any, shall be sufficient to resist the uplift from air inside, skin friction beingrtglectedin this case. If, at any sectionthe total weight acting downwanlsis

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leasthanthe uplift pressure of air inside, additional kentledge shall be placedon the well.

If it is notpossibleto makethe well heavy enough duringexcavation, “blowingdown” may beused. The men should be withdrawnandair pressure reduced,Thewell shouldthenbeginto movewith small reductionin air psessure.“Blowingdown” should only be usedwhen the groundis such that it will not heaveup inside the chamberwhenthepressureis reduced.When the well does notmove with theseductionin air pressure,kentledgeshould be added~,“Blowingdown” should be in short stagesand the drop should not exceed,03 metre atany stage. To control sinking during blowing down, use of packings arerecomsnended.

b) The pneumaticsinking plant andother allied machinery shall not only be of properdesign and make, but also shall be worked by competent and well trainedpersonnel. Every part of the machinery and its fixtures shall be minutelyexamined beforeinstallationanduse.Availability ofappropriatespares,standbys,safety of personnelas recommendedin 15:4138 for working in compressedairmust be ensured at site. Codes far safety and for working in compressedairand other labour laws and practices prevalent in the country, as specifiedtoprovide safe, efficient and expeditious sinking shall be followed,

c) inflammable materials shall not be taken into air locks and smoking shall beprohibited. Wherever gasesare suspectedto be issuing out of dredgehole, thesante shall be analysed by trained personnel and necessaryprecautions adoptedto avoid hazard to life and equipment,

d) Where blasting is resorted to, it shall be carefully controlled andall precautionsregarding blasting shall be observed. Workers shall be allowedinside afterblasting only when acompetentandqualified person hasexamined the chamberand steining thoroughly and found the sameto be safe,

1207.7. Precautions During Sinkinga) When the wells have to be sunk closeto each other and clear distance between

them is not greater than the diameter of wells, sinking shall be taken up on allwells and they shall be sunk altemately so that sinking of wells proceedsuniformly. Simultaneous and even dredging shall be carried out in the wells insuch a manner that the difference in the levels of the sump and cutting edgein the adjacentwells doesnot exceedhalf the clear gapbetweenthem. Pluggingof all the wells shall be done together.

b) During sinking of dumb-bell or double D-shaped wells, the excavation in boththe dredge holes should be carried out simultaneously and equally.

c) Bore chart shall be referred to constantly during sinking for taking adequatecare while piercing different types of strata. The type of soil as obtainedduring the well sinking should be compared with bore chart s& as totake prompt decisions.

d) Before seasonal floods all wells on which sinking is in progress shall besunk to sufficient depthsbelow the designed scour level. Punher~theyshallbe temporarily filled and plugged so that they do not suffer any tilt or shiftduring the floods.

e) All necessary precautions shall be taken againstany possible damage to the

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Well Foundations Seclion 1200

foundationsof existingstructuresin the vicinity of the wells,prior to commence-mènt of dredging from inside the welL

f) The dredgedmaterial shall not be allowed to accumulate over the well. It shallbe dumped and spread,as far away as possible, and then continuously andsimultaneouslyremoved,as directed by the Engineer.In casethe river streamflows along one edge of the well being sunk, the dredgedmaterial shall notbe dumped on the dry side of the bankbut on the side on which the overcurrent flows.

g) Very deep rump shall not be madebelow the well curb, as it entails risk ofjumping(suddensinking) of the well. The depthof rump shall begenerallylimitedto one-sixth of the outes diameter/least lateral dimensionof the well in plan.Normally, the depthof sump shall not exceed3.0 metresbelow the level of thecutting edge unless otherwise specifically permittedby the Engineer.

h) hi casea well sinks suddenly with a jerk, the steinjpg of the well shall beexamined to the satisfaction of the Engineer to see that no damagehas occurredto it,

i) In pneumatic sinking, the well shall not, at any time, be droppedto a depthgreater than 500 mm by the method of “blowing down”,

j) Dewatering shall be avoided if sand blows are expected. Any equipmentandmen workmg inside the well shall be broughtout of the well as soon as thereare any indications of a sand-blow.

k) Sandblowing in wells can often be minimisedby keeping the level of waterinside the well higher than the water table and also by adding heavy kentledge.

I) In soft strata prone to settlement/creep,the constmctionof theabutmentwellsshall be taken up only after the approach embankment for a sufficient distancenear the abutment has been completed.

1207.8. Tilts and Shifts

The inclination of the well from the vertical is known as tilt andthe horizontal displacement of the centreof the well at the foundinglevel from its theoretical position is known as shift.

Unlessotherwisespecified,the tilt of any well shall not exceed 1(horizontal) in 80 (vertical), and the shift at the Well base shall notbe more than 150 mm in any resultantdirection.

Tilts andshifts shall be carefully checkedandrecordedin the formatvideAppendix1200/11regularlyduring sinking operations.For the purposeof measuringthe tilts along the two axesof the bridge, reducedlevelof the marks painted on the surface of the steining of the well shallbe taken.For determination of shift, locations of the endsof the twodiametersshall be preciselymeasuredalongthe two axes,with referenceto fixed reference points.

Whenever any tilt is noticed, adequate preventive measures likeplacing eccentric kentledge, pulling, strutting, anchoring or dredging


unevenly and depositing dredge material unequally,putting obstaclesbelowcutting edge.Waterjetting etc., shall beadoptedbeforeany furthersinking. After correction, the dredged material shall be spread outuniformly.

A pair of wells close to each other have a tendency to comecloser while sinking. Timber struts may be introduced in between thesteining of thesewells to prevent tilting.

Tilts occurring in awell during sinking in dipping rocky stratacanbe safeguardedby suitably supporting the curb.

In the event of a well developingtilt or shift beyond thespecifiedpermissiblevalues,the Contractorshall haveto carry out, athis own cost, suitable remedial measuresto the satisfactionof theEngineer,to bring the tilt and shift within permissiblevalues, as faras practicable.

If the resultanttilt and / or shift of any well exceedsthe specifiedpermissiblevalues, generallyit should not exceedI in 50 and 300 mmrespectively.The well so sunkshall be regardedas not conforming tospecifications and a sub-standard work. The Engineer in his solediscretion, may consider accepting such a well, provided

(1) Calculations for foundationpressuresand steining stresses,accounting rot theactual tilt and shift furnished by the Contractor show that the well is safe.Any remedial measuresrequiredto bring the stresseswithin permissiblevalues(such asincrease in thedimensionof thewell cap, provision of dummy weightsoct the well cap etc, shall be carried out by theContractorwithout claimingfor any extra cost,

(ii) The Contractor shall agree to reduction in rates in accordancewith Clause1215(g).

In casetheEngineer,in hisdiscretion,rejectsthe well, theContractorshall dismantle therejectedwell to theextentdirected by the Engineerandremove the debris. Further, the Contractor shall, at his own riskand expense complete the bridge with modified span arrangementacceptableto the Engineer.

1207,9. Seating of Wells

The well shall be uniformly seatedat the founding strata. itshallbe ensured by test borings that the propertiesof the soil encounteredat the founding strata and upto a depth of one and a half times thewell diameter is identical to that adopted in the design. The procedurefor test borings shall satisfy the provisions of these specifications.In case the soil encountered is inferior to that adopted in design,

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Well Foundations Se~tion1200

the well shall be re-designed’ by the Engineeradopting the soilproperties actually encountered and the founding level intimated to theContractor,who shall carry out the work.

In caseof seatingof wells in hard rocky strata, where the rockprofile is steeplysloping,pneumaticmethodsof sinkingmay be adoptedto seat the well evenly as directed by the Engineer. The decision ofadoptingpneumaticsinking shallbe taken by theEngineer. Thecuttingedgemay also be embeddedfor a suitable depthin the rocky strata,as decidedby the Engineerkeeping in view the quality of rock. Asan additional measure of safety,the well shall be anchored to the rockystrataby anchor bars provided in the steining of the well, as shownon the drawing irrespective of the fact that tensiondevelops or notat the baseof the well under design loads. After the well has beenevenly seated on good hard rock, arrangements shall be madeto facilitate proper inspectionin dry and visible conditions before thebottom plug is laid.

1208. BOrIOM PLUGFor bottom plug, the concrete mix shall be designed (in dry

condition) to attain the concretestrengthas mentioned on the drawingand shall contain 10 per cent more cement than that required forthe samemix placeddry, to cater for underwaterconcreting. However,the total cementcontentshall not be less than 363 kg/cu.m.of concretewith a slump in the rangeof 150 mm to 200 mm. Admixtures maybe added to the concrete to impart the required characteristics indicatedherein.

Concretefor the bottom plug shall be laid by trernie pipe method.Tremie concretewhen started shall be continued without interruptionfor full concretingin thebottom plug. The concreteproduction equipmentandplacementequipmentshould be sufficient to enable under waterconcreting within stipulatedtime.Necessarystandby equipmentshouldbe available for emergency situation.

Beforecommencingplugging,all loose material from the bottom ofthe well shall be removed.

Concreting shall be done in one continuousoperation till the dredgehole is filled upto the requiredheight and thereaftersounding shallbe taken upto ensure that the concrete has been laid to the requiredheight.

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Least disturbanceshall be causedto the water inside the wellwhile laying concretein the bottom plug.

Concreteshall not be disturbedin any way for at least 14 days.

In order to check any rise in the level of the bottom plugsoundings should be takenat the closeof concreting and once everyday for the subsequent3 days.

The soundnessof the bottom plug may be tested by dewatering thewell by 5 metresbelow the surroundingwater level and checkingtherise of water. The rate of rise shall preferably be less than 10 cmsper hour. In case the rate is higher, suitable remedial measures asdirected by the Engineer,shall be taken by the Contractorat hisown cost.

1209. SAND FILLING

Sand filling shall commenceafter a period of 3 days of laying ofbottom plug. Also, the height of the bottom plug shall be veri-fied before starting sand filling.

Sand shall be clean and free from earth, clay clods, roots,boulders,shingles,etc. and shall be compactedas directed.Sand fillingshall be carried out upto the level shownon the drawing, or as directedby the Engineer.

1210. TOP PLUG

After filling sandupto therequiredlevel a plug of concreteshallbe provided over it as shown on the drawing, or as directedbythe Engineer.

1211 WELL CAP

A reinforced cementconcretewell cap will be provided over thetop of the steining in accordancewith the drawing. Formwork will bepreparedconformingto theshapeof well cap. Concretingshall be carriedout in dry condition. A properly designed false steining may beprovided where possible to ensure that the well cap is laid in dryconditions.

The bottom of the well cap shall be laid preferably as low aspossible,taking account the water level prevalent at the time of casting.

Bond rods of steining shall be anchored into the well cap.

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1212. TOLERANCESThe permissible tilt and shift shall not exceed I (horizontal) in 80

(vertical) and the shift at the well base shall not be more than 150mm in any resultantdirection.

For the well steining and well cap the permissible tolerancesshall be as follows

a) Variation in dimension : ÷50mm - 10 mm

b) Misplacement from specified position in plan : 15 mm

c) Surface irregularities measuredwith 3 m straight edge: 5 mm

d) Variation of levels at the top : ±25mm

1213. TESTS AND STANDARDS OF ACCEPTANCEThe materials shall be tested in accordancewith theseSpecifica-

tions and shall inSt the prescribedcriteria.The work shall conform to these Specificationsand shall meet the

prescribedstandardsof acceptance.


All quantities shall be measuredfrom the drawing, or as orderedby the Engineer, excepting those required to be provided by theContractor at his cost.

a) The cutting edgeshall bemeasuredin tonnesbased on the net weightof metalused in it, as per Section 1900.

b) The concretein curb, well steiningand well cap shall be measured in cubicmetres in eachof theitems as per Section1700. The reinforcementsshall bemeasuredin tonnea separately in eachof the items, as per Section 1600.

c) The measurement for well sinking shall be made in twining metres fordifferentdepthsand in different typesof strata(for example,predominantlysand/clay soil, soft rock, hard rock, etc) as specified in the Contract. The depthof sinking shall be measuredfrom the level specifiedin theContract.If nolevel has been specified in the Contract,sinking shall be measuredfrom shelow walerlevel or from the level at which the cutting edge waslaid, whicheveris higher.

d) The qusntity of concretein bottom and top plug shall be measuredin cubicmetres as per Section 1700.

e) The quantity of sandfilling shall be measured in cubic metres.

fl Pneumatic sinking, where required shall be paid as a separate item and

shall be measuredin cubic metres of material to be excavated.

1215. RATEa) The Contract unit rates ofcutting edge shall cover all costsof labour, material,

tools, plant and equipment,including placing in position, samplinj and testing,

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I-. -


and, supervision, all as per respective Section of Stnsctural Steel Workand as describedin this section,

h) The Contract unit ratesfor concrete in curb, steining,bottom plug, top plugand well cap, shall cover all costs of labour, material, tools, plant andequipment, forthwork and staging including placing in position,samplingandtesting, and, supervision, all as per respectiveSection of StnscturalConcreteand as describedin this section.

c) The Contractunit rates for reinforcementin curb, steining, and well cap, shallcoverall costsof labour,material, tools,plant and equipment,including bendingto shape, placing in position,sampling, testing and supervision, all as perrespective Section of Steel Reinforcementand as described in this section.

d) The Contract unit rates for sandfilling shall cover all costsof labour,material,tools, plant andequipment, including placing in position,sampling,testing andsupervision, all as described in this section.

e) The Concreteunit rates for sinking shall cover the costs of labour, tools, andequipmentand plant and for all operationsand other incidentalsfor sinking ofwell including seatingexceptingrprovisionsof pneumaticsinking as describedinthis Section. The unit rates shall specify the stratasuchas typesof soil, rock,etc. The rate shall cover all testing and supervision requiredfor the work.

I) The Contract unit rate of material to be excavated by pneumatic sinkingshall cover all costs & labour, material, tools,plant and other equipmentandother incidentals and safety provisionsand supervisionrequired for pneumaticsinking as per this Section.

g) Reduction in contractunit rates for sinking as a penalty, in’ pursuance of clause1207,8.

If any well with tilt and/orshift exceedingbeyondpermissiblevaluesis acceptedby the Engineer, the Contractorshall give a ~reductioninthe ratesas followsS,Nu, Amount of tilt and/or shift

.

Pereent deduetlorson the rate(s) forsinkIng of wholesidl

1. Tilt exceedingthe specifiedpermissib4evalue butequal to or within 1 in 60

5 per cent

2. Tilt exceeding1 in 60but equal to or within I in 50

10 per cent

3. ‘lilt exceeding I in 50 20 per cent

4. Shift exceedingthe specifiedpennissiblevalue but equal to or within 200 mm

2 per cent

5. Shift exceeding200 mm but equalto or within 300 mm

5 per cent

6. Shift exceeding300 mm 10 per cent

Penalties for excessivetilt and shift shall be deductedseparately.

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Brick Masonry

1300

Brick Masonry

Brick Masonry Secuon 1300

1301. DESCRIPTION

This work shall consist of construction of structureswith bricksjointed togetherby cementmortar in accordancewith the details shownon the drawings or as approved by the Engineer.

1302. MATERIALS

All materials to be used in the work shall conform to therequirements laid down in Section 1000.

1303. PERSONNEL

Only trained personnel shall be employed for construction and’supervision.

1304. CEMENT MORTAR

Cementand sandshall be mixed in specifiedproportionsgiven inthe drawings. Cementshall be proportionedby weight, taking the unitweightof cementas 1.44 tonne per cubic metre. Sand shall be pro-portioned by volume taking into accountdue allowance for bulking.All mortar shall be mixed with a ~ninimum quantity of water toproducedesiredworkability consistentwith maximumdensityof mortar.The mix shall be clean andfree from injurious typeof soil/acid/alkali!organic matter or deleterioussubstances.

The mixing shall preferably be done in a mechanical mixeroperatedmanuallyor by power. Hand mixing can be resortedto aslong as uniform densityof the mix andits strength are assuredsubjectto prior approval of the Engineer. Where permitted, specificpermissionis to be given by the Engineer.Hand mixing operation shallbe carried out on a clean water-tight platform, where cement andsandshall be first mixeddry in the requiredproportion by being turnedover and over, backwardsand forwards several times till the mixtureis of uniform colour. Thereafter, minimum quantity of water shall beaddedto bring the mortar to the consistencyof a stiff paste. The mortarshall be mixed for at least two minutes after addition of water.

Mortar shall be mixed only in such quantity as required forimmediate use. The mix which has developedinitial set shall not beused. Initial set of mortar with ordinary Portland Cement shallnormally beconsideredto havetakenplacein 30 minutes after mixing.In casethe mortar has stiffened during initial setting time becauseof evaporationof water, the same can be re-tempered by adding water

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Section1300 Brick Masonry

as frequently as needed to restorethe requisite consistency,but thisre-temperingshall not be permitted after30 minutes.Mortar unusedfor more than 30 minutesshall be rejectedand removedfrom siteof work.

1305. SOAKING OF BRICKS

All bricks shall be thoroughly soakedin a tank filled with waterfor a minimum periodof onehour prior to being laid. Soakedbricksshall be removed &om the tank sufficiently in advance sothat theyare skin dry at the time of actual laying. Such soakedbricks shallbe stackedon a clean placewhere they are not contaminatedwithdirt, earth, etc.

1306. JOINTS

The thickness of joints shall not exceed10mm, All joints onexposed faces shall be tooled to give concavefinish.

1307. LAYING

All brickwork shall be laid in an English bond, even and true toline, in accordancewith the drawingor as directed by the Engineer,plumb and level and all joints accurately kept Half and cut bricksshall not be used except when necessary to complete the bond.Closer in such cases shall be cut to the required size and usednear the ends of the walls. The bricks used at the face and also atall angles forming thejunction of any two walls shall beselectedwholebricks of uniform size, with hue and rectangularfaces.

All bricks shall be laid with frogs up on a full bed of mortarexcept in the caseof tile bricks. Each brick shall be properly beddedandset in position by slightly pressing whilelaying, so that the mortargets’-into all their surface pores to ensure proper adhesion.All headand sidejoints shall be completelyfilled by applyingsufficient mortarto brick alreadyplaced and on brick to be placed.All joints shallbe properly flushed and packed with mortar so that no hollow spacesare left. No bats or cut bricks shall be usedexceptto obtain dimensionsof thedifferentcoursesfor specifiedbondsor wherevera desiredshapeso requires.

The brick work shall be built in uniform layers, and for thispurpose woodenstraight edge with graduations indicating thicknessof eachcourse includingjoint shall beused. Cornersand other advancedwork shall be raked back. Brickwork shall be done true to plumb orin specifiedbatter. All coursesshall be laid truly horizontal and

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Brick Masonry Section1300

vertical joints shall be truly vertical. Vertical joints in alternatecourses shall comedirectly one over the other. During construction,no part of work shall rise more than one metre above the generalconstructionlevel, to avoid unequal settlementand improperjointing.Where this is not possiblein the opinion of the Engineer, the worksshall be rakedback accordingto the bond (and not toothed)at an anglenot steeperthan 45 degreeswith prior approval of the Engineer.Toothingmay alsobe permittedwherefuture extensionis contemplated.

Beforelaying bricksin foundation,the foundationslabshall be thor-oughly hacked,sweptcleanan~wetted. A layerof mortar not less than12 mm thick shall be spreadon the surface Of the foundation slaband the first courseof bricks shall be laid.

1308. JOINTING OLD AND NEW WORK

Where freshmasonryis to join with masonrythatis partially/entirelyset, the exposedjointing surfaceof the set masonryshall be cleaned,roughenedand wetted,so as to effect the bestpossible bond with thenewwork. All loosebricksandmortar or othermaterialshall beremoved.

ln the caseof verticalor inclinedjoints, it shall be further ensuredthat proper bond betweenthe old and new masonry is obtainedby interlocking the bricks. Any portionof the brickwork that has beencompletedshall remain undisturbeduntil thoroughly set.

In case‘of sharp cornersspecially in skew bridges,a flat cutbackof 100 mm shall be provided so as to have proper and bondedlayingof bricks;

1309. CURINGGreenwork shall be protectedfrom rain by suitable covering and

shall be kept constantlymoist on all faces for a minimum period ofseven days.Brick work carriedout during the day shall be suitablymarked indicating the dateon which the work is done so as to keepa watch on the curing period. The top of the masonrywork shall beleft flooded with water at the close of the day. Watering may bedone carefully so as not to disturb or wash out the green mortar.

During hot weather, all finished or partly completedwork shallbe covered or wettedin sucha manneras will prevent rapid dryingof the brickwork.

During the period of curing of brick work: it shall be suitablyprotected from all damages.At the close of day’s work or for other

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Section 1300 Brick Masonry

period of cessation,watering and curing shall haveto be maintained.Should the mortar perish i.e. becomedry, white or powdery throughneglectof curing, work shall bepulled down and rebuilt as directedby the Engineer.If any stains appear during watering, the sameshallbe removed from the face.

1310. SCAFFOLDING

The scaffolding shall be sound, strong andsafe to withstand allloads likely to come upon it. The holes which provide restingspacefor horizontal members shall not be left in masonry under one metrein width or immediatelynearthe skew backs of arches.The holes leftin the masonrywork for supporting the scaffoldingshall be filled andmadegood.Scaffolding shall be got approved by the Engineer. However,the Contractorshall be responsiblefor its safety.

1311. EQUIPMENT

All tools and equipmentusedfor mixing, transportingand layingof mortar andbricks shall beclean and free from set mortar,dirtor other injurious foreign substances.

1312. FINISHING OF SURFACES

1312.1. General

All brickwork shall be finished in a workmanlike mannerwith thethickness of joints, mannerof striking or tooling as describedin thdseabove specifications.

The surfaces can be finished by “jointing” or “pointing” or by“plastering” as given in the drawings.

For a surfacewhich is to be subsequentlyplasteredor pointed, thejoints shall besquarely rakedout to a depth of 15 mm, while the mortaris still green.The raked joints shall be well brushedto remove dustand loose particlesand the surface shall be thoroughly washedwithwater, cleanedand wetted.

The mortar for finishing shall be prepared as per Clause 1304.

1312.2. Jointing

In jointing, the face of the mortar shall be worked out whilestill green to give a finished surface flush with the face of the brickwork. Thefacesof brick workshall becleaned to removeany splashesof mortar during the course of raising the brick work.

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Brick Masonry Section1300

1312.3. Pointing

Pointing shall be carried out using mortar not leaner than 1:3 byvolume of cementand sandor as shown on the drawing. The mortarshall be filled and pressedinto the raked joints before giving therequired finish. The pointing shall be ruled type for which it shall,while still green,be ruled along the centre with half round tools ofsuch width as may be specifiedby the Engineer. The super flush mortarshall then be taken off from the edges of the lines and the surfaceofthe masonry shall be cleanedof all mortar, The work shall conformto IS:2212.

1312.4. Plastering

Plastering shall be done where shown on the drawing. Superficialplasteringmay be done, if necessary,only in structuressituatedin fastflowing rivers or in severelyaggressiveenvironment.

Plasteringshall be startedfrom tOp and worked down. All putlogholes shall be properly filled in advanceof the plastering while thescaffolding is being taken down. Wooden screeds75 mm wide and ofthe thicknessof the plastershall be fixed vertically 2.5 to 4 metresapart,to actasgaugesandguides in applying the plaster.Themortarshall be laid on the wall between the screeds using the plaster’sfloatand pressingthe mortar so that the raked joints are properly filled.The plaster shall then be finished off with a wooden straight edgereaching across the screeds.The straightedge shall be worked on thescreedswith a small upward and sidewaysmotion 50 mm to 75 mmat a time. Finally, the surface shall be finished off with a plasterer’swoodenfloat. Metal floats shall not be used.

When recommencing the plastering beyond the work suspendedearlier, the edgesof the old plaster shall be scrapped, cleanedandwetted before plaster is applied to the adjacent areas.

No portion of the surfaceshall be left unfinished for patchingupat a later period.

The plaster shall be finishedtrue to plumb surfaceand to theproperdegreeof smoothnessas directedby the Engineer.

The average thickness of plaster shall not be less than thespecified thickness.The minimum thickne~over~anyportion of thesurface shall not be less than the specified thickness by more than3mm.

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Section 1300 Brick Masonry

Any cracks which appearin the surfaceand all portions whichsound hollow when tapped, or are found to be soft or otherwisedefective, shall be cut in rectangularshape and re~doneas directedby the Engineer.

1312.5. Curing of Finishes

Curing shall be commenced as soon as the mortar usedfor finishing has hardened sufficiently not to be damaged duringcuring. It shall be keptwet for a period of at least 7 days. Duringthis period, it shall be suitably protected from all damages.

1312.6. Scaffolding for Finishes

Stage scaffolding shall be provided for the work. This shall beindependentof the structure.

1313. ARCHITECTURAL COPING FOR WINGIRETURN/PARAPET WALL

This work shall consistof providing an Architectural coping forwing/return/parapetwalls.

The material usedshall be cementmortar 1:3 or as shown on thedrawings prepared in accordance with Clause 1304.

The cementmortar shall be laid evenly to an averagethicknessof15 mm to the full width of the top of the wall and in continuationa band of 15 mm thicknessand 150 mm depth shall be madeout ofthe mortar along the top outer face of the walls.

1314. ACCEPTANCE OF WORK

All work shall be true to the lines and levels as indicated onthe drawing or as directed by the Engineer, subject to tolerancesasindicated in these specifications.

Mortar cubes shall be testedin accordance with !S:2250 forcompressivestrength, consistencyof mortar and its water retentivity.The frequencyof testingshall be one sample for every 2 cubicmetiesof mortar, subject to a minimum 3 samples for a day’s work.

In caseof plaster finish, the minimum surface thickness shallnot be less than the specified thicknessby more than 3mm.


All brick work shall be measuredin cubicmetres.Any extra workdone by theContractoroverthe specifieddimensions shall beignored.

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Brick Masonry Section 1300

In arches, the length of areh shall be measured as the mean

length betweenthe extradosand intrados.

The work of plasteringandpointing shall be measuredin squaremetresof the surfacetreated.

Architectural coping shall be measuredin linear metres.

1316. RATEThe contractunit rate for brick work shall include the cost of

all Labour, materials,tools and plant, scaffolding and otherexpensesincidentalto the satisfactorycompletion of the work, sampling, testingand supervisionas described in thesespecificationsand as shown onthe drawings.

The contract unit rate for plastering shall include the cost of allLabour, materials, tools and plant, scaffolding and all incidentalexpenses,samplingand testing and supervisionas describedin thesespecifications.

The contract unit rate for pointing shalt include erecting andremoval of scaffolding,all labour, materials, and equipment incidentalto completethe pointing,raking out joints, cleaning,wetting, filling withmortar, trowelling; pointing and watering, sampling and testing andsupervision as described in these specifications.

The contractunit rate for architecturalcoping shall include costof all labour, materials, tools and plant, sampling and testing andsupervisionas describedin thesespecifications.

387

StoneMasonry

1400

StoneMasonry

Stone Masonry Section 1400

1401. DESCRIPTION

This work shall consistof the constructionof structureswith stonesjointed togetherby cementmortarin accordancewith the details shownon thedrawings andthesespecificationsor asapprovedby theEngineer.

1402. MATERIALS

All materials used in stone masonryshall conform to Section 1000except cement mortar for stone masonrywhich shall conform toClause1304.

1403. PERSONNEL

Only trained personnelshall beemployedfor construction andsupervision.

1404. TYPE OF MASONRY

The typeof masonryused for structures shall be random masonry(coursed oruncoursed)orcoursedrubble masonry(First sort).However,for bridge work generally, course rubblestone masonryshall be used.The actual typeof masonry used for different parts of structures shallbe specified on the drawings.

For facing work, ashlarmasonry shallbe used where indicated onthe llrawings.

1405. CONSTRUCTION OPERATIONS

1405.1. General Requirements

The dressingof stone shall be as specifiedfor individual typemasonry work and it shall also conform to thegeneralrequirementsof 15:1597 and requirement for dressing of stonecovered in 15:1129.Other specific requirements are covered separatelywith respecttoparticular types of rubble stone work.

1405.2. Laying

1405.2.1.The masonry work shall be laid to lines, levels, curvesand shapes as shown in the plan. The height in cach course shall bekept sameand every stone shall be fine tooled on all beds joints andface full and true. The exposedfaces shall be gauged out, grooved,regulated andsunk or plain moulded as the casemay be. The facesof each stonebetween thedraft be left rough as the stonecomesfromquarry exceptwhere sacrificial layer is to be provided or plastering isresorted to due to aggressiveenvironment.

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Section1400 StoneMasonry

1405.2.2. Stones shall be sufficiently wetted before laying topreventabsorption of water from mortar.

Stratified stones must be laid on their naturalbeds. All bedjointsshall be normal to the pressureupon them.

Stonesin the hearting shall be laid on their broadestface thatgivesa better opportunity to fill the spacesbetweenstones.

The courses of the masonryshall ordinarily be pre-determined.They shallgenerallybe of thesameheight.When thereis to be variationin the height of courses,the larger coursesare to be placed at lowerlevels, heightsof coursesdecreasing gradually towards the top of thewall. The practice of placing loose mortar on the courseanti pouringwater on it to fill the gaps in stonesis not acceptable.Mortar maybe fluid mixed thoroughlyand then poured in thejoints. No dry orhollow space shall be left anywherein the masonryand each stoneshall have all the embeddedfacescompletely covered with mortar.

In taperedwalls, the beds of the stonesand the planes of courseshould be at right anglesto the batter. In caseof bridge piers with batteron both sides, the courseshall be horizontal.

The bed which is to receive the stone shall be cleaned, wettedand covered with a layer of fresh mortar. All stonesshall be laidfull in mortar both in bed and vertical joints and settled carefully inplace with a wooden mallet immediately on placement and solidlyembeddedin mortar before it has sel Clean chips and spalls shall bewedged into the mortar joints and bed wherever necessary to avoidthick beds or joints of mortar. When the foundation masonryis laiddirectly on rock, the face stonesof the first courseshall be dressedto fit into rock snugly when pressed down in the mortar beddingover the rock. No dry or hollow spaceshall be left anywherein themasonryand each stone shall haveall the embeddedfacescompletelycoveredwith mortar, For masonry works over rock, a levelling courseof 100 mm thicknessand in concrete M 15 shall be laid over rockand then stonemasonrywork shall be laid without foundationconcreteblock.

Faceworks and hearting shall be brought up evenly but the top ofeach courseshall not be levelled up by the use of flat chips.

For sham cornersspecially in skew bridges,through stonesshall beused in order to avoid spalling of corners.

In case any stone already set in mortar is disturbedor the joints

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StoneMasonry SecLion1400

broken, it ~hallbe takenout without disturbing the adjoining stonesandjoints. Dry mortar and stones thoroughly cleanedfrom thejointsand stonesand the stonesresetin fresh mortar. Attempt must neverbe made to slide one stone on top of another, freshly laid.

Shaping and dressingshall be done before the stone is laid inthe work. No dressingand hammering, which will loosen themasonry, will be allowedafter it is onceplaced. All necessarychasesfor joggles, dowels and clampsshould be formed before hand.

Sufficient transversebondsshall be provided by the use of bondstone extending from the front to the backof the wall and in caseof thick wall from outside to the interior and vice versa. In the lattercase,bond stonesshall overlap each other in their arrangement.

In case headers are not available, precast headers of M 15concreteshall be used.Cast~in-situheadersare not permitted.

Stonesshall breakjoint on the face for at least half the height ofthe course and the bond shall be carefully maintainedthrough~out.

In band work at all anglejunctions of waIls, the stonesat eachalternate course shall be carried into each of the respectivewallsso as to unite the work thoroughly.

The practice of building up thin faces tied with occasionalthrough stonesand filling up the middle with small stuff or even drypacking is not acceptable.

All quoins and the anglesof the openingshall be made fromselected stones,carefully squaredand bedded and arranged to bondalternatelylong and short in both directions~

All vertical joints shall be truly vertical. Vertical joints shall bestaggered as far as possible. Distance between the nearer verticaljoints of upper layer and lower shall not be less than half the heightof the course.

Only rectangular shaped bond stonesor headers shall be used.Bond stonesshall overlap each other by 150 mm or more.

All connectedmasonry in a structure shall be carried up nearlyat oneuniform level throughoutbut when,breaksare unavoidablethemasonry shall be raked in sufficiently long steps to facilitatejointing of old andnew work. The steppingof raking shall not be morethan 45 degreeswith the horizontal.

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section 1400 StoneMasonry

14053. Random Masonry (Uncoursedand Coursed)

1405.3.1. Dressing : Stone shall be hammer dressed on the face,the sides and beds to enable it to come in proximity with theneighbouringstone. The bushingon theexposedface shall not be morethan 40 mm.

1405.32.insertion of chips : Chips and spallsof stonemay be usedwherever necessaryto avoid thick mortar beds or joints and it shallbe ensured that no hollow spacesare left anywherein the masonry.The chips shall not be used below hearting stonesto bring theseuptothe level of face stones. Use of chips shall be restricted to fillingof interstices between ‘the adjacentstonesin hearting and they shallnot exceed20 per cent of the quantity of stone masonry~.

1405.3.3.Hearting stones: The hearting or interior filling of thewall face shall consistof rubble stonesnot less than 150 mm in anydirection, carefully laid, hammered down with a wooden malletinto position and solidly bedded in mortar.The hearting should belaid nearly level with facing and backing.

1405.3.4.Bond stones: Through bond stones shall be providedin masonry upto 600 mm thickness and in caseof masonryabove600 mm thickness,a set of two or morebond stonesoverlappingeachotherat leastby 150 mm shall be providedin a line from face to back.in case of highly absorbent types of stones (porous limestone andsandstones,etc.,)the bond stoneshall extendonly abouttwo-third intothe wall, as through stonesin such casesmay give rise to penetrationof dampnessand therefore, for all thicknessesof such masonry,a set’of two or more bond stonesoverlapping each other by at least 150mm shall be provided, One bond stone or a set of bond stonesshallbe provided for every 0.50 sq. m. of the masonry surface.

1405.3.5.Quoin stone:Quoin stonei.e. stonespeciallyselectedandneatly dressed for forming an external angle in masonry work, shallnot be less than 0.03 cubic metre in voltime.

1405.3.6. Plum stone : The plum stonesare selectedlong stonesembeddedvertically in the interior of the masonryto form a bondbetween successivecoursesand shall be provided at about 900 mmintervals.

1405.3.7.Laying: The masonryshall be laid with or without coursesas specified. The quoins shall be laid header and stretcher alternately.Every stone shall be fitted to the adjacentstone so as to form neat

394

StoneMasonry Section1400

and close joint. Facestone shall extend and bond well in the back.These shall be arrangedto break joints, as much as possible,and to avoid long vertical lines of joints.

1405.3.8.Joints : The face joints shall not be more than 20 mmthick, but shall be sufficiently thick to preventstone-to-stonecontactand shall be completely filled with mortar.

1405.4. Square Rubble - Coursed Rubble (First Sort)

1405.4.1.Dressing : Face stones shall be hammerdressedon allbeds and joints so as to give them rectangularshape.These shallbe square on all joints andbeds.The bedjoints shall be chiseldraftedfor at least 80 mm back from the face and for at least 40 mm forthe side joints. No portion of the dressed surface shall show a depthof gap more than 6 mm from the straight edge placed on it. Theremainingunexposedportion of the stone shall not project beyond thesurfaceof bed and side joints. The requirements regarding bushingshall be the same as for random rubble masonry.

1405.4.2.Hearting stones : The hearting or interior filling of thewall face shall consistof flat beddedstone carefully laid, on preparedbeds in mortar. The use of chips shall be restrictedto the fillingof interstices between the adjacent stones in hearting and theseshallnot exceed 1Q per cent of the quantity of masonry.While using chipsit shall be ensuredthat no hollow spacesare left anywhere in themasonry.

1405.4.3. Bond stones : The requirements regarding through orbond stoneshall be the sameas for randomrubble masonry,but these,shall be provided at 1.5 metre to 1.8 metreapartclearin everycourse.

1405.4.4.Quoin stone : The quoins shall be of the sameheightof the course in which theseoccurandshall be formed of headerstonesnot lessthan 450mm in length. They shall belaid lengthwisealternatelyalong eachface, square in their bedswhich shall be fairly dressedto a depth of at least 100 mm.

1405.4.5. Face stone : Face stones shall tail into the work fornot less than their heightsand at least one-third of the stonesshalltail into the work for a length not less thantwice their height.Theseshall be laid as headersand stretchersalternately.

1405.4.6,Laying: The stonesshall be laid on horizontal coursesandall verticaljoints should be truly vertical. The quoin stonesshouldbe laid header and stretcher alternately and shall be laid square

395

Section 14(X) StoneMasonry

on their beds,which shallbe roughchiseldressedto a depthof at least100 mm.

1405.4.7.Joints : The face joints shall not be more than 10 mmthick, but shall be sufficiently thick to preventstone-to-stonecontactand shall be completely filled with mortar.

1405,5. Ashlar Masonry (Plain Asbiar)

1405.5.1. Dressing : Every stone shall be cut to the required sizeand shape, chiseldressedon all beds andjoints so as to be fn~efromall bushing. Dressed surfaceshall not show a depth of gap of morethan 3 mm from straight edgeplacedon it. The exposedfaces andjoints, 6 mm from the face shall be fine tooledso that a straight edgecan be laid along the face of the stone in contact with every point.All visible angles and edges shall be true and square and free fromchippings.The cornerstones(quoins) shall be dressedsquareandcornershall be straight and vertical.

1405.5.2.Bond stones : Through bond stones‘shall be providedin masonry upto 600 mm thicknessand in caseof masonry above600 mm thickness,a set of two or morebond stonesoverlapping eachotherat leastby 150 mm shall be provided in a line from face to back.In caseof highly absorbenttypes of stones(porous limestone andsandstones,etc.,) the bond stone shall extendonly about,two-third intothe wall, as through stonesin suchcasesmay give rise to penetrationof dampness and, therefore, for all thicknessesof such masonry aset of two or more bond stonesoverlapping each other by at least 150mm shall be provided.One bond stone or a set of bond stonesshallbe 1.5 metres to 1.8 metres apartclear in every course.

1405.5.3.Laying : The faceStone shall be laid headerand stretcheralternately, the headerbeing arrangedto comeas nearly as possiblein the middle of stretchersabove and below. Stonesshall be laidin regular coursesnot less than 300 mm in height andall courses ofthe same heightunlessotherwisespecified.No stone shall be lessin width than its height or less in length than twice its height, unlessotherwise specified.

1405.5.4.Joints : All joints shall be full of mortar.Theseshall notbe less than 3 mm thick. Facejoints shall be uniform throughout,anda uniform recess of 20 mm depth from face shall be left with the helpof a stone plate during the progressof work.

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StoneMasonry Section 1400

1405.6L Pointing

Pointing shall be carried out using mortar not leanerthan 1:3 byvolume of cementand sand or as shown on the drawing. The mortarshall be filled and pressed into the raked out joints before givingthe required finish. The pointing shall conform to Clause 1312.3 ofthe specification. The work shall conform to 15:2212. The thicknessof joints shall not be less than 3 mm for Ashlar masonry. However,the maximumthicknessof joints in different works shall be as follows:

Random Rubble 20 mm

Coursed Rubble L5 mm

Ashlar Maonry 5 mm

l405.7. Curing

Curing shall conform to Clauses1309 and 1312.5

1405.8. Scaffolding

For scaffolding Clause 1310 shall apply.1405.9. Weep Holes

Weep holes shall conform to Clause2706.

1405.10.Jointing with Existing Structures

For Jointingwith existingstructures,the specificationsgiven underClause 1308 shall apply.

1406. ARCHITECTURAL COPING FOR WING/RETURNIPARAPET WALLS

Architectural coping for wing/return/parapetwalls shall conform to:lause 1311

1407, TESTS AND STANDARD OF ACCEPTANCE

All work shall be done to the lines and levels as indicated onhe drawing or as directed by the Engineer subject to tolerancesaspecified in thesespecifications.

Mortar cubes shall be taken in accordance with 15:2250 forcompressivestrength,consistencyof mortar and its water retentivity.The frequencyof testing shall be one sample for every two cubicmetres of mortar sul~jectto a minimum 3 samplesfor a thy’s work.

1408, MEASUREMItNTS FOR PAYMENT

Stone masonry shall be measuredin cubic metres.

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Section1400 StoneMasonry

In arches, the length of arch shall be measured as the meanlength betweenthe extradosand intrados.

The work of pointing shall be measuredin square metres.

Architectural coping shall be measuredin linear metres.

1409. RATE

The contract unit rate for stone masonry shall include the costof all labour,materials,tools andplant,scaffolding, samplingandtesting,supervisionandotherexpensesincidentalto the satisfactorycompletionof the work as described herein above.

The contract unit rate for pointing shall include erecting andremoval of scaffolding, all labour, materials and equipmentincidentalto completepointing, raking out joints, cleaning,wetting, filling withmortar, trowelling, pointing and watering, sampling and testing andsupervision as described in these specifications.

The contract rate for architecturalcoping shall include the cost ofall labour,materials,toolsandplant,samplingand testirgandsupervisionas describedin these specifications.

398

Formwork

1500

Formwork

Formwork Section 1500

1501. DESCRIPTION

Formwork shall includeall temporaryor permanentforms requiredfor forming the concreteof the shape,dimensions and surfacefinishas shownon thedrawing or as directedby the Engineer,together withall props, staging, centering, scaffolding andtemporary constructionrequired for their support. The design,erection and removal of formworkshall conform to IRC:87 “Guidelines for Design and Erection ofFalsework for Road Bridges” and these specifications.

1502. MATERIALS

All materialsshall complywith therequirementsof IRC:87. Materialsand componentsused for formwork shall be examined for ~lamageorexcessivedeteriorationbefore use / re-useand shall be used only iffound suitable after necessaryrepairs.In caseof timber formwork, theinspectionshall not only cover physicaldamagesbut alsosignsof attacksby decay, rot or insect attack or the development of splits.

Forms shall be constructedwith metal or timber. The metal usedfor forms shall be of such thicknessthat the forms remain true toshape. All bolts shouldbe countersunk.The use of approvedinternalsteel ties or steel or plastic spacers shall be permitted.Structuralsteel tubesusedas supportfor forms shall havea minimum wall thicknessof 4 mm. Other materialsconforming to the requirementsof IRC:87may also be used if approved by the Engineer.

1503. bESIGN OF FORMWORK

1503.1. The Contractor shall furnish the design and drawing ofcompleteforniwork (i.e. theforms aswell astheir supports) for approvalof the Engineerbeforeany erection is takenup. If proprietarysystemof formwork is used,the Contractorshall furnish detailed informationas per Appendix1500/i to the Engineerfor approval.

Notwithstanding any approvalor reviewof drawing and design bythe Engineer, the Contractor shall be entirely responsible for theadequacyand safety for formwork.

1503.2. The design of the formwork shall conform to provisionsofIRC:87. It shall ensure that the forms can be conveniently removedwithout disturbing the concrete.The design shall facilitate properand safe accessto all parts of formwork for inspection.

1503.3.In the case of prestressedconcrete superstructure,careful

401

Section 1500 Formwork

considerationshall be given to redistributionof loads on props due to

prestressing.

1504. WORKMANSHIP

1594,1. The formwork shall be robust and strong and the jointsshall be leak-proof.

Balli shall not be used as staging. Staging must have crossbracings and diagonal bracings in both directions. Staging shall beprovidedwith an appropriatelydesignedbaseplate resting on firm strata.

1504.2. The numberof joints in the formwork shall be kept to aminimum by using large size panels. The design shall provide forproper“soldiers” to facilitate alignment.All joints shall be leak proofand must be properly sealed.Use of PVC JOINT sealing tapes,foam rubber or PVC T-section is essential to prevent leakage ofgrout.

1504.3. As far as practicable,clamps shall be used to hold theforms together. Where use of nails is unavoidableminimum numberof nails shall be used and theseshall be left projecting so that theycan be withdrawn easily. Use of doubleheadednails shall be preferred.

1504.4.Use Qf ties shall berestricted,as faras practicable.Whereverties are used they shall be used with HDPE sheathingso that the tiescan easily be removed. No parts prone to corrosion shall be leftprojecting or nearthe surface.The sheathing shall be grouted withcement mortar of the same strength as that of the structure.

1594.5. Unless otherwisespecified,or directed,chamfersor filletsof sizes25 mm x 25 mm shall be providedat all anglesof the formworkto avoid sharp corners. The chamfers, bevelled edges and mould-ings shall be madein the formwork itself, Opening for fixturesandother fittings shall be provided in the shuueringas directed by theEngineer.

1504.6. Shuttering for walls, slopingmembersand thin sectionsof considerableheight shall be provided with temporaryopenings topermit inspection and cleaning out before placing of concrete.

1504.7. The formwork shall be constructed with precamberto thesofflt to allow for deflection of the formwork. Pre-camber to allowfor deflection of formwork shall be in addition to that indiôated for theperthanentstructure in the drawings.

1504.8.Where centering trussesor launching trusses are adopted

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Formwork Section1500

for casting of superstructure,thejoints of the centeringtrusses,whetherwelded, riveted or bolted should be thoroughly checkedperiodically.Also, variousmembersof the centering trussesshould be periodicallyexamined for proper alignmentand unintended deformation beforeproceedingwith the concreting.They shall alsobe periodically checkedfor any deterioration in quality due to steel corrosion.

1504.9. The formwork shall be so madeas to producea finishedconcretetrue to shape, line and levels and dimensionsas shown onthe drawings, subject to the tolerancesspecified in respectivesectionsof these specifications,or as directedby the Engineer.

1504.10. Where metal forms are used,all bolts and rivetsshall becountersunkandwell groundto provideasmooth,planesurface.Where timber is used it shall be well seasoned,free from looseknots,projecting nails, splits or other defects that may mar the surfaceofconcrete.

1504.11.Forms shall be madesufficiently rigid by the useof tiesand bracingsto preventany displacementor sagging between supports.They shall l~estrong enoughto withstandall pressure, ramming andvibration during and after placing the concrete.Screw jacks or hardwood wedgeswhererequiredshall beprovidedto make up anysettlementin the formwork either before or during the placing of concrete.

1504.12. The formwork shall take due account of the calculatedamount of positive or negativecamberso as to ensurethe correctfinal shape of the structures,having regard to the deformation offalse work, scaffoldingor proppingand the instantaneousor deferreddeformationdue to various causesaffecting prestressedstructures.

1504.13.Suitable camber shall beprovided to horizontal membersof structure, specially in Ion~spans to counteract the effects ofdeflection.The formwork shall be so fixed asto provide for suchcamber,

1504.14. The formwork shall be coated with an~approved releaseagent that will effectively preventsticking and will not stain the concretesurface. Lubricating (machineoils) shall be prohibited for use ascoating.

1505. FORMED SURFACE AND FINISH

The formwork shall be lined with material approved by theEngineer so as to provide a smooth finish of uniform texture andappearance. This material shall leave no stain on the concrete andso fixed to its backingas not to impart any blemishes. It shall beof the same type and obtained from only one source throughout

403

Section1500 Formwork

for the construction of any onestructure.The contractor shall makegood any ithperfections in the resulting finish as required by theEngineer. Internal ties and -. embeddedmetal parts shall be carefullydetailed and their use shall be subject to the approval of tfie Engineer.

1506. PRECAUTIONS(i) Special measures in the design of formwork shall be taken to ensure that it

doesnot hinder the shrinkage of concrete, The sof fit of the fomiwork shallbe so designed as to ensure that the formworit does not restrain the shorteningand/or hogging of beams during prestressissg. The formsmay be removed atthe earliest opportunity subject to the minimum time for removal of forms withprops retained in position.

(ii) Where necessary, forsnwork shall be so arranged that the soffit form, properlysupported on props only can be retained irs position for such period as maybe required by matu:ring conditions.

(iii) Any cut-outs or openings provided in any stmcturai member to facilitate erectionof formwork shall be closed with the same grade of concrete as the adjoiningstructure immediately after removal of fomswork ensuring watertight joints.

(iv) Provision shall be made for safe access en, to and about the forrnwork at thelevels as required.

(v) Close watch shall be maintained to check for settlement of formwork duringconcreting. Any settlement of fomswork during concreting shall ho promptlyrectified.

(vi) Water used for curing should not be allowed to stagnate near the base platessupporting the staging and should be properly drained.

1507. PREPARATION OF FORMWORK BEFORECONCRETING

The inside surfaces of forms shall, except in the case ofpermanentform work or where otherwise agreedto by the Engineerbe coated with a releaseagentsupplied by approved manufacturerorof an approvedmaterial to preventadhesionof concreteto the formwork.Releaseagents shall be applied strictly in accordancewith the manu-facturer’s instructions and shall not be allowed to come into contactwith any reinforcementor prestressing tendons and anchorages.Different release agentsshall not be used in formwork for exposedconcrete.

Before re-useof forms, the following actions shall be taken(i) The contact surfaces of the forms shall be cleaned carefully and dried before

applying a release agent

(ii) It should be ensured that the release agent is appropriate to the surface tobe coated, The same type and make of release agent shall be used throughouton similar fomswork materials and different types should not be mixed.

404

Formwork Section 1500

(iii) The form surfacesshall be evenlyand thinly coated with eleare ageuL Theverticalsurfaceshall be treated beforehorizontalsurfaceandany excesswipedOut.

(iv) The release agent shall not come in contact with reinforcementor thehardenedconcrete

All forms shall he thoroughly cleaned immediately beforecon~creting.

The Contractor shall give the Engineer due notice before placingany concrete in the forms to permit him to inspect and approvetheformwork, but such inspection shall not relieve the contractor ofhis responsibility for safety of formwork, men, machinery, materialsand finish or tolerances of concrete.

1S08. REMOVAL OF FORMWORK

The schemefor removal of formwork (i.e. de-shuuering and de-centering) shall be plannedin advanceand furnished to the Engineerfor scrutiny and approval. No formwork or any part thereofshallbe removed without prior approval of. the Engineer.

The formwork shall be so removed as not to causeany damage~to concrete. Centering shall be gradually and uniformly lowered insuch a manner as to permit the concrete to take stressesdue to itsown weight uniformly andgradually to avoid any shock or vibration.

Where not specifically approved, the time of removal of formwork(when ordinary PortlandCement is used without any admixtures at anambient temperaturesexceeding 10 degrees Celsius) shall be asunder

a) Walls, piers, abutments, 12 to 48 hours as may 1~ecolwnns and vertical faces decidedby the Engineerof structuralmembers

b) Soffits of Slabs 3 days(with props left under)

c) Props(left under slabs) : 14 days

d) Softit of Girders : 7 days(with propsleft under)

e) Props (left under girders) 21 days

Where thereare re-entrantangles in the concrete sections, theformwork should be removed at thesesectionsas soon as possible afterthe concrete.hasset, in order to avoid cracking due to shrinkageofconcrete.

405

Section1500 Formwork

1509. RE-USE OF FORMWORK

When formwork is dismantled,its individual components shall beexamined for damage and damagedpieces shall be removed for rec—tification. Such examination shall always be carried Out beforebeing usedagain. Before re-use all components shall be cleaned ofdeposits of soil,, concrete o~other unwantedmaterials. Threadedparts shall be oiled after cleaning.

All bent steel props shall be straightenedbefore re-use. Themaximum deviation from straightness is 1/600 of the length. Themaximum permissibleaxial loadsin usedprops shall be suitably reduceddepending upon their condition. The condition of the timber components,plywood and steel shuttering plates shall be examined closely fordistortion and defects before re-use.

1510. SPECIALISE1) FORMWORK

Specialised formwork may be required in the caseof slipform work,underwater concreting, segmentalconstruction etc. Such specialisedform-work shall be designed and detailedby competent agencies and a setof complete working drawings and installation instructions shall besupplied to the Engineer. The site personnel shall be trained inthe erectionand dismantlingas well asoperation of such specialisedformwork. In case proprietary equipment is used, the supplier shallsupply drawings, details, installation instructions, etc.~in the form ofmanuals alongwith the formwork. Where specialised formwork is used,closeco-ordinationwith the designof permanentstructureis necessary.

For slipform the rate of slipping the formwork shall be designedfor eachindividual casetaking into accountvarious parameters includingthe gradeof concrete,concrete strength, concrete temperature, ambienttemperature,concrete admixtures, etc.In the caseof segmentalconstruc-tion, the concrete mix shall be normallydesignedfor developinghighearly strength so that the formwork is releasedas early as possible.

in order to verify the time and sequenceof striking/removal ofspecialisedformwork, routine field tests for the consistency of concreteand strengthdevelopment are mandatory and shall be carried outbefore adoption.

For specialisedformwork, the form lining material may be eitherplywood or steel sheetof appropriatethickness.,Plywood is preferredwhere superior quality of surfaceis desired, whereassteel sheetingisnormally used where large number of repetitions are involved.

406

Formwork Section1500


The materials shall be tested in accordancewith theseSpecifica-tions and shall meet the prescribed criteria.

The work shall conform to these Specifications andshall meet theprescribedstandardsof acceptance.


Unless stated otherwise the rate for concrete in Plain Concrete orReinforced Concrete or PrestressedConcrete shall be deemedto includeall formwork required in accordance with this section and shalt not bemeasured separately.

Where it is specificallystipulated in the Contract that the formworkshall be paid for separately, measurementof formwork shall be takenin squaremetres of the surface area of concretewhich is in contact withformwork.

1513. RATE

The unit rate of the Plain Concrete or Reinforced Concrete orPrestressed Concrete as defined in respective sectionsshall be deemed

•to cover the costs of all formwork, including cost of all materials,labour, tools and plant required for design,construction and removalof formwork and supervision as described in this section includingproperly supporting the members until the concrete is cured, set andhardened as required.

Wherethecontract unit rate for formwork is specifically providedas a separateitem, it shall include the cost of all materials,labour,tools andplantrequiredfor design,construction andremoval of formworkand supervision as~described in this Section including properlysupporting the members until the concrete is cured, set and hardenedas required.

407

SteelReinforcement (Untensioned)

16D0

SteelReinforcement(Untensioned)

Steel Reinforcement (Untensioned) Section 1600

1601, DESCRIPTIONThis work shall consistof furnishing and placing coated or

uncoatedmild steel or high strength deformed reinforcement bars(untensioned) of the shapeanddimensionsshown on the drawingsandconforming to these Specificationsor as approved by the Engineer.

1602. GENERALSteel for reinforcementshallmeetwith the requirementsof Section

1000.

Reinforcementsmay be either mild steel/mediumtensile steel or highstrength deformedbars. They may be uncoatedor coated with epoxyor with approvedprotectivecoatings.

1603. PROTECTION OF REINFORCEMENT

Uncoated reinforcing steel shall be protectedfrom rusting orchloride contamination. Reinforcementsshall be free from rust, mortar,loose mill scale,grease,oil or paints.This may be ensured either byusing reinforcement fresh from the factory or thoroughly cleaning allreinforcement ui remove rust using any suitable method such as sandblasting, mechanical wire brushing, etc., as directed by the Engineer.Reinforcementsshall be storedon blocks, racks or platforms and abovethe ground in a clean anddry condition and shall be suitably markedto facilitate inspection and identification.

Portions of uncoated reinforcing steel and dowels projecting fromconcrete, shall be protected within one week after initial placingof concrete with a brush coat of neat cement mixed with water toa consistencyof thick paint. This coating shall be removed by lightlytapping with a hammer or other tool not more than one week beforeplacing of the adjacent pour of concrete.Coated reinforcing steel shallbe protected againstdamage to the coating. If the coating on the barsis damaged during transportation or handling and cannotbe repaired,the sameshall be rejected.

1604. BENDING OF REINFORCEMENT

Bar bending scheduleshall be furnished by the Contractorand gotapproved by the Engineer before start of work.

Reinforcing steel shall conform - to the dimensions and shapesgiven in the approved Bar Bending Schedules.

411

I~~s.—. -.~ .... .- -

Section 1600 Steel Reinforcement (Untensioned)

Bars shall be bent cold to the specifiedshapeand dimensionsoras directedby the Engineerusinga properbarbender,operatedby handor power to obtain the correct radii of bendsand shape.

Bars shall not be bentor straightenedin a mannerthat will damagethe parent material or the coating.

Bars bent duringtransportor handling shall bestraightenedbeforebeing usedon work and shall not be heatedto facilitate straightening.

1605. PLACING OF REINFORCEMENT

a) The reinforcementcage should generally be fabricatedin the yard at ground leveland then shifted andplaced in position.The reinforcementshall he placed strictlyin accordance with the dr%wings and shall be assembledin position onlywhen the structure is otherwise ready for plac:ing of concrete. Prolongedtimegap betweenassemblingof reinforcements and casting of concrete, whichmay result in rust formation on the surface, shall not be permitted.

b) Reinforcement bars shall be placed accurately in position as shown on thedrawings. The bars, crossing one another shall be tied together at everyintersection with binding wire (annealed), conforming to lS:280 to make theskeleton of she reinrorcement rigid such that the reinforcement does not getdisplaced during placing of concrete,or any other operation, The diameterof binding wire shall not be lesa than 1 mm.

c) liars shall he kept in position usually by the following methods:

(i) In caseof beam and slab construction, industrially produced polymer roverblocks of thickness equal to the specified cover shall be placed betweenthebars and formwork subject to satisfactory evidence that the polymercomposition is not hannful to concreteand reinforcement. Cover blocksmade of concrete may be permiued by the Engineer, provided they havethe same strength and specification as those of the member.

(ii) tn case of dowels Mr columns and walls, the vertical reinforcement shallbe kept in position by means of timber templates with slots cut in themaccurately, or with coverSockstied to the reinforcement. Timbertemplatesshall be removed after the concretinghas progressed upto a level justbelow their location.

(iii) Layers of reinforeernentsshall be separatedby spacerbars at approximatelyone metre intervals. The minimum diameter of spacerbars shall be 12 mmor equal to maximum size of main reinfoscanent or maximum size ofcoarseaggregate,whichever is greater. Horizontal reinforcementshall notbe allowed to sag betweensupports.

(iv) Necessary stays, blocks, metal chairs, spacers,metal hangers,supportingwiies etc, or other subsidiaryreinforcementshall be provided to fix thereinforcementsfirmly in its correct position.

(v) Use of pebbles,broken stone, metal pipe,brick, mortar or woodenblocksetc., as devices for positioning reinforcement shall noI~be permitted.

d) liars coated with epoxy or any other approved protective coating shall be

412

SteelReinforcement(Untensioned) Section1600

placed on supportsthat do not damage the coating. Supportsshall be installedin a manner suchthat planesof weakness are notcreated in hardened concrete.The coatedreinforcing steel shall be held in place by use of plastic or plasticcoated binding wires especially manufacturedfor the purpose. Reference shallbe made to Section 1000 for other requirements.

e) Placing and fixing of reinforcement shall be inspected and approved by theEngineer before concrete is deposited.

1606. BAR SPLICES

1606.1. Lapping

All reinforcementshall be furnishedin full lengthsas indicated onthe drawing.No splicing of bars,exceptwhere shown on thedrawing,will be permittedwithout approvalof the Engineer.The lçngths of thespliceshallbe as indicatedon drawing or asapprovedby the Engineer.Where practicable, overlapping bars shall not touch each other, andshallbe kept apartby 25 mm or 1 !/4 timesthemaximum size of coarseaggregate,whichever is greater.If this is not feasible,overlappingbarsshall be bound with annealedsteel binding wire, not less than 1 mmdiameter and twisted tight in such a manneras to maintain minimumclear cover to the reinforcementfrom the concrete surface. Lappedsplicesshall be staggeredor locatedat points,along the span wherestressesare low.

1606.2. Welding

1606.2.1. Splicing by welding of reinforcementwill be permittedonly if detailed on the drawing or approvedby the Engineer.Weldshall develop an ultimate strengthequal to or greaterthan~thatof thebars connected.

1606.2.2.While welding may bepermittedfor mild steel reinforcingbarsconforming to 15:432, welding of deformed bars conforming tolS:i 786 shallin generalbeprohibited.Weldingmaybe permittedin caseof bars of other than S 240 grade including specialwelding gradeof S 415 gradebarsconformingto 15:1786,for which necessarychemicalanalysis hasbeensecured and the carbonequivalent (CE) calculatedfrom the chemical composition using the formula

Mn Cr+Mg+V Ni+Cu

CE= C+-j-+ ~ +

is 0.4 or less.

1606,2.3. The method of welding shall conform to 15:2751 and15:9417andto any ~upplernentalspecificationsto the satisfactionof theEngineer.

413

Section 1600 SteelReinforcement (Untensioned)

Welding may be carried out by metal arc welding process.Oxy-acetelenewelding shall not be permissible.Any othtr processmay betised subjectto the approvalof the Engineer and necessary additionalrequirementsto ensuresatisfactoryjoint performance.Precautions onover heating, choice of electrode, selection of correctturrent in arcwelding etc., should be strictly observed.

All bars shall be butt welded exceptfor smaller diameterbars(diameter of less than20 mm) which may be lap welded. Single-V orDouble-V butt joints may generallybe used. For vertical bars singlebevel or double bevel jointsmay be used.

Weldedjoints shall be locatedwell away from bendsand not lessthan twice the bar diameteraway from a bend.

Generally, shop welding in controlled conditions is to bepreferred, where feasible.Site welding where necessary‘shall, however,be permitted when the facilities, equipment, process,consumables,operators, weldingprocedureare adequateto produce and maintainuniform quality at par with that attainable in shop Nelding to thesatisfactionof the Engineer.

Joint welding procedures which are to be ~employed shallinvariably be establishedby a procedure specification. All weldersand welding operatorsto be employedshall have to be qualified bytestsprescribedin IS:2751. inspection of welds shall conform toIS:822 and destructive or non-destructive testingmay be undertakenwhen deemednecessary.Joints with weld defects detected by visualinspection or dimensional check inspection shall not be accepted.

Suitable meansshall be provided for holding the bars securely inposition during welding. It must beensuredthat no voids are leftin welding. When welding is done in 2 or 3 stages,previoussurfaceshall becleanedproperly.Bars shall becleanedof all loose scale,rust,grease,paint ‘and other foreign matter beforecarl%ring out welding.Only competent and experienced welders shall beemployed on thework with the approvalof the Engineer.No welding shall be doneoncoatedbars.

M.S. electrodesused for welding shall conform to IS:8l4.

1606.2.4.Welded joints shall prefeiably be locatedat points wheresteel will not be subject to more than 75 per cent of the maximumpermissiblestresses and welds so staggered thatat any one section,not more than 20 per cent of the bars are welded.

414

SteelReinforcement(Untensioned) Section1600

1606.2.5.Welded pieces ofreinforcementshall betested,Specimensshall be taken from the site andthe numberand frequencyof testsshall be as directedby the Engineer.

1606.3. Mechanical Couplingof Bars

Bars may bejoined with approvedpatentedmechanicaldevicesasindicated on the drawingor asapprovedby theEngineere.g. by specialgrade steel sleevesswftgged on to bars in end to end contactor byscrewed couplers. In casesuch devices arepermitted by theEngineer,they shall develop at least 125 per cent of the characteristicstrengthof the reinforcementbar.

1607, TESTING AND ACCEPTANCE

The material shall betestedin accordancewith relevant IS speci-ficationsand necessarytest certificatesshall befurnished.Additionaltests, if required,will be got carried out by the Contractorat his owncost.

The fabrication,furnishing andplacing of reinforcementshall be inaccordancewith thesespecificationsand shall bechecked andacceptedby the Engineer.


Reinforcement shall be measured inlength including hooks, ifany, separatelyfor differentdiametersas actuallyusedin work, excludingoverlaps. From the length so measured,the weight of reinforcementshall be calculatedin tonneson thebasisof IS:1732.Wastage,overlaps,couplings, welded joints, spacerbars, chairs, stays, hangersandannealedsteel wire or” othermethods, for binding and placing shallnot be measuredand costof these itemsshall bedeemedto beincludedin the rates for reinforcement.

1609. RATEThe contractunit ratefor coated/uncoatedreinforcementshall cover

the costof material, fabricating, transporting, storing, bending,placing,binding andfixing in position as shownon the drawings as per thesespecifications andas directed by the Engineer, includingall labour,equipment, supplies,incidentals,sampling, testing and supervision.

The unit rate for coatedreinforcementshall bedeemed to alsoinclude costof all material,labour, tools and plant, royalty, transpor-tation andexpertise requiredto carry out the work. The rateshall alsocover sampling, testing and supervision required for thework.

415

Structural Concrete

1700

Structural Concrete

Structural Concrete Section 1700

1701. DESCRW~ION

The work shall consistof furnishing and placing structural concreteand incidental constructionin accordancewith thesespecificationsandin conformity with the lines, gradesand dimensions,as shown on thedrawings Or as directedby the Engineer.

1702. MATERIALS

All materialsshall conform to Section 1000of theseSpecifications.

1703. GRADES OF CONCRETE1703.1. The gradesof concreteshall be designated by the charac-

teristic strengthasgivenin Table 1700-I, wherethecharacteristicstrengthis definedas the strengthof concretebelow which not morethan 5 percent of the test resultsare expectedto fall.

TABLE 1700-1.

,Grade Designation Specifiedof 150

characteristicCompressivemm tithes at 28 days, in

strengthMPa

M 15 15M 20 20M 25 25M 30 30M 35 35M 40 40M 45 45M 50 50M 55 55

1703.2.The lowest gradesof concretein bridgesandcorrespondingminimum cementcontentsand water-cementratios shall be maintainedas indicated in Tables 1700-2 and 1700-3.TABLE 1700-2 FOR BRIDGES WITH PRFSTRESSEDCONCREFE OR THOSE

WITH INDIVIDUAL SPAN LENGTHS MORE THAN 30M ORTHOSE THAT ARE BUILT WITH INNOVATIVE DESIGN/CON-STRUCTION

(A) MINIMUM CEMENTCONTENT AND MAXIMUM WATER CEMENT RATIO

Structural Member Mlii. cementcontentfor all exposure

condlilom(kglcnin)

Max. water cementratio

ExposureconditionsNormal Severe

a) FCC membersb) RCC membersc) PSC members

360400 ,400

0.45 0.450.45 0.400.40 0.40

419

a .. ..d.-- ~

Section1700 Stiucuiral Concrete

(B) MINIMUM STRENGTH OF CONCRETE

Member Conditions of Exposure

Moderate Severe

a) PCCniranbersb) RcCmernbersc) PSCmembers ,

M25~ M30M35 M40M35 M40

TABLE 1700-3. FOR BRUSGESOTHER THAN THOSE MENTIONED IN TABLE1700~2AND FOR CULVERTS AND OTHER INCIDENTAL CON-STRUCTION

(A) MINIMUM CEMENT CONTENT AND MAXIMUM WATER CEMENT RATIO

Structural Member

~~

Mtn. cement content(kg/cii,m)

Max. water cementratio



a) FCC membersb) RCC members

250 310310 400

0.50 0.450.45 0.40

(B) MINIMUM STRENGTH OF CONCRETE

Member Conditions of Exposure

Moderate Severe

a) PCCmembers MiS M20b) RCCmembers M20 M25

Notes Applicable to Tables 1700-2 and 1700-3

(I) The minimum cementcontentis based on 20 mm aggregate (nominalmax. size),For 40mm and larger sizeaggregates,it may bereducedsuitably but the reductionshall not be more than 10 per cent

(ii) For underwaterconcretinj,the cementcontentshall be increasedby 10 per cent.

Cmii) Severeconditionsof exposureshall meanalternatewetting and drying dueto seaspray, alternatewetting and drying combined with freezing and buried in soilhaving corrosive effect

(iv) Moderateconditionsof exposure shall mean other that thosementioned in (iii)abovt

The cementcontent shall be as low as possible but not less thanthe quantities specifiedabove. In no caseshall it exceed540 kg/cu.m.of concrete.

1703.3. Concrete used in any componentor structure shall bespecifiedby designationalong with prescribedmethod of designof mixi.e. “Design Mix” or “Nominal Mix”. For all items of concrete, only“Design Mix” shall be used, except where “Nominal Mix” concrete ispermitted as per drawing or by the Engineey.”Nominal Mix” may be

420

StructuralConcrete Section1700

permitted only for minor bridges and culverts or other incidentalconstructionwherestrengthrequirementsare upto M 20 only. “NominalMix” may also be permitted for non-structuralconcreteor for scr~dbelow open foundations.

1703.4.If the Contractorso elects,the Engineer may permit the useof higher gradeconcrete than that specifiedon the drawing, in whicheventthe higher gradeconcreteshall meetthe specifications applicablethereto without additional compensation.

1704. PROPORTIONING OF CONCRETEPrior to the startof construction, the Contractor shall designthe mix

in caseof “Design Mix Concrete” or proposeno?ninalmix in caseof“Nominal Mix Concrete”,and submit to the Engineerfor approval, theproportionsof materials,including admixturesto be used.Water-reducingadmixtures(including plasticisersor super-plasticisers) may be used atthe Contractor’s option, subject to the approval of the Engineer. Othertypesof admixtures shall be prohibited, unless specificallypermitted bythe Engineer.

1704.1. Requirementsof Consistency

The mix shallhavetheconsistencywhichwill allow properplacementand consolidation in the requiredposition. Every attemptshall be madeto obtain uniform consistency.

The optimum consistencyfor varioustypesof structuresshall be asindicated in Table 1700-4,or ~s directedby the Engineer.The slumpof concreteshall be checked as per IS:516.

TABLE 17004

TYPE SLUMP (mm)

I (a) Structureswith exposed inclined’surface requiring low 25slump concreteto allow proper compaction

(b) plain cement concrete 25

2. RCC structureswith widely spaced reinforcements;e.g. solid 40 ‘ 50columns,piers, abatments,footings, well steining

3. RCC struclures with fair degreeof congestionof 50 - 75reinforcement;e.g. pier and abutmentcaps,box culverts wellcurb, well cap, walls with thickness greater than 300 mm

4. RCC and PSC structureswith highly congested 75 ‘ 125reinforcementse.g. deck slab girders, box girders,walls with thicknesslessthan 300 mm

5. Underwaterconcretingthroughtremie 100 200e.g. bottom plug, cast-in-situpiling

421.

Section1700 StructuralConcrete

1704.2. Requirements for Designed Mixes

1704.2.1.Target mean strength

The targetmeanstrengthof specimenshall exceedthespecifiedchar-acteristic compressivestrength by at least the “current margin”.

(i) The currentmargin for a concretemix shall be determinedby the Contractor andshall be taken as 1.64 times the standarddeviationof sampletest results takenfrom at least 40 separatebatches of concrete of nominally similar proportionsproducedat site by the sameplant under similar supervision,over a periodexceeding 5 days, but not exceeding 6 months.

(ii) Where there is insufficient data to satisfy the above, the currentmargin for theinitial design mix shall be taken as given in Table 1700-5

TABLE 1700.5.

ConcreteGrade Current Margin Target Mean StrengthCM Pa) (MPa)

M 15 10 ‘ 25M 20 JO 30N4 25 11 36MMM

303540

121212

424752

M 45 13 58M 50 13 63M 55 14 69

The initial currentmargin given in the Table 1700-5 shall be usedtifl sufficient data is available to determinethe current margin as persub-clause(i) above,

1704.2.2.Trial mixesThe Contractorshall givenoticeto enabletheEngineerto be present

at the making of trial mixes and preliminary testingof the cubes. TheContractorshallpreparetrial mixes,usingsamplesof approvedmaterialstypical of those he proposesto use in the works, for all gradesto theEngineer’ssatisfactionprior to commencementof concreting.The initialtrial mixes shall generally be carried out in an establishedlaboratoryapprovedby the Engineer.In exceptionalcases,theEngineermay permitthe initial trial mixes to be preparedat the site laboratory of theContractor,if a full fledgedconcretelaboratoryhas beenestablishedwellbefore the start of construction, to his entire satisfaction.In all casescompletetestingof materialsforming the constituentsof proposedDesignMix shall have beencarried out prior to making trial mixes.

Sampling and testingproceduresshall be in accordancewith thesespecifications.

422


When the site laboratoryis utilised for preparinginitial mix design,the concretingplant and meansof transportemployedto makethe trialmixes shall be similar to that proposedto be used in the works.

Testcubesshall be takenfrom trial mixesas follows. For each mix,set of six cubesshall be madefrom each of threeconsecutivebatches.Three cubesfrom each set of six shall be testedat an age of 28 daysand threeat an earlier age approvedby the Engineer.The cubesshallbe made,cured, stored,transportedand testedin accordancewith thesespecifications.The averagestrengthof the nine cubesat 28 days shallexceedthe specifiedcharacteristicstrengthby the currentmargin minus3.5 MPa.

1704.23.Control of strength .of design mixesa) Adjustment to Mix Proportions

Adjustmentsto mix proportionsarrivedas in the trial mixesshall bemadesubjectto the Engineer’s approval, in order to minimise the variability of strength andto maintain the target meanstrength. Such adjustments tall not be taken to implyany change in the current margin.

b) Changeof Current Margin

When required by the Engineer, the Contractor shall recalculate thecurrent marginin accajdancewith Clause 1704.2.1. The recalculatedvalue shall be adopted asdirected by the Engineer, and is shall becomethe currentmargin for concreteproduced subsequently.

c) Additional Trial Mixes

During production,the Contractorshall carry out trial mixesand tests,if requiredby the Engineer, before substantialchanges are made in the material or in theproportionsof the materials to be used, except when adjustmentsto the mixproportionsare carried out in accordancewith sub-clauseCa) above.

1704.3. Requirementsof Nominal Mix Concrete

Requirements for nominal mix concrete unless otherwise specified,shall be as detailed in Table 1700-6.

TABLE 1700-6. PROPORTIONS FOR NOMINAL MIX CONCRETE

ConcreteGrade

Total Quantity of dry aggregateby massper 50 kg of cement to betaken asthe sum of Individualmassesof flue and coarseaggregates (kg)

Proportion of fine toCoarseaggregate(by mass)

MIS

M20

350

250

Generally 1:2, subject toupper limit 1:1.5 andlower limit of 1:2.5

—do—--

423

Section 1700 StructuralConcrete

1704.4, Additional Requirements

Concrete shall meet with any other requirementsas specifiedon thedrawing or as directed by the Engineer. Additional requirementsshallalso consist of the following overall limits of deleterious substances inconcrete

a) The total chloridecontentof all constituentsor concreteas a percentageof massof cementin mix shall be limited to values given below:

- PrestiessedConcrete : 0.1 per cent

- Reinforced concrete exposed to chlorides in service : 0,2 per cent(e.g. structures located nearseacoast)

- Other reinforced concreteconstruction : 0.3 per cent

b) The total sulphuric anhydride(SO,) content of all the constituents of concreteasa peitentageof mass of cement in the mix shall be limited so 4 per cent

1704.5. Suitability of ProposedMix Proportions

The Contractor shall submit the following information for theEngineer’s approval

a) Nature and source of each material

6) Quantitiesof each material per cubic metre cYf fully compactedconcrete

c) Either of the following

(i) appropriate existing data as evidenceof satisfactory previous perfosmancefor the target mean strength, current margin, consistencyand water/cementratio and any other additional requirement(s) as specific

1

(ii) full details of tests on trial mixes.

d) Statementgiving theproposedmix proportions for nominal mix concrete.

Any changein the sourceof materialor in the mix proportionsshall’be subject to the Engineer’sprior approval.

t705. ADMIXTURES

Useof admixturessuchassuperplasticisersfor concretemay be madewith the approval of the Engineer.

As the selectionof an appropriateconcreteadmixtureis an integralpart of the mix design,the manufacturersshall recommendthe use ofany one of his productsonly after obtaining completeknowledgeof allthe actual constituentsof concreteas well as methodologiesof manu-facture, transportationand compactionof concreteproposedto be usedin the project.

1706. SiZE OF COARSE AGGREGATE

The size (maximum nominal) of coarseaggregatesfor concreteto

424

StructuralConcrete Section 1700

be used in various componentsshall be given as Table 1700-7.TABLE 1700-7.

Components Maximum Nominal Size o(mm)

f CoarseAggregate

I) RCC well curb 20

ii) RCCJPCCwell steining 40

iii) Well cap or Pile CapSolid type piers and abutments 40

iv) RCC work in girders,slabs,wearingcoat, kerb, approachslab, hollow piers andabutments,pier/abutmentcaps, piles

20

v) PSC work 20

vi) Any other item As specified by Engineer

Maximum nominal size ofsmaller of the following values

aggregatesshall also be restrictedto the

a) 10 mm less than the minimum lateralcleardistancebetweenmain reinforcements

b) 10 mm less than the minimum clear cover to the reinforcements

The proportionsof the various individual size of aggregatesshallbe so adjustedthat the grading producesdensestmix and the gradingcurve correspondsto the maximumnominal sizeadoptedfor the concretemix.

‘1707. EQUIPMENT

Unlessspecifiedotherwise,equipmentfor production, transportationand compactionof concreteshall be as under

a) For Producsicmof Concrete

i) For overall bridgelength of test than200 metres- batchtypeconcretemixerdieselor electricoperated,with a minimumsizeof 200litres,automaticwatermeasuring system and integral weigher (hydraulic/pneumatictype)

ii) For overall bridge length of 200 metres or more - concretebatching andmixing plant fully automaticwith minimum capacityof 15 cu.m.perhour.

All measuringdevicesof the equipment shall be maintained in aclean andserviceablecondition. Its accuracy shall be checked over therange in use, when set up at each site and thereafter periodically asdirected by the Engineer.

The accuracyof the measuringdevicesshall fall within, the followinglimits:

425


Measurementof Cement ± 3 per centof the quantityof cementin eachbatch

Measurementof Water ± 3 per cent of the quantity of waterin each batch

Measurementof Aggregate ±3 per centof shequantityof aggregatein eachbatch

Measurementof Admixture ± 5 percentof the quantity of admixturein eachbatch

b) For ConcreteTransportationi) Concrete dumpersii) Poweredhoistsiii) asutesiv) Buckets handledby cranesv) Transit truck mixervi) Concrete pumpvji) Concretedistributor boomsviii) Belt conveyorix) Cranes with skipsx) Tremies

c) For Compaction of Concrete

size 25 mm to 70 mmminimum 500 wattsfull width of carriageway(upto two lanes)

1708. MIXING CONCRETE

Concreteshall be mixed either in a concretemixer or in a batchingand mixing plant, as per thesespecifications,Handmixing shall not bepermitted. The mixer or the plant shall be at an approvedlocationconsidering the properties9f tl~emixes and the transportationarrange-ments available with the Contractor. The mixer or the plant shall beapprovedby the Engineer.

Mixing shall be continuedtill materialsareuniformly distributedanda uniform colour of the entire mass is obtained,and each individualparticle of the coarse aggregateshows complete coating of mortarcontaining its proportionateamount of cement.In no case shall mixingbe done for less than 2 minutes.

Mixers which have beenout of use for more than30 minutesshallbe thoroughly cleaned before putting in a new batch,Unlessotherwiseagreedto by the Engineer,the first batchof concretefrom the mixershall contain only two thirdsof the normal quantity of coarseaggregate.Mixing plant shall be thoroughlycleanedbeforechangingfrom one typeof cement to another.

dependingupon actual requirementminimum 2 sconescapacityminimum 0.5 tonne capacity

i) Internal vibratorsii) Form vibratorsiii) Screed vibrasors

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1709. TRANSPORTING, PLACING AND COMPACTION OFCONCRETE

The method of transporting andplacing concreteshall be approvedby the Engineer.Concreteshall be transportedand placed as nearaspracticableto its final position, so that no contamination,segregationor lossof itsconstituentmaterialstakesplace.Concreteshallnot befreelydropped into place from a height exceeding 1.5 metres.

When concreteis conveyedby chute, the plant shall be of such sizeand designas to ensurepractically continuousflow. Slope of the chuteshall be soadjustedthat the concreteflows without the useof excessivequantity of water and without any segregationof its ingredients.Thedelivery end of the chute shall be as close as possible to the point ofdeposit. The chute shall be thoroughly flushed with water before andafter each working period and the w~terused for this purposeshall bedischargedoutside tbe formwork.

All formwork andreinforcementcontainedin it shall be cleanedandmade free from standing water, dust, snow or ice immediately beforeplacing of concrete.

No concreteshall be placedin any part of the structureuntil theapproval of the Engineerhas been obtained.

If concreting is not startedwithin 24 hours of the approval beinggiven, it shall have to be obtainedagain from theEngineer.Concretingthen shall proceedcontinuouslyover the area betweenthe constructionjoints. Freshconcreteshall not be placedagainstconcretewhich hasbeenin position for morethan 30 minutesunlessa properconstructionjointis formed.

Except where otherwiseagreedto by the Engineer,concrete shallbe depositedin horizontal layersto a compacteddepthof not more than450 mm when internal vibrators are used and not exceeding300 mmin all other cases.

Concretewhen depositedshall havea temperatureof not less than5 degreesCelsius,and not more than 40 degreesCelsius. It shall becompactedin its final position within 30 minutesof its dischargefromthe mixer, unless carried in properly designed agitators, operatingcontinuously,when this time shaltbe within 1 hour of the addition ofcementto themix andwithin 30 minutesof its dischargefrom theagitator.It may be necessaryto addretardingadmixturesto concreteif trials show

427


that the periods indicatedabove are unacceptable.In all such matters,the Engineer’sdecision shall be final.

Concreteshall be thoroughlycompacted byvibration or othermeansduring placing and worked around the reinforcement, tendonsor ductformers,embedded fixturesandinto cornersof the formwork to producea densehomogeneousvoid-free masshavingthe requiredsurfacefinish.When vibrators areused,vibration shallbe donecontinuously duringtheplacingof eachbatchof concreteuntil theexpulsionof air has practicallyceased andin amanner thatdoesnot promotesegregation.Over vibrationshall beavoidedto minimise the risk of forming a weak surfacelayer.Whenexternalvibrators areused,thedesignof formwork and dispositionof vibrator shall besuch as to ensureefficient compactionand to avoidsurfaceblemishes. Vibrationsshaltnot be applied throughreinforcementand where vibratorsof immersion type areused,contactwith reinforce-mentandall insertslike ductsetc.,shall beavoided.The internalvibratorsshall beinsertedin an orderlymannerandthe distance betweeninsertionsshould beaboutone andahalf timestheradiusof theareavisibly affectedby vibration. Additional vibrators in serviceablecondition shall be keptat site so that they can be usedin the eventof breakdowns.

Mechanical vibrators used shallcomply with IS:2502, IS:2506,JS:2514and IS:4656.

1710. CONSTRUCTION JOINTS

Constructionjoints shall be avoidedas far as possibleandin no casethe locationsof suchjoints shall bechangedor increasedfrom thoseshown on the drawings, exceptwith expressapprovalof the Engineer.The joints shalkbeprovided in a direction perpendicularto the memberaxis.

Location, preparation of surface and concreting of Constructionjoints shall conform to the additional specifications givenin Appendix1700/!.

1711. CONCRETING UNDER WATER

When it is~necessaryto depositconcrete underwater, the methods,equipment, materials and proportions of mix to be used shall be g~tapprovedfrom the Engineerbefore any work is started.Concreteshallcontain 10 per cent more cement than thatrequired for the samemixplaced in the dry.

Concreteshall not be placed in water having a temperaturebelow

428


5 degreesCelsius. The temperatureof the concrete, when deposited,shall not be less than 16 degreesCelsius, nor more than 40 degreesCelsius.

Coffer damsor forms shall be sufficiently tight to ensurestill waterconditions, if practicable,and in any caseto reduce the flow of waterto less than 3 metresper minute through the spaceinto which concreteis to bedeposite4.Cofferdamsor forms in still water shall be sufficientlytight to preventloss of mortar through the joints in the walls. Pumpingshall not be done while concrete is being placed, or until 24 hoursthereafter.To minimise the formation of laltance,great care shall beexercisednot to disturb the concreteas far S possiblewhile it is beingdeposited.

All under water concreting shall be carried out by tremie methodonly, using tremie of appropriatediameter.The numberand spacingofthe tremiesshouldbe workedout toensureproperconcreting.The tremieconcretingwhen startedshouldcontinuewithout interruption for the fullheight of the member being concreted.Tht concrete production andplacement equipment should be sufficient to enable the underwaterconcrete to be completed uninterrupted within the stipulated time.Necessarystand-byequipmentshould be available for emergencysitu-ation.

The top section of the tremie shall have a hopper large enoughtohold onefull batch of the mix or the entire contentsof the transportingbucket as the casemay be. The tremie pipe shall not be less than 200mm in diameterandshallbelargeenoughto allow a free flow of concreteandstrongenoughto withstandtheexternalpressureof thewaterin whichit is suspended,even if a partial vacuum develops inside the pipe.Preferably,flanged steel pipe of adequatestrength~for the job shall beused.A separatelifting device shall be provided for each tremie pipewith its hopper at the upper end. Unless the lower end of the pipe isequipped with an approved automatic check valve, the upper end of thepipeshall bepluggedwith a waddingof gunny sackingor otherapprovedmaterial before delivering the concrete to the tremiepipe through thehopper;so that when the concreteis forced down from the hopper tothe pipe, it will force the plug (and along with it any water in the pipe)down thepipe and out of the bottomend, thus establishinga continuousstream of concrete.It will be necessaryto raiseslowly the tremie inorder to allow a uniform flow of concrete,but it shall not be emptiedso that water is not allowed to enterabove the concretein the pipe.At all timesafter placing of concrete is startedand until all the requiycd

429


quantity hasbeen placed, the lower end of the tremie pipe shall be keptbelow the surfaceof the plastic concrete.This will causethe concreteto build up from below insteadof flowing out over the surface and thusavoid formationof layersof laitance.If the chargein the tremie is lostwhile depositing,the tremie shall be raised abovethe concrete surfaceandunlesssealedby a checkvalve, it shall be repluggedat the top end,as at the beginning,before refilling for depositing further concrete.

1712. ADVERSE WEATHER CONDITIONS

1712.1. Cold Weather Concreting

Where concrete is to be deposited at or near freezing temperature,precautionsshall be takel) to ensurethat at the time of placing, it hasa temperatureof not lessthan5 degreesCelsiusandthat the temperatureof the concreteshall be maintainedabove4 degreesCelsiusuntil it hasthoroughly hardened.When necessary,concrete ingredients shall beheatedbefore mixing but cementshall not be heatedartificially otherthan by the heat transmittedto it from otheringredientsof the concrete.Stock-piledaggregatemay be heatedby the use of thy heat or steam.Aggregatesshall not be heateddirectly by gas or on sheetmetal overfire. In general,the temperatureof aggregatesor water shall not exceed65 degreesCelsius. Salt or other chemicalsshall not be used for theprevention of freezing. No frozen material or materialscontaining iceshall be used. All concretedamagedby frost shall be removed, It isrecommendedthat concrete exposed to freezing weather shall haveentrainedair and the water contentof the mix shall not exceed30 litresper 50 kg of cement.

1712.2. Hot Weather Conditions

When depositingconcretein very hot weather,precautionsshall betakenso thatthe temperatureof wet concretedoesnot exceed40 degreesCelsius while placing. Thisshall beachievedby stackingaggregateunderthe shadeand keeping them moist, using cold water, reducing the timebetween mixing and placing to the minimum, cooling formwork bysprinkling water, starting curing before concretedriesout andrestrictingconcretingas far as possibleto early morningsand late evenings.Whenice is used to cool mixing water, it will be considered a part of thewater in design mix. Underno circumstancesshall the mixing operationbe considered complete until all ice in the mixing drum has melted.

The Contractorwill be requiredto statehis methodologyfor the En-gineer’s approval when temperatures of concreteare likely to exceed40degreesCelsius during the work.

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1713. PROTECTION AND CURING

Concreting operations shall not commence until adequatearrange-ments for concrete curing have been made by the Contractor.

Curing andprotection of concreteshall start immediately after com-paction of the concrete to protect it from

a) Prematuredrying out particularly by solar radiation and wind

b) High internal thermal gradients

c) Leachingour by rain and flowing water

d) Rapid cooling duringthe first few daysafter placing

e) Low temperatureor frost

0 Vibration and impact which may disrupt the concreteand interfere with its bondto the reinforcement

Where membersareof considerablesizeandlength, with high cementcontent,acceleratedcuring methodsmay be applied,as approvedby theEngineer.

1713.1. Water Curing

Water for turing shall be as specified in Section 1000.

Sea water shall not be used for curing. Sea water shall not comeinto contact with concrete members unless it has attained adequatestrength.

Exposedsurfacesof concrete shall be kept continuouslyin a dampor wetconditionby ponding or by covering with a layer of sacks,canvas,Hessianor similar materialsandshall be kept constantly wet for a periodof not less than 14 days from the date of placing of concrete.

1713.2. Steam Curing

Where steamcuring is adopted,it shall be ensuredthat it is donein a suitable enclosureto contain the live steam in order to minimisemoisture and heat losses.The initial applicationof the steamshall beafter about four hours of placementof concreteto allow the initial setof the concrete to take place.

Whereretardersare used,the waiting period before application ofthe steamshall be increasedto aboutsix hours.

The steamshall be at 100 per centrelativehumidityto preventlossof moistureandto provide excessmoisturefor proper hydration of thecement.The applicationof steam shall not’be directly on the concreteand the ambientair temperatureshall increaseat a rate not exceeding

431


5 degreesCelsius per hour until a maximum temperatureof 60 degreesCelsius to 70 degreesCelsiusis reached.Themaximumtemperatureshallbe maintaineduntil the concretehasreachedthe desiredstrength.

When steamcuring is discontinued, the ambient air temperatureshallnot dropat a rate exceeding5 degreesCelsiusper houruntil a temperatureof about 10 degreesCelsius above the temperatureof the air to whichthe concreteWill be exposed,has been reached.

The concrete shall not be exposed to temperatures below freezingfor at least six days after curing.

1713.3, Curing Compounds

Curing compoundsshall only be permitted in special circumstancesand will require specific approval of the Engineer.Curing compoundsshall not be used on any surfacewhich requiresfurther finishing to beapplied. All constructionjoints shall be moist, cure4 and no curingcompound will be permitted in locations where concretesurfacesarerequired to be bonded together.

Curingcompoundsshall be continuously agitated during use. All con-crete cured by this method shall receive two applicationsof the curingcompound.The first coat shall be applied immediatelyafter acceptanceof concretefinish. If the surfaceis dry, the concreteshall be saturatedwith waler and curing compoundapplied as soon as the surfacefilmof waterdisappears.The secondapplication,shall be madeafter the firstapplicationhasset.Placementin more thantwo coatsmaybe requiredto prevent streaking.

1714. FINISHING

Immediatelyafter the removal of forms, exposedbars or bolts, ifany, shall be cut inside the concrete member to a depth of ai least50 mm below the surfaceof the concreteand the resulting holes filledwith cementmortar.All fins causedby form joints, all cavitiesproducedby the removal of form ties and all other holes and depressions,honeycombspots, broken edges or corners,and other defects,shall bethoroughly cleaned, saturatedwith water, and carefully pointed andrendered true with mortar of cement and fine aggregatemixed in theproportionsused in the gradeof concretethat is being finishedand ofas dry a consistencyas is possibleto use. Considerable pressureshallbe applied in filling and pointing to ensure thorough filling in all voids.Surfaceswhich have been pointed shall be kept moist for a period of

432


twenty four hours.Specialprepackagedproprietarymortarsshall be usedwhere appropriateor where specified in the thawing.

All constructionand expansionjoints in the completedwork shallhe left carefully tooled andfree from anymortararid concrete.Expansionjoint filler shall be left exposedfor its full length with clean and trueedges,

Immediately on removal of forms, the concrete work shall beexaminedby the Engineerbefore any defects are made good.

a) The work that has saggedor containshoneycombingto anextent detrimentaltostructural safety or architectural a~earassceshall be rejected.

b) Surface defect of a minor nature may be accepted.On acceptanceof such workby the Engineer, the sameshall be rectified as directed by the Engineer.

1715. TOLERANCES

Tolerancesfor dimensions/shapeof various componentsshall be asindicatedin thesespecificationsor shown on thedrawingsor as directedby the Engineer.


1716.1. Concreteshall conform to the surfacefinish and toleranceas prescribed in these specifications for respectivecomponents.

1716.2, Random samplingand lot by lot of acceptanceinspectionshall be made for the 28 days cubestrength of concrete.

1716.2.1.Concreteunder acceptanceshall be notionally divided intoloLs for the purposeof sampling,before commencementof work. Thedelimitation of lots shall be determinedby the following

(i) No individual lot shall be more than 30 cu.m. in volume

(ii) At least one cube formthg an item of the sample representingthe lot shall betaken from concrete of the same grade and mix proportions cast on any day.

(iii) Different gradesof mixes of concrete shall be divided into separatelots

(iv) Concreteof a lot shall be usedin the sameidentifiable componentof thebridge

1716,2.2.Sampling and testingI. Concrete for making 3 test cubesshall be takenfrom a batch of concreteat point

of delivery into construction,according to procedurelaid down in 15:1199.

2, A randorrtsamplingprocedureto ensurethat eachof the concretebatchesformingthe lot under acceptanceinspectionhasequal chanceof beingchosenfor takingcubesshall be adopted.

3. 150 mm cubes shall be made, cured and tested at the age of 28 days forcompressivestrengthin accordancewith 15:516. The 28~daytest strength resultfor eachcube shall form an item of the sample.

433


1716.2.3.Test specimenand samplestrength Threetestspecimensshall be madefrom eachsamplefor testingat 28 days.Additional cubesmay he requiredfor variouspurposessuchas to determinethe strengthof concreteat 7 days or for any other purpose.

The test strengthof the sampleshall be the averageof the strengthof 3 cubes.The individual variation should not be more than±15 percent of the average.

1716.2.4. Frequency : The minimum frequency of sampling ofconcreteof each grade shall be in accordancewith Table 1700-8

TABLE I7OO~8

Quantity of ConcreteIn work, m’ No. of samples

1-56~1516-3031-5051 and above

12344 plus one additional samplefor eachactditional 50 m

5 or part thereof

At least one sampleshall be taken from each shift of work,

1716.2.5. Acceptancecriteria

CompressiveStrength

When both the following conditionsare met, the concretecomplieswith the specifiedcompressivestrength

a) The mean strength determined from any group of four consecutivesamples shouldexceed the specified characteristic compressivestrength.

b) Strengthof any sampleis not less than the specified characteristic compressivestrength minus 3 MPa.

The quantity of concreterepresentedby the test resultsinclude thebatchesfrom which the first and last sampleswere taken, togetherwithall intervening batches.

Chloride and Sulphate Content

The total chloride and sulphuric anhydride(SO3) contentof all the

constituentsof concreteas a percentageof mass of cementin the mixshall not exceedthe values given in this section of the specifications.

1716.3. Density of Fresh Concrete

Where minimum densityof freshconcreteis specified,the meanofany four consecutivesamplesshall not be less than the specified valueand any individual sample result shall not be less than 97.5 per centof the specified value,

414

StructuralConcreic Section1700

1716,4. Density of Hardened Concrete

Whereminimum densityof hardenedconcreteis specified,the meanof any four consecutivesamplesshallnot be less thanthe specifiedvalueand any individual sample result shall not be less than 97.5 per centof the specified value.

1716.5. Permeability Test

Theconcreteshouldpassthefollowing test if it is properlycompactedand is not consideredpermeable.

(i) Preparea cylindrical test specimen 150 mm dia and 160 mm Isigh

(ii) After 28 days of curing, the test specimcn is fitted in a machine such that thcspecimencan be placedin waterunder pressureupto 7 bars.A typical machineis shown in Appen4Lz 1700/fl.

(iii) At first a pressure of one bar ir applied for 48 hours, followed by 3 bars for24 hours and 7 bars for next 24 hours.

(iv) After the passageof the above period, the specimenis taken out and split in themiddle by compressionapplied on two round bars on opposite sides above andbelow,

(v) The water penetrationin the brokencore is to be measured with a scale and thedepth of penetration assessedin mm (max. permissible limit 25 mm).

1716.6. If the concreteis not able to meet any of the standardsofacceptanceas prescribed,the effect of such deficiency on the Structureshall be investigatedby the Contractoras directedby the Engineer.TheEngineermay accept the concreteas sub-standardwork. Any additionalwork required by the Engineerfor such acceptanceshall be carried outby the Contractor at his cost. In case the concrete is not found to beacceptabiL after investigation,the Contractorshall remove the rejectedconcrete forthwith.


Structuralconcreteshall be measuredin cubic metres.In reinforcedor prestressedconcrete, the volume occupied by reinforcement orprestressingcablesand sheathingshall not be deducted.The slab shallbe measuredas running continuouslythroughandthebeamas theportionbelow the slab.

1718. RATE

The contractunit rate for structuralconcreteshall covercostsof allmaterials,labour,tools, plantand equipmentrequired for mixing, trans-portingand placing in position, vibrating and compacting,finithing andcuring as per this Section or as directedby the Engineer,including all

435

Section1700 Structural Concrete

incidental expenses,sampling and testing, quality assuranceand super-vision. Unless mentioned separatelyas an item in the Contract, thecontract unit rate for concreteshall also include the costof providing,fixing andremoving formwork required for concretework as per Section1500.

Whereconcrete is found to be acceptableas sub-standardwork, theContractorshall pay a discountover the contract unit rate, as decidedby the Engineer.For deficiencyin compressivestrengthof concretewhenacceptedby the Engineer,the reductionin rate may be applied as under

Design Strength — ObservedStrengthPer cent reductton = . x 100Design Strength

436

Prestressing

1800

Prestressing

Prestressing Section 1800

1801. DESCRIFFION

Structuralconcretecontaining prestressedsteel reinforcementto in-troduce precompressionis termed as prestressedconcrete.

The work shall be carried out in accordancewith the drawing andthese specificationsor as approved by the Engineer.

Concrete and untensioned steel for theconstructionof prestressedconcretemembersshall conform to the requirementsof sections1700and 1600 for Structural Concrete and SteelReinforcement respectivelyin so far as the requirementsof these Sections apply and are notspecifically modified by requirements set forth herein.

1802. MATERIALS

~J8O2.1.All materials shall conform to Section 1000.

L~ 1802.2. Sheathing~4802.2,1.The sheathing ducts shall be of the spiral corrugated

type, Unless otherwise specified, the material shall be Cold RolledCold Annealed (CRCA) Mild Steel conforming to !S:513 intended formechanicaltreatmentandsurfacerefining but not for quenchhardeningor tempering.

The material shall normally be bright finished. However, wherespecified, as in case of use in aggressive environment,galva..aired or lead-cOatedmild steel strips shall be used.

The thickness of sheathing shall be as shown on the drawing, butshall not be less than 0.3 mm, 0.4 mm and0.5 mm for sheathingductshaving internal diameterof 50 mm, 75 mm and 90 mm respectively.For bigger diameterof ducts, thicknessof sheathingshall be basedon recommendationsof prestressingsystem supplier or as directedbythe Engineer.

The sheathing shall conform to the requirement as per testsspecified in Appendix 1800/!.

For major projects, the sheathingducts should preferably bemanufacturedat the project site utilising appropriate machines.With

an arrangement,long lengthsof sheathingductsmay be used withconsequent reduction in the number of joints and couplers. Wheresheathing duct joints are unavoidable, such joints shall be made

439

Section1800 Prestressirg

slurry tight by the use of corrugatedthreadedsleevecouplerswhichmay be tightly screwed onto the outer side of the sheathingducts.

The length of the couplershould not be less than 150 mm butshould be increasedupto 200 mm whereverpracticable.The jointsbetweentheendsof thecouplerandthe ductshallbe sealedwith adhesiveseating tape to preventpenetrationof cement slurry during concreting.The couplers of adjacent ducts should be staggered whereverpracticable. As far as possible, couplersshould not be located incurvedzones. The corrugated sleevecouplers are beingconvenientlymanufacturedusing the sheath making machinewith the next highersize of die set.

1802.2.2. The intemat area of the sheathing duct shall be inaccordancewith the recommendationsof the system manufacturerandshall be about three times the area of the tendons. In caseof 6T13,t2Tt3 and t9Tl3 sizes of tendons comprising 12/13 mm dia strands,the inner diameter of the sheathing shall not be less than 50 mm,75 mm and 90 mm respectivelyor those shown in the drawing, whichever is greater.

Where prestressing tendons are required to be threadedafterconcreting the diameterof sheathingshall be about 5 mm larger thanthat required as above.

1862,2.3.In severeenvironment,cablesshall be threadedafter con-creting. In such cases a temporary tendonshall be inserted in thesheathing or the sheathingshall be stiffened by other suitable methodrluring concreting.

1802.3. Anchorages

1802.3,1. Anchoragesshall be procured from authorisedmanufac-turers only. Anchoragesshall conform to BS:4447. Test certificatesfrom a laboratory fully equipped to carry out the tests shall befurnished to the Engineer.Such testcertificates shall not be more thani2 monthsold at the time of making the proposalfor adoption of aparticular system for the project.

No damaged anchorages shall be used. Steel parts shall beprotected from corrosionatalt times.Threadedparis shall be protectedby greasedwrappings and tapped holes shallbe protectedby suitableplugs until used.The anchorage componentsshall be kept free frommortar and loose rust and any othc”’ deleteriouscoating.

440


1802.3.2. Swages of prestressing strand and button-heads ofprestressing wire, where provided shall develop a strength of at least 95per centof the specifiedbreaking load of the strandor wire as the casemaybe. Whereswaging/button-headingis envisaged,theContractorshallfurnish details of his methodologyandobtain approval of the Engineer,prior to his taking up the work.

1802.3.3. Untensioned Steel reinforcements,aroundanchoragesshallconform to the details of prestressingsystemand as shown on thedrawing.

1803. TESTING OF PRESTRESSING STEELANDANCHORAGES

All materials specified for testing shall be fumished free of costand shall be delivered in time for tests to be made welt in advanceof anticipated time of use.

All wire, strand or bars to be shipped to the site shall be assigneda lot number and tagged for identificationpurposes.Anchorageassembliesto be shipped shall he like-wise identified;

All samples submitted shall be representative of the lot to hefurnished and in the ease of wire or strand, shalt be taken from thesamemaster roll, The Contractor shalt furnish samples of at least 5.0in length selected from each tot for testing. Also, two anchorageassemblies,completewith distribution plates of each size or types tobe used, shall he furnishedalongwith short lengthsof strandsasrequired.

\/1804 WORKMANSHIP

1804,1. Cleaning

Tendons shall he free from loose rust, oil, grease, tar, paint, mudor any other deleterious substance.

Cleaning of the steel may be carried out by immersion in suitablesolve!nt solutions, wire brushing or passing through a pressure boxcontaining carbonindum powder. Flowever, the tendons shalt not bebrought to a polished condition,

i804.2. Straightening

High tensile steel wire and strand shall be supplied in coils nfsufficiently large diameter such that tendons shall retain their physicalproperties and shall he straight as it unwinds fror the coil. Tendonsof any type that are damaged, kinked or bent shalt not be used,

441

Section 1800 Prestressing

The packing of prestiessing wire/strand shall be removed onlyjust prior to making of cablefor plaeemeniSuitablestandsshall beprovided to facilitate uncoiling of wire~1strandswithout damage tosteel. Care shallbe taken to avoid the possibility of steel cominginto,contactwith the ground.

1804.3. Positioning

1804.3.1.Post-Tensioning

Prestressing tendonsshall be accurately located and maintainedin position, both vertically and horizontally,as per drawings.

Tendons shall be so arrangedthat theyhave a smooth profilewithout sudden bends or kinks.

The locationing of prestressedcablesshall be such as to facili-tate easyplacement andvibration of concrete in betweenthe tendons.High capacity tendonshall be usedto reduce the number of cablestherebyeliminating the necessityof grouping.The selected profilesof the tendonsshall be such that theic anchorages arenot located inthe top deck surface.Where two or more rows of cables have tobe used, the cables shalt be vertically in line to enable easy flowof concrete. The clear vertical and horizontal distancesbetweenanytwo cablesshall in no case be less than 100mm anywherealong thelength of the superstructure. .Where precast segments are used,the clear distance shall be at least 150 mm.

Sheathing shall be placedin correct position and profile byproviding suitable ladders and spacers. Such ladders may be pro -vided a. ~ntervalsofapproximately 1.0 m. Sheathingshall be tied rigidlywith such ladders/spacerbars so that they do not get disturbed duringconcreting.

The method of supporting and fixing shall be such that profile ofcables is not disturbed during vibrations,by pressureof wet concrete,by workmen or by construction traffic.

Sheathing in which the permanenttendon will not be in placeduring concreting shall have a temporary tendon insertedor shall bestiffened by some othermethod to the approval of the Engineer.The temporary tendon shall be pulled out before threadingthepermanenttendoninto place by a special threadingmachineor othercontrivance.

Where possible tendons shalt not be placed until immediately

Prestressing Section1800

prior to stressing.Tendonsshall be handledwith care to avoiddamageor contaminatiqn,to either the tendon or the sheathing.Any tendonsdamagedor contaminatedshall be cleanedor replaced.

1804.3.2. Pre-Tensioning.Prestressingsteel shall be accuratelylocated and maintained in position, both vertically and horizontally, asper drawings.

1804.3.3.Each anchoragedeviceshall be set squareto the line ofactionof the corresponding prestressingtendonand shall be positionedsecurely to preventmovementduring concreting.

The anchoragedevicesshall be c!eaned to the satisfaction of theEngineerprior to the placing of concrete.After concreting, any mortaror concretewhich adheresto bearing or wedging surfaces,shall beremoved immediately.

1804.4. Cutting

Cutting and trimming of wires or strands shall be done bysuitable mechanical or Ilame cutters.When a flame cutter is used,care shall he taken to ensurethat the Ilame does not come in contactwith other stressed steel. The location of flame cutting of wire orstrand shall be kept beyond75 mmof where the tendon will be grippedby the anchorage or jacks.

In post-tensioningtheendsof prestressingsteel projectingbeyondthe anchorages,shall be cut after the grout has set,

1804.5. Pnitectionof PrestressingSteel

Prestressingsteel shall be continuously protected againstcorro-sion, until grouted. The corrosion protectorshall have no deleteriouseffect on the steel or concrete or, on the bond strength of steelto concrete. (Jrouting shall conform to these specifications or as directedby the Engineer.

In thecaseof externalprestressing,steelshall be encased in suitablepolyethelene pipes before grouting.

1804.6. Sheathingi’he joints of all sheathingsshall he. water-tight. Specialattention

shall be paid to thejunction at the anchorageend, where the sheathingmust~tightly fit on the protruding trumpet end of anchorage andthereaflersealed preferably with heat shrink tape, to make it water-proof.

443

Section1800 Prestressing

The heat-shrink tape is supplied in the form of bandage rollswhich can be usedfor all diametersof sheathing ducts. Thebandageis coatedon the undersidewith a heatsensitiveadhesiveso that afterheating the bandage material shrinks on the sheathing duct andensuresfonnationof aleak-proofjoint. The heatingis effectedby meansof a soft gas flame.

A sheathmaking machineshould be positionedat the siteof workfor large projects so that sheathingcan be preparedas and when itis required for construction.

The sheathingand all joints shall be water tight. Any temporaryopening in the sheathingshall be satisfactorilyplugged and all jointsbetweensheathingand any other part of the piestressing system shallbe e.fiectively sealedto prevententry of mortar,dust, water or otherdeleteriousmatter. Sheathing shall be neatly fitted at joints withoutinternal projection or reduction of diameter.

Enlarged portions of the sheathingat couplings or anchoragesshall be of sufficient tength to provide for the extensionof the tendons.

1804.7. Grout Vents

Groi~tvents of at least 20 mm diametershall be provided at bothends of the sheathingand at all valleys and crests along its length.Additional vents with plugs shall also be prov’ded along the lengthof sheathingsuch that the spacingsof consecutivevents do not exceed21) rn. Each of the grout vents shall be provided with a plug orsimilar device capableof withstanding a pressure Of 1.0 MPa withoutthe loss of water, air pressure or grout.

1804.8 Anchorages

All bearingsurflicesof the anchoragesshall be cleanedprior to con-cretmg and tensioning.

Anchor cones,blocks and plates shall he securely positioned andmaintained during concreting such that the centre line of the ductpassesaxially through the anchorageassembly.

The~ anchorages shall he recessed from the concretesurfaceby aminimum cover of 11)1) mm.

After the prestressingoperationsare completed and prestressingwires/strands are cuL, the surfaceshall he painted with two coatsof epoxy of suitable formulation havinga dry film thickness of 80

444

Prcstressing Section1800

microns per coat and entire recess shall be filled with concreteornon-shrink/pre-packagedmortar or epoxy concrete.

1804.9. Structural Concrete

Structural concreteshall conform to Section 1700.The formwomkshall conform to Section 1500.

\/t8O5. SUPERVISION

Al! prestressingand grouting operationsshall be undertaken bytrained personnelonly. A representativeof supplier of the prestressingsystemshall be presentduring all tensioning andgrouting operationsand shall ensure,monitor and certify their correctness.

~•fl. TENSIONING EQUiPMENTAll tensioningequipment shall beprocuredfrom authorisedmanu-

facturers only and be approvedby the Engineerprior to use. Wherehydraulicjacksareused,they shall be power-drivenunlessotherwise ap-proved by the Engineer.The tensioning equipmentshalt satisfy thefollowing requirements

(i) The meansof attachments of the prestressing steet to the jack or any othertensioning apparatusshalt be safe and secure.

(ii) Where two or more wires/strandsconstitute a tendon, a singlemultipill stressingjack shalt be used which is capable of tensioning simulsaneousty atl the wi reel

strands of the tendon. Suitable facilities for handling and attaching the multi~putt jack to the tendonsshalt be provided.

(iii) The tensioning equipment shalt be such that it can apply controtted total forcegradually on the concretewithout inducing dangerous tecondary stressesin steel,anchorage or concrete; and

(iv) Means shalt be provided for direct measurementof the force by use of dynamo~metersor pressuregaugesfined in the hydraulic system itself to determine thepressure in the jacks. Facilitiesshalt also be provided for the tinear measurementof the extension of prestressing steel to the nearest mm and of any slip of thegripping devicesat trai ~sfer.

All dynamometers andpressuregaugesincluding a master gaugeshall be calibrated by an approved laboratory immediately prior to useand then at intervals not exceeding3 months and the true forcedeterminedfrom the calibration curve.

Pressuregaugesshall be concentric scaletype gaugesaccuratetowithin two per cent of their full capacity.The minimum nominalsize of gaugeshallbe 100mm. Thegaugeshall be so selectedthat whenthe tendonis stressedto 75 per centof its breaking load, the gaugeis reading between50 percent and 80 per cent of its full capacity.

445

Sectiont800 Prestressing

Suitable safety devices shall be fitted to protect pressuregaugesagainst sudden releaseof pressure.

Provision shall be made for the attachment of the master gauge to

be used as a checkwheneverrequestedfor by the Engineer.

POST-TENSiONINGTensioning force shall be applied in gradual andsteady stepsand

carried out in sucha mannerthat the applied tensions andelongationscan be nieasuredat all times. The sequenceof stressing,appliedtensions and elongations shall be in accordancewith the approveddrawing or as directed by the Engineer.

It shallbe ensuredthat in no case,theloadis applied to the concretebefore it attains the strengthspecifiedon the drawing or as stipulatedby the preStressingsystem supplier, whichever is more.

After prestressing steel has beenanchored,the force exerted by thetensioning equipment shall be decreasedgradually and steadily soas to avoid shock to the prestressing steel or 2nchorage.

The tensioning force applied to any tendonshall be determinedbydirect reading of the pressuregaugesor dynamo-meters and bycomparison of the measured elongation with the calculatedelonga-tion. Thecalculated elongation shall beinvariablyadjusted with respectto the modulus of elasticity of steel for the particular lot as given bythe manufacturer.

The difference between calculated and observed tension and

elongation during prestressingoperationsshall be regulated as follows:

a) tf the calculated elongation is reached before the specified gaugepressureis obtained,continue tensioning titt attaining thespecifiedgaugepressure,providedthe elongation does not exceed t .05 times the catculated elongation. If 1.05times the catculatedelongation is reachedbefore the specified gauge pressureit auaincd,stop stressing and inform the Engineer.

b) tf the catcutated elongationhas not beenreachedat thespecifiedgaugepressure,continue tensioning by intervats âf 5 kg/sq. c.m. until the calculated elongationis reached provided the gauge pressure does not exceed 1.05 times thespecified gauge pressure.

c) tf theotongationat 1.05 times thespecifiedgauge pressure is less than 0.95times the calculated elongation, the following measuresmust be taken, insuccession,to determine the causeof this lack of discrepancy

i) Check the correct functioningof the acit, pump and teada.

ii) Desensionthe cable.Slide it in its duct to check that it is not blocked by

446


mortar which has entered through holes in the sheath.Retensionthe cableif free.

iii) Re—establish themodulus of elasticity of steel for the particular lot from anapprovedlaboratory.

If the requiredelongation is still not obtained, further finishing operationssuchas cutting or sealing, should not be undertaken without the approsal ofthe Engineer.

d) When stressing from one end only, the slip at the end remote from the jackshall be accurately measured and an appropriateallowancemadein themeasuredextensionat the jacking end.

A complete record of prestressingoperationsalongwith elongationand jack pressuredata shall be maintained in the format given inAppendix/800/Ii. The numberof stages of prestressing and groutingshall be reducedto a minimum, preferably 2 in the caseof simplysupportedgirders.

~ GROUTING OF PRESTRESSED TENDONS

Grouting shall conform to Appendix1800/I!!. A record of groutingoperations shall be maintainedin the format given in Appendix1800/IV.

1809. PRE-TENSIONJNG

1809,1. General

The planning and construction aspectsof the tensioning bed,tensioning bench, abutmentsat location of anchorage,steamcuringsystem,formwork of the concreteelementsand arrangementsfor de-moulding, lifting, stackingand transportation of the pre-tensionedconcrete elementsare all specialised items and shall be entrustedtoengineersspecifically experiencedin this type of work.

1809.2. StressingBed for Pre-tensioning

The abutmentsand bed for pre-tensioningof tendons shall bedesignedto withstand the total tensioning force.

A notice shall be displayedadjacentto the stressingbed showingthe maximum tensioningforce permitted.

Where concreteelementsare castand prestressedindividually, thestressingbenchor moulds shall be rigid enough to sustainthe reactionof the prestressingforce without distortion.

In the long line methodof prestressing,sufficient locatorplatesshould be distributed throughoutthe length of the bed to ensure that

447


the wires are maintainedin their proper position during concreting.The moulds shall be free to slide in the direction of their lengthandthus permit the transfer of theprestressingforce to alt the concreteelementsalong the wholeline.

Sufficientspaceshall be left in betweentheendsof concreteelementsto permit accessfor cutting the strands/wires aftertransfer. Hold-downs ordeflectors shaltbe usedfor holding or deflecting the tendonsin required position firmly. Deflectors which are in contactwith thetendon shallhave a diameter not less than the tendon or 15 mm,whicheveris greater.

The tensioning force requiredto be applied as stated on thedrawings shalt be the force remaining in the strands/wiresafter allstrands/wires have beeninchoredto the abutments of the stressingbed andafter theanchorage sliphas already takenplace.The tensioningforce shall bedeterminedby direct reading of the pressure gaugesor dynamo-meters andby the measuredelongation after slip.

The Contractor shall submitmethod of tensioning the tendonsincluding the arrangementand layoutof prestressing bedsandall tendondeflection points to the Engineer for approval beforemanufacturecommences.

l’he Contractor shallcarryout trial stressingoperationsto establishthe frictional resistance offered by the hold-downs and the slip duringanchoring.

Where sheathingof pre-tensionedtendonsis required to preventbond over a specifiedlength, it shall consistof plastic tubing or othermaterialapprovedby the Engineerandshall be of aquality, diameterand thickness such that bond shall be effectively prevented.Thetubing shall be fastenedto the tendon in such a manner thatcementmortar cannotenter. The Engineermay order that the pull-in of thetendon be measured during the transfer of prestress.

The Contractorshall alsosubmitcalculationsshowing thatthe hold-downs have been designed and constructed to withstand concentratedloads resulting from the application of the tensioning force.

1809.3, Tensioning Procedure

The tensioning of the wires and strandsshall be done not toomuch in advanceof concreting.

The tensioning force shall be applied gradually and uniformly.

448


In order to remove slack and to lift tendons off the bed floor, aninitial force approved by the Engineer shall be applied to the tendons.Allowance shall be made for this force in calculating the requiredelongation.

Tendons shall be markedfor measurementof elongationafter theinitial force hasbeenapplied.When requiredby the Engineer,tendonsshall be markedat both the jacking end and deadend of the stressingbed and at couplersif usedso that slip and draw-in may be measured.

Where deflected strandshavebeen specified, the Engineer maydirect the elongationor straingaugemeasurementsbe taken at variouspositionsalong the tendonto determinethe force in the tendonat thosepositions.

1809,4. Transfer of Prestress

While the processof tensioningcan be accomplishedby means ofhydraulic jacks, some positive mechanicalmeans shall be provided tomaintain the tensionduring the entire period between the tensioningof the wires/strandsand transferof the prestressingforce to the concreteelement.

Transfer of prestressshall not proceed until the Engineer hasapproved the proposedmethod.Tendons and deflection devicesshallbe released in such a pre-determinedorder that unacceptabletensilestressesare not induced in the concrete.

Prior to transferof the force to the units, all tendonsshall be testedfor tightnessand any loose tendonshall be reported to the Engineerwho will decide whether the ti1~itsaffected shall be rejected.

The Engineer may require that tendonsbe marked at each endof any unit to allow measurementof the pull-in of the concrete.

Tendonsshall be releasedgradually and preferably simultaneously.

Under no circumstancesshall tendonsbe cut while under ten~on.

On completionof the transferof prestress,the projecting lengthsoftendon shall be cut off flush with the end surface of the unit, unlessotherwise shown, by a method approvedby the Engineer.

In no case shall thetransferof prestressingforce to theconcreteelementstake placebeforeconcreteattains the strength specified in thedrawings. To determinethe specified strength, additional cube testingshall be undertakenat the Contractor’scost. In casesteam curing isemployed, the cubesshall be pLaced in the sameenvironmentas the

t49


concreteelementsto obtain an accurate assessmentof concretestrengthat the time of transfer.

The sequenceof transferof prestressingforce shall be done strictlyas indicated in the drawings andensuring that eccentricitiesof theprestressingforce in the vertical and horizontaldirectionsof the concreteelement is a minimum during the entire sequence.

The maximum slip of any tendonduring transfershall not exceed3 mm at any end of the concreteelement. In case this slip is exceeded,the concreteelementin question shalt be rejected.

1809.5. Protection of Ends

The exposedends of the tendonsand the concrete surfacesof theends of the units shall bewire brushed cleanof alt rust, loose mortar,greaseand dirt.

The exposedendsof the tendonsandconcretesurfacewithin 50 mmof tendons shalt be then abradedto provide a clean soundsurface.An epoxy tar paint suitably formulated to give a dry film thicknessof 80 micronsper coat shalt thenbe immediately appliedover the endsof the tendons unless otherwisedirected.

A secondcoat of paint shalt be applied prior to the drying outof the first coat.

ifl SAFETY PRECAUTIONS DURING TENSIONING

~dareshalt be taken during tensioningtoensurethe safety of allpersons in the vicinity.

Jacksshall besecuredin such a mannerthat they will be held inposition, should they lose their grip on the tendons.

No person shall be allowed to stand behindthe jacks or close tothe line of the tendonswhite tensioningis in progress.

The operationsof the jacks and the measurementof the elongationand associatedoperationsshall be carried out in such a mannerandfrom such a position that the safetyof all concerned is ensured.

A safetybarrier shall beprovidedatboth endsto preventanytendon,which might becomeloose from recoiling unchecked.

During actual tensioning operation,warning sign shall bedisplayedat both ends of the tendon,

After prestressing,concreteshallneitherbe drilled nor anyportion

450


cut nor chippedaway nor disturbed, without expressapprovatofthe Engineer.

No welding shall be permitted on or near tendonsnor shall anyheat be applied to tendons. Any tendon which has beenaffected bywelding, weld spatter or heat shall be rejected.

ipt: TRANSPORTATION AND STORAGE OF UNIT S

Precast girders shall be transported in an upright position.Pointsof supportand the direction of reactionswith respect to the girdershallapproximately bethe sameduring transportation,and storageas whenthe girder is placed in final position.

When membersare to be stacked,they shall be firmly supportedat such bearing positionsas will ensurethat the stresses induced ththem are always less than the permissible design stresses.Further,inclined sidesupportsshall beprovidedat the endsandalong thelengthof a precastgirder to prevent lateral movementsor instability.

Care shall betaken during storage,hoisting and handling of thepiecast units to preventtheir crackingor beingdamaged.Units damagedby improper storing or handling shallbe replacedby the Contractorat his expense.

N A~12.TOLERANCES

Permissibletolerancesfor positional deviationof Prestressing tendonsshalt be limited to the following

a) Variation 1mm the specified horizontal profite 5 mm

h) Variation 1mm the specified vertical pmfile 5 mm

c) Variation 1mm the specified position in member 5 mm

$13, TESTS AND STANDARDS OF ACCEPTANCE

~the materials shall be tested in accordancewith theseSpecifica-tions and shall meet the prescribed criteria,

The work shall conform to theseSpecificationsand shall meettheprescribedstandardsof acceptance.

\$4. MEASUREMENTS,FOR PAYMENT

Prestressed Concreteshall be measuredin cubic metres. Thevolume occupied by mild steelreinforcement/HYSD bars,high tensitesteel, sheathingand anchoragesshall not be deducted.

High tensile (prestressing)steel shall bepaid for separately andits lengthshall bemeasuredasactually!icorporatedin the finished work.

451

Section1800 Prestressing

From the length so measuredits weight shall be calculatedin tonneson theoreticalbasis and paid for.

Anchorage devices, additional length of cables for attaching jack,ductsor sheathing,grout,non-prestressedsteelreinforcementfixed to theanchoragedevices,makingof recessesand filling the same,protectionby painting with epoxy and furnishing samplesfor testing shall allbe deemedto be included in the item of high tensile steel and shallnot be measured separately.

RATEThe contract unit rate for cast-in-placeprestressedconcrete shall

cover the cost of all materials, labour, tools and plant required formixing, placing in position, vibrating and compacting,finishing as perdirections of the Engineer, curing and other incidental expensesforproducingconcreteof specifiedstrengthto completethe structureor itscomponentsas shown on the drawingsandaccordingto specifications.The contract unit rate shall also include the cost of making, fixingand removing of all centring and forms requiredfor the work unlessotherwise specified in the Contract.

For precast prestressedconcretemembers,the rate in addition toaboveshall alsoinclude the costof all materials,labour, tools andplantrequiredto transportand place thesemembersin their final positionas shown on the drawings and as directed by the Engineer.

The cdntractunit rate for high tensile steel shall cover the cost ofmaterial, labour, tools and plant required for manufacturing,placing,tensioning,anchoringand groutingthehigh tensilesteel in theprestressedconcreteas shown on the drawingsandas per specificationshereinaboveor as directedby the Engineer.

The cost of anchoragedevices, additional length of cables forattachingjack, ducts or sheathing,grout,non-prestressedsteelreinforce-ment fixed to the anchoragedevices,making of recessesand filling thes~me,protectionby paintingwith epoxyandfurnishingsamplesfor testingshall all be included in the unit rate:Rate shall also include paymentsif any to be madeto the supplier of the prestressingsystem who hasto monitor, ensureand certify the correctnessof all operations.

452

Structural Steel

1900

Structural Steel

Structural Steel Section 1900

1901. DESCRIFFION

This work shall include furnishing, fabricating,transporting,erectingand painting structural steel, rivet steel, cast steel, steet forgings, castiron and otherincidentalmetalconstructionof thekind, sizeandquantityin conformity with the drawingsand thesespecificationsor as desiredby the Engineer.

1902. GENERALGeneral requirementsrelatingto thesupplyof materialshallconform

to the specificationsof IS:1387, for the purposeof which the suppliershall be the Contractor and the purchasershall be the Engineer.

Finished rolled material shall be free from cracks, flaws, injuriousseams,laps, blisters, raggedand imperfect edges and other defects.Itshall havea smooth and uniform finish, and shall be straightenedinthe mill before shipment.They shall also be free from loosemill scale,rust, pits or other defects affecting its strengthand durability.

The acceptanceof any materialon inspectionatthe mill i.e. rollingmills, foundry or fabricating plant where material for the work ismanufactured,shall not be a bar to its subsequentrejection, if founddefective.

Unless specified otherwise, high tensile steel rivet conforming toIS: 1149 shall be used for membersof high tensile steel conformingto 15:961 and shall not be used for mild steel members.

Unless specified otherwise,bolted connection of structuraljointsusing high tensile friction grip bolts shall comply with requirementsof 15:4000.

Cast iron shall not be used in any portion of the bridge structure,except where it is subject to direct compression.

1903. MATERIALS

1903.1.All materialsshall conform to Section 1000.Special require-ments are given below

Mild steel for bolts and nuts shall conform to 15:226 but have aminimum tensile strength of 44 kg/sq. mm. and minimum percentageelongation of 14. High tensile steel for bolts and nuts shall conformto IS:961 but with a minimum tensile strength of 58 kg/sq. mm. Highstrengthfriction grip bolts shall be permittedfor useonly on satisfactory

455

Section1900 StructuralSteel

evidence of performance to the requirements (not coveredby thesespecifications)specified by the Engineeror included in the specialprovisions.

For cast steel, the yield stressshall bedetermined and shall notbe less than 50 per cent of the minimum tensile strength.

Plain washersshall beof steel.Tapered or otherspecially shapedwashersshall be of steel, or malleable cast iron.

Parallel barrel drifts shall have a tensile strength not less than55 kg/sq.mm. withelongation of not less than 20 per cent measured ona gauge length of 44So (So = cross sectional!!area).

1903.2.Materials for castingsand forgings, fastenersand weldingconsumablesshall be as under

1903.2.1.Castingsand Forgings : Steel castingsandforgings shallcomply with the requirementsof the following Indian Standards,as ap-propriate

IS: 1030 Carbon Steel Castings for General Engineering purposes

IS:1875 Carbon SteelBillets, blooms, slabs,bars for forgings

IS:2004 Carbon SteelForgings for GeneralEngineeringpurposes

IS:2644 High Tensile Steel Casings

lS:4367 Alloy & tool steel forgings for general industrial use1903,2.2.Fasteners : Bolts, nuts, washers and rivets shall comply

with the following or relevant IS Standardsas appropriate

IS: 1929 Hot forged steel rivets for hot closing (12-36mm dia)

IS:2l55 Cold forged steel rivets for hot closing (6-16mm dia)

IS:1363 Hexagonhead bolts, screw and nuts productgradeC

IS:1364 Hexagonheadbolts, screw & nuts product grade A & B

IS: 1367 Technical supply conditionsfor threadedsteel fastener(Parts 1 to 18)

IS:3640 Hexagon fit bolts

IS:3757 High tensile friction grip bolts

IS:6623 High strength structural nuts

IS:6639 Hexagon bolts for steel structure

IS:5624 Foundation bolts

456

StructuralSteel

IS:7002 Prevailing torque type steel hexagon lock nuts

IS:5369 Plain washersand lock washers - general requirements

IS:5370 Plain washers with outside dia = 3 X inside dia

IS:5372 Taper washers for channels (ISMC)

IS:5374 Taper Washers for I beams (ISMB)

ES:6610 Heavy washers for steeL structures

IS:6649 Hardened and tempered washers for high strength struc-tural bolts and nuts

1903.2.3.Welding consumables

Welding consumablesShallcomply with the following Indian Stand-ards as appropriate

IS:814 Covered Electrodesfor Metal Arc Welding of structural(Part 1) steel for welding other than sheetsIS:8 14 For welding Sheets(Pail 2)

IS: 1278

IS: 1395

Filler rods and wires for gas welding

Low and medium alloy Steel covered electrodes formanual Metal Arc Welding

IS:36l3 Acceptance Tests for wire flux combinations for sub-merged arc welding of structural steel

IS:7280 Bare wire electrodes for gas shielded arc welding ofstructural steel

15:6419 Welding rods and bare electrodes for gas shieldedarcwelding of structural steel

IS:6560 Molybdenum and chromium-molybdenum low alloy steelwelding rods and bare electrodesfor gas shieldedarcwelding

1903.3. In aggressiveenvironment,corrosionresistantsteel can beused. Theseare low-alloyed steels containing a total of 1 per cent - 2percent alloys, in particular,copper,chromium,nickelandphosphorous.

1903.4. Paints

All materials for paintsandenamelsshall conform to the require-metnsspecified on the drawings or other specialprovisions laid downby the Engineer.

Section1900

457


The type of paints which can be used shall be as followsa) Ordinary i.e. pants based on drying oils, alkyd resin, modified alkyd resin,

phenolic varnish epoxy

I,) Chanical Resistant - one pack type (ready for use) and two pack type (mixedbefore use).

c) Vinyl

d) Chlorinaiedrubber

e) Bituminous

1) Epoxy

g) Polyurethane

h) Zinc rich

Unlessotherwisespecified,paintsshall conform to the relevant ISspecifications. The paints which have been tested for the followingqualities as per specificationsgiven in the relevant IS codesonly shallbe used

- Weight test (weight for 10 litre of paint, thoroughly mixed)

- Drying time

- Consistency

- Dry thickness and rate of consulnl*ion.

1904. FABRICATION1904.1. General

All work shall be in accordance with the drawings and as perthese specificationswith care being taken that all parts of an assem-bly fit accurately together. All members shall carry mark numberanditem number and, if required, serial number.

Unless specifically requiredunder the contract, correspondingpartsneed not be interchangeable,but the parts shall be match marked asrequired under Clause 1904.7.

Templates,jigs and otherappliancesused for ensuringtheaccuracyof the work shallbe of mild steel; wherespecially required,theseshallbe bushed with hard steel. All measurementsshall be made by meansof steel tape or other device properly calibrated. Where bridge materialshave beenused as templates for drilling, these shall be inspected andpassedby the Engineer before they are used in the finished structure.

All structural steel members and partsshall have straight edgesandblunt surfaces. If necessary,they shall be straightened or flattened by

458

StructuralSteel Section1900

pressure unless they are required to be of curvilinear forms. Theyshall also be free from twist. Pressure applied for straightening orflattening shall be such as would not injure the materials. Hammeringshall not be permitted.Adjacent surfacesor edgesshall be in closecontact or at uniform distancethroughout.

The Contractorshall submithis programmeof work to the Engineerfor hisapprovalatleast15 daysbefore the commencementof fabrication.This programmeshall include the proposedsystem of identification anderectionmarks together withcomplete detailsof fabrication and weldingprocedures.

The Contractor shall prepareshopdrawings for fabricating anymember andobtain approval oftheEngineerbeforethe start of work.Complete information regardingthe location, type, size and extent ofall welds shall be clearlyshown on the shop drawings.Thesedrawingsshall distinguish between shop and field welds.

1904.2. Preparation of Edges and Ends

All structural steel-parts,where required,shall be sheared, cropped,sawnor flame cutandground accuratelyto the requireddimension andshape.

End/edge planing andcutting shall be done byany one of thefollowing prescribed methods or left as rolled

a) Shearing, cropping, sawing1 machining, machine flame cutting.

b) Hand flame cutting with subsequentgrinding to a smooth edge.

c) Shearededges of plate not more than16 mm thick with subsequent grindingth smoothprofile, which are for secondaryuse such as ssiffeners and gussets.

If ends of stiffeners are requiredto be fitted, they shall be ground,so that the maximum gap over 60 per cent of the contact areadoes notexceed0.25 mm.

Where flame cutting or shearing is used, at least one of thefollowing requirements shall besatisfied.

a) The cut edge is not subjectedto applied stress.

b) The edge isincorporatedin weld.

c) The hantness of cut edge does not exceed350 HV30.d) The material is removedfrom edge to the extent of 2 mm orminimum necessary,

so that the hardness is less than 350 HV 30.

e) Edge is suitably heattreatedby approved methodto the satisfaction of theEngineerand shownthat cracks had not developed bydyepenetrantor magnetic particletest.

459


f) Thicknessof plate is less than 40 mm for machine flame cutting for snateriakconfomiing to l&226 and IS:2062,The requirementof hardness below350 IN30 of flame cur edgesthould be specified by the Engineer.

Wherever specifiedby the Engineer,the flame cut edgesshall beground or machined over and above the requirement(a) to (1).

Where machining for edge preparationin butt joint is specified, theends shall be machined after the members have been fabricated.

Outside edgesof plate and section,which are prone to corrosionshall be smoothedby grinding or filing.

In the caseof high tensile steelat least6 mm of the material fromthe flame cut edge shall be removed by machining.

Longitudinal edgesof all plates andcover platesin plate girders andbuiIt.~upmembersshall be machinedexcept in the following cases

a) Rolled edgesof single universalplates or flats maynor be machined.

b) Covers to single flange pktes may be left unmachined.

c) Machine flame cutting insteadof machiningis acceç~ablefor edgesof single platesin compressionand for edges of singleplates,25 mm or less thick, in tension.

d) Edges of ~ingteshapedplatesover 25 mm thick not capableof being machinedby ordinary method may be machine flame cut and the and surfaceground.

e) Edgesof universal plates or flats of the same nominalwidth used in tiersmaybe left unmachined,if so authorisedby the Engineer.

All edges of splice andgusset plates12 mm thick and over shallbe machined and those less than 12 mm thick may be shearedandground.

The ends of platesand sections formingthe main componentsofplate girdersor of built~upmembersshall be machined, machineflamecut, sawn or hand flame cut and ground.

Where ends of stiffeners are required to be fitted, they shall bemachined, machineflame cut, sawn,sbearedandground, or handflamecut and ground.

The ends of lacing barshall be roundedunlessotherwiserequired.

Other edgesandends of mild steel parts may be shearedand anyburrs at edges shall be removed.

1904.3. Preparation of Boles

1904,3.1.Drilling and punching Holes for rivets, black bolts,high.strengthbolts and countersunk bolts/rivets (excluding close toleranceand turn fined bolts) shall be either punched or drilled. The diameter

460


of holes shall be 1.5 mm larger for bolts/rivets less than 25 mm diaand 2.0 mm., for more than or equal to 25 mm.

All holes shall be drilled except for secondary members such as,floor plate, handrails etc. Members which do not carry the main loadcan be punchedsubjectto the thickness of member not exceeding12 mm for material conforming to lS:226.

Holes through more than one thicknessof material or when any ofthe main material thickness exceeds20 mm for steel conforming tolS:2062 or 16 mm for steelconforming to IS:961, IS:8500, shall eitherbe sub-drilled or sub-punchedto a diameterof 3 mm less than therequired size and then reamed to the required size. The reaming ofmaterial more than one thicknessshall be done after assembly.

Where several platesor sectionsform a compound member, theyshall, where practicable,be firmly connectedtogether by clamps ortacking bolts, and the holesbe drilled through the group in one operation.Alternatively,andin the caseof repetitionwork, the platesandsectionsmay be drilled separatelyfrom jigs and templates. Jigs and templatesshall be checked at least once after every 25 operations.All burrsshall be removed.

In the caseof repetition of spans, the erection of every span shallnot be insisted upon, except where close tolerance or turned boltsare used,providedthatmethods areadoptedto ensurestrict interchangea-bility. In such cases, one span in ten or any number less than ten ofeach type shall be erected from pieces selectedat random by theEngineerandshould therebe any failure of the piecesto fit, all similarspansshall be erectedcomplete.In theevent of spans being provedcompletelyinterchangeable,all correspondingpartsshall carry the samemark so that sorting of the materials at site is facilitated.

1904.3.2.Block drilling : Where the number of plates to be rivetedexceedsthreeor the total thickness is 90 mm or more, the rivet holes,unless they have been drilled through steel bushed jigs, shall be drilledout in place 3 mm all round after assembling.In such cases,the workshall be thoroughly bolted together.

1904.3.3.Size of holes: The sizesof holes in millimetres are givenin Table 1900-i below:

461

Seclion 1900 StructuralSteel

TABLE 1900-i DtAMVFER OF HOLES FOR RIVV1’S

Nozninaldiaof Rivets (mm) ma of Holes (mm)

12 13.514 15.516 17.518 19.520 21.522 23.524 25.527 29.030 32.033 35.0

1904.3.4. Close tolerance bolts and barrel bolts : Holes for close.toleranceand turn fitted bolts. The diameter of the holes shall beequal to the nominal diameter of the bolt shank minus 0.15 mm to0.0 mm.

The membersto be connectedwith close toleranceor tum fittedbolts shall be firmly held togetherby service boltsor clamped‘anddrilled through all thicknessesin one operation and subsequentlyreamedto requiredsize within specified limit of accuracyas specifiedin 15:919 tolerancegrade H8.

The holes not drilled through all thicknessesat one operationshall be drilled to smaller sizeand reamedafter assembly.

1904.3.5,Holes for high strength friction grip bolts : All holesshall be drilled after removal of burrs. Where the number of’’pliesin the grip does not exceedthree, the diametersof holes shall be1.6mm larger than those of bolts and for more than threeplies in grip,the diametersof hole in outer pliesshall beas above and dia of holesin inner plies shall not be less than 1.6 mm and not more than3.2 mm larger than those in bolts, unlessotherwisespecifiedby theEngineer.

1904.3.6.Removal of burrs : The work shall be takenapart afterdrilling and all burrs left by drilling and the sharpedgesof all rivetholes completely removed.

1904.4. Rivet and Riveting

The diameterof rivets shown on the drawings shall bethe sizebefore heating. Each rivet shallbe of sufficient lengthto form a headof the standarddimensionsas given in IS handbook on SteelSections,Part I. It shall be free from burrs on the undersideof the head.

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When countersunk heads are required,the headsshall fill thecountersunk. The included angle of the headshall be as follows

a) For plates over 14 mm thickness 90 degrees

b) For plates upto and including 14 mm thickness 120 degrees

The toleranceon the diameterof rivets shall be in accordancewithIS: 1148 andIS: 1149 for mild steel rivets andhigh tensile steel rivetsrespectivelyand unless otherwisespecified, the toleranceshall beminustolerance.

Rivets shall be driven whenhot so asto fill the hole as com-pletely as possibleand shall beof sufficient lengthto - form a headofstandarddimension.When counter-sunkheadis required,the head shallfill the counter-sunk hole. Projection after counter-sinkingshall beground off wherever necessary.

Rivets shall be heateduniformly to a “light cherry red” colourbetween650degrees Celsiusto 700degreesCelsius for hydraulic rivetingand“orangecolour” for pneumaticriveting of mild steel rivets andshallbe red hot from head to the point when insertedand shall be upsetin its entire lengthso as to fill the hole as completely as possiblewhenhot. Rivets, after being heated andbefore being insertedin the holeshall bemadefree from scaleby striking the hot rivet on a hardsurface.

Whereverpossible, the rivetsshall bemachinedriven,preferably bydirect acting riveters. The driving pressureshall be maintainedonthe rivets for a short time after the upsetting is completed. High tensilesteel rivetsshall beheated upto 1100degreesCelsius. Any rivet whosepoint is heatedmore than prescribed,shall not be driven.

Where flush surface is required, any projecting metal shall bechipped or ground off.

Before riveting is commenced,all work shall beproperly bolteup sothatthevarious sectionsandplatesare in close contactthroughout.Drifts shall only be used for drawing the work into position andshallnot be usedto such an extent as todistort the holes.Drifts of a largersizethan the nominal diameter of the hole shall not be used. The rivetingshall be done by hydraulic or pneumaticmachineunless otherwisespecifiedby the Engineer.

Driven rivets, when struck sharply on the headby a quarterpoundrivet testing hammer, shall be free from movement and vibrations.Assembledriveted joint surfaces,including those adjacentto the rivet

463

Section 1900 Structural Steel

heads,shall be free from scale,dirt, loosescale, burrs, other foreignmaterials and defects that would prevent solid seating of parts.

All loose or burnt rivets and rivets with cracked or badly formeddefectiveheadsor with headswhich are unduly eccentricwith the shanks,shall be removedand replaced.In removing rivets, the headshall beshearedoff and the rivet punched out SO as not to injure the adjacentmetal and, if necessary, they shall be drilled out. Recupping orrecaulking shall not be permitted. The parts not completely rivetedin theshop shall be securedby bolts to preventdamageduringtransportand handling.

1904.5. Bolts, Nuts and Washers

1904.5.1. Black bolts (black all over) : Black bolts are forgedboltsin which the shanks,headsand nuts do not receiveany further treatmentexcept cutting of screw threads. They shall be true to shape and sizeand shall have the standarddimensionsas shown on the drawings,

1904.5.2.Close tolerance bolts : Closetolerance bolts shall be facedunder the head and turned on the shank.

1904.5.3.Turnedbarrelbolts: The diameterof thescrewedportionof turned barrel bolts shall be 1.5 mm smaller than the diameterofthe barrel unlessotherwisespecifiedby the Engineer.The diameterofthe bolts as given on the drawing shall be the nominal diameterofthe barrel. The length of the barrel shall be such that it bearsfully onall the partsconnected.The threadedportionof each bolt shall projectthrough the nut by at leastone thread.Facesof headsand nuts bearingon steel work shall be machined.

1904.5.4.High strength friction bolts and boltedconnections:Thegeneral requirement shall be asper relevantIS specificationsmentionedin clause 5.3 of (Fasteners)of IRC:24. Unless otherwisespecifiedbythe Engineer,bolted connectionsof structural joints usinghigh tensilefriction grip bolts shall comply with requirementsmentionedin IS:4000.

1904.5.5.Washers : In all caseswhere the full bearingareaofthe bolt is to be developed, the bolt shall be provided with a steelwasher under the nut of sufficient thicknessto avoid anythreadedportionof the bolt being within the thicknessof the parts bolted together andto prevent the nut when screwed up, from bearingon the bolt.

For closetoleranceor turned barrel bolts, steelwashers whosefacesgive a true bearingshall be provided under the nut. The washer shallhave a hole diameternot less than 1.5 mm larger than the barrel and

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StructuralSteel Section 1900

a thickness of not less than 6 mm so that the nut when screwed up,will not bear on the shoulder of the bolt.

Taper washers with correct angle of tapershall be provided underall heads and nuts bearing on bevelled surfaces.

Spring washersmay be used under nuts to prevent slackening ofthe nuts when excessivevibrations occur.

Where the heads or nuts bear on timber, squarewashers havinga length of each side not less than threetimes the diameter of boltsor round washers having a diameter of 3h/~ times the diameter ofbolts and with a thickness not less than one quarter of diameter shallbe provided.

1904.5.6. Studs : Ordinary studs may be used for holding partstogether, the holes in one of the parts being tapped to take the threadof the stud. Counter-sunk studs may be used for making connectionswhere the surfaces are required to be clear of all obstruction, suchas protruding heads of bolts or rivets, studsmay also be welded on thesteel work in the positions required.

1904.5.7.Service bolts: Service boltsshall havethe sameclearanceas black bolts andwhere it is requiredthat there should be no movementprior to final riveting, sufficient drifts or close tolerance bolts shall beused to locate the work.

1904.5.8.Tightening bolts: Bolted connectionjoints with black boltsand high strength bolts shall be inspected for compliance of codalrequirements.

The Engineer shall observethe installationandtightening of boltsto ensure that correct tightening procedure is used and shall determine

• that all bolts are tightened. Regardlessof tightening method used,tightening of bolts in a joint should commenceat the most rigidly fixedor stiffest point and progress towards the free edges, both in initialsnugging and in final tightening.

The tightness of bolts in connection shall be checked by inspec-tion wrench, which can be torque wrench, power wrench or calibratedwrench.

Tightness of 10 per cent bolts, but not less than two bolts, selectedat random in each connection shall be checked by applying inspectiontorque. If no nut or bolt head is turnedby this application, connectioncanbe acceptedas properly tightened, but if any nut or headhas turnedall bolts shall be checkedand, if necessary, re-tightened.

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Section1900 Structural Steel

1904.5.9.Drifts : The barrel shall be drawn or machinedto therequired diameterfor a length of not less than one diameter overthe combined thicknessof the metalthrough which the drifts have topass. The diameter of the parallel barrel shall be equal to thenominal diameter of the hole subject to a toleranceof +0 mm and -

0.125 mm. Both endsof the drift for a length equal to 11/2 times thediameter of the parallel portion of the bar shall be turned downwith a taper to a diameter at the end equal to one-half that of parallelportion.

1904.6. Pins and Pin Holes

1904.6.1. Pins : The pins shall be parallel throughout andshall have a smooth surface free from flaws. They shall be ofsufficient length to ensure that all parts connectedthereby shallhave a full bearingon them. Where the ends are threaded,they shallbe turned to a smaller diameterat the ends for the thread andshall beprovided with a pilot nut, where necessary,to ~protectthe thread whenbeing drawn t~place.

Pins more than 175 mm in length or diameter shall be forged andannealed. -

1904.6.2.Pin holes : Pin holesshall bebored trueto gauge,smooth,straight at right angles to the axis of the memberand parallel witheach other, unless otherwiserequired. The tolerancein the length oftensionmembersfrom outsideto outsideof pin bolesandof compressionmembers from inside to inside of pin holes shall beone millimetre.In built-up members,the boring shall be done after the membershavebeenriveted or welded.

The specified diameterof thepin holeshallbe its minimum diameter.The resulting clearance between the pin and the hole shall not be lessthan 0.5 mm and not more than 1.0 mm.

1904.7. Shop Erection and Match Marking

Before being dispatched,the steel work shall be temporarilyerected in the fabrication shop for inspectionby the Engineereitherwholly or in suchportion as the Engineermay require so that he maybe satisfiedboth in respectof the alignmentand fit of all connections.For this purpose,sufficient number of parallel drifts and service boltstightly screwedup shall be employed. All parts shall fit accuratelyand be in accordance with drawings and specifications.

The steelwork shall be temporarily assembledat placeof fabrication.

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Assembly shall be of full truss or girder, unless progressive trussor girder assembly, full chord assembly,progressivechord assemblyor special complete structureassemblyis specifiedby the Engineer.

The field connectionsof main membersof trusses,arches,continuousbeams, spans,bends,plategirders and rigid frameassembled,aligned,accuracy of holesand cambershall be checked by Engineer and thenonly reaming of sub-sizeholes to specified size shall be taken up.

After the work has beenpassedby the Engineerandbefore it isdismantled, each part shall be carefully marked for re-erection withdistinguishing marks and stampedwith durable markings. Drawingsshowing thesemarkings correctly shall be supplied to the Engineer.

Unloading, handling and storage~f steel work as per thesespecifications shall be the responsibility of the Contractor.The cost ofrepairsor of rejected material, its removal and the cost of transportingreplacementmaterial to the site shall be borne by the Contractor.

Where closetolerance or turned barrelbolts areusedfor those caseswhere interchangeability is not insisted upon, each span shall be erectedand members of each span marked distinctly.

1904.8. Welding

1904.8.1.All welding shall be done with the prior approval of theEngineer and the workmanship shall conform to the specificationsofIS:823 or other relevant Indian Standardsas appropriate.

When material thickness is 20 mm or more, specialprecautions likepreheatingshall be taken as laid down in IS:823. Surfacesand edgesto be weldedshall be smooth,uniform and fret from fins, tears,cracksandother discontinuities. Surface shall also be free from looseor thickscale,slagrust,moisture, oil and otherforeign materials. Surfaces within50 mm of any weld location shall be free from any paint or othermaterial that may prevent proper weldingor causeobjectionable fumesduring welding.

The general welding proceduresincluding particularsof theprepa-ration of fusion faces for metal arc welding shall be carried out inaccordancewith IS:9595.

The welding proceduresfor shop and site welds including edgepreparationof fusion facesshall be submitted in writing in accordancewith Clause22 of IS :9595 for the approval of the Engineerbeforecommencing fabrication and shall also be as per details shown on the

467


drawings. Any deviation from above has to be approved by Engineer.Preparation of edges shall, wherever practicable, be doneby machinemethods.

Machine flame cut edges shall be substantially as smooth andregular as those produced by edge planing and. shall be left free ofslag. Manual flame cutting shall be permitted by the Engineer only wheremachine cutting is not practicable.

Electrodes to be used for metal arc welding shall comply withrelevant IS specificationsmentionedin IRC:24. Procedure test shall becarried out as per IS:8613 to find out suitable wire-flux combinationfor welded joint.

Assemblyof partsfor welding shall be in accordancewith provisionsof IS:9595.

The welded temporary attachmentshould be avoided as far aspossible,otherwisethemethodof making any temporary attachment shallbe approvedby theEngineer.Any scarsfrom temporaryattachmentshallbe removedby cutting, chipping and surfaceshall be finishedsmoothby grinding to the satisfaction of the Engineer.

Welding shall not be done when the air temperatureis less than10 degreesCelsius.Welding shall not be done when the surfacesaremoist, during periodsof strong winds or in snowy weatherunless thework and the welding operatorsare adequately protected.

1904.8.2.For welding of any particular type of joint, welders shallqualify to the satisfactionof theEngineerin accordancewith appropriatewelders qualification test as prescribedin any of the Indian StandardsIS:817, IS:1966,IS: 1393,IS:7307 (part I), IS:7310(Part I) and IS:7318(part I) as relevant.

1904.8.3.In assembling andjoining parts of a structure or of built-up members, the procedureand sequenceof welding shall be such asto avoid distortion and minimise shrinkage stress.

All requirements regarding pre-heating of parent material andinterpass temperature shall be in accordancewith provision of IS:9595.

19048.4.Peening of weld shall be carried out wherever specifiedby the Engineer

a) If specified,peeningmay beemployedto beeffectiveon eachweld~1ayerexceptfirst.

b) The peening should be carriedout after weld has cooled by light blows from

468


a power hammerusing a round nose tool. Care shall be takento preventscaling or flaking of weld and’ basemetal from over peening.

1904.8.5.Where the Engineer has specified the butt welds are tobe ground flush, the loss of parent metal shall not be greaterthanthat allowedfor minor surfacedefects.The ends of butt joints shall bewelded so as to provide full throat thickness. This may be done by useof extension pieces,crossruns or other meansapproved by the Engineer.Extension piecesshall be removedafter the joint has cooled and theends of the weld shall be finished smooth and flush with the faces ofthe abutting parts.

The joints and welds listed below are prohibited type, which donot perform well under cyclic loading.

a) Butt joints not fully welded throughout their cross-section

b) Groove welds made from one side only without any backing grip

c) Inteimittent groove welds

d) Intermittentfillet welds

e) Bevel-groovesand J-grooves in butt joints for other than horizontal position.

f) Plug and slot welds

1904.8.6. The run-on and run-off plate extension shall be usedprovidingfull throat thicknessat the endof butt welded joints. Theseplates shall comply with the following requirements.

(i) One pair of ~‘run-on”and one pair of “nm-off” plates prepared from samethicknessand profile as the parent metal shall be attachedto start and finishof all butt welds preferably by clamps.

(ii) When “nm-on” and“run-off’ plates shall be removedby flame cutting, it shouldbe rut at more than 3 mm from parentmetal and remaining metal shall beremovedby grinding or by an~’ other method approvedby the Engineer.

1904.8.7. Welding of stud shear connectors : The stud shearconnectorsshall be welded in accordance with the manufacturer’sinstructions including preheating.

The stud and the surface to which studs are welded shall be freefrom scale,moisture, rust and other foreign material. The stud baseshallnot be painted, galvanisedor cadmium platedprior to welding.

Welding shall not be carried out when temperature is below 10degrees Celsiusor surface is wet or during periodsof strong winds unlessthe work and the welder is adequately protected.

The welds shall be visually free from cracks and shall be capableof developing at least the nominal ultimate strength of studs.

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The proceduraltrial for welding the stud shall be carried out whenspecified by the Engineer.

1904.9. Tolerances

Tolerances in dimensionsof componentsof fabricatedstructuralsteelwork shall be specifiedon the drawingsand shall be subject to theapprovalof the Engineer before fabrication. Unless specified,all partsof an assemblyshall fit together accurately within tolerancesspecifiedin Table 1900-2.

A machined bearingsurface, where specified by the Engineer,shall be machined within a deviation of 0.25 mm for surfaces that canbe inscribedwithin a squareof side 05 in.

TABLE 1900.2 FABRICATION TOLERANCES

A. INDIVIDUAL COMPONENTS

1. Lengtha) Member with both ends finished for ±1 mm

contact bearingb) Individual componentsof memberswith + 0 mm

end plate conneution - 2 mmc) Other members

I) Upto and including 12 M ±2mmii) Over 12 M ±3.5mm

2. WidthWidth of built-up girders ~3 mm

b) Deviation in the width of members +0 mmrequiredto be inserted in other members -3 mm

3. DepthDeviation in the depths of solid +3 mmweb and open web girders -2 mm

4. Straightnessa) Deviation from streighiness of 1./3000 subject to a

columns maximsin of 15 mmwhere L is length ofmember

1) In elevation +5 rum-0mm

ii) In plan 111000 subject to a- maximum of 10 mm

5. Deviation of centre line of web from centreline of flanges in built-up membersat contartsurfaces - 3 mm

470

Deviation from flatness of plate of webs ofbuilt-up membersin a length equal to thedepth of the member

7. Tilt of flange of plate girdersa) At splices and stiffeners,at

supports, at the top flanges ofplate girders and at bearings

b) at other places

8, Deviation from squarenessofflange to web of columns andbox girders

9. Deviation from squarenessoffixed baseplate (not machined)to axis of column. This dimensionshall be measuredparallel to thelongitudinal axis of the column atpoints where the outer surfacesofthe column sectionsmake contactwith the baseplate

10. Deviation from squarenessofmachinedends to axes of columns

11. Deviation from squarenessofmachinedendsto axes of beamsor girder

12. Ends of members abutting at jointsthroughcleats or end plates,permissibledeviation fromsquarenessof ends

Section 1900

0.005 d to a maximumof 2 mm where d is depthof the member

0.005 b to aminimum of 2 mm where bis width of the member

0.015 b to amaximum of 4 mm whereb is width of the member

111000. whereL is nominal lengthof the diagonal

D/500, where D isthe distancefromthe column axis tothe point underconsiderationonthe baseplate

D/1000, where D isas definedin 9 above

D/1000, where D isas definedin 9above

1/600 of depth ofmember subjecttoa maximum of 1.5 mm

1905.1. General

1905. ERECTION

The provisions of this item shall apply to erection of steel bridgesuperstructuresor main membersof bridge superstructures, composedofsteel, which span betweensupports.

If the sub-structureandthesuperstructureare built under separatecontracts, the departmentwill provide the substructure,constructedtocorrect lines, dimensions and elevations properly finished and willestablish the lines and the elevation required for setting steel.

StructuralSteel

6.

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TheContractor shall erect the structural steel,remove the tempo-rary construction, and do all the work required to complete theconstructionincluded in the contract in accordancewith the drawingsand the specifications and to the entire satisfactionof the Engineer.

1905.2. Organisation and Equipment

The Contractor shallsubmiterectionplanspreparedby the fabricator,showing amethod andprocedureof erection,compatiblewith the detailsof fabrication.

A detailed schememust be prepared showing stage-wiseactivities,with complete drawings andworking phase-wiseinstructions.This shouldbe based on detailed stage-wise calculation and take into accountspecifications and capacity of erection equipment machinery, tools,tacklesto be usedandtemporaryworking loadsasper Coclal provisions.

The scheme should be based on site conditions e.g. hydrology,rainfall, flood timings and intensity, soil andsub-soilconditionsin theriver bed and banks, maximumwater depth,temperatureand climaticconditions and available working space,etc.

The schemeshould indicateprecisely the type of temporaryfas-tenersto be used as also the minimum percentageof permanentfastenersto be fitted during the stageerection. The working drawings shouldgive clearly the temporaryjigs, fixtures, clamps,spacersupports,etc.

Unless otherwiseprovidedin the contract,thecontractor shallsupplyanderectall necessaryfalseworkandstaging andshall supply all labour,tools, erectionplant and other materials necessaryto carry out the workcomplete in all respects.

The Contractor shall supply all rivets, bolts, nuts, washers, etc.required to complete erection at site with an allowance for wastage,etc., of 12 1/ percentof the net number of field rivets, bolts, washersrequired, or a minimum of five number of each item.

Service bolts‘and nuts, ordinary platters, washers and drifts for usein the erectionof work shall be supplied - at 60 per cent (45 per cernbolts and 15 per cent drifts) of the number of field rivets per spanin each size (this includes wastage). A reduction in the quantitiesofservicebolts, etc., may however, be specifiedby the Engineer if morethan one span of each type is ordered.

Prior to actual commencementof erection all equipment, machinery,tools, tackles, ropes, etc. need to be tested to ensuretheir efficient

472


working. Frequent visual inspectionis essentialin vulnerableareastodetect displacements,distress,drainages,etc.

Deflection and vibratory tests shall be conductedin respectofsupporting structures, launching truss as also the structure under erectionand unusual observationsreviewed; loosenessof fittings areto be noted.

For welded structures,welders’ qualificatons and skill are to bechecked as per standardnorms. Non-destructivetests of joints as perdesigner’s directives are to be carried out.

Precisionnon-destructivetestinginstrumentsavailable in the marketshould be usedfor noting variousimportantparametersof the structuresfrequently and systematicrecord is to be kept.

Safety requirementsshouldconform to IS:7205, IS :7273and IS:7269as applicable and should be a consideration of safety, economy andrapidity.

Erection work should start with completeresourcesmobilised asper latest approved drawings and after a thorough survey offoundations and other related structural work. In case of work ofmagnitude, maximum mechanisationis to be adopted.

The structureshould be divided into erectablemodulesas per thescheme.This should be pre-assembledin a suitable yard/platform andits matching with members of the adjacent module checked by trialassemblybefore erection.

The structureshall be set out to the requiredlines and levels. Thestocks and massesare to be carefully preserved.The steelwork shouldbe erected, adjusted and completed in the required position to thespecifiedline andlevelswith sufficient drifts and bolts. Packing materialsare to be available to maintain this condition. Organised “QualitySurveillance”checks need to be exercisedfrequently.

Before starting work, the Contractor shall obtain necessaryapproval of the Engineer as to the method adoptedfor erection, thennmber and character of tools and plants. The approvalof the Engineershall not relieve the Contractor of his responsibility for the safety ofhis method or equipment or from carrying out the work fully inaccordancewith the drawingsand specifications.

During the progressof work, the Contractorshall have a competentEngineer or foreman in charge of the work, who shall be adequate-ly experienced in steel erection and acceptable to the Engineer.

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1905.3. Handling and Storing of Materials

Suitable area for storageof structuresand componentsshall belocated near the site of work. The accessroad should be free fromwater logging during the working period andthe storagearea should beon levelled and firm ground.

The store shouldbe providedwith adequate handling equipmentse.g road mobile crane, gantries,derricks, chain pulley blocks, winchof capacityas required.Stackingareashould be plannedand have racks,standssleeper,accesstracks, etc., and properly lighted.

Storage should be plannedto suit erection work sequence andavoid damageor distortion. Excessivelyrusted,bentor damagedsteelshall be rejected, Methods of storageand handling steel, whetherfabricatedor not shall be subject to the approval of the Engineer.

Fabricatedmaterials are to be stored with erection marks visible,such as not to come into contact with earthsurfaceor water andshouldbe accessibleto handling equipment.

Small fitting hand tools are to be kept in containersin coveredstores.

All materials,consumables,including raw steelor fabricatedmaterialshall be storedspecification-wiseand size-wise abovethe grounduponplatforms, skids or other supports.It shall be kept free from dirt andother foreign matter and shall be protected as far as possiblefromcorrosionand distortion. The electrodes shall be storedspecification-wise and shall be kept in dry warm condition in properly designedracks. The bolts, nuts, washersand other fastenersshall be storedonracks above the ground with protectiveoil coatingin gunny bags.Thepaint shall be stored under cover in air-tight containers.

IS:7293 and IS:7969 dealing with handling of materials andequipments for safeworking shouldbe followed. Safety nuts andboltsasdirected are to be used while working. The Contractor shall be heldresponsible for loss or damageto anymaterial paid for by the Departmentwhile in his care or for any damageto such material resulting from hiswork.

1905.4. Formwork

The formwork shall be properly designed,substantiallybuilt andmaintainedfor all anticipated loads. The Contractor, if required, shallsubmit plans for approval to the Engineer. Approval of the plans,however,shall not relieve the Contractor of his responsibility.

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1905.5, Straightening Bent Material

The straightening of plates,anglesand other shapesshall be doneby methods not likely to produce fracture or any injury. The metal shallnot be heated unlesspermittedby the Engineer for special cases,whenthe heating shall not be to a temperaturehigher than that producinga dark “cherry red” colour, followed by as slow cooling as possible.Following the straightening of a bend or buckle the surface shall becarefully investigated for evidence of fracture.Sharpkinks and bendsmay be the cause for rejection of material.

1905.6. Assembling Steel

The partsshall be accuratelyassembledas shown on the drawingsand match marks shall be followed. The material shall be careful-ly handled so that no parts will be bent, broken or otherwisedamaged.

Hammering which will injure or distort the membersshall not bedone. Bearing surface or surfacesto be in permanent contact shallbe cleaned,before the members areassembled.The truss spans shallbe erectedon blocking, so placedas to give the proper camber. Theblocking shall be left in place until the tendon chord splices arefully riveted and all other truss connections pinned and bolted. Rivetsin splices of butt joints of compressionmembers andrivets in railingsshall not be driven until the span has been swung.

All joint surfacefor boltedconnections including bolts,nuts,washersshall be free from scale,dirt, burrs, other foreign materials and defectsthat would prevent solid seatingof parts. The slopeof surface of boltedparts in contact with bolt head and nut shall not exceed 1 in 20,plane normal to bolt axis, otherwisesuitable tapered washer shall beused.

All fasteners shall have a washer under nut or bolt headwhichever is turned in tightening.

Any connection to be riveted or bolted shall be securedin closecontact with service bolts or with a sufficient number of permanentbolts before the rivetsare driven or before theconnectionsare finallybolted. Joints shall normally be made by filling not less than 50 percent of holes with service bolts and barreldrifts in the ratio 4:1. Theservice bolts are to be fully tightened up as soon as the joint isassembled. Connections to be made by close toleranceor barrel boltsshall be completed as soon as practicableafter assembly.

475


Any connection to be site weldedshall be securely held inposition by approved methods to ensure accurate alignment, camber andelevation before welding is commenced.

The field riveting, welding, bolted and pin connection shallconform to the requirements of Clause l9()4 as appropriate.

The correction of minor misfits involving harmless amounts ofreaming, cutting and chipping will be considered a legitimate partof erection.However, any error in the shop fabrication or deformationresulting from handling and transportation which prevents properassemblingand fitting up of parts by moderateuse of drifts o~bya moderateamount of reaming and slight chipping or cutting shall bereportedimmediately to the Engineerand his approval of the methodof correction obtained. The correctionshall be made in the presenceof the Engineer.

1905.7. Field Inspection

1905,7.1. General

All materials,equipmentand work of erection shall be subject tothe inspection of the Engineerwho shall be provided with all facilities~nc!udinglabour and tools requiredat all reasonabletimes. Any workfound defective is liable to be rejected.

1905.7.2.No protectivetreatmentshall be applied to the work untilthe appropriate inspectionandtesting hasbeen carried out. The stageinspection shall be carried out for all operations so as to ensure thecorrectnessof fabrication and good quality. Girder dimensions andcambershall not he finally checked until all welding and heatingoperationsare completedand the member has cooled to a uniformtemperature.

1905.7.3,Testing of material : Structural steel shall be tested formechanicaland chemical properties as per various IS codesas mayhe applicable and shall conform to requirements specified in IS:226,IS:2062, IS:1l587, IS:1977, IS:8500 and IS:961, etc.

Rivets, bolts, nuts, washers, welding consumables, steel forging,casting and stainlesssteelshall be tested for mechanical andchemicalproperties in the appropriateIS Code.

Rolling and cutting tolerance shall be as per lS:1852. The thick-ness tolerance check measurementsfor the plate and rolled sectionsshall be taken at not less than 15 mm from edge.~

476


Laminationsin plates shall be carried Out by ultra-sonic testing orany other specified methods.

Steel work shall be inspectedfor surface defects and exposededge laminationsduring fabricationandblastcleaning.Significant edgelaminations found shall be reportedto the Engineerfor his decision.

Chipping, grinding, machiningor ultrasonic testing shall be used todeterminedepth of imperfection.

1905.7.4. Bolted connections : Bolts and bolted connectionjointswith high strength friction grip bolts shall be inspectedand tested,according to IS:4000.

Rivets and riveted connectionshall he inspectedand tested forcomplianceof coda! requirements.

The firmness of joint shall be checkedby 0.2 mm filler gauge,which shall not go inside underthe rivet headby more than3 mm. Thereshall not be any gap between members to be riveted.

Driven rivets shall be checked.with rivet testing hammer. Whenstnick sharply on head with rivet testing hammer,rivet shall be freefrom movementand vibration.

All loose rivets and rivets with cracks, badlyformed or deficientheadsor with headswhich are eccentric with shanks,shall be cut outand replaced.

The alignmentof platesat all boltedsplicejoints and welded buttjoints shall be checked for compliancewith coda! requirements.

Testing of flame cut and shearededges is to be done, where thehardnesscriteria given in the code are adopted. Hardnesstesting shallbe carried out on six ~pecimens.

1905.7.5.Welding and welding consumables: Welding procedure,welded connection and testing shall be in compliance with cbdalrequirements.

All facilities necessaryfor stageinspectionduring welding and oncompletion shall be provided to the Engineer or their inspect-ing Authority by manufacturer.

Adequate means of identification either by identification mark orother record shall be provided to enable each weld to be traced tothe welder(s) by whom it was carried out.

477

Section1900 StrucunalSteel

All metal arc welding shall be in compliance with IS:9595 provi-sions.

The method of inspectionshall be in accordance with IS:822 andextentof inspectionand testingshallbe in accordancewith the relevantstandards or in the absenceof such a standard, as agreedwith theEngineer.

Proceduretests

The Destructiveand Non-Destructivetest of weld shall be carriedout according to IS:7307 (Part I).

Non-DestructiveTesting of Welds

One or more of the following methods may be applied forinspection or testing of weld

(i) Visual Inspection All welds shall be visually inspected,which should coverall defectsof weld such as size, porosity, crack an the weld or in the HAZ(Heat Affected Zone) etc. Suitable magnifying glassmay be used for visualinspection. A weld shall be acceptableby visual inspectionif it shows that

a) The weld has no cracks.

b) Through fusion exists betweenweld and basemetal and betweenadjacentlayers of weld metal.

c) Weld profiles arein accordancewith requisiteclausesof IS:9595 orasagreedwith the Engineer

d) The weld shall be of full cross section,except for the endsof intermittentfillet welds outside their effeclive length.

e) When weld is transverseto the primaay stress,undercutshalt not be morethan 025 mm deepin the part that is undercutand shall not be more than0.5 mm deepwhen the weld is parallel to the primary stressin the part thatis undercut.

1) The fillet weld in any single continuousweld shall be permitted to undernan the nominal fillet weld size specifiedby 1.6 mm without correctionprovided that undersizeponion of the weld does not exceed 10 per centof the length of the weld. On the web.to..flangewelds on girders,no under-nan is permittedat the ends for a length equal to twice the width of theflange.

g) The piping porosity in fillet welds shall not exceedone in each 100 mmof weld length and the maximum diametershall not exceed2.4 mm, exceptfor fillet welds connectingssiffenersto web wherethe sumof diametersofpipingporosity shall not exceed9.5 mm in any 25 mm length of weld andshall not exceed 19 mm in any 300 man length of weld.

h) The full penetrationgroove wetd in butt joints transv~rseto the directionof computed tensile stress shall have no piping porosity. For all other groovewelds, the piping porosity ~haIi not exceedonein 100 mm of length andthe maximum diameter shall not exceed2.4 mm.

478


(ii) Magnetic Particle and RadiographicInspection:Welds that are subject to radio-graphic or magnetic particle testing in addition to visual inspection shall haveno crack.

Magnetic particle test shall be carriedout for detection of crack and otherdiscontinuity in the weld accordingto IS:5334.

Radiographictest shall be carried out for detectionof intemal flaws in the weldsuch as crack, piping porosity inclusion, lack of fusion, incomplete penetration,etc. This test mat be carried out as per 15:1182 and 15:4853.

Acceptance Criteria The weld shall be unacceptableif radiographic or magneticparticle testing shows any of the type of discontintrities indicated in the code.

(iii) UltrasonicInspection : The Ultrasonic testing in addition to visual inspection shallbe carried out for detectionof internal flawsin the weld such as cracks, pipingporosity inclusion, lack of fusion, incompletepenetration,etc. Acceptancecriteriashall be as per 15:4260or any other relevant IS Specification and as agreedto by the Engineer.

iv) Liquid PenetrationInspection The liquid penetrant teat shall be carried out fordetection of surfacedefect in the weld, as per 15:3658, in addition to visualinspection.

The non-destnjctive testing of following welds be carried out using one ofthe method or methodsdescribedat (ii),(iii) and(iv) above, as may be agreedto by the Engineer.

a) All transverse butt welds in tension flange

b) 10 per centof the length of longitudinaland transversebutt weldsin tensionflanges.

c) 5 per cent of the length of longitudinal and transverse butt welds inconspressionflanges.

ci) All transverse butt welds in webs adjacent to tension flanges as specifiedby the Engineer.

The particular length of welds in webs to be tested shall beagreedwith the Engineer, in caseof (b) or (c).

Where specified by the Engineer, bearing stiffeners or bearingdiaphragmsadjacentto welds, flange platesadjacentto web/flangewelds,plates at cruciform welds, platesin box girder construction adjacenttocornerweldsor otherdetailsshall beultrasonicallytestedafter fabrication.

Any lamination, lamellar tearing or other defect found shall berecordedand reportedto Engineerfor his decision.

Testing of Welding for Cast Steel The testing of weld for caststeel shall be carried out as may be agreed to by the Engineer.

Stud Shear Connectors Stud shear connectorsshall be subjectedto the following tests

479


to the Engineerwho will determine whether the component/membermay

be acceptedwithout rectification, with rectification or rejected.

1906. PAINTING

1906.1.General

Unless otherwise specified, all metal work shall be given approvedshop coats as well as field coats of painting. The item of work shallinclude preparation of metal surfaces, applicationof protective coveringand drying of the paint coatingsand supply of all tools, scaffolding,labour and materials necessary.

Coatings shall be applied only to dry surfaces and the coatedsurfaces shall not be exposed torain or frost before they aredry. Thecoatings shall be applied to all surfaces excludingshear connectorsand inner surfaces of fully sealed hollow sections. Care shall betaken during coating of adjacent surfacesto build up primer on the shear~connectors.

1906.1.1.Types of paints

(i) Ordinary Paints

Theseinclude paints basedon dryingoils, alkyd resin,modifiedalkydresin, phenolic varnish epoxy, etc.

Alkyd resin paints for the protection of steel structures are basedpartly on natural oils andpartly on synthetic resins. These paints shallbe usedfor steel structures in atmosphereswhich arenot too aggressive.

Oil based paints can be used for steel structuresin cases wherethe surfacepreparationcannotbe ideal. Ordinary painting cangenerallybe sub-dividedinto two groups:

a) Primary Coats

This shall be applied immediately after the surface preparationandshould have the properties of adhesion, corrosion inhibition andimper-viousness to water and air.

b) Finishing Coats

These are applied over the primary coat and should have theproperties of durability, abrasion resistance,aestheticappearanceandsmooth finish.

481


(ii) Chemical ResistantPaints

The more highly corrosion resistantpaintscan be divided into twomain groups

a) One pack paints (ready for use)

b) Two pack paints (mixed before use)

The two pack paints shall be mixed together immediately beforeuse since they are workablethereafteronly for a restrictedperiodof time and dry up as a result of a reactionbetweentheir componentsand yield hard tough films with resistanceto abrasion.

(iii) Vinyl Paints

These are based on polyvinyl resins such as polyvinyl-chloride(PVC) and polyvinyl-acetate,etc.

Certain types of vinyl resin paints yield thick, relatively soft andrubberlike coatingswith goodchemicalresistance.They can be repaintedwithout difficulty.

(iv) ChlorinatedRubberPaints

These paints also have good chemical resistance.The main fieldsof applications shall be in aggressive environments. In general,chlorinated rubber paints do not have a high gloss.

(v) Bituminous Paints

As a paint vehicle, bituminous is inferior, but because of thelow price, this shouldbe applied in greater thickness (upto severalmillimetres) and may be suitable for some situations. A significantadvantageof bitumenpaints is their impermeabilityto ingressof water.However, bituminous paints do not withstandeffectively detrimentaleffects of oil.

(vi) Epoxy Paints

These resin paintshave good adherenceto a well prepared sub-strata. They are mechanically strong and resistant to chemicals. Adisadvantageof epoxy resin paints is that it can rapidly becomedullwhen exposedto strong sunlight. These disadvantagesdo not, however,greatly influence their protectivepower.

(vii) Polyurethane Paints

The chemical and mechanical behaviour of polyurethane paintresembles thoseof epoxy paint very much. However, polyurethane paintretains its gloss for a longer period. Becauseof the high price of

482


polyurethane paint, a combination of the two viz., polyurethane andepoxy paints may sometimesbe used.

(viii) Zinc Rich Paints

Insteadof introducing an inhibitive pigment into paint,metallic zinccan be used and such paints can provide cathodic protection to steel,

1906.1.2.Surfaceswhich are inaccessible for cleaningandpaintingafter fabricationshall be paintedasspecifiedbeforebeing assembledforriveting.

All rivets, bolts, nuts, washersetc., are to be thoroughlycleanedand dipped into boiling linseed oil conforming to IS:77.

All machinedsurfacesare to be well coatedwith a mixture of whitelead conforming to IS:34 and Mutton Tallow conforming to IS:887.

For site paintings, the whole of the steel work shall be given thesecondcover coat after final passing and after touching up the primerand cover coats, if damagedin transit.

1906.1.3. Choice of painting system

The choiceof suitable painting system is dependenton factorssuchas:

- Available application methodsviz, brush, roller or spray

- Durability in a specific environment

Availability of skilled manpower

Cost I benefit etc.

It is therefore necessaryto consult various manufacturers of paintand ascertaintheaboveaspectswhile decidingon the appropriate choiceof painting system.

1906.1.4,Quality of paint The paints which have been tested forthe following qualities as per the specificationsgiven in the relevant IScodes should only be used

Weight Test (weight per 10 litre of paint thoroughly mixed)

- Drying time

Flexibility and Adhesion

Consistency

- Dry thicknessand rate of consumption

1906.1.5. Unless otherwisespecified,all painting and protectivecoating work shall be done in accordancewith IS:l477 (Part 1).

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1906.2. Surface Preparation

Steel surfaceto be paintedeither at the fabricating shop or at thesite of work shall be preparedin a thorough manner with a view toensuring complete removal of mill scale by one of the followingprocessesas agreed to betweenthe fabricator and the Engineer:

a) Dsy or wet gi’t / Sand blasting

b) Pickling which should be restrictedto single plates, ban and sections

c) F1an~ecleaning

Primary coat shall be applied as soonas practicableafter cleaningand in case of flame cleaning, primary coat shall be applied whilethe metal is still warm.

All slag from welds shall be removed before painting. Surfacesshall be maintaineddry and free from dirt and oil. Work out of doorsin frosty or humid weather shall be avoided.

1906.3. Coatings

Prime coat to beused shall conform to the specification of primersapproved by the Engineer.Metal coatingsshall be regardedas primingcoatings. Primer shall be applied to the blastcleanedsurface before anydeterioration of the surface is visible. In any case,the surface shallreceive one coat of primer within 4 hours of abrasiveblastcleaning.

All coats shall be compatible with each other. When metal coat-ings are used, the undercoat shall be compatible with the metalconcerned. The undercoat and finishing coat shall preferably be fromthe samemanufacturer.Successive coats of paintsshalt beof differentshadesor colours and each shall be allowed to dry thoroughly beforethe next is applied. Particularcare shall be takenwith the priming andpainting of edges,corners, welds and rivets. Typical guidelinesforepoxy based paints and the conventional panting system for bridgegirders as given below may be complied with

a) Epoxy Based Paintingi) Surfacepreparation Remove oil/grease by useof petroleumhydrocarbon

solution (IS:1745) and Grit blasting to near white metal surface.

ii) Paint system: 2 coats of epoxy zinc phosphate primer 60 micron Total5 coats= 200 micron

b) Conventional Painting System for areas where corrosion isnot severe

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Priming Coat

One heavy coat or ready mixed paint, red lead primer conformingto IS:102

or

One coat of ready mixedzinc chrome primer conforming to IS: 104followed by one coat of ready mixed red oxide zinc chrome primerconforming to IS:2074.

or

Two coatsof zinc chromatesred oxide primerconformingto IS:2074

Finishing Coats

Two cover coatsof red oxide paint conforming to IS:123 or anyother approvedpaint shall be applied over the primer coat. One coatshall be applied before the fabricated steel work leaves the shop. Afterthe steel work is erectedat site, the second coat shall be given aftertouching tip the primer and the cover coats if damagedin transit.

c) Conventional Painting System for areas where corrosion issevere

Primh~gCoat

Two coats of ready mixed red lead primer conforming to IS:102

or

One coat of ready mixed zinc chrome primer conforming to IS: 104followed by one coat of zinc chromate conforming oxide primer toIS:2074.

Finishing Coats :

Two coats of aluminum paint conforming to IS:2339 shall be ap-plied over the primer coat. One coat shall be applied before thefabricated steel work leaves the shop. After the steel work is erectedat site, the secondcoat shall be given after touching up the primer andthe cover coats if damaged in transit.

1906.4. Painting in the Shop

All fabricated steel shall be painted in the shops after inspectionand acceptancewith at leastonepriming coat, unlessthe exposedsurfacesare subsequentlyto be cleaned at site or are metal coated. No primershall be applied to galvanised surfaces.

485

Section 1900 StructuralSteel

Shop contact surfaces, if specifically required to be painted, shallbe brought together while the paint is still wet.

Field contact surfaces and surfaces to be in contact with cementshall be paintedwith primer only. No paint shall be applied within50mm of designedlocationof field welds.Paintshall be completelydriedbefore loading and transporting to site.

Surface not in contact but inaccessible alter shop assembly shallreceivethe fully specified protective treatmentbefore assembly.

Where surfaces are to be welded, the steel shall not be paintedor metalcoated within a suitable distance from any edgesto be weldedif the specifiedpaint or metal coating would be harmful to weldersoris expected to impair the quality of site welds.

Exposed machined surfaces shall be adequatelyprotected.

1906.5. Painting at Site

Surfaceswhich will beinaccessibleaftersite assemblyshall receivethe full specifiedprotective treatmentbefore assembly.

Surfaceswhich will be in contactafter siteassemblyshall receivea coatof paint (in addition to any shop priming) andshallbe broughttogether while the paint is still wet.

Damaged or deterioratedpaint surfaces shall be first made goodwith the same type of coat as the shop coat.

Where steel has receiveda metal coating in the shop, this coat-ing shall be completedon site soas to be continuous overany welds,bolts and site rivets.

Specified protective treatmentshall be completedafter erection.

1906.6. Methods of Application

The methods of application of all paint coatings shall be inaccordancewith themanufacturer’swritten recommendationandshallbe as approved by the Engineer.Spray painting may be permittedprovided it will not cause inconvenience to the public andis appropriateto the type of structure being coated. Areas hard to gain accesstofor painting and areasshaded for spray application shall be coatedfirst by brushing.

Oil based red lead primers must be applied by brush only, takingcare to work into all corners and crevices.

The primer, intermediate and finishing coats shall all be applied so


as to provide smoothcoatingsof uniform thickness.Wrinkled or blisteredcoatings or coatings with pinholes,sags,lumps or other blemishes shallnot be accepted.Where the Engineer so directs, the coating shall beremoved by abrasive blast cleaning and replaced at the Contractor’sexpense.

1906.7. Guideline of Specifications for Protective Coating

System in Different Environments

Since the seriousnessof the problem of corrosion depends uponatmospheric conditions and these vary enormously, there is no singleprotective system or method of application that is suitable for everysituation.

However, as a guide, broad recommendationsare given in Table1900-3 for various typesof coatingsin various environmental conditionswhich should be complied with, Approximate life to first maintenanceis also indicated and can be used as a guide.

TABLE 1900.3: RECOMMENDATIONSFOR TYPES OFPROTECTIVE COATINGS

i) Wire brush to remove all loose rustand scale; 2 coatsdrying oil typeprimer, 1 under coat alkyd typepaint; I finishing coat alkydtype. Total dry film thickness= 150 pin

ii) Wire brush to remove all looserust and scale 2 coatsdrying oiltype primer~2 under coatsmicaceousiron oxide (MXO) pigmentedphenolicmodified drying oil. Totaldry film thickness= 170 ~un

iii) Blast clean the surface; 2 coatsof quick drying primer~undercoat alkyd type paint; Ifinishing coat alkyd type.Total dry film thickness:130 - 150 pm

iv) Blast clean the surface; 2 coats ofdrying type oil primer, 1 undercoatmicaceousiron oxide pigmented dryingoil type paint. Total dry filmthickness: 165 - 190 ~tm

Environment

Suitable for mild conditionswhereappearanceis of someimportanceandwhere regular maintenance is intended,This systemmay deteriorate to a markedextent if it is exposedto moderateaggressiveatmosphericconditions forlengthy period

Similar to (i) but where appearanceis not very importantprovides longer lifein mild condition. Will provide upto 5yearslife to first maintenancein pollutedinland environment

Comparedto (i), this would provide alonger life in mild conditions arid couldbe usedin less mild situation e.g.inland polluted, where maintenancecould easily be caniedour atregular intervals

Suitable for general structural steelwork exposedto ordinary pollutedinland environmentswhereappearanceis not of primary importance.

System

487

Section 1900 StructuralSteel

v) Blast clean the surface; 2 coatsofmetallic lead pigmentedchlorinatedrubberprimer, I undercoat of highbuild chlorinatedrubber. 1 finishingcoat of chlorinatedrubber.Total dryfilm thickness 200 pm

vi) Blast cleanthe surface;350 - 450 pm thickness.coal tar epoxy.

vii) Pickle; hot dip galvanised(Zinc). Total thickness : 85 pin

viii) Grit blast, hot dip galvanised.(Zinc). Total thickness= 140 pan

ix) Grit blast; I coat of sprayedzinc/aluminum followed by suitable sealerTotal thickness= 150 pro

Suitablefor structuresin reasonablyaggressiveconditionse.g.nearthecoast.Will provide long-term protection than(iv) in non-coastalsituations.Alsosuitablefor aggressiveInterior situationssuchas industrial areas.

Suitable for seawater splashzonesor for conditionsof occurrenceoffrequentsalt sprays.

Suitable for steel work in reasonablymild conditions Life of 15-20 yearsbefore first maintenancecould beexpectedin many siwations

Provides a longer life than (vii)becauseof thicker zinc coating

Expectedto provide long termprotection approx 15-20 yearsin aggressiveatmosphere


The materials .shall be tested itt accordance with relevant IS speci-fications and necessary test certificates shall be furnished. Additionaltests,if required, shall be got carried out by the Contractor at his owncost.

Thefabrication,furnishing, erecting,painting of structural steel workshall be in accordance with these specifications and shall be checkedand acceptedby the Engineer.


The measurementsof this Item shall be in tonnes basedon the netweight of metal in the fabricated structure computed on the basis ofnominal weight of materials.

The weight of rolled and cast steelandcast iron shall be determinedfrom the dimensions shown on the drawings on the following basis

Rolled or cast steel : 7.84 x 1O~kg/cu. cm.

Cast Iron 7.21 x IO’ kg/cu. cm.

Weight of structural sections shall be nominal weight

Weight of castings shall be computed from the dimensions shownon the drawings with an addition of 5 per cent for fillets and over-runs.

488

StnscturalSteel Section1900

Weight of weld fillets and the weight of protective coatingsshallnot be included.

Weight of rivet headsshall be computed by taking the weight of100 snap heads as given in Table 1900-4.

When specially agreed upon, allowance for snap headsmay be takenas a flat percentageof the total weight. This percentage may be takenas 3 per cent or modified by mutual ~greement.

TABLE 1900-4 WEIGHT OF RIVET HEADS

Din or Rivet as manufacturedmm

Weight of 100 snap headskg

12 1.314 2.116 3.418 4.4520 6.122 8.124 10.527 15.030 20.533 27.2

The Contractor shall supply detailed calculation sheetsfor the weightof the metal in the fabricated structure.

No additions shall be made for the weight of protective coatingor weld fillets.

Where computed weight forms the basisfor payment, the weightshall becalculatedfor exact cut sizesof membersused in the structure,deductions being made for all cuts, except for rivet holes. Additionsshall be made for the rivet heads as mentionedabove.

When specially agreedupon, the basis for payment may be thebridge weight complete, according to specificationsincluded in specialprovisions of the Contract.

1909. RATE

The contract unit rate for the completedstructural steel work shallinclude the cost of all materials, labour, tools, plant and equipmentrequiredfor fabrication,connections,oiling, painting,temporary erection,inspection, tests and complete final erection as shownon the drawingsand as specified in these Specifications.

489

Bearings

2000

Bearings

Bearings Section 2000

2001. DESCRIPTION

This work shall consist of furnishing and fixing bearings in positionin accordance with thedetails shown on the drawings,to the requirementsof these specificationsor as directed by the Engineer.

2002. GENERALi) Bearing plates, bars, rockers,assembliesandotherexpansionorfixed devicesshall

be constructedin accordancewith the detailsshownon the drawings.

ii) Thebeanngsmayeitherbe supplieddirectly to the Engineerby the manufacturerto be installedby the Contractoror the Contractoris to supply and install shebearings as part of the contract.In the formercue, the manufacturershall beassociatedwith the installation of the bearings to the full satisfactionof theEngineer,whereasin the latter case,the Contractor shall be solely responsiblefor thesatisfactorysupply and installation of thebearing,Inthedetaileddescriptionof the specification, a general reference shall be made to the Contractor ormanufacturerand the interpresarionshall be as per termsof contract.

iii) The Contractorshall exercise the utmostcare in setting and fixing all bearingsin their correctpositions and ensuringthat uniformity is obtainedon all bearingsurfaces.

iv) Bearings shall be handled with care and stored under cover.

v) When bearingassembliesor plates are shown on the drawings to be placed (notembedded)directly on concrete, theconcretebearing area shall be constructedslightly above grade (not exceeding 12 miss) and shall be finished by grinding.

vi) It shall be ensuredthat thebearingsareset truly level and in exactpositionas indicated on the drawings so as to have full and even bearing on theseats. Thin mortar pads (not exceeding12 miss) may evenbe made to meetwith this requirement.

vii) It shall be ensured that the bottoms of girders to be rtceived on the bearingsareplaneat the locations of thesebearingsandcareshall be takenthat the bearingsare not displaced while placing the girders.

viii) MS. bearings sliding on M.S. Plates shalt not be permitted. For sliding platebearingsstainless,steel surfacesliding on stainlesssteelplatewith mild steelmatrixshell be used. The other option shall be to provide PTFE surface sliding onstainless steel.

ix) Some typesof bearings which have been successfullyused in various bridgesin India have been covered by these Specifications. For innovative types ofstructuresor in specialcases, special types of bearingsto suit the requirementsmay have to be provided for which special specificationsmay be laid downbythe Engineer.

2003. STEEL BEARINGS

2003,1. Materials

The material for steel bearingsshall conform to the requirements

493

Section2000 Bearings

of Section 1000. Some additional requirementsfor materials for steelbearings are indicated below

a) Railway axles (R 19) are also acceptable as forged steel for rollers.

b) For the purposeof checkingthe soundnessof cast steelcomponents, castingsshall be ultrasonically examined following proceduresas per 15:7666 withacceptancestandard as per IS:9565. The castings may also be checked by anyother acceptedmethod of non..destnsctive testing as specified in 15 1030.Quality level of castings shall be level 3 as per iS:9565.

The grease forbearingsshall conform to the requirements of IS:503(Grade 4).

2003.2. Construction Operationsa) All work shall conform strictly to the drawings and shall be in accordance with

the provisions of this section.Care shall he taken to ensure that all parts of anassembly fit accurately together. The workmanshipshall satisfy all relevantprovisions laid down in Section 1900.

b) Knuckle pins, rolling surfacesof the rollers and bearingsurface of the bearingplatesshall be machinedand all bolt holesshall be drilled. The whole bearingsshall be fitted and finished as required for good quality machined work to thesatisfactionof the Engineer.However,in caseof bearings which are to be grousedor bedded on a suitable yielding material on any surfacewhich is to be inpermanentcontact with the grout or the yielding material may be left unmachined.

c) In prestressed concreteconstruction where launching of girders is employed,in orderto avoid slipping or jumping of rollers due to vibeation or jolts, adequatemeasuresmay be taken to ensurethat the roller assemblyis not disturbed. Itis normal practice to provide rockerbearings on the launching end and placeUse beam on the rocker end slightly in advance of placing on the roller.

d) During concretingof girders,the bearingsshall be held in position securelybyproviding temporaryconnectionbetween the top and bottom plates in caseoffixed bearings and betweentopplate, baseplate and saddleplatein caseof roIler~cum-rocker bearing or by any other suitable arrangement which prevents therelative displacement of the components.

e) In prestressedprecast girders, where recessesare left on the underside of girdersto receive the anchor bolts, grout holes extending to the beam sides or to thedeck level shall be provided. The cement sand grout shall have a mix of 1:1.

2003.3. Workmanshipa) Fabrication shall be carried out by an organisation experiencedand qualified to

undertake precision engineering of this type and be approved by the Engineer.

h) Workmanship shall be of good quality, neatly finished and of good appearance.

c) Castings shall be tnseto the forms and dimensionsshown on the drawings andshall be free from pouring faults, sponginess,cracks,blow holesandother defectson position, affecting their appearanceor strength. Warped or distorted castingswill not be accepted.Exposedsurfacesshall be smooth and dense.

494

Bearings Section2000

d) All castings shall be cleanedby sand or shot blasting to remove sand or scaleand to present a cleanuniform surface.

e) All irregularities,fins or risers shall be groundoff flush with the adjacentsurface.Castings with visible cracks, blow holes or similar blemishesshall be rejectedif the imperfections are located in bearingsurfacesor cannotbe remedied tothe approval of the Engineer.

1) imperfections which are not located in bearing surfacesshall be cleanedout,filled with weld metal of the appropriatecomposition and ground flush.

g) All surfacesof major componentslike top plates, saddleplates,baseplates,rollersof thebearingsshall be machined all over for correct alignment, interchangeability,proper fitting, etc.

2003.4, Tolerances

Tolerancesfor its individualcomponentsor of the assembledbearingsshall be as shown on the drawingsor subject to the approvalof theEngineer.

Unless otherwisespecified,the following tolerancesshall bemain-tained

Diameter of Rollers, Knuckle Pins and BoresTolerances on diameterof rollers and all convex surfaces shall

conform to K7 of IS:919.Tolerances on diameterof a]] concavesurfacesshall conform to

D8 of IS:919.

Height of Bearings

Tolerances on heightof any componentcastingshall not exceed+0.5mm. No minus toleranceshall be allowed. The edgesof all ribsshall be parallel throughout their length.

Base Plate

Toleranceon length and width of the baseplate shall not exceed+1.0 mm, toleranceon the thicknessof the plate shall not exceed+0.5 mm. No minus toleranceshall be allowed. All rocking, rolling andsliding surfaces shall have a machine smooth finish to 20 micronmaximum mean deviation as per IS:3073.

Castings

No minus toleranceshall be allowed in the thicknessof any partof the castings. The edgesof all ribs shall be parallel through-out their length.

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2003.5. Installation of Steel Bearings

2003.5.1.Generala) Bearings shall be placed in the positions as shown on the drawings with all

bearingsurfaces in full contact and to the tolerancesas specified.

b) Roller and rocker bearings shall be placed so that their axles of rotations arehorizontalandnomial to thedirection of movementof themembersthey support.Upperand lower bearing plates shall be set horizontal in both directions.

c) During installation the bearings shall be pre.set with respect to thebearingaxis to accountfor the movement due to the following

i) Temperaturevariation betweenthe averagetemperatureprevailingat the timeof installation and the meandesign temperature.

ii) Shrinkage, creep and elastic shortening.

d) For bridges in gradient, the beanngplatesshall be placed in a horizontal plane.

2003.5.2. Placinga) On supporting stmctures, pockets shall be provided to receiveanchor bolts;

one side of the pocket shall project beyond the bearingplate. The pocket shallbe filled with mortar of mix li andtheconcretebearingarea also shall be finishedlevel by a thin and stiff mortarpadof mix 1:1 (the thickness not exceeding12mm) just beforeplacingof bearing assemblies or bottom plate on theconcreteseat.

b) in caseof precastgirders a recessof 6 mm shall be provided on the undersidewith a level fsnish for housing the beatingplate. A thin and stiff mortar padof mix 1:1 with thickness not exceeding 3 mm shall be provided over thetop plate before lowering the precastbeam in position in order to ensure fulland even pressure on the plate surface.

c) It shall be ensuredthat while placing the girders, thebearingsare in their exactpositions as indicated on the approved drawing and not displaced therefrom.

d) All concretesurfacesto be in contactwith the mortarshall be thoroughly cleanedandkept saturatedwith water for a period not less than24 hours beforeplacingmortar and operations are to be carriedout when the surfacetemperaturesofthe exposed bearingsare the minimum practical.

e) No ntortar that is more than 30 minutes old after completion of mixing, shallbe used.

f) After placingand finishing the mortar,thebearingshall be checked for positionand shimsor other temporarysupportsremovedandthe mortar made good. Ifthe bearing has moved, it or the plate shall be lifted, the mortar removed andthe whole procedure repeated.

g) Exposed faces of the mortar shall be cured under dampHessian for 7days.

h) Placing of the bearingand mortar shall only be carried out in the presenceofthe Engineer.


2003.5,3. Checking, cleaning and lubrication : Before erection,each bearingshallbe uncrated, disassembledandchecked.Any damagedparts shall be made good for approval.

All bearings with sliding surfaces shall be cleanedand lightlylubricated with an approved lubricant immediately before erection.

2003,5.4.Testingi) The materialsto be used in the bearingsshall conform to the specifications

laid down in clause2003.1.

ii) If inquired, a suitablenumberof complete bearings asspecifiedby anacceptingauthorityshall be testedto 1.25 times thedesignload. Recoveryshouldbe 100per ceent. Contact surfacesshall be examinedby illumination sourcefor anydefects,cracks, etc. Segmentalrollers shall be tested for design movements.

iii) For largelots (consistingof 12 sets or more), a quality control report shallbe submittedas detailedbelow:

a) Unless otherwise agreed upon by the Engineerand the manufacturer,the latter shall furnisha completereport on theprocessof quality control.The Engineermay appointanauthorisedinspectionagency for inspectionpurposeon his behalf. Suchan inspectionagencyshall alsosubmit reportsto the Engineerregardingvarious testsperformedon thebeating or certifythe acceptanceof the beatings.

b) Test certificatesof all raw materialsshall be submitted.If manufacturer’stest certificatesarenot availablefor the rawmaterials,the bearingsmenu.facturershallperformthe necessaryconfirmatory testsas per relevantcodesof practice and shall furnish the test results.

c) A detailed quality control system induding stage by stage inspection,starting from rawmaterialsupto the finished bearingshall be submittedbythe bearingmanufacturer.

d) The Engineershall reserve the right to witness suchinspectionat manu~facturer’s works with or without prior permissionof the manufacturer, Forthis, the beatingmanufacturershall have in.plant testing facilities as faras possible and practicable.

e) The bearing manufacturershall maIntain a list of consumption of rawmaterial for a period of at least previous one year.

0 Test certificatesof bearingsmanufacturedduring precedingone year shallbe madeavailable at the manufacturer’sworks.

g) In case the lot size of similar bearingsexceeds12 sets as per the directionof the Engineer,one extra set of bearings for each 24 sets of beatingsor part thereof, shall be manufactured and the cost of suchextra bearingsshall be borne by the user.

h) The Engineer shall selectthe extra bearing(s) at random and shall performvarious tests including destructive testing on it at his discretion, either atthe manufacturer’s works or at any other approved test laboratory,notwith.standing the test reports submitted.

497


i) In case there is a major discrepancy regarding material, the engineer shalldeclare the whole lot of bearings as unacceptable.

j) In case minor defects in fabrication, like welding or machining, is foundin the test bearing before destructive testing and if the test hearing is foundto he acceptableafter destructive testing, the minor defects in the testbearings shall not he a bar to the acceptanceof the entire lot.

k) The opinion of the Engineer in cases (i) and (3) above shall be binding onthe manufacturer.

2004. SPECIAL BEARINGS

2004.1. Spherical Bearing

This bearingonly takescareof vertical load and horizontal forcedue 10 sliding friction. The bearing will permit uniaxial translatorymovementalong longitudinal axis of the bridge and rotation alongallaxes.

The bearing shall consist of the following pacts

Bottom Plate

A bottom plate with concavesurface is integrally cast on circular!squareplate. The bottom plate is connected to the sub-structure bymeansof tight fitted anchorbolts, which are embeddedin concrete.The material of bottom plate shall be cast steel.

Pure unfilled quality dimpled PTFEof specifiedthicknessshall beprovided on top of concavesurface of bottom plate in order to allowsmooth rotation.

Saddle Plate

A saddleplate with square/circular/rectangulartop andconvexsurfaceat bottom shall be placedin the concave surface of bottom plate.The radiusof curvatureof the convexbottom of the saddle plate shallhe slightly less thanthat of theconcavetop surface of the bottom plateto enstiresufficient contactover a small area. Rotationalong all axesshall be permittedalong the contact surfaceof the saddleplate andwe bottom plate. Pure unfilled quality dimpled PTFE sheet shall berecessedto specified depth of recessover the top of saddle plate.Suitableelastomericsealshall beprovidedon the saddleplate to preventingressof dirt and moisture.The material of saddleplate shall be caststeel.

Top Plate

The top plate shall havestainlesssteelplate welded to its bottomwhich shall slide over PTFE. The assembly shall be connected to

498


the superstructure by tight fitted anchor bolts. Translatorymovementsalonglongitudinalaxis of bridge shall be accommodated at the PTFE/Stainlesssteel sliding surface. The materialof top plate shall be caststeel.

Guide Plate

Guide Plates shall be welded to saddleplate so as to permit onlylongitudinal movement. The material of guide plates should be caststeel.

2004.2. Pin Bearing

Pin bearing shall ensure fixity by arresting translatorymovement.The pin bearing shall not take any vertical load, It will take care ofthe longitudinal horizontal force of the entire superstructure unit aswell as transverse horizontal force developed at the fixed end.

A pin bearingshall consistof ashortheightstructuralbuilt-upcolumnembedded in pier cap and the protruding length inside soffit of deckshall have rocker plateson all four sides, which permit rotation.

Pin bearingshall resist horizontal forcefrom any direction andwillpermit rotation but will not bearanyvertical load. The material ofpin bearingincludingrockerplatesshall be high tensilesteelconformingto IS:961.

2004.3.In generalthe slidingsphericalandpin bearingshallconformto BS:5400,Parts9.1and9.2andall relevantclausesof this specification.Bearingsshall be guaranteedfor designloadsandmovements.The termbearingshall include the entire assemblycovering all the accessoriesrequired for operation, erectionand dismantling for replacement.Allbearings shall be of replaceabletype~These bearings should bebased on their design to the specifications mentioned/internationalspecifications.The manufacturer shouldget their designapproved fromappropriate authority and the manufacturer should be associatedwith installation of bearings.

2004.4. Materials

All materials, particularly the following, shall be original, unusedor non-re-cycled conforming to relevant specifications

Cast Stcel~Mild Steel, StainlessSteel shalt conform to Clause2003.1.

- Copolymer Poly Tr~r*Fluora Ethylene (FIFE) unfittedquality shall have requiredpropertiesas per BS:5400 and thickness shall be as specified.

Anchor Bolts shall be as per relevant IS specifications.

499


2004.5. Seating of Pin Bearing

i) Backingplatewith studsweldedon thefaceoppositeto theseatingof manufactureshill be deliveredby themannfacnner.

ii) This backing plateshall be aecuraretypositionedon thereinforcementgrid ofthe pedestaland IevdletL

iii) Studsshalt be tack welded/tiedso the reinforcementto keep the backing plate

inpruperlocation during casting.iv) Depth of embecknent of the backingplate in the concreteshall be as per

relevantdrawing.

v) The mundbaseof thepot(bottom) of thepin beatingassemblyshallbe connectedto thebacking pLates by anchorscrewsafter concretingof tier cap/pedestal.

vi) In order so ensure’successfultranth~rof large horizontalforces so be resistedby the Pin bearing,greatcare shall be taken in desaihngthe reinforcement inthesub.stnrcsurcandthe super-structureadjacentto the studsin the backingplate.

2004.6. AcceptanceTest on SphericalBearings1. ALl bearings shalt be checkedfor overall dimensions

2. All bearings shall be load tested to 1.25 limes designvertical load

3. A pair of bearingsselectedat random shall undergotestingin order to determinecoefficient of friction which shall be less than01)5.

4. Two beatingsselectedat randomshall be testedfor pennissiblemeanon.

2004.7. Acceptance Test on Pin Bearings1. All bearingsshall be checked for overall dimensions.

2. ALl bearings shalt be load tested (if required,for design horizontal load only)

2005. ELASTOMERIC BEARINGS

The term “bearing” in this caserefers to an elastomeric bearingconsistingof oneor more internal layers of elastomerbonded to internalsteel laminatesby the processof vulcanisation. The bearingshall caterfor translationand/orrotationof thesuperstructureby elasticdeformation.

2005.1. Raw Material

Chloroprene (CR) only shall be used in the manufactureof bear-ing.

Gradesof raw elastomerof proven use in elastomeric bearings,with low crystallization rates and adequateshelf life (e.g. NeopreneWRT, Bayprenelit), SkypreneB-5 and Denka S-40V) shall be used.

No reclaimedrubber or vulcanized wastesor natural rubber shallbe used.

The raw elastomercontent of thecompound shall not be lower than

500


60 per cent by its weight.The ash contentshall not exceed5 percent.(as per testsconductedin accordancewith ASTM D-297, sub-section10).

EPDM andother similar candidateelastomersfor bridge bearinguseshall not be pennitted.

Properties

The elastomershall comform to the propertiesspecified in Table2000.1

TABLE 200e.l.PROPERTIESOF ELASTOMER

Propcrtly UnIt Test Method, IS Value of thespedftcatlcsa cbaracteristkreference • spedfled

Physical Prupesties

1.1. Hardness IRHD IS:3400 60 + 5(PastIi)

12. Minimum Tensile Ml’s IS:3400 17Strength (PanI)

1.3. Minimum Elongation Per cent IS:3400 400atbreak (Part!)

2. Max ~mwn CompressionSet Per cent IS:3400

(PartX)duration temperature(h) (deg C)+Oto 100±1 35242

3. AcceleratedAgemgIS:3400(Pastry)duration temperature(h) (dcgC)

CR 70 l00~1

3.1 Max changeinHardness IRHD +15

3.2. Max change in Percent .15Tensile Strength

3.3. Max changeinElongation Per cent -40

Shear modulus of theelastotherbearingshall neither be less than0.80 MPa nor greaterthan 1.20 MPa.

The adhesion strength of elastomer to steel plates determined

501


according to IS:3400 (Part XIV) method A shall not be less than 7kN/m.

For elastomericbearings(CR) used in adverseclimatic conditionsthe following ozone resistancetest shall be satisfied

The ozoneresistanceof elastomershall be provedsatisfactory whenassessedby testaccordingto IS:3400(Part XX). The strain, temperature,duration and ozone concentration of the test shall be 20 per cent,40 ~ I degreeCelsius, 96 h and 50 pphm by volume respectively,

No cr~ickingdetectedby visual observationat the end of the testshall be consideredsatisfactory.No specific tests forassessmentof lowtemperatureresistance may be deemednecessary.

NOTE : For useof elastomerin extremecold climates, theEngineermay specify special grade of low temperatureresistant elastomerin conformitywith operatingambienttemperatureconditions.The sped.fications of such special grade elastomer including the tests for lowtemperatureresistanceshall be mutually agreedto by the Engineer andthe producersupplierandareoutsidethe purview of thesespecifications.

Laminates of mild steel conformingto IS:226shall only be per-mitted to be used. Use of any other material like fibre glassor similarfabric as laminatesshall not be permitted.

The manufacturersof elastomericbearingsshall satisfytheEngineerthat they havein-housefacilities for testing theelastomerfor carryingout the following tests in accordancewith the relevantprovisions ofASTM D-297.

a) Identification of polymers to confirm the usageofChioroprene(Appendix X-2)

b) Ash content test to determinethepercentage(sub-section34)

c) Specific gravity test : (tub-section15)

d) Polymer content test : (sub-section 10)

The Engineershall invariably get the test (a) performedwithin hispresenceor in the presenceof his authorisedrepresentativeto satisfythe requirement.In caseof any disputesregardinginterpretationof resultstheEngineermay carry out testasper ASTM S-3452-78(Chromatographytest) at the manufacturer’scost in a recognisedtest house.

The elastomerspecimento conductthe Lest shall be obtainedfromthe bearingsselectedat random for destructivetest. Remainingpartof the test bearingshall be preservedby the Engineer for any Lest tobe done in future, if required.

502


2005.2. Fabrication

Bearingwith steellaminatesshallbe castas a single unit in amouldand vulcanised under heat and pressure.

Casting of elementsin separateunits and subsequentbondingshall not be permitted,norshall cutting from largesizecastbe permitted.

Bearingsof similar size to be usedin particularbridge projectshallbe producedby identical processand in one lot as far as practicable.Phasedproduction may only be resortedto when the total numberofbearings is large enough.

The moulds used shall have standardsurfacefinish adequatetoproduce bearingsfree from any surface blemishes.

Steel platesfor laminatesshall be sandblasted,clean of all millscales and shall be free form all contaminants prior to bonding byvulcanisation.Rustedplateswith pitting shall not be used. All edgesofplates shall be rounded.

Spacers used in mould to ensurecoverand location of laminatesshall be of maximumsize andnumberpracticable. Any hole atsurfaceor in edgecover shall be filled in subsequently.

Care shall be taken to ensure uniform vulcanising conditions andhomogeneity of elastomerthroughthe surfaceandbody of bearings.

The bearingsshall be fabricated with the tolerances specified inTable 2000-2.

TABLE ~.2 TOLERANCES

ITEMS TOLERANCES

Overall plan dimensions -0, + 6 mm2. Total beaiing thickness -0, + 5 mm3. Parallelisma) Of top surfaceof bearing with

respect to the bottom surface as datum I in 200b) Of one side surfacewith

respectto the other as datum 1 in 1004& Thicknessof individual internal ±20 per cent (max. of 2 mm)

layer of elastomerb) Thicknessof individual outer layer .0, + 1 mm5a. Plan dimensions of laminates -3mrn,+0b) Thickness of laminates ~l0 per centc) Parallelism of laminatewith

respectto bearingbase as datum 1 in 100

503

Section2000 Beatings

The vulcanising equipmen~ressshall be such that between theplattens of pressthe pressure and temperature are uniform andcapableof being maintained atconstantvaluesas required for effecting a uniformvulcanisationof the bearing.

The moulding dies utilised for manufacturing the bearings shallbe so set inside the platten of the pressso that the pressuredevelopedduring vulcanisation of the product is evenly distributed and thethicknessmaintained at all placesare within acceptable tolerance limitstaking into consideration the shrinkage allowance of valcanizate.

The raw compoundwhich hasbeenintroduced inside the metal diesfor vulcanisation shall be accurately weighed each time and it mustbe ensuredthat sufficient quantity hasbeenput inside the die for properflow of material at every place so that a homogeneousandcompactbearing is produced without any sign of sponginessor deficiency ofmaterial at any place.

Before any vulcanizate of any batch of production is used forproducing vulcanised bearings, test pieces in the form of stand-ard slabandbuttons shall be preparedin accordancewith prescribedstandardsand salient propertiestestedand recordedregularly againsteach batch of j~oductionto monitor the quality of the products.

2005.3. AcceptanceSpecifications

The manufacturershall haveall the test facilities required for theprocessandacceptancecontroltestsinstalledathis plant to the completesatisfaction of the Engineer.The test facilities and their operationshallbe open to inspection by the Engineeron demand.

All acceptanceand processcontrol testsshall be conductedat themanufacturer’splant.Cost of all materials, equipmentandlabour shallbe borneby the manufacturerunless otherwisespecified or speciallyagreedto betweenthe manufacturer and Engineer.

Acceptancetesting shall be commencedwith the prior submittaloftesting programmeby the manufacturerto the Engineerand afterobtaining his approval.

Any acceptance testingdelayedbeyond 180 days of productionshall requirespecialapprovalof the Engineerand mOdified acceptancespecification, if deemed necessaryby him.

All acceptancetesting shall be conducted by the inspector withaid of the personnelhaving adequateexpertiseandexperience in rubber

504


testing provided by the manufacturer, working under the supervisionof the Inspectorand to his complete satisfaction.

Lot by lot inspection and acceptanceshall be made.

2005.3.1.Acceptancelot : A lot under acceptanceshall compriseall bearings,including the pair of extratest bearingswhere applicableof equal or near equalsize produced under identical conditions ofmanufactureto be supplied for a particular project.

The size andcomposition of acceptancelot shall be got approvedby the Engineer.

For the purposeof gradinglevelsof acceptance,testing lots shallbe classified as follows

i) A lot size of 24 or larger numberof bearingsshall be definedas a large lot

ii) A lot size of less than 24 bearingsshall be definedas a small tot

When the numberof bearingsof equal or near equalsize forasingle bridge project is large and phased productionand accept-ance is permitted,the number of bearingssuppliedin any single phaseof supply shall comprisea lot under acceptance.When such phasedsupply is made, each such lot shall be consideredas a large lotfor the purposeof acceptance testing.

2005.3.2.Levelsof acceptanceinspection : The level of acceptancetesting shall generallybe graded into the following two levelsdependingon lot size

Level I acceptance testing

Level 2 acceptancetesting

Acceptance testing Level 1 is a higher level inspection and shallbe applicable to large lots only, unless otherwise specified.This shallinvolve manufacture of two extra bearings for each lot to be used astest bearing and eventually consumed in destructive testing.

Acceptance testing Level 2 shall be applicable to small lotsonly, (i.e. less than 24 lots) for which one extra bearing shall bemanufactured.Out of the lot one bearing shall be selecled at randomfor carrying out material tests.This bearingshall be excluded fromthe lot accepted.

Acceptance inspection level 1 maybe specifiedat the solediscretionof the engineer taking into account the specialimportance of bridgeproject for small lots also under the purview of special acceptance

505


inspection.The cost of extrabearings, in suchcasesshall be borneby the user, while the costof all othermaterials,equipmentandtestingshall be borne by the manufacturer.

2005.3.3, Testing : Acceptancetesting shalt comprise general in-spection, test on specially mouldedtest pieces and test on completebearings or sections for measurementof variousquality characteristicsdetailed below

2005.3.3,1.Acceptancetesting level I

General InspectionAll bearings of the lot shall be visually inspected for any defects in surfacefinish, shapeor any other discernible superficial defects.

2. All bearings of the lot shall be checked for tolerances specified in Table 2DO0~2.

3. All bearings of the lot shall be subjectedto axial load to correspond to ~m(i.e. average compressivestress) = 15 MPa applied in stepsandheld constantwhile visual examination is made to check for discernible defectslike

a) Misalignment of reinforcing plates

b) Poor bond. at laminate/steelinterface

c) Variation in thickness of elastomer layers

d) Any surface defects

e) Low stiffness

Deflection under loadsbetweenom=5 MPa and~m=l5 MPa shallbe measuredand recordedfor all bearingswith sufficient accuracy(~5 per cent), Variation in stiffness of any individual bearing from themeanof the measuredvaluesfor all such bearings of the lot shall notbe larger than 20 per cent (of the mean value).

Tests on specially moulded test pieces1. Test pieces shall be moulded by the manufacturer with identical compound

and under identical vulcanising conditions as used in the manufacture of thebearings of the acceptance,lot, The process shall be open to inspection by theEngineer.

2. Test piecesoffered for inspection shall be identified by suitable markings andduly certified by the manufacturer.

3. The quality characteristics to be tested are listed below. The specificationreferencesin parenthesisshall define the corresponding specification for testpiece, test method and criterion for acceptance.

Composition(see Note I below)Hardness (Table 2000-1 , 1.1)

506


Tensile strength (Table 2000-1 , 1.2)Elongation at Break (Table 2000-1 , 1.3)Compression Set (Table 2000-1 , 2)AcceleratedAgeing (Table 2000-1 , 3)Adhesion Strength(Clause2005.1)OzoneResistance(seeNote 2 below)

Note I.

For acceptancetestingthe propertiesenumeratedin Clause2005.1andspecific gravity of elastomerof test piecesfrom test bearingshallbecomparedwith thosefor correspondingspecially mouldedtest piecesfurnished by themanufacturer.Thefollowing variationsshallbedeemedmaximum acceptable

Specific Gravity ± 0.2

Ash Content ±0.5 per centHardness(Table 2000-1 , 1.1)Tensile strength (Table 2000-1 , 1.2)Elongation at Break (Table 2000-1 , 1.3)CompressionSet (Table 2000-I , 2)AcceleratedAgeing (Table 2000-1 , 3)Adhesion Strength (Clause 2005.1)

Note 2.

Ozone resistancetest can be waived by the Engineerfor bearingsof CR when satisfactoryresultsof ozone resistance tests on similargrade of elastomermay be availablefrom process control records ordevelopmenttest data furnished by the manufacturer.

Where such process control data are not available or thefrequency of testing~not deemedadequate, ozone resistance test shallbe mandatory for acceptanceof bearings of CR.

However, such tests may not be insisted for bearings not locatedunder adverse conditions of exposureand where the test on accel-erated ageingcould be consideredas adequate.

Process and acceptancecontrol tests for ozone resistance by anindependent testing agency shall be acceptable.

Tests on Complete Bearings or SectionsI. Two bearings thall be selectedat random from the lot as test bearings. These

bearingsshall be excluded from the lot accepted.

507


2. The following tests shall be conductedon test bearings

Test for determination of shearmodulusTest for detennination of elastic modulusTest for determination of shear modulus (short teim loading)Test for determination of adhesionstrengthTest for determinationof ultimate compressivestrength

The testspecificationsandacceptancecriteria shall conform to those~given in Appendix 2 of IRC:83 (Part II).

2005.3.3.2. Acceptance testing level 2

General Inspection.This shall conform to the provision in Clause2005.3.3.1 in all respects.

Test on specially moulded test pieces.This shall conform to theprovisions in Clause2005.3.3.1 in all respects.

Test on complete bearings. Test for determination of shearmodulus shall be conducted using two bearings of the lot selectedatrandom and conforming to relevant provisions of Clause 2005.3.3.1.These bearings shall however be part of the lot accepted. Theremaining tests stipulated in aforesaid clause shall be carried out Ofl

all bearings selected at random which shall be excluded from thelot accepted.

2005.3.4. Special acceptance inspection : Special acceptanceinspection may comprise the following

1. Acceptance testing by an independent external agency with separate orsupplementaltest facilities provided by it.

2. Acceptancetesting on test piecespreparedfrom the surfaceor body of the testbearings instead of specially moulded test pieces.

3. Acceptancetests not coveredby these specificationsbut accordingto the speci-fications laid down by the Engineer.

Special acceptance inspection may be specified under the follow-ing conditions

a) Special contract agreement

b) Unsatisfactoryevidenceof process or acceptancecontrol

2005.3.5. Inspection certificate : A lot under inspection shall beacceptedby the Inspector and so certified, when no defect is foundwith respectto any of the quality characteristics tested on samplesdrawn from the lot according to specificationslaid down in Clause2005.3.3 covering general inspection tests on specially moulded testpieces and on complete bearings.

508


In caseof any bearing with defect, the lot shall be rejected bythe Inspector and so certified.

In case any bearing is found to be defective with respect toany quality characteristic, discerned by general inspection testsspecified in Clauses 2005.3.3.1 and 2005.3.3.2, tests on speciallymoulded test pieces and complete bearingsas applicable according toClauses2005.3.3.1and 2005.3.3.2 shall nevertheless be completed.If the said lot, rejected by general inspection,satisfies the acceptancecriteria in respect of these other tests, the lot and individualbearings found defective shall be àlearly identified in the inspectioncertificate,

The manufacturer shall obtain from the inspector,authorised bythe Engineer, immediately on completionof his inspection,an inspectioncertificatewhich shall include the detailsof alot or lots accepted/rejectedby him and records of all test measurements.

2005.3,6.Quality control certificate: The manufacturershallcertifyfor each lot of bearing under ac~eptance:

That an adequatesystem of continuous quality control was operat-ed in his plant.

That the entire processremained in control during the productionof the lot of bearings under acceptance as verified from the qualitycontrol records/chartswhich shall be open to inspection of Engineer/Inspector on demand.

A certifiedcopy of results of processcontrol testing doneon samplesof elastomerused in the production of the lot shall be appended andshall include at least the following information

Compositionof compound - raw elastomerahdash content, the gradeof raw elastomerused(including name, source,age on shelf), test resultsof hardness, tensile strength, elongation at break, compression set,accelerated ageing, etc.

A higher level certification of the processquality control shall becalled for at the sole discretion of the Engineer in special casese.g.where adequateinspection of bearings similar to those comprising thelot under inspection produced in the same plant is not availablewith the Engineer or in caseof any evidenceof processor acceptancecontrol being deemed unsatisfactory. The higher level certificationshall comprise submittal of a complete quality control report as given

509


in Appendix 3 of JRC:83 (Part II) supplementing the quality controlcertificate,

2005.3.7Acceptance The manufacturer shall furnish the followingto Engineer for the acceptancejudgement

Quality control certificate as lain down in Clause 200516.

2. Inspection certificate as laid down in Clause2O053.5~.

The manufacturer shall furnish any supplementaryinformation onthe system of quality control and/or process and acceptance controltesting as may be deemednecessaryby the Engineer.

In caseof any evidenceof processor acceptai~cecontrol testingbeing deemed unsatisfactoryby him, Engineer at his solediscretionmay call for a special acceptanceof the lot according to specificationslaid down by him, withoutany prejudiceto his right to reject the lot.The entire cost of such supplementary inspectionshall be borne bythe manufacturer.

The Engineershall be the sole authority for accep~anccof a loton scrutiny of the certificatesalongwith any supplementaryevidenceand complete satisfaction therewith.

In case of rejection of a lot, the Engineer shall reserve the right.to call for special acceptanceinspectionfor the succeedinglots offeredfor inspection,according to the specificationslaid down by him. Theenhire cost of such tightenedinspection shall be borne by the manu-facturer.

2005.4. Cerification and Marking

Bearings shall be transportedto bridgesite after final acceptanceby Engineer and shall be accompanied by an authenticated copy of thecertificate to that effect.

An information card giving the following details for the bearings,duly certified by the manufacturershall also be appended

Name of manufacturerDate of manufactureElastomergrade usedBearing dimensionsProductionbatch no.Acceptance lot no.Date of testing

510


Specific bridge location, if anyExplanation of markingsused on the bearing

All bearingsshall havesuitable index markingsidentifying the in-formation. The markings shall be madein indelible ink or flexiblepaint and if practicable should be visible after installation. Thetop of the bearing and direction of installationshall be indicated.

2005.5. Storage and l~andling

Each elastomericbearing shall be clearly labelledor marked. Thebearing shall be wrappedin a cover.They shall be packed in timbercrateswith suitable arrangementto preventmovement and to protectcorners and edges.

Care shall be taken to avoid mechanical damage, contaminationwith oil, greaseand dirt, undueexposureto sunlightand weatherto thebearings during transportand handling prior to and during installation.

2005.6. Installation

Installation of multiple bearingsone behind the other on asingle line of support shall be of identical dimensions.

Bearingsmust be placedbetweentrue horizontalsurfaces(maximumtolerance0.2 per cent perpendicularto theload) andat trueplan positionof their control lines markedon receiving surfaces(maximum tolerance± 3 mm).

Concretesurfacesshall be free from local irregularities (maximumtolerance±i mm in height).

Designshall be checkedfor theactual inclination in seating if largerinaccuraciesthan those specified are permitted.

For cast-in-placeconcreteconstructionof superstructure,wherebear-ings are installedprior to its concreting,the forms aroundthe bearingsshallbe soft enoughfor easyremoval.Forms shall also fit the bearingssnugly and preventany leakageof mortar grout. Any mortar contami-nating the bearings during concreting shall be completely removedbefore setting.

For precast concreteor steel superstructureelements,fixing ofbearing to them may be doneby applicationof epoxy resin adhesiveto interface,after specified surfacepreparation. The specifications foradhesivematerial,workmanship and control shall be approvedby theEngineer.Careshall be taken to guard against faulty application andconsequentbehaviour of the adhesivelayerasa lubricant.Thebonding

511


by the adhesive shallbedeemedeffectiveonly asa devicefor installationand shall not be deemedto securebearingsagainstdisplacement forthe purposeof design.

As a measureof ample safety againstaccidentaldisplacement,thebearingsshall be placedin a recessasshown in Fig. 9 of IRC:83 (PartII).

2005.7. Seating of Elastomerk Bearings on a Non-HorizontalPlane

Installation of elastomericbearingson a Non-Horizontal Planeshallbe as follows

I) Elastorneric bearings shall be deliveredwith MS backing platefastenedto thebearing from the manufacturer.

ii) Template of 6 mm M.S. plateandof sizesameas bearing holding base platewith matchingholesfor the anchorscrewsshall beused.Anchors shall be finedto thetemplateswith theanchorscrewsbut with MS washersin placeof elastomerwashers.The above template assemblyshall be fitted in the fomtwork at itsproperlocation and in a vertical plane.

iii) After casting of the pedestaland removal of the fonnwork, the template is tobe removed.

A. Installation with race plate and without templateb-situ castingI) The sub-assemblyof elastomericbearingwish theMS backingplateshall be fitted

to the embedded anchorswith anchor screwsand elastomericwashersreplacingthe steel washer.

ii) A clearanceis requiredbetweenthestainlesssteelface ofthe eleazomencbeatingand that of the vertical face of the face plate with stainlesssteel top installedon theprojection belowthe soffit. This shaltbe achievedby inserting removablesteelsheetingof thicknessasper thedrawing,duringpreparationof the formworkbefore casting of the superstnremre.

iii) The face plate with stainless steel top and packplate shall beassembled withthe anchorswith elastomeric washersandanchorscrews. The assembly shallbe fined in the formwork at its proper location and in a verticalplane. Theremovable steel shims shall be removedat an appropriatetime after the castingof the super-strocture.

B, Installation with face plate and with template in-situ castingi) Templateof 6 mm MS plateand of size sameas face pimp with stainless steel

top and matchingholes for the anchorscrewsshall be used.Anchors shall befitted to thetemplateswith the anchorscrewsbut with MS washersin placeof elastoiner washers.Separatescrewsmay be used in caseof inconvenienceof in thelength of original anchorscrews.Theabovetemplateassemblyshallbe fitted in the fonnworic for the super-stroctureat its proper location and ina vertical plane.

ii) After removal of the superstructurefonnwosk, the templateshall be removed.

512


iii) The face plate with the requiredthicknessof pack plate shall be loosely fittedto theanchorsembeddedin theprojectionbelowthe superstmcture,with elastomerwashers and anchorscrews.

iv) The sub-assemblyof elastomeric beatingwith the MS backing plate shall befined to the embeddedanchorsin the pedestalwith anchorscrewsandelastomericwashers replaang the steelwasherthis time.

v) The required clearancebetweenthettainlesssteel face of the elastosnericbearingandthat of the vertical face plate installed on the projectionbelow the soffitshall be checked.After adjustmentof the requiredworking clearancethe smallgap betweentheverticalface of the prcpectionbelowthe soffit andthe backof the faceplate (with packplates, if any) shall be groutedwith epoxy grout.

2006. POT BEARINGS

2006.1. General

2006.1.1.Pot typebearings shall consistof a metal piston supportedby a disc or unreinforcedelastomerconfinedwithin a metal cylinderto take care of rotation. Horizontal movement, if required,shall’ witha systemof sealingrings be providedby sliding surfacesof PTFE padssliding againststainlesssteel mating surfaces. The pot bearingsshallconsistof cast steel assembliesor fabricatedstructuralsteel assemblies.

2006,1.2.Provisionsof IRC-83 (Part I) shall be applicable for allmetallic elements.Provisionsof IRC:83 (Part II) shall be applicablefor all elastomerelements.When any itemsarenot coveredby IRC:83(Parts I and II), the same shall be as per guidelinesgiven hereunderand BS:5400(Sections9.1 and9.2), exceptthatno natural rubber shallbe permitted. If there is any conflict betweenBS on the one handand IRC on the other, the provisions of IRC will be guiding.

2006.13.Cosliding element

mbinationbearingsusinganyjudicioshall be permitted. As for example

us combination and:

Name Ru~atlonElement

SlidingElement

Generally for

Pot Pot None Vertical Load

Elastomer Elastomer None* Horizontal Buffer

Pot PTFE Pot l9?E-SS~ Vertical Load andHorizontal Load

Spherical Spherical PTFE.SS~ Vertical Load andKnuckle PiPE Knuckle Horizontal Load

Elastoiner PTFE Elastomer FT?E-SS~ TransverseGuide

ElastomerSS~ Elastomer SS.SS’ TransverseGuide

Etastomershall permit movementby shear** StainlessSteel

513


For specialand innovativebridges, new combinationsbeyond whatis shown may be required. The samemay be usedg1~approval bythe Engineer.

200&2. Fabricationi) The surface mating with theFIFE in thesliding pair shall be corrosionresistant

stainless steel,Normally, the stainless steel shall form the uppercomponent.The stainlesssteel shall overlap the PTFFafter full movementon all sid~.Ifstainlesssteel sheetis used,it should be bondedby continuous weldingátongthe edges.Adhesiveor any otherbonding can be approvedby theEngineer.Thesurraceshall be preparedby thorough cleaning to remove grease,dust or anyother foreign substance.

ii) PiPE modularsheetsof the sliding pair shall be located by confinementassistedby bonding. ConfinedPTFE shall be recessedinto themetal backingplate. Theshouldersof the recess shall be sharpand squareto restrict thenow of PTFE.

iii) The thicknessof thePTFE shall not be less than 4.5 mm with projection abovethe recessnot exceeding2.0 mm. When the piston is subjectedto tilting, theseal must slide alongthe wall andalter its shapeaccordingto theangle of tiltAt the sametime, it must be sufficiently rigid to bridge the gap betweenthe piston and the wall of the pot. However,the percentageof plan area ofthe lubrication cavities to the gross area shall not exceed25 per cent. Thedepthof the cavity shall not exceed 2.0 mm.

iv) The diameterto thicknessratio of the confined elastomershall not exceed15.The surface of the confined elastomer shall be smooth.

v) A seal shall beprovidedto preventextrusion oftheconfmedelastomerbetweenthe piston and the pot wall, The seal should stay functional underthe loadsand rotations acting on it. Additional seal shall be provided to prevententryof dust! into the pot. Sealing rings for .pot bearingsshall be fabricatedfromstainlesssteel.When thepiston is subjected to tilting, thesealmust slide alongthe wall and alter its shape accordingto the angle of tilt. At the sametime,it must be sufficiently rigid to bridgethe gap betweenthepiston andthe wallof the pot,

vi) The hardness of the pistonand pot wall at their contact region shall beminimum 350 BHN to reduce wear. The surfacefinish of thepot baseincontact with the confined elastomershall be very smooth.

vii) All bearings shall be installed with anchor and anchorscrews or somesimilar devicesuch that while replacing, the bearingscan beremovedwithminimum lifting of the supersirueturt

viii) The extemal surfaces of the assembliesshall be completely cleanedby sandblasting. After sandblasting, dustshall be removedfrom thesw’faceusingcleananddry compressedair or a cleanbrush after which suitable coating shall beapplied.

ix) Pot bearingsincluding all parts as shownon the drawingsshall be fully shopassembledat the manufacturer’s works to ensureproperfitting of all parts.

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2006.3. Materialsa) Steel

i) Structural steel shall conform to 15:226 and 15:2062, as applicable.

ii) Cast steel shall conform to Cr 280-520W of 15:1030.0,3 to 0.5 per centcopper may be addedto increase the corrosion resistanceproperties.

ii) Stainlesssteel shall conform to AlS1:304 or XO4CrISNiIO of 15:6911 forordinary applications.For applicationswith adverse/corrosiveenvironment,the stainless steel shall conform to AlSt:316L or O2Crl7Nil2Mo2 of15:6911.

b) PTFE

PTFE (poly tetrafluoro ethylene)shall be of unfilled pure virgin quality. It shallbe free sintered.The mechanicalpropertiesof unfilled PiPE shall comply withGradeA of BS:3784.

c) Elastomer

‘ftc confined elastonser inside pot will have the following properties

a) Hardness IRlID 1S3400(Part II) 50 + 5

h) Mm tensile MPa TS:3400(Part 1) 15.5strength

c) Mm elongationat break,) shall be as per Table 2000-1Max compressionset and ) “Propertiesof Elastomer”Acceleratedageing

For other details, refer to Clause2005.1.

2006.4. Workmanship

2006.4.1. WeldingAll welding shall conform to IS:9595with electrodesof suitablegrade

as per IS:814. Preheatingand post weld stress relieving shall be doneas per TS:9595.

2006.4.2. Cast steel assemblies Cast steel for pot bearingassembliesshall conform to requirementsof relevant IS. Castingsshallhe true to the forms and dimensions shown on the drawings, andshall be free from pouring faults, sponginess,cracks,blow holes andother defects affecting their appearanceor their strength. Warpedordistortedcastingsshall not be accepted.Exposedsurfacesshallt;e smoothand dense.

All irregularities,fins or risers shall be ground off flush with theadjacentsurface. Castingswith visible cracks., blow holes, or similarblemishesshall be rejectedif the imperfections are located on bearingsurfaces or cannot be remedied to the satisfactionof the Engineer.

515


Imperfectionswhich arenot locatedon bearingsurfacesshallbe cleanedOut, filled with weld metal of the appropriatecomposilionandgroundflush with adjacentsurfaces.

2006.4.3.Structuralsteelassemblies:Defects arising from thefabrication of the steel shall be inspectedby the Engineer,who willdecidewhether the materialsmay be repaired by the Contractororwill be rejected.The cost of repairsor replacementshall be borne bythe Contractor.

All steel whether fabricatedor not, shall be stored above theground on platforms,skids,or othersupports,and adequatelyprotectedagainstcorrosion. Excessivelyrusted, bent or damagedsteel shall berejected.

All plate.s shall be flat androlled barsand shapesstraightbeforemarkingout or beingworked . Straighteningshallbe doneby methodswhich shall not damagethe material.Sharpkinks and bendsshalt bethe causefor rejection.

Steelmay be flame cut to shapeandlengthsothata regularsurface,free from excessivegougesand striationsis obtained.Flamecutting byhand shall be done only with the approval of the Engineer.

Exposedcorners shalt be machinedor ground.

2006.4.4. Tolerancesi) Plan dimensions : -o to +5 mm

ii) Overall height : -0 to +3 mm

iii) Heightof elastomer : ±5 per cer~t

iv) Heightof any steel component

a) Machined : .0 to + I mmb) Unmachined Class 2 of lS:4897

v) Stainless steel sliding surface

a) Flatness : 0.0004L.whereL = length indirection of measurement

b) Surface Finish Ra � 0.2.5 pm as per IS:3(Y73

2006.4.5. Paintingi) All non-working surfaces shall be coatedwith two coats of epoxy primer and

oneor more coat eachof epoxy intermediate and finish, total thickness ~g0.150p.m or any other painting schemeas approvedby the Engineer.

ii) Silicon grease shall be applied at the PTFEISS inierface after testing.

iii) Anchor sleevesshall be cement coated at the manufacturer’s works.

516


2006.5. Test

2006.5,1. Raw materials Necessary test certificates for allraw materials as in Clause 2006.3 above shall be furnished bymanufacturers. Reference may also be made to Clause2005.1 for testson elastomers.

2006.5.2. Test on casting : Tests specified in IS:1030 shallbe performed. Castings shall be ultrasonically tested andcertificates submitted. Quality level of castings shall be level 3 as perIS:9565.

2006,5.3. Test on welding All welding shall be tested byDye Penetration method.But welding shall be testedby Ultrasonicmethod. Soundness of welding shall be certified by the manufacturer.

2006.5.4.Acceptance test on bearingI) All bearings shall be checkedfor overall dimenuons.

ii) All bearings shall be load testedto Li times maximum designcapacityincluding seismicforce. Bearing testedat higher loads cannot be used.

iii) A pair of bearings arlectedat randomwill undergotestingin oidcr to detenninethe coefficient of friction “if. Thecoefficientof fricuon shall be ~ 0.05 atthe deMgn load.

iv) Two bearings selected at random shall be tested for pemthsiblerotation.

2006.6. Installation of POT-cum-PTFEBearings

2006.6.1.Generali) Care shall be takenduring installationof the bearings to permit their correct

functioning in accordancewith the design scheme.

ii) To prevent contamination,dismantling of the bearings at site shall not bedone.

iii) The load shall be transferredonto thebearingsonly when thebeddingmaterialhas developedsufficient strength.The props for the forrnwork shall only beremovedafter lapseof appropriatetime. In special cases,this canbe ensuredbysuitable deviceslike jacks, etc.

iv) Temporary dampsand shims (introducedto maintain working clearance) shallbe removed at ass appropriatetime, before the bearingis required to permitmovement.

v) Permitted installationtoleranceof the bearingfrom plane of sliding shall bemaintained,

vi) Cementbasednon-shrinkgroutwith air releasingadditiveandepoxybasedgrout,whichever is specified shall be first tried at the site. For theproprietarygroutmixes, appropriateinstructionsfrom the manufacturershall be followed speciallywith regard to the following

517


a) Preparauon~>r.oncretecleaning, roughening,pre.soaking,etc.

h) Fonzts->sturdiness, leak proofing, shape, hraderfunnel vents,etc.

c) earingBase->cleaning,etc.

d) Plaeernent..>rnircing,consistency!,time period, finishing, etc.

e) Protection->curing,ambient temperature,etc.

2006.6.2. In-situ casting of superstructure

i) Pormwork around the bearingshall be carefully sealedto prevent leakage.

ii) Sliding platesshall be fully supported and care taken to prevent tilting, dis.placement or distortion of the bearingsunder the weight of wet concrete.

iii) Bearings shall bc protected during concreting operation. Any snortarcontaminating the bearing shall be completely removed before it sets.

2006.6,3. Seating of bearing

A. Using Templatei) Templatewith requiredrigidity andmatching holescorrespondingto thebase

of the bearing shall he used.

ii) All the anchorsshall be fitted to the tower face of the templateusing theanchor screws but with steel washer replacing the elastomer washers,Separate screws may be used in case of inconvenience in the length of theoriginal anchor screws.

iii) The. templateassemblyshall be locatedwith regard to level and alignment.It shall beensuredthat the sop of the anchorslie in a horizontal plane atthe requiredelevation. ‘I’he anchorsshall be tied/weldedso reinforcementsto avoid displacementduring concreting.

is) Concretingof she pedessallpiercap shall be done to a level leaving a gapof 25~~51)rnnt below she template.

s) The template and steel washersshall be removed prior to placementof she hearingassembly with temporary clamps.The bearingassemblyshall he Fitted to the anchorswith the help of anchorscrewsand elastosncrwashers.Level at the bearing shalt be checked.

vi) The gap below the bearingassemblyshall be grouted with cementbasedgrout. Referencemay be madeto Clause2006.6.1 (vi).

B. Without Tempiale with Gap

i) Pocketscommensuratewith the sizesof the anchorsshalt bekept in pedestalsduring concretingof the same.The pedestalshall be castapproximately25mm shon of the required finished level.

ii) Anchors shall be fitted to the bearingbettom with elastomer washers andanchor screws.The bearing assemblyshalt be seatedin the location onsteel chairs/packs.‘flat anchorsfitted belowthe bearingshall go into pocketsin the bed block. Level and alignment of the bearing shall he checked. itshalt be ensured that the bearing sits in a horizontal plane.

518


iii) The gap below the bearing assembly including anchor pockets shall begroutedwith cementbasedgrouL Referencemay be made soClause 2006.6.1(vi).

C. Without Templatewithout Gap

Elongated pockets commensuratewith the sizes of the anchorsshall be kept in pedestalsduring concretingof the same. The geometryand location of the anchorpockets (with tapered funnel extension,ifrequired) shall be such that after placementof the bearingthe pocketscan be successfullygrouted. The pedestalshall be cast 5 mm - 15tnm short of the requiredfinished level. The required level shall beachieved by chipping beforeplacementof thebearing.Carefulcontrolshall be exercised to cast at the exact finished level or 1 mm -

3 mm down from the requiredfinished level.

D. Seatingof bearingsshall be as per manufacturer’sinstructions.

2007. INSPECTION AND TESTING

Where any patents are used,the manufacturer’scertificate withtest proofs shall be sttbmittedalongwith the design and got approvedby the Engineerbefore their itse in work.

2008. TESTS AND STANDARDS OF ACCEPTANCEThe materials shall be tested in accordancewith thesespecifica-

tions and shall meet the prescribedcriteria.

The work shall confonn to thesespecificationsand shall meet theprescribedstandardsof acceptance.


Bearings shall bemeasuredin numbers,according to their capaci-ties and particular specificationsgiven on the drawings.

The quantity of elastomericbearingsshall be measuredin cubiccentimetresof finished dimensions.

2010. RATE

The contractunit rate of each type of bearingshall include the costof supplying and fixing the bearingsin position completeas specifiedon the drawingsor as decidedby the Engineer.

The rateshall alsoinclude thecostof samplesandtheir testing whendesiredby the Engineer.

In caseof steelbearingsthe rateshall include the costof all nuts,

519


bolts, the costof all testsprescribedin the specificationsand shown onthe drawings.

Where the Departmentsuppliesthe bearings,the rate for fixing themshall include the costof anchor bolts, their fixing, transport of bearingsfrom the placeof supply to the site,handlingandplacing them in positionas per direction of the Engineer.

520

OpenFoundations

2100

Open Foundations

Open Foundations Section 2100

2101. DESCRIPTION

The work shall cover furnishing and providing plain or reinforcedconcrete Ibundationplaced in open excavation,in accordancewith thedrawings and these specificationsor as directed by the Engineer.

2102. MATERIALS

Mate~rialsshall conform to Section 1000 of these Specifications.

2103. GENERAL

A method statementfor construction indicating the following shallhe submitted by the Contractor for approval of the Engineer,wellin advanceof the commencementof open foundation

i) Sourcesof Materials

ii) Design,erection and removal of forenwork

iii) Prodectior, sraesportation, laying and curing of concrete

iv) Persomtct employed for execution and supervision

v) Teats and sampliitg procedures

vi) Equipmentdetails

vii) Any other point

Necessary arrangementsfor execution under water wherevernecessary, shall he included in method statement.

Dimensions, lines and levels shall be set out and checked withrespect to permanentreferencelines and permanentbench mark.

2104. WORKMANSHIP

2104.1. Preparation of Foundations

Excavation for laying the foundationshall be carried out in accord-ance with Section 300 of thesespecifications.The last 300 mm ofexcavationshall be done just before laying of lean concretebelowfoundation.

in the event of excavationhaving beenmade deeper than thatshown on the drawing or as orderedby the Engineer, the extradepthshall be made up with MlS concrete in case of foundation restingon soil and foundationgradeconcretefor foundations in rock, at thecost of the Contractorand shall be considered as incidental work.Special care shall be taken not to disturb the bearing surface. Openfotindationsshall be constructed in dry conditionsand the Contractor

523

Section2100 OpenFoundations

shall provide for adequate dewateringarrangementsto the satisfactionof the Engineer.

2104.2. Setting Out

The plan dimensionsof the foundation shall be setout at the bottomof foundation trench and checkedwith respectto original referencelineand axis. It shall be ensuredthat at no point the bearing surface ishigher than the founding level shown on the drawing or as directedby the Engineer.

2104.3. Construction

Where the bearing surfaceis earth, a layer of M15 concreteshall be provided below foundationconcrete.The thicknessof leanconcrete layer shall be 100 mm minimum unless otherwise specified.

No formwork is necessary for the lean concrete layer. Forfoundation concrete work, side formwork shall be used. Formwork fortop of the foundation concrete shall also be provided, if its top hasslopes steeper than I (vertical) to 3 (horizontal). When concrete is laidin slopewithout top formwork, the slumpof theconcreteshallbecarefullymaintainedto ensurethat compactionis possible without slippagedownthe slopeof freshly placedconcrete. In certaincasesit may be necessaryto build the top formwork progressively as the concreting proceedsup the slope.Reinforcementshall be laid as shown on the drawing.

Before laying of lean concretelayer, the earth surfaceshall becleanedof all loose material and wetted, Careshall be taken to avoidmuddy surface. If any portionof the surfacehasbeenspoiled by over-wetting, the same shall be removed.Concrete M15 shall be laid to thethicknessas required.No construction joint shall be provided in the leanconcrete.

Before laying foundation concrete,the lean concrete or hard rocksurfaceshall be cleanedof all loose material and lightly moistened.Foundation concreteof required dimensions and shape shall be laidcontinuously upto the location of constructionjoint shown on thedrawing or as directed by the Engineer.

Formwork and concreteshall conform to Sections1500 and 1700respectively of these specifications.Furnishing and providing steelreinforcement shall conform to Section 1600.

The concrete surface shall be finished smoothwith a trowel. Thelocation of construction joint and its treatment shall be done as per

524

Open Foundations Section2100

requirements of Section 1700. Formwork shall be removed not earlierthan 24 hours after placing of concrete. Where formwork has beenprovided for top surface,thesameshall beremoved as soon as concretehas hardened.Curing of concrete shall be carried out by wettingof formwork before removal. After its removal, curing shall be doneby laying not less than 10 cm of loosemoistenedsand,free from clodor gravel and shall be kept continuously moist for a period of 7 days.

Dewatering, where necessaryfor laying of concrete, shall becarried out adopting any one of the following proceduresor any othermethod approvedby the Engineer:

i) A pit or trench deeper than the foundation level as necessarymay bedug beyond the foundation pit ckinng constructionso that the water level iskept below the foundation level.

ii) Water table is depressedby well point system or other methods.

iii) Useof steellconcresecaissonsor sheetpiling for creatingan enclosure for thefoundations,which can subsequently be dawatered,

Before backfihling is commenced,loosesand laid on foundation shallbe removed and dispersedas directed by the Engineer.

All spacesexcavatedand not occupied by the foundation or otherpermanentworks shallberefilled with earthuptosurface of surroundingground in accordancewith Section 300. In case of excavation in rock,the annular spacearound foundation shall be filled with Ml 5 concreteupto the top of rock.

The protective works, where provided shall be completed beforethe floods so that the foundationdoes not get undermined.


The materials shall be tested in accordancewith theseSpecifica-tions and shall meet the prescribedcriteria.

• The work shall conform to these Specificationsand shall meet theprescribed standards of acceptance.

No point of the surfaceof the leanconcretein the caseof foundationon soil or the surfaceof hard rock in the case of foundation of hardrock, shalt be higher than the founding level shown on the drawingor as orderedby the Engineer. Levels of the surface shall be takenat intervalsof not more than 3 metres centre to centre, subject to aminimum of nine levels on the surface.

525

Section2100 OpenFoundations

2106. TOLERANCESa) Variation in dimensions ÷50mm - 10 mm

b) Misplacementrrom specifiedposition in plan 15 mm

c) Surface irregularities measuredwith 3 m straight edge 5 mm

ci) Variation of levcls at the top ±25mm

2107. MEASUREMENT FOR PAYMENT

Excavation in foundationshall be measured in accordance withSection 300 basedon the quantity orderedor as shown on the drawing.

Lean concrete shall be measuredin cubic metres in accordancewith Section 1700, based on the quantity orderedor as shown on thedrawing.

Concrete in foundation shall be measured in cubic metres inaccordancewith Section i700, basedon thequantity orderedor as shownon l.he drawing.

~einforcementsteel shall bemeasuredin tonnesin accordancewithSection 1600,basedon thequantity orderedor as shown on thedrawing.

2108. RATE

The contract unit ratesfor excavationin foundation, lean concreteandconcretein foundationaftd reinforcementsteelshall include all worksas given in respectivesections of these specifications and cover allincidental items for furnishing and providing openfoundation as mentionedin this Section,

526

Sub-structure

2200

Sub-structure

Sub-structure Section 2200.

2201. DESCRIPTION

The work shall cover furnishing and providing of masonry orreinforced concretesub-structurein accordance with the drawingsandas per these specifications or as directed by the Engineer.

2202. MATERIALS

Materials shall conform to Section 1000 of these Specifications.

2203. GENERALA method statementfor construction indicating the following shall

be submitted by the Contractor for approvalof the Engineer,well inadvance of the commencementof sub-structure

1) Sourcesof Materials

ii) Design, erectionand removal of fosmwork

iii) Production, transportation,laying and ewing of concrete

iv) Personnelemployed for execution and supervision

v) Testsand sampling procedures

vi) Equipment details

vii) Any other point

Arrangements for executionunder water wherever necessary, shallbe includedin method statement.

Dimensions, lines and levels shall be set out and checked withrespect to permanentreferencelines and permanentbench mark.

2204. PIERS AND ABUTMENTS

Masonry, formwork, concrete and reinforcement for piers andabutments shall conform to relevant sections of thesespecifications.In case of concrete piers, the number of horizontal construction jointsshall be kept minimum. Construction joints shall be avoided in splashzones unlessspecifically permittedby the Engineerand provided theyare treated in accordance with special provisions. No vertical con-struction joint shall be provided.The work shall conform strictly to thedrawings or as directedby the Engineer.

In caseof tall piers andabutments,useof slipform shall be preferred.The design, erectionand raising of slipform shall be subject to specialspecifications which will be furnished by the Contractor. The concreteshall also be subject to additional specifications as necessary. All

529

Section2200 Sub-Structure

specificationsand arrangementsshall be subject to the approval of theEngineer.

The surface of foundation/well capflile cap shall be scrapped withwire brush and all loose materials removed. In case reinforcing barsprojectingfrom foundationsarecoatedwith cementslurry, the same shallbe removed by tapping, hammering or wire brushing. Care shall betaken to remove all loose materials around reinforcements. Justbefore commencingmasonryor concrete work, the surfaceshall bethoroughly wetted.

in case of solid (non-spill through type) abutments, weep holesas shown on the drawingsor as directed by the Engineer, shall beprovided in conformity with Section 2706.

The surface finish shall be smooth, except the earth face ofabutmentswhich shall be rough finished.

In caseof abutments likely to experience considerable movementon accountof backfill of approaches and settlementof foundations,the construction of the abutment shall be followed by filling up ofembankmentin layers to the full height to allow for the anticipatedmovementduring construction period beforecasting of superstructure.

2205. PIER CAP AND ABUTMENT CAP

Formwork, reinforcement and concreteshall conform to relevantsectionsof these specifications.

The locations and levelsof pier cap/abutmentcap/pedestalsand boltsfor fixing bearings shall be checkedcarefully to ensurealignmentin ac-cordancewith the drawingsof the bridge.

The surfaceof cap shall be finished smoothandshall have a slopefor draining of water as shownon the drawingsor as directed bythe Engineer.For short span slab bridges with continuous supporton pier caps, the surface shall be casthorizontal. The top surfaceof the pedestalon which bearingsare to be placed shall also be casthorizontal.

The surfaceon which elastomericbearingsare to be placed shallbe wood float finished to a level plane which shall not vary more than1.5 mm from straight edgeplaced in any directionacross the area. Thesurfaceon which other bearings(steel bearings, pot bearings) are tobe placed shall be castabout 25 mm below the bottom level of bearingsand as indicatedon the drawings.

530

Sub-structure Section2200

2206. DIRT/ BALLAST WALL, RETURN WALL ANDWING WALL

Masonry, concrete and reinforcementshall conform to relevantsectionsof these specifications.

In case of cantilever return walls, no constructionjoint shallgenerally be permitted.Wherever feasible, the concreting in cantileverreturn walls shall be carried out in continuation of the ballast wall.

For gravity type masonryand concrete return and wing wall, thest face of foundationshallbepreparedin the samemannerasprescribedfor construction of abutmeniNo horizontalconstructionjoint shall beprovided. If shown on drawing or directed by the Engineer, verticalconstruction joint may be provided.Vertical expansiongap of 20 mmshall be provided in return wall/wing wall at every 10 metre intervalsor as directed by the Engineer. Weep holes shall be provided asprescribedfor abutments or as shown on the drawings.

Formwork, reinforcement and concrete in dirt/ballast wall shallconform to relevantsectionsof these specifications.

The finish of the surfaceon the earthside shall be rough while thefront face shall be smooth finished.

Architectural coping for wing wall/return wall in brick masonryshallconform to section 1300.

2207, TESTS AND STANDARDS OF ACCEPTANCEThe materials shall be tested in accordancewith thesespecifica-

tions and shall meet the prescribedcriteria.

The work shall conform to these specificationsand shall meet theprescribedstandardsof acceptance.

2208. TOLERANCES IN CONCRETE ELEMENTS(a) Variation in cross-sectiohaldimensions +10 mm, -5 mm

(b) Misplacementfrom specified position in plan 10 mm

(c) Variation of levels at the top ±10mm

(d) Variations of reduced levels of bearingareas ±5 snm

(e) Variations from plumb over fuil beigld : ±10mm

(0 Swfaceirregularitiesmeasuredwith 3 m atraigjn edge

All surfacesexceptbearingareas 5 mm

Bearing areas 3 mm

531

Section2200 Sub-Structure


Masonry in sub-structureshall be measured in cubic metres inaccordancewith Section 1300or 1400,basedon the quantitiesorderedor as shown on the drawing.

Concrete in sub-structure shall be measuredin cubic metres inaccordancewith Section 1700,basedon the quantity orderedor asshownon the drawing. No deduction shall be madefor weepholes.

Steel in concreteof sub-structures shall be measured in tonnes,inaccordancewith Section 1600,basedon the quantityorderedor as shownon the drawing.

Weep holes shall be measuredas per Section 2700,basedon thequantity ordered or as shown on the drawings.

2210. RATEThe contract unit rates for masonry,concrete,reinforcementand

weep holes shall include all works as given in respectivesections ofthesespecifications and cover all incidental items for furnishing andproviding substructure as mentioned in this Section.

532

ConcreteSuperstructure

2300

Concrete Superstructure

Concrete Superstructure Section 2300

2301. DESCRIPTIONThe work shall cover furnishing and providing of concretesuper-

structure in accordancewith the drawings as per thesespecificationsoras directed by the Engineer.

2302. MATERIALS

Materials shall conform to Section 1000 of these Specifications.

2303. GENERAL2303.1. A method statementfor construction, indicating the follow-

ing, shall be submitted by the Contractor for approvalof the Engineer,well in advanceof the commencementof the construction of superstruc-ture

i) Sourcesof Materials

ii) Design,erectionand removal of fonnwodc

iii) Production,transportation,laying and curing of concrete

iv) Prestressing sysiem, if applicable

v) Personnel employed for execution and supervision

vi) Testa and samplingprocedure

vii) Equipmentdetails

viii) Any other point

2303.2. Dimensions, lines and levels shall be set Out and checkedwith respectto permanent referencelines andpermanentbench mark sothat the final product is in accordancewith the drawings or as directedby the Engineer.

2303.3.The work shall conform to the following sectionsbesidesstipulations in this section with regard to specific type of construction:

i) Formwosk Section 1500ii) Strel Reinforcement Section 1600iii) Structural Concrete Section 1700iv) Prestressing Section 1800

Additionally, someof thecommon types of superstructureconstruc-tion shall have featuresas discussedin this Section.

2304. REINFORCED CONCRETE CONSTRUCTION

2304.1. Solid Slabs

Where adjacent span of slab has alreadybeencast, the expansionjoint and filler boardshall be placedabutting the already cast span which

535

Section2300 ConcreteSuperstructure

shall form the shutter on that side of the new span to be cast.Thewhole of the slab shall be cast with reinforcement embedded for theroad kerb andrailings. No other construction joint shallbeallowedexceptwith the express permission of the Engineer.

Where wearing coat is required to be provided, after the deckslab has been cast, the surfaceof the slab shall be finished rough,but true to lines and levels as shown on the drawings, before theconcrete hashardened.The areasof constructionjointsshall be treatedin the prescribedmanner.

The top of the slab shallbe coveredwith cleanmoist sandas soonas thetop surfacehashardened.Curing shallbe carriedout asper Section1700.

Where the slab is resting on bearings,the same shall be placedin position in accordancewith the drawings,beforecastingof deck slab.

2304.2. RCC 1-Beam and Slab

Provision of construction joint shall conform to the drawingsor asper directionsof the Engineer. No constructionjoint shall be providedbetween the bottom bulb and the web. If not indicated on the drawing,construction joint m~aybe provided at the junction of the web and thefillet between the web and the deck slab with the permission of theEngineer.

The portions of deck slab near expansion joints shall be castalongwith reinforcementsandembedmentsfor expansionjoints. For thispurpose,the portion of deck slab near expansion joints may be castin a subsequentstage, if permitted by the Engineer.

The surface finish of the deck slab shall be finished rough but trueto lines and levels as shown on the drawings before the concretehas hardened.Careshall be taken for setting of bearings as indicatedon the drawings.

2305. PRESTRESSED CONCRETE CONSTRUCTION

2305.1. PSC Girder and Composite RCC Slab

PSC Girder may be precast or cast-in-situ as mentioned on thedrawing or asdirected by the Engineer. Girders may be post-tensionedor pre-tensioned. Where precast construction is required to be adopted,selectionof casting yard anddetails of methodology and of equipmentfor shifting an~J launching of girders shall be included in the methodstatement.

536

CuncreteSuperstructure Section2300

In caseof cast-in~~situconstruction,the sequenceof construction in-cluding side shifting of girders, if applicable, and placing on bearingsshall be in accordance with the drawings.

The PSC girder constituting the top flange, web and the bottomflange shall be concretedin a single operation without any constructionjoint.

The portions of deck slab nearexpansion joints shall be castalong-with reinforcements and embedments for expansion joints. For thispurpose,the portion of deck slab near expansion joints may be castin a subsequentstage,if permitted by the Engineer.

The surface finish of the deck slab shall be finished rough buttrue to lines and levelsas shown on the drawings before the concretehas hardened,Care shall be takenfor setting of bearingsas indicatedon the drawings.

2305.2. Box Girder

Box girders may be simply supported or continuous. Simplysupported box girders shall have minimum construction joints asapproved by! the Engineer. In the caseof continuous box girders thesequenceof con~tructionand location of construction joints shall strictlyfollow the drawings.

The box section shall be constructed with a maximum of one con-struction joint located in the web below the fillet between the deckslab and web.If permittedby the Engineer,oneadditional constructionjoint may be permitted and this construction joint shall be! locatedin the web above the fillet between the soffit slab and web.

The portions of deck slab nearexpansionjoints shall be castalongwith reinfotcementsand embedmentsfor expansion joints. For thispurpose, the portion of deck slab nearexpansion joints may be castin a subsequentstage, if permitted by the Engineer.

The surfacefinish of the deckslabshall be finished roughbut trueto lines and levels as shown on the drawings before the concretehas hardened. Care shall be taken for setting of bearings as indicatedon the drawings.

2305.3. Cantilever Construction

Continuity~of untensionedreinforcement from one segment to thenext must be ensured by providing full lap length as necessary.

537

Section2300 ConcreteSuperstructure

The design of the superstructure shall take into account the followingaspectswhich form an integral part of the construction operations

a) Stability against overturning for each statical condition through which theassembly passes, shall be checked.

b) Stresses at eachprecedingsegmentjoint with the addition of evesy segment orchangeof statical conditions shall be checked,The load of equipmentas wellas construction live load shall be taken into accotmL

c) Precanibenngof the superstructure during constructionshall be done in such amanner that the finally constructed structureunder permanentload attainsthefinal profile intended in the drawings.

2306. TOLERANCES

2306.1. Precast Concrete Superstructure

Variation in cross-sectionaldimensionsa) upto and including 2m : ±5 mm

over 2m ±5 mm

b) Variation in length overall and length between shall not exceed±10mmbearings or ±0.1per cent of the

span length, whicheveris lesser

c) Permissiblesurface irregularitieswhen measuredwith a 3 m straight edge or template

2306.2. Cast-in-Situ Superstructurea) Variations ir~thicknessof top and bottom slab

for box girders, top and bottomflange forT.girders or slabs

b) Variations in web thickness

c) Variations in overall depth or width

d) Variation in length overall and length betweenbearings

e) Permissiblesurfaceirregularities whenmeasuredwith a 3 m straight edge or template

2307, TESTS AND STANDARDS OF ACCEPTANCE

The materials shall be tested in accordancewith thesespecifica-tions and shall meet the prescribedcriteria.

The work shall conform to these specifications and shall meet theprescribedstandardsof acceptance.

5 mm

-5 mm to +10 mm

-5 mm to +10 mm

±5 mm

shall not exceed+10mmOr ±0.1per can of thespan length, whicheveris lesser5 mm

538

ConcreteSuperstructure Section2300


Concrete in superstructure shall be measuredin accordance withSection 1700, based on the quantity ordered or as shown on thedrawings.

Steel reinforcement(untensioned)in superstructureshall be measuredin accordance with Section 1600, basedon the quantity orderedor asshown on the drawings.

High tensile steel(prestressing)in superstructureshall bemeasuredin accordance with Section 1800, basedon the quantity ordered or asshown on the drawings.

2309. RATEThe contract unit rates for concrete,steel reinforcement (unten~

sioned) and high tensile steel (prestressing) shall include all works asgiven in respectivesectionsof thesespecificationsand coverall incidentalitems for furnishing and providing superstructureas mentioned in thissection.

Surfaceand Sub-surface

GeotechnicalExploration

2400

Surfaceand Sub-surfaceGeotechnicalExploration

Surface and Sub-surface Section 2400Geotechnical Exp’oration

2401. GENERAL

2401.1. The objective of sub-surfaceexplorationis to determinethesuitability or otherwiseof the soil or rock surrounding the foundationandsoil parametersandrockcharacteristicsfor the design of foundationby in-situ testing or testingof sampIe~’corestaken out of exploration.The sub-surfaceexploration shall be planned in sucha way that differenttypesof soil upto the desireddepth and their profile for the full proposedlength of the bridge can be recorded and other information suchas mechanicaland physical propertieslike grain-size distribution, sen-sitivity, any existenceof deleteriousmaterial in soil or ground water,etc., are determinedalongwith soil parametersand rock characteristics.The sub-surfaceexploration shall also throw light on porosity of rockand subsidence due to mining, ground water level, artesiancondition,if any, likely sinking and driving effort, likely constructionaldiffi-culties, etc.

2401,2, Field Investigation

Field investigationsof sub-surfacehas.usually three phasesi) Reconnaissance

ii) Preliminary Explorations

iii) Detailed Explorations

2401.2.1. Reconnaissanceincludes a review of available topo-graphic and geological information, aerial photographsand data fromprevious investigationsand site examinatiorr.

2401.2.2. Preliminary investigation shall include the study ofexisting geological information,previoussite reports,geological maps,air photos, etc. and surface geological examination. For large andimportantstructuresthe information maybesupplementedby geophysicalmethods.In somecaseswhereno previous sub-stratadata are available,exploratorygeophysical investigation may need to be supplementedby resorting to a few bore-holes. Thesewill help to narrow down thenumberof sitesunder considerationand also to locate the most desirablelocation for detailed sub-surface investigation like bore or drill holes,sounding probes,etc.

2401.2.3.The scope of detailed investigation for bridges may bedecided basedon data obtainedafter preliminary investigation. Based ondata obtainedafter preliminary investigations,the bridge site, typeof

543

Section 2400 SurfaceandSub-surfaceGeotechnicalExploration

structurewith spanarrangementandthelocationandtypeof foundations,shall be tentatively decided. Thereafter,the scope of detailed inves-tigation including the extent of exploration, number of bore-holes,type of soundings, type of tests, number of tests,etc., shall be decided,so that adequatedata considered to be necessaryfor the detaileddesign and execution, are obtained.

2401.2.4 The width of exploration One purposeof ‘detailedexploration for high embankments is to ascertain the average shearstrength of each strata. The other purpose is to ascertain thecompressibilityof the clayey strata. It is, therefore, necessary thatdetailed and well illustrated description of the characteristicsofstratification should be prepared. After the general shapeand trend ofthe boundaries of the various soil depositshave been determined andrough assessment of their strength has been made by sUb-surfacesounding, with or without sampling in exploratory boring, the locationof bore-hole(s) for undisturbed sampling shall be decided. At leastone representativeundisturbedsample shouldbe collected from eachstrata,When the homogeneousstrata is very thick, one representativesample shall be collected for each 3 m thicknessof the strata.

2401.3. Soil investigationfor foundations shall contain a programmefor boring and retrieval of samples. The field work shall consist ofexcavation, drilling of bore-holes for the purposes of collection ofundisturbed and disturbed samples,standardpenetration tests,in-situ vanetests, static and dynamic cone penetration tests, other field tests, asspecified by the Engineerand preparation of bore-logs. Collection andpreservation for testing of disturbed and undisturbed samplesfrom bore-holes, borrow pits, etc., asspecified by the Engineer shall form a partof the above. All in-situ tests shall be supplemented by laboratoryinvestigations.Relevant Indiab Standardssuch as 15:1498, IS:1888,IS:1892, 15:2131,IS:2132, IS:2720,15:4434and IS:4968 and AppendixI of IRC:78, etc., shall be followed for guidance.

2401.4.The soundings by dynamic method shall becarried outin bore-holes usinga standardsampler as specified in IS:2131.

2402. PRELIMINARY INVESTIGATION

2402.1. Foundations

2402.1.1.Preliminary exploration shall be carriedout to determinethe soil profile showing the boundaries betweenthe different soil typesand between loose and dense parts in the same type of deposits.

544

Surface and Sub-surfaceGeotachnicalExploration Section2400

For guidancereferencemay be madet~LRC:75. For this purpose,asafirst step,asuitabletypeof sub-surfacesounding(e.g. static or dynamiccone penetration test) shall be carried out. As many soundings asnecessaryshould be made, until thepenetrationdatais completeenoughto leave no doubt concerning the general shape and the trend ofboundariesof the various soil deposits. Exploratory drill holes shouldthen be madeat one or two locationswhereaveragecondition prevailsand near those few points where the penetrationdiagrams indicatemaximum deviations from the average.

2402.1.2.The exploration shallcover the ~ntirelength of the bridgeand also extend at either side for a distanceabout twice the depthbelow bed of the last main foundations.If there is any necessity fordesigning investigation for approachesparticularly on soft soil or withhigh embankmentor there is a possibility of considering alternativesbetweenvia~luctor earthen embankment,the extended length ançllocation of the borings beyond the proposed .iccation of abutmentshould be determinedand executed.

2402.1.3. The depth of explorationshould be at least iV2 timesthe minimum width of foundation below the proposedfoundation level.Wheresuch investigationendin any unsuitable or questionablefoundationmaterial the exploration shall be extended to a sufficientdepthintofirm and stablesoils or rock but not less thanfour times the minimumdepth of foundation below the earlier contemplated foundation level.In caseof good sound rock the stipulation of minimum depth ma~be decreasedbasedon difficulty to conduct core drilling and theminimum depth may be resthctedto 3 metres.

2402.2. Guidebund and Embankment

The depth of exploration should includeall strata likely to affectstability of the embankment, guide bund and/or causeundesirablesettlement.In general,the requirement of settlementgoverns the depthof exploration for high embankments in particular. However, boringscan be terminated at shallowerdepths whenfirm strataor bed rockis encountered. Ordinarily, the boring shall be taken to a depth of atleast 1.5 times the height of embankmentandguidebund. However,where highly compressiblestrataareencountered,the boring may haveto be taken deeper. In order to ensure that farm strata is sufficientlythick, the boring should extend 3 metre into the firm strata.

545

Section2400 SurfaceandSub-surfacet3coteclmicalExploration

2403. DETAILED EXPLORATION

2403.1.The exploration shall cover the entire lengthof the bridgeand also extend at either end for a distanceof about twice the depthbelow bed of the lastmain foundationto assesstheeffectof the approachembankment on the end foundations. Generally the sub-surface inves-tigations (preliminary anddetailed) for bridges shall extend to a depthbelow the anticipated foundation level equal to aboutone and a halftimes the width of the foundation. However, where such investigationsend in anyunsuitable or questionablefoundation material, theexplorationshall be extended to a sufficient depth into firm and stable soils or torock.

2403.2.The type andextent of exploration shall be divided intothe following groups as per requirement of foundation design andlikely method of data collection

i Foundationrequiring shallow depth of exploralion

i~) Foundationrequiring large depthof exploration

iii) Fills behindabutmentsand protectionwo~ts

24033. Location Boring

Where the datamadeavailable by detailed exploration indicatesappreciable variation or where variations in a particular foundationare li~el’,to appreciably affect the construction(specially in caseof bridge foundations resting on rock), it will be necessaryto resortto additional bores/soundings to establish complete profile of theunderlying strata, The additional borings /soundingsshall be decideddepending upon the extent of variation at a particular foundationlocation and should cover the entire area of the particular foundation.

2403.4. Construction Stage Exploration

Whenever achangein the sub-soil strata/rockprofile is encounteredduring construction,explorations shall be resortedto establishthe correctdata for further decisions.

2403.5.Logging of bore..holesby radio-active methodsshall be donefor detailed investigations as specifiedin the contract or in spe-cial provisions.

2403.6.For bridge works, the investigations shall be comprehen-sive enough to, enable the designer to estimate or determine the fol-lowing

i) the engineeringpropertiesof the soit/rodç

546

Surfaceand Sub-surfaceGeotechnicalExploration Section2400

ii) the l~cationand extent of soft layers and gas pockets, if any, under the hardfounding strata,

iii) the geological condition like type of rock, faults, fissuresor sabsidencedue tomining, porosity etc.,

iv) the ground water level,

v) artesianconditions,if any,

vi) quality of water in contact with the foundation,

vii) the depthand extent of scour,

viii) suitabledepthof foundation,

ix) the bearingcapacityof the foundation,

a) probablesettlementand probablediffertstial settlementof the‘foundations,

xi) likely sinking or driving effort, and

xii) likely coustmctiondifficulties.

2404. EXPLORATION FOR BRIDGE FOUNDATIONS REST-ING ON ROCK

2404.1. Investigation and interpretation of data for rock isa specialised work. To arrive at the characteristic strength of rockmass, relianceshall be placedmore on in-situ tests in comparisonto laboratory tests. An engineering geologist shall also be associatedin the exploration programme.

2404.2.Identification andclassificationof rock typesfor engineeringpurposes may in generalbe limited to broad, basic geologicalclassesin accordancewith acceptedpractice. Strengthof parent rock aloneis of limited value because overall characteristicsdepend considerablyon character,spacingand distribution of discontinuities of the rockmass,suchas the joints, beddingplanes,faults and weatheredseams.An importantfactoraffecting the behaviouris the weatheredzoneat top.

24043. Basic Information Required from Explorationsi) Depth of rock strataand its variation ovdr the site,

ii) Whetherisolatedboulderor massiverock formation,

iii) Extent and characterof weatheredzone,

iv) Stmcnueof rock. including beddingplanes,fauks,fissures,solution cavitiesetc.,

v) Propertiesof rock m si-strength,geological formation, etc.,

vi) Erodibilily of rock to the extentpossible.

vii) Colour of water.

547

Section2400 Surfaceand,Sub-surfaceGeotechnicalExploration

2404.4. Exploration Programme

If preliminary investigationshave revealed presence of rockwithin levels where the foundation is to rest, it is essentialto take updetailed investigationto collect necessary information mentio~ied inclause2404.3.The exploratorybore-hole shall be drilled into the rockto a depth of about 3 metresto distinguisha boulderfrom a continuousrock formation.

2404.5. The extent of exploration shall be adequate enough togive a completepicture of the rock profile both in depth and acrossthe channel width to assessthe constructional difficulties in reach-ing the foundation levels.

2404.6. The depth of boring in rock dependsprimarily on localgeology, credibility of the rock, extent of structural loads to betransferred to foundationetc. Normally, it shall pass throughthe upperweatheredor otherwiseweakzone,well into the soundrock. Minimumdepth of boring in sound rock shall be 3 metres.

2404.7. Detailed Investigationfor Rock

2404.7.1.This coverssounding, boring and drilling. An adequateinvestigation programmeshall be plannedto cover the whole area forgenera! characteristicsand in particular the foundation location, toobtain definite information regarding rock-depth and its variation overthe foundationarea. The detailedprogrammeof explorationwill dependon the type and depth of over-burden,the size and importance ofthe structure, etc. To decide this, geophysical methods adoptedat the preliminary investigationstagewill be helpful, this databeingsupplementedby sounding, bore-holesand.drill holes.

2404.7.2. Drilling throughrock is a very specialisedwork andeverycareshall be taken to notice and record any small change duringdrilling. The time required to drill through a certaindepth, amountof core recovery,physical condition, length of piecesof core~.joints,colour of water residue,weatheringand evidence of disturbance andother effects shall be carefully noticed and entered in the drillinglog. For guidance,IS:5313 may be referred to. The data shallbe presented in accordance with 15:4464.

244)4.7.3. The cores shall be storedproperly in accordancewithJS:4078.

548

SurfaceandSub-surfaceGeotechnicalExploration Section2400

2404.7.4.The rockcoresobtainedshall be subjectedto followinglaboratory tests:

i) Visual identification for texture, stmctuie, composition, colour and grain size.

ii) Laboratorytests shall bedonefor specificgravity, porosityandmoisturecontent.

2404.7.5.In-situ tests shall be made in accordancewith IS:7292;IS:73l7; and IS:7746. In addition, laboratorytests can also be madeon samples.

2404.7.6.Usc of in-situ tests for measuringstrength and deforma-tion characteristicsshall be made. Use of bore-hole photography willbe desirableto evaluatethe presenceof faults, fissures or cavities,etc..

2404.8. Special Cases

2404.8.1.Investigation for conglomerate : A drill hole shall bemade sameas for rock. The samplescollected shall be subjected tosuitable tests depending upon the material, special care shall be takento ascertainerodibility of the matrix. Where possible,specially forshallow foundation, Plate Load Test shall be conducted.

2404.8.2, Investigation for laterites : The investigationshall begenerally similar to that required for cohesive soils, use of penetrationtestsshall be preferred, if suitable correlation charts are available. Thismay be static or dynamic penetration tests or vane sheartests. In thecase of hard laterite, recoursemay have to be made to core drillingas for soft rocks. For lateritesat shallow depths, use of Plate LoadTest may be advantageous.

2404.9. Caution

2404.9.1.The interpretation of laboratory results on rock samplesdependsupon the relationship of the specimenstestedto the overall rockcharacteristics,enumerated in Appendix 1 of IRC:78. For this purpose,careshall be exercisedin the choiceof specimen size and its orientationin relation to the joint pattern.

2404,9.2.In somecases,the foundationbehaviour will be dominatedby a possible mode of failure involving movement along some jointsurface, fissuresor weak layer within a generally strong rock systemandalso by possible weathering. In-situ sheartests may be conductedwherever feasible, as such testsare likely to give more representativedata than the shear tests conducted on core samples.

549

Section2400 SurfaceandSub-surfaceGeotecimicalExploration

2404.10.Presentationor Data

The data shall be given in diagrammaticform in 3 sheetsgivingthe following details

Sheet 1: Plan showing the position of bore-holes clearly markedso as to fix the position at a future date.

Sheet2 : This shall contain the bore-log chart and test resultsofthe samples separately for each bore-hole/pit etc.

Sheet 3 : This shallcontainpictorial representationof the bore-log data to get an overall picture of the soil profile at the cross-section of the river.

NOTE : For guidance,refer to lRC:78~.

2405. BORING

Boring shall be done by any of the following methods dependingon the soil type and types of samplesrequiredfor the investigation:

i) Auger Boring

ii) Shell and Auger Boring

iii) PercussionBoring

iv) W.jh Boring

v) Rotary Boring

For preliminary and detailed sub-surface investigation onlyrotary drills shall be used.The casingshall alsobe invariably providedwith diametersnot lessthan 150 mm upto the level of rock, if any.However, useof percussionor washboring equipment shall be permittedonly to penetrate through bouldery or gravelly strata for progressingthe boring but not for the collection of samples. While conductingdetailed borings, the resistanceto the speed of drilling i.e. rate ofpenetration,core loss, etc., asalready specified in Appendix3 of IRC:78shall be carefully recorded to evaluate the different types of strataand to distinguish specially sand from sandstone,clay from shale,etc.

2406. RECORDS OF BORINGS AND TRIAL PiTS

2406.1. The field recordsfor the preliminary and detaIled explo-ration shall contain the date when the boring was made, the locationof the boring with referenceto a permanentsystemof co-ordinates andthe elevation of the ground surface with respect to a permanentbench mark. They shall include elevation at which the water table axtdthe upperboundaryof eachof the successivesoil stratawere encountered,

550


the investigator’sclassification of the layer on the basis of generalinformation obtainedfrom field examination (refer to Appendix 2.1 ofIRC:75) and the value of the resistanceobtainedby meansof StandardPenetration Test.The type of tools used for borings shall be recorded.If the tools were changed,the depth at which the change was madeand the reasonthereofshall alsobe noted. Incompleteand abandonedborings shall be described with no lesscare than successfullycompleteddrill holes.The notes shall contain everything of significance observedon the job such as the elevation at which wash water was lost fromthe hole.

2406.2. For all borings and.trial pits, necessaryinformation asdetailedbelow shall be given. A site plan showing the disposition ofthe bore holes shall also be attached

a) Agency

b) Location with referencemap

c) Pit1Bor~-ho1enumber

d) Reduced level (RI.) of ground suiface or other referencepoint

e) Dates of starting andcompletion

0 Name of supervisor

g) Scalesof p’ans and sections

It) Dimensions,methods of advancing exploration such as by hand tools, blasting.boring, etc.

i) Generaldescriptionofatratametwithand RLs at which they aremet

j) Position and ahitudeof contaas,faults, strong joint, slidcen sides,etc.

k) Inflow of water, methodsof controlling the water, required capacity of pumps

for dewateringI) Thelevelatwhichthe sub-soil water is met with

m) Dip and strike of bedding andof cleavage.

n) Visual descriptionof strata

o) Results of field testse.g. SPT, in-situ vane shear test etc.

p) Any other information and remarks.

2406.3. Upon removal of sampling tube, the length of the ~implein the tube and the length betweenthe top of the tube and the topof the sample in the tube shall be measuredand recorded.

2407. METHODS OF SAMPLING

There are two typesof samplesviz. (a) Disturbed sample (b)

551

Section2400 SurfaceandSub-surfaceGeotechnicalExploration

Undisturbed sample.IS:1892 and IS:2132

The usual methods for sampling conforming toare given below

Natureof Ground Type of Sample Method of Sampling

Soil Disturbed

~Undisturbed

Hand SamplesAuger San~plesShdl SamplesHand SamplesTube Samples

Rock Disturbed

Undisturbed

Wash Samplesfrompercussionor rotary drilling

Cores

2408. PROCEDURE FOR TAKING SAMPLES

2408i. For proper identification of sub-surface material, sampleshould be recovered containing all the constituents of the materials intheirproperproportion.In clayeydepositssuchsamplescould be collectedby split spoon samplers.In the caseof sandy deposits,sampling spoonsshall be fitted with suitable devices for retaining samples. Alldata required for soil identification (Appendix 2.1 of IRC:75) shouldbe collected from the samples so extracted when undisturbed samples,which are more desirable for collection of someof the data, are notavailable. Penetrationtest shouldbe carriedout with the standardsplit-spoon sampleror penetrometersif the soil is coarse grained.When itis known in advancethat the soil profile is fairly regular, preliminaryanddetailedinvestigationmay be combined.Tubesamplerscan beusedin place of split spoonsamplers for collectingsamples in clayeystrata.

2408.2. Disturbed Soil Samples

2408.2.1. Disturbed samples of soil shall be obtained in thecourseof excavation and boring. For procuringsamplesfrom below theground water level, where possible, special type of samplershall beused. Where StandardPenetration Test is conducted,representativesamples shall be obtained from the split spoon. While collectingdisturbedsamples from borrow areas it shall be ensuredthat the samples‘collected represent all types of borrow materials to be used in theconstructionof embankmentand sub-grade.

2408.2.2.The size of sample generally required shall be as givenin Table 2400-1.

552

SurfaceandSub-surfaleGeotechnicalExploration Section2400

TABLE 2400-1SIZ~OF SOIL SAMPLE REQUIRED

S. No. PURPOSE OF SAMPLE SOIL TYPE WEIGW.1 OP SREQUIRED Kg

AMPLE

I. Soil identification, Cohesivesoils 1natural moisture Sands andcontenttests, Gravels 3 ‘

mechanicalanalysisand index properties,

• chemical tests

2, CompressiontestS Cohesivesoilsand sand 12.5

3. Comprehensive Cohesivesoils 25 - 50examinationof and sandsconstructionmaterial Gravelly soil 50 - 100and borrow areasoilincluding soil ‘

stabilisaticn

2408.2.3, While taking out disturbedsoil samples,StandardPene-tration Test may also be conductedto find out the bearingcapacityof the sub-soils at specified levels.

2408.3. Undisturbed SoØSamples

24083.1. The location of the bore-hole shall be as indicatedon the drawing or given by the Engineer.

The depth of the bore-hole shall be as indicated on the drawingor shall be governed by the criteria given therein or as directedby theEngineer.

24083,2. Samplesshall be obtained in such a manner that theirmoisture contentandstructuredo not get altered.This may be ensuredby careful protection and packing and by use of correctly designedsampler.

2408.3.3. Standard Penetration Test may have to be conducted ineach case to obtain additionaldataas directed by the Engineer. In softclay, in-situ vane sheartest as per JS:4434 may have to be conducted.Where all the three operations have to be carriedout in one layer, thesequenceshall be undisturbedsoil sampling followed by in-situ vanesheartest, followed by Standard PenetrationTest.

2408.3.4.For compression test samples,a core of 40 mm diameterand about 150 to 200 mm length may be sufficient, but for otherlaboratory tests, a core of 100 mm diameter and 300 mm length

553


shall be taken as far as possible,unless otherwise specified by theEngineer.

2408.3.5.The upper few millimetres of both types of sample shallbe rejected as the soil at the bottom of the bore hole usually getsdisturbed by the boring tools.

2408.4. Rock Samples

2408,4.1.Disturbed samples:The sludge from percussion boringsor from rotary borings which have failed to yield a core, shall becollectedfor a disturbedsample.It may be recovered from circulatingwater by settlementin a trough.

2408.4.2.Undisturbed samples Block samplestakenfrom therockformation shall be dressed to a size of about 90 x 75 x 50 mm.

For core samples - cores of rock shall be takth by means ofrotary drills fitted with a coring bit with core retainer, if warranted.

2408.4.3. In case of rock at shallow depths which can beconveniently reached, test pits or trenches are the most depend-able and valuable methodssince they permit a direct examinationof the surface, the weatheredzone and presenceof any discontinuities.It is also possible to take representative samplesfor tests.For guidance,IS:4453 may be referred to.

2409. PROTECTION, HANDLING AND LABELLING OFSAMPLES

2409.1. Careshall be taken in handling and labelling of samplesso that they are receivedin afit statefor examination and testing andcan be correctly identified as coming from a specified trial pit orboring.

2409.2.The disturbed material in the upper end of the tube shallbe completely removed before applying wax for sealing. The lengthand type of sample so removed should be recorded.

2409.3. The soil at the lower end of the tube shall be reamedto a distance of about 20 mm. After cleaning, both ends shall be sealedwith wax applied in a way that will prevent wax from entering the sample.Wax used for sealing should not be heatedto more than a few degreesabove its melting temperature. The empty spacein thesamplers, if any,should be filled with moist soil, saw dust, etc., and the ends coveredwith tight fitting caps.

554

Surface andSub-surfaceGeotechnicalExploration Section2400

2409.4. Labels giving the following information should be affixedto the tubes

a) Tube number

b) Job designation

c) Sample location

d) Boring number

e) Sample number

f) Depth

g) Penetration

h) Gross recoveiyratio

The tube and boring numbersshould be marked in duplicate.

Duplicate markings of the boring number and sample number ona sheet which will not be affected by moisture should be enclosedinside the tube.

2410. TESTS FOR EXPLORATION OF SHALLOWFOUNDATIONS OF BRIDGES

2410.1. Testpits or trenchesare the most dependableand valuablemethods of exploration since they permit direct visual examinationandmore reliably the type of soil and their stratification.This will alsoallow in-situ tests like plate bearing tests, sheartests and uni-axialjacking tests, etc.

2410.2. Tests shall be conducted on undisturbed samples,whichmay be obtained from çpenpits. The use of Plate Load Test (as per15:1888) is considered desirable to ascertainthe safe bearingpressureandsettlementcharacteristics.A few exploratoryboreholesor soundingsshall be made to safeguardagainst presence of weak strataunderlyingthe foundation. This shall extend to a depth of about P12 times theproposedwidth of foundation.

The laboratoryresults shall correlatewith in-situ tests like PlateLoad Tests and PenetrationTest results.

2411, TESTS FOR EXPLORATION FOR DE1~PFOUNDA-TIONS OF BRIDGES

2411.1. The teststo be conducted at various locations for propertiesof soil, etc., aredifferent for cohesive and cohensionlesssoils.Theseare enumerated below and shall be carried out, whereverpracticable,according to soil type.

555

• ••_&..•.—•— - .•


2411.1.1. Cohesionlesssoila) aassifkationtests,density, etc.

b) Field tests.

- Plate Load test as per IS:l88&

• Dynamic Penetration test as per IS:2l31 and Use of Dynamic Conepenetrationtest asper 15:4968 (Part I or Pan 2) maybe conductedwhereconsideredappropriate

c) Laboratory tests : Sharing strength test - triaxial or box sheartest - in caseofthe possibility of rise of water table, the tests shall be done on sawratedsamples.

2411.1.2.Cohesive soils -

a) Classification tests,density, etc.

b) Field tests

- Plate Load Test.- UnconfinedCompressionTest as per 15:2720 (Part 10).- Vane ShearTestas per 15:4434.- Static Cone PenetrationTest (15:4968 Part3),

c) Laboratorytests : Shearingstrengthtest - triaxial tests(15:2720Part 9). Consoli-dation Test (15:2720Part 15)

Note : Where dewatering is expected,samplesmay be tested forpermeability (15:2720Part 17.).

2411.2.The sub-surfaceexploration for bridge works can be dividedinto 3 zones

i) betweenbed level and upto anticipatedmaximum scour depth (below H.F+L.)

ii) from the maximum scour depth to the foundation level.

iii) from foundation level to about P4 timesthe width of the foundationbelow it.

2411.3.The sub-soil water shall be tested for chemical propertiesto ascertainthe hazardof deterioration to foundations. Wheredewateringis expectedto be required, permeabilitycharacteristicsshall be deter-mined.

2411.4.For the different zonescategorisedin pant 2411.2 the datarequired, such as soil classification, particle size distribution, shearingstrength characteristics, method of sampling disturbedand undisturbedsamples, testing, including particle size distribution, shear strength, un-confined compression test, shall be complied with.

2412. TESTING OF MATERIAL FOR GUIDE BUND ANDHiGH EMBANKMENT AND ITS FOUNDATIONS

2412.1. The soil properties for the embankment foundation shallbe as specified in particular specifications and shall be got verified

556


prior to construction operation. In case the actual soil propertiesdo not match the particularspecification, then embankmentdesignshallbe revised.

2412.2. Field investigation for the embankment material should becarriedout to collect generalinformation as indicated in IRC:75. Fordetails refer to Clause 305.

Field investigatior.sfor sub-soilstratashall consistof taking minimumtwo bore holes for each approach to a bridge along centre line of thealignment at adistanceof 50 m and120m behindtheabutmentpositionson both sides. The depth of bore holes below the ground level Enayordinarily be 2.5 times the maximum height of the embankment subjectto minimum depth of 20 m. Thin walled sampling tubes of 100 m~ninternal diameter and 450 mm minimum length conforming to IS:2132shall be used for collecting undisturbed samples from bore-holesat an interval of 2.5 to 3.5 m. Standardpenetration test should beconducted immediately after undisturbed sample is collected.

2412.3.In addition to the relevant identification tests, mentionedin IRC:75, it shall be necessaryto conduct some of the followingtests on the undisturbed samples collectedfrom the sub-strata. Thechoiceof testis primarily determinedby the type of soil, type of stabilityanalysis (vide Table 2400-2), availability of apparatusand cost ofinvestigation.

TABLE 2400.2 SHEAR STRENGTH TESTS FOR STABILITY ANALYSIS

S.No.

Stagein LIfeof Embankment

StrengthParameters

ShearTest Type ofAnalysis

1. (a) During construction Unconsolidatedundrained Totalor immediatepost-construction

cuu, ~uU

triaxial shear test onundisthibedsamplesand on compactedembankmentmaterial

stressanalysis

1 (b) — do — S~ Unconlinedcompressiontest in laboratoryorvanesheartest

— do —

I (c) During construction c~’ Consolidatedundrained Effectiveor immediate test with pore-pressure stresspost-construction measurementon as analysis

compactedsoil samplesofembankment materials and onundisturbedsamples

2. Long term stability C~ — do — — do —

557

Section24(X) SurfaceandSub-surfaceGeotechnicalExploration

2412.4. Laboratory Investigations of Embankment Material

2412.4,1.The following testsshould be conductedon representativesamplesof embankment materialS. NO. TEST TEST METHOI)

I) GradationTest (SieveAnalysis) 15:2720 (Part 4)ii) Aucrberg Limit Test IS:2720 (Part 5)iii) StandardProctorTest IS:2720 (Part 7)iv) Natural Moisture Content 15:2720 (Part 2)

2412.4.2In addition to the above, there is need for shear strengthtests on compacted samples of the fill material. For this purpose, therelative compaction should be 95 per cent of the Standard Proctormaximum dry density and moisture content, sameas that likely to prevailin the embankmentduring the period covered by the stability analysisor to be used in the field during construction. Undrained test shallbe run on cohesive soils and sheer strength parameters should beascertained for the ranges of normal pressures which are likely to beexperiencedin the field. In caseswhere effective stress analysis isrequiredto be done, pore-pressuremeasurementsshouldalsobe madeduring the undrained tests and effective strength and pore-pressureparametersshouldbe found out. For fill materialof cohesionlesssoils,a directshearbox test (!S:2720-Part13) may be conducted to ascertainshearstrength of soil.

2412.4.3. The results of reconnaissance,field and laboratoryinvestigations for embankments shall be consolidated into a well-knitreport. The record of findings andrecommendations,if any, may be pre-sented in the form of written test, graphs, figures and tables, asappropriate for different types of data and findings.

Information and datato be contained in the report should includegenerallocationmap, pertinentgeological information on reconnaissanceobservations, sub-soil profile (Fig. 2,1 of IRC:75), boring logs andsummaryof sub-soil properties(Fig. 2.2 of IRC:75), graphsand tablesrelated to laboratory investigations,resultsof borrowareainvestigations(Fig, 2.3 of IRC:75) and recommendations,if any.

The undisturbed samplesshall be collected from each layer ofsub-soil unless the stratum is such that undisturbed samplescannotbe collectedusing ordinary sampler. Where indicated by the Engineer,undisturbed samples shall be collected using piston sampler or core-cutter or such specialdevices.In thick layers undisturbed samples shallbe collected at 3 m interval.

558



In case of bridge and road structures,the work of boring andtrial pits shall be consideredas incidental to the foundation worksand nothing extra shallbepaidunlessotherwisespecifiedin the contractIn caseswhere it is specified to be paid separately,like contract forsoil investigation,the work shall be measured in running metresforboring, in cubic meters for trial pits, in number of samplesfor collectionof disturbed andundisturbedsamplesand in number of tests for eachtype of test.

2414. RATE

The contract unit rateshall include the cost of all labour,materials,tools and plant an5equipmentrequiredfor doing the boring or makingpits as per these specifications, taking out and packing the samples,sending and getting them testedin approvedlaboratoriesand makingavailable the test reportasspecifiedor directed by the Engineerinclusiveof all incidental costs to complete the work as per the specifications.

559

River Training Work

and Protection Work

2500

River Training Workand Protection Work

Section 2500River. Training Workand Protection work

2501 DESCRIPTION

River training andprotectionwork shall includeconstructionof guidebunds, guide walls, bank protection, flooring andapproach embankmentprotection as required for ensuring safety of the bridge structureandits approachesagainstdamageby flood/flowing water. Constructionof various componentsshall conformto IRC:89 and thesespecificationsor as directed by the Engineer.

2502. GUIDE BUND

2502.1. This work shall consistof constructionof embankmentofguide bund and provision of pitching/rivetmenton slopes, apron, toeprotection, curtain walls etc. asindicatedon the drawing in accordancewith these specitkationsor as approvedby the Engineer.

The provisions given hereunder are applicable only to guide bundsfor bridges across alluvial rivers. Guide bonds for bridges acrosssubmontanerivers shall call for supplemental specifications.

2502.2.The alignment and layout of guidebund shall be as indicatedon the drawing or as approvedby the Engineer.The construction ofembankmentfor guide band shall conform to provisionsof SecLion 300of theseSpecifications.Pitching, filter underneathpitching and turfing,apron, toe protection, curtain walls, etc., shall be as per these specifi-cations.

2502.3.Guide bandsshall generally be madeof locally availablematerials from theriver bedpreferablycohesionlessmaterials.Trial pitsshall be taken in borrow holes to examine suitability of soil forconstructionand also to decide the types of earth moving machineryto be arranged.The borrow pits should be sufficiently away fromthe location of the launching apron.No borrow pits should be dug onthe river side of the guide bunds.

Constructionof guide band shall be taken in hand alongwith theconstruction of the bridge. Every effort shall be made to completethe work of theguide bund in one working season.Where there is anydoubt about completion of the whole guide bund within one workingseason,suitablemeasuresshall beplannedandexecuted for protectionof completed work. In such cases the constructionof guide bund shallbe started from abutmenttowards upstream.

563

Section2500 RiverTrainingWork & ProtectionWoat

2502.4,Constructionof apronandpitching of the guidebonds shallgenerally confonu to clause 2503 and 2504 of these Specifications.Sufficient, length of pit along the guide bond shall be readywithinone to two monthsof commencementof work so that the placingof stonesin the apronand in the slopepitching can be commenced.As a guideline,earthwork should be completed within 80 per centof working seasonand about 70 per cern working season shall beavailablefor laying apron andpitching. No portiono the guidebondshould be left below HFL before the onsetof monsoon.: Bottom ofapronpit shall beas low aspermitted by sub-soilwaler/lowest waterlevel. Sufficient labour and appropriateearthmoving machinery andtrained staff shall be deployed in construction.

2502.5.The Contractor shall furnish hisplanningfor approval ofthe Engineer regardingtransportof stonesfrom the quarries to thesite of work inking into accountthe quantitiesof stone required to betransportedeveryday, train/truck,etc.,deployed,availableferry or boatsandlabour availablefor loading andunloadingandfbr laying within thetime framefor constructionof guide bond. Adequatereserveof stonesshould be maintainedfor major works as decidedby the Engineer.Reservestonesshall be stackedfar away from the main channel ofthe river.

2502.6. Where the alignment of guide bond or the approachembankmentcrosses a brunch channelof the river, the branchchannelmay be either diverted to the main channelof the river with the helpof spurs, etc. or closed by a properly designed closing dyke orclosure bund before taking up constructionof guide bond.

2503. APRON

2503.1. General

This work shall consistof laying bouldersdirectly or in wirecrateson the bed of rivers for protection against scour

Wherethe requiredsizeof bouldersarenot availableeconomically,cement concreteblocksofequivalentweight shall be used.The gradeof concreteshall be M 15 nominal mix, (This holds good for pitchingon slopesand flooring also). Cement concreteblocksshall bepreferredwhere practicable.

The stonesused in aprOn shall be sound,hard, durableand fairlyregular in shape.Stone subject to markeddeteriorationby water orweathershall not be used.

564

RiverTrainingWait & ProtectionWork Section2500

Quarry stonesarepreferableto round bouldersas the latter roll offeasily.Angularstonesfit into eachotherbetterandhavegoodinterlockingcharacteristics.

Where the requiredsize stonesare not economically available,cementconcreteblo~ksin Ml 5 gradeconforming to Section 1700 orstones in wire cratesin combinationmaybe iLsed in place of isolatedstonesof equivalentweighL Cementconcreteblocks will be preferred,whereverpracticable.

25032. Laying Boulder Aproth

The size of stone should conform to clause 5,3,7,2 of IRC:89.The size of stone shall be as large as possible. In no case any

fragment shall weigh lessthan40 kg. The specific gravity of stonesshall be as high as possible and it shall not be less than 2.65.

To ensureregular and orderly dispositionof the full intendedquantity of stone in the apron, template cross walls in drymasonryshall be built abouta metre thick andto the full height of thespecified thicknessof the apron at intervalsof 30 metresaft along thelength and width of the apron.Within these wails, the stone thenshallbe hand packed.

The surfaceon which the apron is to be laid shall be levelledand preparedfor the length and width as shown on the drawings. Incasethe surfaceon which apron is to be laid is below the low waterlevel, the ground level may be raisedupto low water level by dumpingearthand the apron laid thereon. The quantity of stone required inthe apronshall be re-workedout by taking the toe of pitching at higherlevel.

2503.3. Laying Wire Crates and Mattresses in the Apron

Wire cratesshall be madefrom hot dippedgalvanizedmild steelwi:re of diameternot lessthan4 mm in annealedcondition havingtensilestrength of 300450 ItPa conforming to IS:280. The galvanizingcoating shallbeheavycoatingfor soft conditionconformingto 15:4826.

The mesh of the crate shall not be more than 150 mm,

Wire cratesfor shallow or accessiblesituationsshall be 3 metre x1.5 metre x 1.25 metre in size. Where these have to be depositedand thereis a chanceof overturning, the crate shall be divided into iimetre compartmentsby cross netting.

ccc

Section2.5(X) River Training Work& ProteaionWork

For deep orinaccessible situations,wire crates can be madesmaller subjectto the approval of the Engineer.

Wire dates built in~-s’itu, shall not he larger than 7.5 metres x 3metres x 0.6 metre, norsmaller than 2 metresx 1 metre x 0.3 metreSides of large crates shall be securely stayed at intervals ofnot more than 1 .50 metres to preventbulging.

The netting shall be madeby fixing a row of spikes on a beamat. a spacing equal to the mesh. The beam must bea little longerthan the width of netting required.The wire is to be cut to lengthsabout threetimes the length of the net required. Eachpiece shall bebent at the middle aroundone of tt~e.~spikesand the weavingcommencedIrVin one corner,

A double twist shall he given at eachintersection.This twisting shallhe carefully doneby meansof a strong iron bar, five and half turnsbeing given to the bar at each splice.

The bottom and two ends of the crate or mattress shall hemacIcat one time. The. other two sides shall hemade separately and shallhe securedtn the bottom and theendsby twisting adjacentwires together.‘The top shall he madeseparatelyand shallbe fixed in the samemanneras the sides after the. crates or mattress have been filled.

Wherever possible, crates shall beplaced in position beforefilling with boulders.The. crates shall befilled by carefully hand~packingthe boulders as. tightly as possible and not by merely throwing instones or boulders.

For laying of wire crates in aprons of bridges,two situationsarise:

i) Where the crates arc to be bidin deep water andhave to be dumped and thenjoined together.

ti) Where depthof water is tow or dry bed is avaitabte,tn such cases,the cratescan be laid at site.

2504. PITCHING / REVETMENT ON SLOPES

2504.1. Description

This work shall consist of covering the slopesof guide hunds,training works and road embaukmentswith stone, boulders, cementconcreteblocksor stonesin wire cratesover a layer of granular materialcalled filter. While river side slopesare given this protection againstriver action,the rear slopes,not subjectedto direct attackof the river,

River Training Work & ProtectionWork Section2500

maybe. protectedagainst ordinary wave splashingby 0.3M.6 metre thickcover of clayey or silty earth and turfed.

2504.2. Pitching/Filter media

2504.2.1.Pitching : The pitching shall be provided as indicated inthe drawings. The thickness and the shape of stone pitching shall heshown on the drawing.

The stone shall be sound,hard, durableandfairly regular in shape.Quarry stone shouldbe used.Roundhouldersshall not he. allowed. Thestone.ssubje.ctto markeddeterioration by water or weathershall not heaccepted.

Thesize and weight of stone shall conform to clause 5.3.5.1 ofl.R,C:89. No stone,weighing les~sthan 40 kg shall, however, he used.The s. izes of spalis ,sha,II be aminimum of 25 mm and shall he suitableto fill the. voids in the pitching.

Where. t.he required size stonesare not economically available.,cement concreteblocks in MIS grade conforming to Section 17(X) orstone.sin.wirecratesmay beusedin placeof isolatedstonesof equivalentweight. Cement concreteblocks will be preferredwhereverpracticable..Use of geosyntheticshas been dealt with in Section 700.

2504,2.2, Filter media : l’he material for the filter shall consistofs.and,gravel, stoneor coarsesand.To preventescapeof the embankmentmaterial through thevoids of the stonepitching/ cementconcreteblocksas well as to allow free movementof waterwithout creatingany uplifthead on the pitching, oneor more layersof gradedmaterials,commonlyknown as a filter medium,shall be provided underneaththe pitching.

The gradation of the filter material shall satisfy the following re~quircme.nts

Provision of a suitablydesignedfilter is necessaryunder the slopepitching to prevent the escapeof underlying embanktnentmaterialthrough the. voids of stone pitching/cementconcreteblocks when suh~jected to the attack of flowing water and wave action, etc. In orderto achieve, this requiretnent,the filter may be provided in one or morelayers satisfying the following criteria

D 15 (Filter)<5

D 85 (Base)(Filter) < 20

D 15 (Base)

567

Section25(X) River Training Work & ProtectionWork

D 50 (Filter)‘—<25

D 50 (Base)Notes I. Fitter design may not be required if embankmentcoonus or cit or Ch

soits with liquid timit greaterthan 30, resistant to nsirraceerosion. tothis case, if a tayer of material is used as bedding forpitching, it shallbe welt graded and its It) 85 size shatt be at teast twice the nsaximumvoid size in pitching.

2. tn the foregoing, 0 15 meansthesize of that sieve which attows15 percent by weightof the fitter materiat to passthrough it and simitar isthe meaningof t) 50 and 1. 85.

3. tf more than one fitter tayer is required, the samerequirementasatxsveshalt be fottowed for each tayer. Thefiner fitter shatt be considered astsase materiat for selection of coarserfitter.

4. The fitter shattbe cotnpactedto a fimi condition. The thicknessof ntteris generally of the orderof 200 mm to 300 nun. Where titter is providedin two tayers, thickness of each layer stsatt be 150 mm..


Before laying the. pitching, the side.sof banksshall he trimmed tothe required slope and profiles put up by means of line and pegs atintervalsof 3 metresto ensureregular straight workanda uniform.. slopethroughout. Depressionsshall be’ filled and thoroughly compacted.

The. filte.r granularmaterial shall he laid over the preparedbaseandsuitably compactedto the thickness.specified on the drawings.

The lowest course of pitchingshall he startedfrom the toe wallantI built up in coursesupwards. Thetoe wail shall he in dry mhhle.masonry(uncoursed)confonningto ‘Clause 1405.3, in caseof dry rubblepitching andshall bein nominal mix cementconcrete(M 15) conformingto Clause. 1704.3. in case. of cementconcreteblock pitching.

The stone pitching shall commencein a trench below the toe ofthe slope. Stoneshall heplacedby derrick or by hand to the requiredlength, thickness anddepth conforming to the drawings. Stones shallhe set normal to the. slope,and placedso that the largest dimensionis: perpendicularto the face of the slope, unless such dimension isi.,,reater than the specified thicknessof pitching.

The largest stonesshall beplaced in th,e bottom coursesand foruse as: headersfor subsequentcourses.

in ha.nd placedpitching, thestone of flat stratified natureshouldhe placed with the principal bedding planenormal to the slope. Thepattern of laying shall besuch that the joints are broken and voids

568

RiverTfaining Work & ProtectionWork Section2500

are minimum by packing with spalls, wherevernecessary,and the topsurface is as smooth as possible.

When full depth of pitching can be formed with a single stone,the stones shall be laid breakingjoints and all interstices‘betweenadjncent stonesshall be filled in with spalis of the proper size andwedged in with hammersto ensuretight packing..

When two or more layers of stonesmust be laid to obtain thedesign thickness of pitching,dry masonryshall be use.d andstone.sshall . he well bonded.To ensure regular and orderly dispositionof the full intendedquantity of stone as shown, template crosswallsin dry masonryshall be built about a metre wide and. to the fullhe.ight of the specified thickness at suitable intervals’ andall alongthe length and width of. the pitching. Within thesewalls the stones:shall he hand packed us specified.

2504.4. Toe Protection

in conformity with clause5.3.7. of IRC:89, a toe wall shall heprovidedatthejunction of slopepitching andlaunchingapronof a guidehund so as to protect the slope pitching from falling even when theapron is not laid at low water level. The toe wall shall he in dry rubblemasonry(uncoursed)conformingto Clause1405.3 in caseof dry rubblepitching or pitching! revetmentwith stonesin wire cratesandin nominalmix cementconcrete(M 15)conforming‘to Clause1704.3 in casece.n’tentconcreteblocks have been used in pitching. For protection of toes ofhank slopesterminatingeither in shortapronsat bedlevels or anchoredin flooring / rocky bed,the provisions of clause8.2.2 of 1RC:89 mayhe complied with, The relevant specificationsof the protectiveworksbr individual componentswill be followed.

2505. RUBBLE STONE/CEMENT CONCRETE BLOCKFLOORING OVER CEMENT CONCRETE BEDDING

2505,1. This work shall consistof constructingntbble stone / c.c.block flooring laid overa cementconcrete(M 15) bedding. The floorprotection will comprise rigid flooring stated above with curtain walls.and flex ible apron.


Excavations‘for laying the beddingandfloor protectionworks shallhe carried out as per specificationsun.derproper supervision. BefOrelaying the foundationandprotection walls, theexcavated trenches shallhe. t.horoug,hly inspected by the Engineer’in..Chargeto ensurethat

569

.Sc.ct’iot’s 250t) RiverTraining Work & ProtectionWorrk

a)i’he.re are no too.se t~cketsand unfitteddepressionsteft in the stench.

h) The soit at the foundingtevct is property compactedto tnie tines and level soas to have an even bedding..

c) Att concrete and oiher ete.rnentsare taid in dry bed.

Cement concrete nominal mix (grade M ‘15) of 300 mm thicknessshall then belaid in accordancewith provisionsgiven in Section 1700c~.xeeptthat the surfaceof the concrete.shall not be given a smoothfinish, ‘The p.aving work shall he embeddedin green concrete.

1”lcioring shall consist of 150 nim thick flat stone/cementconcreteblocks (Nominal’ mix Grade.M 15 conforming to Section 1700). it shallhe beddedon a layerof ceme.ntmortar (1:3)prepared to ClauseI 3&4.Spalls shall be usedto fill in the voids. Thejoints shall then be. filledwith cement mortarand finished neat. The stone shall hre..ak jointsandthe joints shall not excee.d 20 mm in thickness.Spacing of jointsmay he 20 m or so. The top of flooring shall bekept to 3.00 mm belowthe. lowest bed level.

2506, I)RY RUBBLE FLOORING

This work shall consistof constructing dryrubble flooring at crossdrainage works for relatively less important works.

The. base for the flooring shall beprepared to the specifiedlevels’and slopesand compactedsuitablywith hand rammersor other;neansto have an even bedding.

The thicknessol’ flooring shall bemade with one stoneonly. Thestonesshall then be laid closely on the preparedbasein one or morelayersas specifiedandthe bondused shallbe. as specifiedby theEngineer.

2507, CURTAIN WALL AND FLEXIBLE APRON

2507.1. Curtain Wall

The. rigid flooring shall be enclosedby curtain walls (tied to the.wing walls) with a minimum depth belowfloor level of 2 in on upstreamside and2.5 m on downstrea.mside.. The curtain wall ‘will be in cementconcrete.M 15/stonemasonryin cementmortar 1:3. The rigid flooringshall he continued over the top width of curtain wall.

2507.2. Flexible Apron

Flexible. apron 1 m thick comprisinglose stoneboulders (weighingnot lessthan40 kg) shall be. providedbeyondcurtainwalls for aminimumdistance of3 m on upstreamside. and 6 m on downstreamside. The

570

River TrainingWork &. ProtectionWork Section2500

work of floor protectionshall be simultaneouslycompletedalongwith thework on bridge, foundations.


‘the materialsshall. he testedin accordancewith. theseSpecificationsand shall mee.t the prescribedlcriteria.

“the work shall conform to these Specificatknsand shall meet thep~’e.serihed standardsof acceptance.


The protection works’ shall he measuredas’ se.t forth be.!o’w. ifdirected by the. Engineer for me.asure.n’tent,the materials may have tobest.ack.e.dat site before laying and nothing extra will he paid tothe Contractor for this stacking.

The earth work in constructionof embankmentfor guidehued shall‘he measuredin cubic me.tre.s unless otherwisespecified.

The boulders/cementconcreteblocksandwire cratesin a.pronshallbe measuredin cubic metres.

The filter arid stonepitching shall be measuredseparately in cuhien’ie.u’e.s unless’ otherwise specified.

Rubble stone/ee.me.ntconcrete blocks, flooring and cementcon.cretebeddingshallbe mea.stiredin cubic metresfor eachclassof material.

Preparationof basefor laying the f.ooring shall be deemedincidentalto the work,

For laying apron,e.xcavationupto an averagedepth of 150 mm shallhe deemed to he includedin themain item andshall not be measuredseparatelyunlessotherwisespecified,Excavation more t.han 150 mmshall he measuredin cubic metres as given in Clause304.

2510. RATE

The. contract unit rate for the constructionof embankment forguide bund shall coverthecost of all materialsincludingtransportation,laying, compacting,all labour, toEs, equipment,sampling and testing,supervision and all incidentals necessary for completing the workaccording to these specifications.

The contractunit ratefor onecubic metreof finishedwork of apronshall includethe costof all material, labour,toolsandplant fo~completingthe work according to above specifications.Fxeavationupto an averagedepth of 150 mum shall also be deemedto be included in the rate. its

.571

Section2500 River Training Work & ProtectionWork

dressingof the bed,Excavationbeyondthis depth shall be paid forseparately unless otherwise specified.

The contractunit rate for onectibic metreof filter or sto.e/cementconcrete block pitching on slopesshall include the cost of preparingthe b:ases,putting to the profiles, laying and compactingthe filterand s.tone pitching of dry rubble/cementconcrete block rivetment forembankmentslopesto the specifiedthickness, lines, curves,slopesandieve.is and all labour and materialsas well as tools and ‘plant requiredfor the work,

The contract unit rate for rubble stone/cement concrete b~ockflooring shall include the cost of all material, labourand tools and plantfor completing the work as per these specifications.

ExpansionJoints

2600 ‘

ExpansionJoints

ExpansionJoints Section 2690260!. DESCRIPTiON

This work shall consist of fabrication and placing of expansionmints as indicated on the drawing and conforming to thesespeci~fica.tions or as directed by the Engineer.

2602. GENERALa) The expansion~omushalt be designedand duty got approvedtry the Engineer.

It ehalI cater for expected movement and rotation of the ssmctureat the

~ and provide smoothriding surface, It shatt atso be easy for inspection,

snaintcnance and replacement.h) hxpans~ossjoints shalt be robust, durabte, water~mightand reptaceable. Site

fabricated expansionjoints shall beprohibited.‘Expansionjoints shattbe obtainedby the Engineereither directly or through the Contractor from approvedmanufacturersand beof proven type.

c) For bridgeswith prestreesedconcretesuperstructure,with individual span lengthsnorethan 2.0 m orbuilt with innovativedesignfeonstruceionetastomerice spansionjoints of slab seator strip seat type shatt be provided..

Foe slab type of bridgesof spans less than tO metrescontinuous surfacingmay tat provided acrosstheexpansion gaps,suppo:rtedon a 20 mm thick plateplaced and fised at the level of the deck stab,

c) For brid,gcs other than ttsosententionedin (c) abeve with spares atseve1analternativespecificationof stiding steetplatejoint or filled joints with copper

platesmayatso he adopted if approveat by theEngineer,apan ‘1mm elastosneric

expansionjoint of stab seal or strip seat type.1) Vctticular traffic shatt not he allowed overexpansionjoints after its constmc.tion

for such period as may be detemsirsed by the Engineer.

iø Proprietary typedeckjointsoffered by the Contractor in tieu of th’e typespeciliectshall cossepty irs alt respectswith the manufacturer’s specifications and meetthe required range of movementsand rotations and be fit for the purpose ofensur.ing satisfactorylong tersrs performanceits the bridge.

Wherealternativetype proprietarydeckjoints are proposed hy the

Contractor, the following information shall be provided.i) Name and location of itse proposedmanufacturer.

ii) Dimensions and general detailsof mite joint includingmaterial tpecification.s,ltotding down belt or anchoragedetails and instáttationprocedures.’

iii) [iv idence’ .of satisfactoryperfomsanmunder similar envirormsenmalconditionsofsimilar joints being producedby the manufacturer.

.Any acceptanceof alternative types will be at the sole discretionof the Engineer,

Such deck joints shall be installed in accordancewith the manu~

575

Section2600 Expansion Joints

facturer’srecommendationsandto the generalrequirementsof this Speci-flcation.

No expansionjoint shall be provided only for the width of thecarriageway. It shall follow the profile including the kerb and thefootway and facia., if provided. The type of expansionjoint for thelattermayhe madedifferent from that used for the carriageway expansionjoint.

2603. REQUIREMENTS2603.!. The requirementcriterion will be separatelyapplicablefor

the expansionjoint properand the transition zone of attachment to thedeck,

2603.2.There are two typesof performance requirements for the cx.pansionjoint properviz, from the necessityof the bridge and from theroad users e.g. man, animal and vehicle.

2603.3, Performance Requirement with Respect to Bridges

The expansion joint shalla) Withstand the imposesi toad inclusling the impact load frotn live toami anti other

sources.

h) Allow expansionandcontractionmovementdueto temperatstre,creep,shrinkage,preatrettingand structural deformations.

c) Permit relative rotation in elevationand plandue to thecausesas notedakove,

d) Be waterproof.Bridgedeck expansionjoint seals play a critical role in preventingthe degradation of the stmctsaral componentsof the bridge system. Withouteffectivejoint seals,waterpassesthrough thebridgedeck and works harmfullyto corrodesteelcomponentsandcausedeteriorationof theconcrete.Rain watergathers various corroding additives from the atmosphereand also from thecarriageway.

e) Ensure seating.In case bridge deck joints are not seafed,apart from tots ofwaterproofing,grit and otherforms of roaddebriamay enterthe joint Debris,when ‘unpacted with the joint can seriously restrict the movententinstead offacilitating the same, In the caseof proprietary joint.s being accepted foradoption,’the sealingshall be as specified by them,

I) Ensure long life by being resistant to corrosion1

g) Be easy so install,

h) Be easy to maintain. Replaceabilityof expantionjoint shall be one of the basiccriteria for selection of type of expansion joint,

i) Be resistantto the materialt likely to collect/spill over the deck in its normalservice.

576

ExpansionJoints Section2600

2603.4. Performance Requirement with Respect to User

The expansion joint shalla) Provide smoothcontinuity at the top of the deck for riding comfort,

5) Be of skid resistant surface,

c) Be non-damagingto the rubbertyre,

d) Make minimusn noise during vehicularcrosaing,

e) Ensurethat animalpawsand hoovesshould not gee entangledwhere bridges areused by animal drawn traffic,

t) Permit passing of bullock cart steel tyre for bridges where bullock carts ply,

g) Look good aesthetically.

2603.5. Performance Requirement for Transition Zone

It is the zoneof connectionof joint a.ssernblyand the adjoining deck.

The expansion joint shalla) Permit transfer of generatedforces without distress,i.e,, without getting uprooted.

The puwoae will not be served if the bonding is with the wearing coat only.Anchorage must he provided with the deck atnicwral element,

b) Ensurethat surface in the transition zone stays undisturbedduring long termservice,

2604. STEEL PLATE SLIDING EXPANSION JOINTSa) In this typeof buried joint, the wearingcoat shall be made continuousover the

joint. The other altemative shall be to keep a gap in the wearing coat whichis filled up with a seal and filler, to be provided in extremelyhot areas,

b) Materials for steel plates shall conform to Section 1900. The exposed metalliccomponents~hallbe galvanisedor coatedwith approvedanti-corrosivepainL Thethicknessshall be 20 mm or so for obtaining satiafactoryperfonnance.

c) Platesshall be placedto the line, gradeandexpansiongap shewrson the drawingswith any adjustmentrequiredfor temperature,particular care beingtaken ~iththe top of the plates.

d) Plates shall be firmly held in placeduring concretingby methods approvedbythe Engineer.

e) Any temporary boltsor other fixings which prevent relative movement of theadjacentpasts of the joint shall be removed as soon as the concrete has setsufficiently so hold the expansionplates in their correct positions. In any case,temporary bolts or other fittings shall be removedwithin 6 hoursof placingconcreteunless otherwise directedby the Engineer.

Q Care shall be taken to prevent damageto expansionjoint platesor its coating.

g) if any damageoccurs,the platesandcoatings shall he restoredby theContractorto the satisfactionof the Engineer.

h) Plates shall be free ofoil, nan, loosepaint or other similar material before coating.

577

Section26(X) ExpansionJoints

2605, FILLER JOINTSa) The componentsof this type of joint shall be at least2 rem thick corrugated

copperplate placedslightly below the wearingcoat, 20 mm thick compressiblefibre board to protect she edges,20 mm thick pre-mouldedjoins filler filling thegapupto the top level of thewearingcoat, sealedwith a joint sealingcompound.

h) The materialusedfor filling expansion joins shall be bitumen impregnatedfelt.elastotnerorany othersuitablematerial,asspecifiedon thedrawings.! impregnatedfelt shall conform to the requirementsof iS~1838, and shall be got approvedfront the Engineer.The joint filler shall consistof large piecesand assemblyofsmall piecesto make up the required size shall be avoided,

c) Expansion joins mttteriais shall be handledwith care and storedunder coverby the Contractorto preventdamage.

d) Any damage occurring after delivery shall be madegood to the satisfactionofthe Engineerand at the expenteof the Contractor.

e) Joint gapsshall be constructedas shownon the drawings.Surfacesof ~oinrgrooves shall be thoroughly cleanedwith a wire brush to remove all loosematerials and dirt and debris, then washed or jetted out..

f) Pte.mnouldedexpansionjoint filler shalt notbeplacedin position until immediatelyprior to the placing of the abtrtting material. If thetwo adjacentsurfacesofthe joint are to be placed at different times, this type of joint filler shall notbe placed until the secondface is about so be placed.

g) Sealants shall b. installed in accordancewith the manufacturer’s recommen-dastons and all appropriate requirementsfor joins face priming.

h~i Sealantsshall be finished approximately 3 runt below the upp.r surfacesof the

!joint.

i) Joint materials spilt or splashedoito finished surfacesof the bridgeduring jointfilling operationsshall be removedand the surfacesmadegood sothe Engineersapproval.

No joins shall be sealed until inspectedby the Engineerand approval is givento proceed wish the work,

2606. ELASTOMERIC SLAB SEAL EXPANSION JOINT

2606.1. MateriaLsa) Steel inserts shall conform to IS ~226.Use of any othermaterials like fibre-glass

or similar material shall not he permitted.

b) Elastomer for elastosnerieslab unit (11513) shall conform to clause 915.1 ofIRC:83 (Part Ii), compoundedto give hardnessIRIID 60 ~5, subject to thefollowing additional stipulations

i) Chloroprene(CR) only shall be usedin the manufactureof elastomericex-pansionjoints. No reclaimed/naturalrubberor vulcsnisedwastes shall beused.

ii) The chloroprenematerialttsed in themanufactureof elassomeric(expansionjoints) shall be NeopreneWRT, Rayprene110, Skyprene85 or Derrka 5-40V.

578

ExpansionJotnts Section2600

iii) Chioroprenecontent ofthecompoundshall tsot be lower than6111 per centby weighs.The ash contentshall not exceed5 prcent (as per testscortducsedin accordancewith ASTM D.297 fin (1) and (ii) above.

iv) EPDM, and other similar candidate etastoroers foretpansionjoints shallnot be permitted.

c) Elastomericplugs.

d) Spacer hers, markedwith centre to centredistance of fixing holes.

e) Fixing bolts and nuts ntadeof stainless steel.

11) Anchor barscomprisinghooked anchor stiffenertwelded !with lower steel insertsand sinusoidal anchor bars welded with horizontal leg of the edge steelinserts!,‘i’he elaborateanchoringarrangementsof steel insertsshall be pennanentlywelded]tied witlt the steel reinforcetnenL

2606.2. Fabricatkyna) Steel inserts shall be grit blasted andprovided with epoxy paint.

b) Edges of reinforcing steel sectionsshall be rounded,

c) Expansionjoints shalt be fully moulded to the required size in one singlevulcanisingoperation including theencasinglayers! ~t integral and homogeneouspart

st) Tolerances of fabricationshall beat follows

i) Plan dimension .> ±5 mm

ii) Total height -> ±3 mm

2606.3. Supply and Handlingi) The Contractor shall supply all steel-reinforcedelastomeric expa:os!iort joints

including bolts, nuts, sealant, plugs andall other accessories for the effectiveinstallation of the joints including angledjointing sections forkerbs.

ii) Expansionjoins material shall be handledwish care and storedunder cover bythe Consractorto prevent damage.Any damage occurring afterdelivery shallbe made good atsite expenseof the Contractorso the satisfactionof the Iin!gineer.


2606.4.1, Expansion joints shall be installed as per approveddrawhtg. Steel inserts, spacer bars, concreting of pockets, fixing ofeiaslonie,rslab unit and presetting!, etc., shall be done as per the following:

a) Steel inserts

i) Deck casting shall be done leaving pockets or recessFor steel insertsand anchorsof the expansionjoint as per drawing.

ii) Steel insetis shall be toweredas the appropriate locasion inside !the pocket.

iii) The sop of the inseti shall be flush with the finished levelof wearing coursemaintainingthe camber,

iv) Spacer bars, duly set appropriately to the monthof installation!~!shalthefisted under proper supervision.

579

Section2600 ExpansionJoints

v) Anchor rods shall be tied/welded with the existing deck main reinforcement,mainsaining level and alignment

vi) Welding between anchor rods and deck reinforcement is preferable.If welding is not possible, strongsteel sie wires shall be usedfor fastening,under proper supervision.

b) Spacer Bar

i) Spacer bars shalt be used to ensure proper positioning of bolts and alsolevelling of the steel inserts during fixing of the same with the deckreinforeemensand catting second stageconcretingin the pocket thereafter,

ii) The 2nd stage concretingoperation shall preferably he started within24 hours of firing the steel inserts. In such cases, spacer bars shouldbe removed just after concreting is finished. If there is a substantialtimelag between fixing of inserts and concreting,then any oneof the followingmethods shall be adopted, depending on the support condition

a) For simply supportedbridge restingon simple elastomericbearings,(with no dowel pins), insert shall be placed in position with spacerbars at every altemasejoinis. Suchjoints shall be called restrainedjoints hereafter. in other words, mserts shall not he fixed simnulsa-rseously at swoends of one span. If the abovecondition is satisfied,interts with spacer bars shall he kept in position for a substantiallylonger period at such restrainedjoints. Spacer bars shall he removedafter concreting of such restrainedjointsand insertsplaced in positionwith spacer hems at the other unrestrained joints thereafter.

h) For bridges resting on other than elassomeric bearings (includinghearings with dowel pins at one end), after placing and aligningthe inserts and securing the same, the spacer bars shall he removed,Concreting shall be done with great care so that inserts are notdislocated or distorted.

iii) While removing the spacerbar after concreting, one must take care so seethat the concrete is not datnagedduring withdrawal of spacer bar. If thespacer bar happensto be snugly fisted, it shall notbe pulled by any means;it shall he gas cut in two piecesand then removed.

c) Concreting of Pocket

i) Concreting of pocket shall be done with greas care using proper mixconforming so gradesimilar to that of the deckcastingbesidesensuringefficient bonding besweendeck andsteel insert. Also properr.are shalt begiven for ensuring efficient bonding with the already cast concrete.

ii) Needlevibrasors shall be used. Care shall be sakenso thas the position ofsteel insert is not disturbed during vibration.

iii) Spacer bar shall he resnovedwithin an appropriate time before the jointis requiredto pennisnsovenaent

d) Fixing of Elastosnerie Slab Unit (ESIJ)

i) Special jig shall be used to preset the ESU during installation.

ii) ESU (mountedon the jig, if preses)shall be lowered to position.

580

ExpansionJoints Section2600

iii) The line and level on the ESU should he adjusted.

iv) ESU shall be removed and coated with special adhesive

v) ESU shalt he placed in position again, ensuring waterproofjoining atrequiredfaees.

vi) ESU shall he tightenedwith stainless steel nuts and lock washers inposition. Tightened nuts shall be locked with lock washers,

vi) Special sealant shall be poured inside the plug holes.

vii) The etastotneric plugs shall be pressedin position after applying adhesiveon the appropriate surface.

viii) ESU shall he fined in position after completion of wearing course.Whilecompleting this part of the wearing course, adequatecare shall be taken toensure a waterproofjoining with she already existing wearing course.

e) [‘re-Setting

i) The main purposeof presetting of the steel insens as the time nf itsinstallation is to ensureas closely as possible the condition that in thelong nsn as the mean average annusl temperature, the ESU remains atits nominal stare.

ü) Major factors responsible for changing the longitudinal length of thebridge superstructure are indicated below

a) Temperasure variation from annual mean,

b) Changes due to shrinkage of concrete~

c) Changes due to elastic shortening and creep of the prestressedbridgesuperstrucsure.

d) Deformation of superstructure and substructure,if any.

Resultant changes in expansion gap due to first factor can occur in bothdirections from any pre-selectedmeanposition whereaschanges due tocreep and shrinkage are unidirectional such that the expansiongap continuously increases with passageof time,

The steel insert unit of expansion joint can be fixed in anymonth of the year,As statedearlier, the expansiongap betwen bridgesuperstructure may vary from time to time; hence the initial fixingdistancebetween fixing points will obviously depend on the monthof installation of steel insert. The c/c distancebetweenstainlesssteelfixing of bolts as indicated in the drawing can be taken as onlynominal. The same shall be modified by presetting depending on

i) The difference hesweenthe mean temperature of she month of fixing ofsteel insert and the annual average temperasure.

ii) The elapsed period besween the casting and/or prestresaing and fixing ofsteel insert for calculating the remnant creepand shrinkage.

581

Section 261X1 ExpansionJoints

2606.4.2. Special requirementsfor installationi) [‘nor to csnistnctionof bridge deck area adjacent to the joint, the supplier

shall provide detailed working drawingsshowingthe locationof all bolts,recessesand holes necessaryfor the installation of the joint. Reinforcing bars in.supenstntcsumeshall be amendedas required to ensurethat there will be nointerference in the installation of she joint.

ii) All bearing surfacesand recesseswhich are in contact with the joint assemblyshall he checkesl with a straight edge to ensureflatnessof profile.

ins) No bolesshall he sIn lIed for firing bolts within 7 days of concreting Holes forthe bolts shall he drilled to the size and depth shownon the drawitigs

iv) 5ecttons of the jointing making she completed joint shall follow a straightline.

s) ‘l’he. fi sing, hulLs shall not lxi placed in a position sntil at least 4 weeks afterstressingis completed in pose-tensioned box or beam and slab stmctures.Prior to placing sections of joinsing,contactsurfacesshall he cleanedto removeall grease,tar, paint, oil, mud or any other foreign material that may affcosadhesionof the sealant.

ci) Sealsntshall only he applied to dry contact surfaces.Sufficient sealant shall heapplied to the contact surfaces so causeextrusionof sealantwhen the jointingis fised in position.

vii) Final scaling of the finished expansion joint shall be completedimmediately after completion of installation All exposedends,joints betweenunits and other areasof possible leakageshalt be tilled with sealant. All voidsbetweenshe sides of she jointing and concreteor platesshall he filled withsealant.

sin) Bolt cavities shall he cleanedand plugged wish neoprenecavity plugs Priorto placing the plugs sufficient sealant shall he placed in the cavities to causeextrusion of the sealant by the plugs.

ix) All escesssealant shall be removed from the jointing and adjacent areas.

2606.5. Acceptance Test2606.5.1,As per clause918,7 of IRC-83 (Part II), necessaryquality

control certification by the manufacturerin regard to properties ofElastomerand steel will be furnished.

For severe environmefit, ozoneresistancetestas per clause915.2.3of IRC:83 (Part El), shall be carried out for elastomer,

The properties of the elastomershall conform to Table I of clause915.2 of IRC:83 (PartII). The acceptancetesting forelastomermaterialshall conform to clause 91&4,l,2 of IRC:83 (Part II) with additionalcriteria as stated in Clause 2005.

582

Expansion Joints Section2600

2606.5.2.The fabricated expansionjoint shall he subjected tothe frsflowing accepiancetests

i) Routine test.. Each expansion joint shall be tested for at least 100 cycles fora teas movesnent which shall be 10 per cent more than the design expansion)contradion mowesnent.

ii) In addition to routine test, one out of every 20 expansion joints shall he subjectedto the teat movement for 40(X) cycles.

The. lot shalt be rejected if the elastomer material shows signs of fatigue orpesananent set or distress in the teat. The test piece shall not be used in thebridge.

iii) The type test for abrasion resistance shall be carried out for one joint out ofevery 20 not. as per 15:34(X) (Part 3) and the standard deviation shall be within

20 per cent

NJ3. The manufacturer shall preferably have in-house testingfacility. Otherwise,the testing shall be got done by him at his expen e.at any testing establishmentselectedby the Engineer.A manufacttjrerwho cannotcarry out the acceptance testshall not be entitled to supplyelastomericslab seal joint...

2607. STRIP SEAL EXPANSION JOINT

26071. Components

Strip seal expansionjoint shall comprise the following itemsa) Edge beams This special claw leg profiled member shall be of extruded roiled

steel section combining good weldability with notch toughness.

b) Strip seal This shall be of dhloroprene with high tear strength, insensitiveto oil, gasoline, and ozone. It shall have high resistance to aging. This component,provided to ensure water tightness, shalt have bulbous shape of the pan of theseal which is inserted into the groove, provided in the edge beam, The seal shotsldbe vulc.anised in single operation for minimum full length of joint..

c) Rigid Anchorage - This shall be welded to the edge beam at staggered distance,.

ct) Anchortoops - This shall be made of weldable steel connecting the rigid

anchorage with deck reinforcement.

2607,2. Materiala) Edge beams of this special section are at present being directly imported

in India. The steel shall conform to steel grade Rst 37-2 of German Standardor eqtaivalenL

h) Chloroprene of strip seal shalt conform to clause 915.1 of D.C:83 (Past Ii). Thepropertiea of chtoroprene ahait conform to Table 26OO~i.

c) Anchosage steel shall conform to 15:2062,

d) Anchor loop shall confonn to 15:2062,

583


PROPERTY

Hardness

Tensile Strength

Elongation at fracture

Tear Propagation StrengthLongitudinalTransverseShock ElasticityAbrasion

Residual CostpressiveStrain(22 hT7O deg C /30 per cent strain)

Ageing in hot air(14 day s/TO deg C)Change in hardnessChangein tensile strengthChangein elongation at fractureAgeittg in ozone(24 h/5~phxttt25deg C/20 per cent strain)

Swelling behaviour in Oil(116 h/25 per cern C) ASTM Oil no.Volume Change(hangein hardness

ASTM Oil no.3Volunte ChangeChangein hardnessCold HardeningPoirtt

SPECIFIED VALUE

63 ±5 Shore A

Mm Ii MPa

Mm 350 per cent

Mm 10 N/rnntMm 10 N/mmMm 25 per centMm 220 mm

3

Max 28 per cent

Max ÷5ShoreAMax -20 per centMax -20 per cent

No cntcks

Max 5 per centMax 10 ShoreA

Max 25 per centMax 20 Shore AMm -35 deg C

2607.3. Fabrication (Pre-installation)a) Rolled steelprofiles for edge beamsshall be long enoughso cater for a 2-lane

carriageway.Theseshall be cut to size of actssalrequirementsby meansof amitre box saw~Alignment of the cut-to-sizesteel profiles shall then be made inaccordancewith theactualbridge cross~sectionon work tables.For this purpose,the contour of bridge cross-sectionshall be sketchedonto these tables. Afterthe steelprofiles are aligned, they will be chuckedto the tables by meansofscrew clamps and tackedby arc welding.

h) Anchor plates shall be cut to the required size by gascutting. These shallbe welded to the edge beams.

c) Anchor loops shall be bent to the requiredshapeand welded to anchorplates!!

d) The finally assembled joints shall then be clampedand transportedto the worksite.

TABLE 2600-1.STRIP SEAL ELEMENT SPECIFICATION

Sealing element is made of chloropmne andmustbe a extrudedsection.The working movement range of the sealing element shall bcat least80 mm with a maximum of 100 mm at right anglesto the jointand ±40mm parallel to the joint .

584

Expansion Joints Section2600

2607.4. Handling and Storagea) For transportationand storage,auxiliary bracketsshall be provided to hold the

joint assemblytogether.

h) ‘the manufacturer shall supply either directly to the Ergmeer or to theBridge Contractor all the materials of strip seal joints incltading sealantsand all

other accessoriesfor the effective installation of thejointing.

c) Expansion joint, material shall be handled with care. It shall be storedundercover on suitable lumber padding by the Contractorto preventdamage.Anydamageoccurringafter delivery shall be made good at the Bridge Contractorsexpense to the satisfactionof the Engineer.


26073.1.Thewidth of thegapto caterfor movementdueto thermaleffect, prestress, shrinkageand creep, superstructuredeformations (ifany) and sub-structuredeformations(if any) shall he determinedandintimated to the manufacturer.Dependingupon the temperatureat wttichthe joint is likely to be installed, the gap dimensionshall be preset.

26073.2.Taking the width of gap for movementof the joint intoaccount,thedimensionsof the recessin thedecking shall be establishedin accordancewith the drawings or design dataof themanufacturer.The surfacesof the recess shall he thoroughlycleanedand all dirtand debris removed.The exposedreinforcement shall be suitablyadjustedto permit unobstructedlowering of the joint into the recess.

2607,5.3. The recess shall be shuttered in such a way thatdimensions in the joint drawing are maintained,The formwork shallhe tight.

2607,5.4,Immediately prior to placing thejoint, thepresetting shallbe inspected.Should the actual temperatureof the structurebe differentfrom thetemperatureprovidedfor presetting,correctionof the presetlingshall be done. After adjustment,the bracketsshall be tightenedagain.

2607.5.5.The joint shall be lowered in a pre-determined position.Following placement of the joint in the prepared recess, the jointshall be levelled and finally aligned and the anchor loops on one sideof the joint weldedto the exposedreinforcementbars of the structure.Upon completion,the sameprocedure shall be followed for theothersideof the joint. With the expansionjoint finally held at both sides,the auxiliary bracketsshall be released,allowing the joint to take upthe movement of the structure.

2607,5.6.High quality concreteshall then be filled into the recess.The packing concrete must featurelow shrinkageandhave the same

585


slrengl.h as that of the superstrnctnre,hut in any casenot less than M35 grade.(kxxl compactionandearefttl curing of concreteis particularlyirnportanl..After thecnncrete has cured,the movable installation bracketsslill in place shall be removed.

2.607,5,7,Rolledup neoprenestrip sealshall hecut into the requiredlength andinsertedbetween theedgebeamsby usinga crow barpttshingthe bulb of the seal into the steel groovesof the edgebeams. A landingto a bead shall he formedin the thickened endof the edgesof theseal which would force the thickened endagainstthe steel beam dueto wedge effect when the strip seal is buttoned in place.

26073.8.As soon as the concretein the recesshas becomeinttiallysel., a sturdy ramp shall be placed over thejoint to protect the exp..sedsteel beams and neopreneseals from site traffic. Expansionjoint shallnot he expose.d to traffic loading before the carriagewaysurfacing, isplaced.

26073.9.The carriagewaysurfacingshall he finished flush with thetop of the steel sections. The actual junctionof the surfacing/wearingcoat with the steeledge sectionshallbe formed by a wedgeshapedjoint with a sealing compound.The horizontal leg of theedgebeam shallhe cleaned beforehand. It is particularly important to ensurethoroughand careful compactionof the surfacing in order to prevent anypretnaturedepression forming in it,

AcceptanceTesti) All steel elementsshall be finished with corrosion protectionsystem.

ii) For neopreneseal, theacceptancetest shall conformto the requirementsstipulatedsrs Table 2600-1. It shall also be stretch tested,If a manufac.tnreria to supplythis typeofjoint, theywill have to produce a testcertificateaccordingly conductedin a recognisedlaboratory in India or abroad.

iii) In view of theimporlaasceof the built up edge beams, specialinvestigationof fatigue at.rengtlaof this section wish anchoragesto withstand 2 x 10’ loadchange cyclea withoutshowingsigns of damage,will be required.The suppliershall have to produce a test certificate in this regard, conductedin arecognised laboratory,in India or abroad.

iv) The manufacturershall producetest certificates indicating that anchoragesystemhad beersseated in a recognised laboratory to detennineoptimum configura-Sn of anchorage assembty under dynamicloading.

s) ‘l’he manufacturer shall satisfy the Engineer that water tightness test forthe typeof joint has been carried out in arecognired laboratory so check thewater tightness under awaterpressureof 4 bars.

vi) As strip seal typeofjoint is specialisal in nature,generally of theproprietary

586

ExpansionjoLrtt.’~ Section2600

ty ~ the manufacturer shall he rrei uired to producecvidcncr ‘1:”f stir tact’“ry

perfonnanceof this type of joint

2608. TES1’S AND STANDARDS OF ACCEPTAN(.’F

The tnaterials shall be. tested in accordanceweb thesespL,:cit’ira..i ions and shall meet the prescribedcriteria.

The work shall conform to these specifications and shall meet theprescribedstandardsof acceptance.


The. expansion joinl. shall be measuredin rtinning metres. l::’ctriii led joints., the rate per running metre shall include the. cost of .seaIanbr the depth provided in this drawing.

2610. RATE

‘t’he. contractunit rate shall include the costof all material, lahous’,equipment and other incidentalchargesfor fixing the joints completein all respectsas per thesespecifications in the caseof Bridge. Contractorsupplyin~~,the expansionjoint. If the.manufacturersuppliesthe expansionjoint dtreclly to the Engineer,the costof installatton,handlingandfixing,shall he borne by the Bridge Contractor.

587

Wearing Coat and Appurtenances

2700

Wearing Coat andAppurtenances

Wearing Coat and Appurtenances Section 2700

2701. DESCRIPTION

l’his work shall includewearing coat and bridge appurtenances’.such as railing, approach slab, drainage spouts, weep holes inconformity with details shown on the drawing and these peciftca-tions or as approvedby the Engineer.

2702. WEARING COAT

2702.1. Bituminous Wearing Coat

Specificationsfor bituminousconcrete/bitumenmastic in wearingcoat shall conform to Section 500 except for the special require.-mnents as stated hereinafter.

.2702.1.1. Principles of bituminouswearing coat shall ‘comprise.the. following

i) A layerof masticasphalt,6 mm thick after applying a prime coat over thetop of the deck beforethe wearing coat is laid. The prime coat and the layerof mastic asphalt shalt be laid as per Clauses503 and 515 respectively.

ii) 50 mm thick asrthaltic concrete wearing coat in two layers of 25 rum each asper Clause 512.

in cas.eof high rainfall intensityareas,the thicknessof masticas’phalllayer mnay be increasedto i2 mm,

2702.1.2.For high traffic density, an alternative specificationbr ‘wearing course comprising40 mm bituminous concre..te.. ov’eri.aidwith ‘2.5 mm thick bitumen mastic layer can he adopted.The work shallbe done in conformity with Section 500.

270 2. Cement ConcreteWearing Coat

Cementconcretewearing coat may be provided in caseof isolatedhri.dg.e constructionor bridges‘located in remote. areas.It shall not helaid monolithic witll the deck.

The. l.hicknessof wearingcoat shall be 75 mm. The minim’tum gradeof concrete shall he M 30 with water cementratio as 0.4.

Curing of wearing coat earlier than what is generally requiredmay be resortedto, so as to avoid formation of shrinkagecracks in hotweather,

All carriagewayandfo..tpathsurfaces shall have non-skidcharac-teristics.

591

Section2700 WearingCoat & Appurtenances

The cross slope in the deck shall be. kept as 2.5 per cent fordecks, level in longitudinal profile.

2702.3. For providing cross camberno variation in thicknessofwearing coat shall be permitted.

2703. RAILINGS

2703.1. Generala) Bridge railing includes the portion of the structure erected on and above

the kerb for the protection of pedestriansand traffic.

h) Railings shall not be cortstnicted until the centering falsewonlc for thespanhas been released and the spanis self-supporting.For concretewith steelre:inforcenient, specificationsof the items ofcontrolled concreteandreinforcementmentionedunder relevantsectionsof this specificationsshall be applicable.

c) The type of railing shall be carefully erectedtrue to line and grade. Posts shallbe vertical with a tolerance not to exceed6 mm in 3 metres. The pockets leftfor posts shall be filled up with non-shrinkablemortar

d) The type of railing to be constructed shall ‘be as shown on the drawings..

e) Care shall be exercisedin assemblingexpansionjoints in thetailings to ensurethat they function properly.

0 The bridge railings shall be amenable to quick repairs.

g) Railing materials, particularly metal railings, shall be handled and stored withcare, so that the material and parts are kept clean and free from damage.Railing materials shall be stored above the ground on plstfonns, skids, orother supports and kept free from grease,dirt and other contaminants.

Any material which is lost, stolen or damagedafter deliveryshall be replaced or repairedby the Contractor. Methods of repairshall not damagethe material or protective coating.

2703.2. Metal Railings

Materials, fabrication,transportation,erectionandpainting for bridgerailings shall conform to the requirements of section 1900.

All completesteel rail elements,pipe terminalsections, posts,bolts,nuts, hardwareand othersteel fittings shall be galvanisedor paintedwith an approvedpaint.

If galvanised,all elementsof therailing shallbe free from abrasions,rough or sharp edges,and shall not be kinked, twisted or bent. Ifstraightening is necessary,it shall be done by methodsapprovedbythe Engineer.

Damaged galvanised surfaces,edgesof holes and ends of steelrailing cut after galvanisingshall be cleanedand re-galvanised.

592

WearingCost& Appurtenances Section2700

The railing shall be carefully adjustedprior to fixing in place toensure proper matching at abutting joints andcorrectalignment andcamberthroughouttheir length. Holes for field connections shall bedrilled with the railing in place in the structureat proper gradeandalignment.

Unless otherwisespecifiedon the drawings,meta.l railing shall begiven on..e shop coat of paint and threecoatsof paint after erectionif sectionsare not galva.nised.

Railings shall not follow any irregularity in the alignment of thedeck, When shown on the drawings, the rail elementsshall be curvedbefore erection.

2703.3. Cast-in-Situ Concrete Railings

The portion of the railing or parapetwhich is to he cast inplace. shall be constructedin accordancewith the requirementsforStntcturalConcrete in Section 1700. The reinforcementshall conformto Section 1600.

Forms shall either be of single width hoards or shall be. linedwith suitable material duly approved by the Engineer.Form joints inplane surfaceswill not be permitted.

All mouldings,panel work and bevel strips shall be constructedaccording to the details shown on the drawings.... All corners in thefinished work shall be true, sharp and clean-cutand shall be free fromcracks, spallsor otherdefects.Castingof postsshall be done in singlepour,

2703.4.. PrecastConcreteRailings

Precast members for railings shall be of reinforced cementconcrete and shall conform to the specifications given in See-lions 1600 and 1700. The maximum size of the aggregate shall belimited to 12 mm andthe concretegradeshall be M 30. The precastmembers shall be removedfrom the moulds as soon as practicableandshall be kept dampfor a period of at least 10 days. During thisperiod they shall be protectedfrom sun and wind. Any precastmemberthat becomeschipped,marred or crackedbefore or during the’ processof placing shall be rejected, Specialcare shall be taken to watch thesurfaceof the cast-in-situportion of the deck.

2704. APPROACH SLAB

Reinforced concreteapproachslabcovering the entire width of the

593

Section2700 WearingCoat& Appurtenances

roadway shall he. provide..d as per details given on the drawingsor as approvedby the Engineer. Minimum length of approachslab shall be 3.5 m and minimum thickness300 mm,

The cementconcreteand reinforcementshall conform to Sections1700 and 1600 respectively.The base for the approachslab shall heas shown on l.he. drawings’ or as’ directed hy the Engineer.

2705.. DRAINAGE’ SPOUTS

27’05,I. ‘this work shall consist of furnishing andfixing in positionof drainage spouts a.~ddrainage pipes for bridge decks.

l)s am tv& dong km~‘ ludtn il cIt ftt tson shall lx n suetci by.suUicicnt numberof drainagefixtures embeddedin the deck slab, Thespout’s shall he of’ not Ie.s.s than 100 mm in diameterand shall he ofcorrosive resistantmaterial suchas galvanise.d steel with suitable.clean-out fi,x owes. The spacing of drainagespouts shall not exceed 10 m.“the. dischargefrom drainages-pout shall he kept away from the deckstructure,In case.of viaduco in urban areas,the drainage spoutsshouldbe connectedwith suitably locatedpipelines to clis’charge the surfacerun-off to drains provided at ground level.

2705.2. Fabrication

The. drainageassemh]yshall be fabricated1.0 the dimensionsshownon the drawings; all rn ater’i ~Jsshall he corrosio’n resistant; steecomponentsshall he. of mild stee’ conforming to IS:’226, The drairtage.asse.mhlyshall be. seam ‘welded for u’ate.r tightness and then hofidipgalvanised.

2705.3. Placement

The galvanisedassemblyshall be given two coats of bituminouspainting’ befOreplacenient.‘The whole assemblyshall he placed in trueposition, lines’ and. levels as shown in the drawing ‘wit.h.oece.s.sarycut-out i.n the shuttering for deck slab and held in place Firmly.Wherethereinforcementsof the deckare requiredto be cut, equivalent.reinforcementsshall be placed at the corners of the assembly.

2705.4. Finishing

Aflersetling of the deck slab concrete, the shrinkage cr.acksaround the. .asscmhlyshall he totally sealed with polysulphidesealantor bituminous sealantas pe.r IS: 1834 and the excesssealant trimmedto receivethe wearingcoat. After the wearingcoat is completed,similar

594

.1] 1115. c(’11d1 & Appurtenances Section l7tX)

‘.;eriftnt shall he firtishecl to cover at leasl 50 mm on the wearingcc’ut surfaceall round the drainageassembly.

2706. WEEP HOLE

Weep holes shall he provided in solid plain concrcte(retnli.ircedct’s’lc’rciL’, hrick/slnnemasonry,ahutmenl,wing wall and return walls w~

u on lhe ci rawing or directed by the Engineer to drive moisturethe l’uck filling. Weep holes shall he provided with 100 mm d

C’ pipe or 51 rt,tctttres in plo in/reinforcedconcrete,or brick masonrv. Iiti slone masonry, weep holes shall be 80 mm wide, 15(1 turn

Ii ph or’ circularwith I 50mm diameter.Weep holesshallextend throughfull w ith of concrete/masonrywtth slope of about 1 verlical’ 211

lit tt’tttiiil towards the draining’ face The spacingof weepholes shallaenerall~he Ira in either direction or as showrt tn the drawing ss jIb

Ii, t u est at about I 50 mm above the low w ater level or arotsndlevel ssh iche.~cr is higher or as directed by the Engineer.

2707, i’ESTS ANt) Si’ANDARDS OF ACCEPTAN(’F:

TIre materia.ls shall be tested in accordancewith theseSpecit’rca-arid shall meet the prescrihedcriteria,

‘l’he work shall c’onforn’i to these Specification.sand shall meet dieprcscri bed standardsof acceptance.

270$. MEASUREMENTS FOR PAYMENT

‘l”he tneasurcment for payment for wearing coat, railings andapproach slab shall be made as given below

Cement concrete wearingcoatshall he measured in cubic metrr.s AsphaltIcconcrete wearing coat shalt be measured in squaremetres.

.1 Railings shalt he measuredin running metres.

Approach stab and its baseshalt be enc’asurrdseparately in cubic metres.

is I Orainrye spouts shall he measuredin numbers,

Weep holes in conc:reseThric:kmasonry structure shall hemeasuredin rs.trriFs.:ssFor structures in stone masonry,weep holes shall be deezi’md to be includedEn the itrm of stone masonry wortc and shalt not be measuredseparately.

2709. RATE

The contract tinit rate for wearing coat shall include the cost of alllabour,material, tools and plantandother cost necessaryfor completionof the work as per these Specifications.

‘I’he contract unit rateof railings shall include the cost of all labour,

595

Section2700 Wearing Coat& Appurtenances

material, tools andplant requiredfor completing the work as per theseSpecifications..

‘the contract unit rate for approachslab shall include the costol’all labour, tnate.rial, tools and plant required for completing the workas per theseSpecifications. The rate for base shall include cost ofall labour, material, tools and plant required, including preparationofsurfaceand consolidationcomplete in all respects.

‘the contractunit rate for each drainagespout.shall include the coslof all labour, material, tools and plant required for completingthe,: work as per theseSpecifications.It shall also include the cost ofproviding flow drainpipeswith all fixtures upto thepointof grounddrains’wherever sho’wn on the drawings.

The contract unit rate for weep hole shall include the cost ofall labour, material, tools andplant required for completing the workas per these Specifications.

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2800

Repair of Structures

Repair of Structures Section 2800

2801. DESCRIPTiON

Repairof structuresshallbe carriedout in accordancewith therepairplans and thesespecifications or as directed by the Engineer.Whererepair work is not covered by thesespecifications,special specifica~tion may he framed.

Implementation of repair schenesshall also conform to provisionsof IRC:SP:40.

2802. GENERAL

2802.1, EnvironmentalAspect

Care shall be takento ensuresuitablemitigation measuresagainstnoise anddust, pollutionanddamagesto the environswhether temporaryor permanentand shall be taken as incidental to work.

2802,2. PhasingThe sequenceof work shall be in accordancew’ith the drawings or

as directed by the F.~~ngineer.

2802.3. Traffic Management

Traffic management,signage,signalling arrangement,barricading,and lighting arrangementshall be in accordancewith Section 100 andwith t.hese specificationsandshall be consideredas incidentalsto work.

2802.4. Safety Precautions

Adequate precautionsshall be taken for safety .of personnel,roadusers andexistingservices,which, duringexecution, shall beconsideredas incidentals to work.

Personsworking should wear safety helmets and rubber gloves.

2802,5, Dismantling’ and Removal of Material

t)is.mantling of any bridge componentand removal of materialsshall conform to Section 200 and this section and as shown on thedrawings or as directedby the Engineer.

2803. SEALING OF CRACKS BY INJECTIONOF EPOXY RESIN

2803,1. General

The work of epoxy adhesiveutilising the Structural ConcreteBondingProcess shall conform to these specifications.

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Section2800 Repairof Structures

2803.2. The Contractor shall furnish detailedmethodologyof con-stntction including sotirces of supply of material, tools, equipmentandappliances to be used on work, details of personnel and supervi-sion.

2803.3. Personnel

The Contractor’s personnel shall be qualified and experienced inepoxy injection process.

2803.4. Material

The material for injection shall be suitable two-componentlowviscosity epoxy resin, having the required characteristicsof bondingwith concreteand resistanceto moisture penetration.Epoxy mortaror poly.s’ulphide resin may he used for sealing the surface.

The material for epoxy injection shall conform to the followingI) The mixing ratio of resin and hardener shall generally be between I to I and

2 to I by volume subject to manuracturer’srecommendation.

ii) Neitherthemixed epoxy adhesivesnor their individual componentsshall containsolventsand thinners,

iii) The componentsshatl be free of lumps or foreign material, The viscosity of theindividual componentsshall not changemore than ±15per cent when kept inclosedcontainersat 2.5 degrees~etsius after two weeks.

iv) Consistencyrequiremeni

StandardVersIon

Low ViscosityVersion

cpa cpa

Viscosity of Mixed Adhesiveat 25 degreesCelsius (200-300) (t0O-t90)

v) Pot Life of mixed adhesiveat 25 degreesCelsius

1 hour ±15minutes ‘

Si) Set time of miscrl adhesiveat 25 degrees Celsius

3 6 hours

*ln the caseof two componentinjection system where resin and hardener get mixedat point of injection pot life at 25 degreesCelsius shaH be not greaterthan 15 rain ~lOminutes.

2803.5. Equipmentfor injection

The equipmentshall be portable,positive displacementtype pur ~with interlock to provide positive ratio control of exactpropori onsof ihe two componentsatnozzle.Thepumpsshallbe generallyelectr:.’aliypoweredand shall provide in-line metering and mixing. The tolerance.on mix ratio shall be 5 per cent by volume, The injection equipment

600

Repairof Stnictures Section2800

shall have automatic pressurecontrol capable of discharging mixedadhesiveat any pre.setpressurewithin the prescribed limits and shallbe additionally equipped with a manual pressure control.

The injection equipmentshall be equippedwith sensors on boththe componentsA and B reservoirs, that will automaticallystop themachinewhenonly onecomponentis being pumpedto themixing head.

if consideredappropriate,suitablecompressedair operated epoxy in-jection gun can be used with prior approvalof the Engineerfor manualinjection of mix when resin and hardenerhad beenmixed in a separ.ateunit,

2803.6. Preparation

Surfaces adjacentto cracks or otherareasof application shall becleaned of dirt., dust, grease,‘oil .efflorescenceor other foreign matle.rby brushingJwaterjetting/sandblasting. Actds and corrosives shall notbe permitted for cleaning.

Entry ports shall heprovided along thecrackat intervalsof not morethan the thickness of concrete at the location.

Surface sealmaterialshall heappliedto the face of thecrackbetweenthe entry ports,For throughcracks,surfaceseal shall be appliedto bothfaces,

Before proceedingwith the inject.ion, thesurfaceseal material mustgain adequatestrengthwith respectto concretestrength of the member!injection pressure.

2803.7. Epoxy Injection

Injection of epoxy adhesiveshall begin at lowest entry por andcontinue until there is an appearanceof epoxy adhesive~at the nextentry pOrt adjacent to the entry port being pumped.

When epoxy adhesivetravel is indicatedby appearanceat the nextacUacentport, injection shall be discontinuedon the entry port beingpumpeda.nd entry portshall be sealed. Thereafter, epoxyinjection shallhe. transferredto next adjacentport where epoxyadhesivehas appeared.

Epoxy adhesiveinjection shall beperformedcontinuouslyuntil cracksare completely filled.

If port to port travel of epoxy adhesive is not indicated, the workshall immediatelybestopped.In casethe volumeof the injected tnate,rial

601

Section28(X) Repairof Structures

exceeds2 litres for a particular entry port, the work shall be stopped

and the specificationsmay be reviewed.

2803.8. Precautions for Applicationa) t.Jntess otherwise.specified,componentsA and B, i.e., resin and hardener, shall

be at a temperature betweentO degreesCelsiusand 35 degreesCelsiusat thetime of mixing.

is) Temperautre ot structural nsemhee during epoxy injection shall hebetween10 degreesC.elsics and 35 degree.sCelsius unless otherwise specified.

c.) Inssnediatelyprior to use,each cotnponentshslt he thoroughly mixed with acleanpaddle. The paddle shall be of a type that doesnot induce air into thematerial, Separate dean paddle must he used for each component

d) Any heating of theadhesivecomponentsshall he.done by application of instirectheat in case the work is to he done in cold climate,

c) Just before use, the two components shall be thoroughlymixed in. the ratiosspecified by the manufacturer,The length of mixing time shall he in strictaccordancewith manufacturer’srecommendations,When mixed, all ad.i.csiveswith different coloured componentsshall have a uniform colour without streaks.

~fl The use of sulventsand thinners will not he permittedexcept for cleaningof equipment.

2803.9. Testing2803.91,Mateilal Testing’. Prior to approval of the material, the

following testsshall be carried out at site or in an authorisedlaboratoryfor each batch of resin and hardenerand each combination thereof atthe. co:st of the Contractor.

i) Viscosity test for resin and hardenerand the mix - three specimenseach.

ti) Pot life test - thre.e specimenseach.

iii) Bond test - three specimens each.

is) Shear test - six specimenseach, 3 after 24 hours and the other three aftet 72hours of curing

Suhsc.quent~testsshall be. carried out as directedby the Engineer.a) Pot t,ife Tests

i) 500 gm of resin formulation shall be preparedby thoroughly raising theresin and hardener/accelerator/catalyst component in proposed proportionin a I kg capacity hernispheral porcelain bowl by means of a spatula orany other agitating device and nose down the time and the ambienttemperature.

ii) With a cleandry 25 mm size painter’s brush, the resin formulation shallbe applied on a clean dry surface such as cement concrete over iS-20 cm length, starting immediately after mixing the fonnulation andrepeating operation every five minutes. When it becomesjust difficultto spread the resin property with the hmsh, the time is notett The

602

Ret:tais’csf Structures Section2800

time elapsedsince corrspletion csf tnixing of resin fomtulation is taken asits pot life,

iii) One pot life test shalt he performedon commencementof work and thesattte shalt be repeatedeven’ four hostrs..

iv) In case the material fails to satisfy the Pot life test it shall not lx. usedfor injectton.

Wttese theresin and hardenerget mixed at point of injection, the pot life is r.oiirrtportant and no teats may be required.

Ls,t Bond Test

.A standard ISO snm diameterand 300 mm long concretecylinder shalt he eastin 2. piecesby providing a separatingmedia at an axis of 45 degreesCelsiusto tlse longer axis of the cylinder (refer to Fig. 2.800/1).‘I’hree sets of suchsplit cylinders shall he preparedin advance,Two piecesofeach set shall be joined wir.h epexy rnorear at four p. mrs to give a clear gapof shout 0.2 mnns, which will be injected with epoxy resin at site, After epoxyhasbeen cured, load test is esrriedout on the cylinder which shall not he testthan Sf) per cent of the cube strength of the concretemix and the failure shaltnot take place at she ,joint injected with epoxy resin,

~e) SttearTests

Two steelplates,minimssm3mm thick, shall bebondedwith epoxyat site usingthe sameresin mix as used/proposedto he usedfor injection. The assembly shalthe kept in mechanical clamp till epoxy is cured,A total of six specimensshallbe prepared for each hatch of materials.Three test specimensshalt then hesubjectedto a shearforce alongthe axis after 24 hoursand theminimunt shearstrengthbefore failure shalt nut be less than 1 MPa, (refer Fig. 2800/2).

The. remainingtest specimensshall be similarly testedafter 72 hoursof curing. The shearstrength before f’ailure shall not be less than 2.,5MPa,

2803.9,2, Core test : If directedby the Engineer,core tests shallbe. con.ducted for the acceptanceof the work. The selectionof thelocation of cores shall be made under the direction of the Engineerin such a way that damagein critical/stressedareas.of the structureis avoided, The procedurefor the test shall be as under.

The. Contractor shall ohtain 5 cm diameter initial core samplesinthe first 50 linear metres, Thereafter, frequencyof core samplingshall he as specified or as agreedby the Engineer.

The depth of the core shall generally be less than 20 cm.

l’ests and AcceptanceCriteria shall be as followss) Penetration/VisualExamination - a minimum of 90 per cent of the crack shall

be full of epoxy adhesive,

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b) Bond Strength : Concretefailure before adhesivefailure or 40 MPa with no failureof either co~xcreLeor adhesive

If thecorestakenin first 50 m length passtestsas specifiedabove,epoxy adhesive injection work at area represented by cores will beaccepted.

If cores fail either by lack of penetrationor bond strength, workshall not proceedfurther until the areasrepresentedby the coresare re~injected and retested for acceptance.

Filling of Field Control Testing Core HolesThis procedure consists of using two~componentbonding agent

applied to surfaces of cored holes followed by application of Non-Shrink cement grout mix placed by hand trowel, thoroughly roddedand tampedin place,and finished to match finish and texture of existingconcrete to the satisfaction of the Engineer. Materials and proceduresfor filling testing core holesshall be submitted to and approved by theEngineer before proceeding with core testing work.

2803.9.3.Test br injection equipment At all times during thecourse of the work the Contractor shall keep complete and accuraterecords and makeavailable to the Engineer of the pressure and ratiotests specifiedabove so that the efficacy and accuracyof the injectionequipment is verified.

In addition, the Engineerat any time without prior intimation of theContractor may request the Contractor to conduct the tests specifiedbelow, in the presenceof the Engineer.

a) Pres~areTest

The mixing headof the injection equipment shall be disconnected and the twoadhesivecomponentdeliverylines shall be attachedto the pressurecheck device,which shall consist of two independent vatved nozzlescapable of sensingthepressure. The cheek device shall be closedand equipment operated until thegauge pressure in each tine reads 5 MPa, The. pumps shall be stopped andthe gaugepressure shall not drop below 4 MPa within 2 minutes.

The preasure test shall be run for each injection unit at the beginning andafter break of every shift.

b) Ratio Test

The mixing head of the injection equipment shall be disconnectedand the twoadhesive componentsshall be pumped simultaneously through the ratio checkdevice, which shall consist of two independent valved nozzles.There shallbe a pressure gaugecapable of controlling back pressureby opening or closingvalved nozzles capable of sensingthe backpressurebehindeach valve.Thedischarge pressureshall be adjusted to read 5 bar for both adhesive components,

605

Section2800 Repair of Structures

which shall be simultaneously dischargedinto separatecalibrated containersduring the same time period and the amounts dischargedinto the calibratedcontainers simultaneously during the sameperiod shall be compared to de-termine that thevolume/discharge conformsto themanufacturer’s recommendedra.tio for applicable material.

2804. EPOXY MORTAR FOR REPLACEMENT OFSPALLED CONCRETE

2804.1. Material

2804.1.1. Formulation

The epoxy resins for use in the mortar shall be obtained from areputed manufacturerand the mortar shall be prepared in conform-i ty with the manufacturer’s recommendations.

They shalt generally conform to the following:

Pot Life : 90 minutes at 25 degreesCelsius

60 minutes at 30 degreesCelsius

45 minutes at 35 degreesCelsius

Bond Strength : 12 MPa

Tensile Strength : 16 MPa

The Contractor shall carry out tests on the samples made out orrequirements indicated above.

The sand content in the mortarshall be in accordance with thedesiredconsistency.

2804.2. Proportioning and Mixing

The resin and hardener shall be mixed before adding the dryfiller. The mixed ready to use mortar should not contain lumps ofunwetted filler and should be uniform in colour. For a total weightøf 1 kg or less,handmixing will be sufficient. For quantities in excessof 1 kg, the component shall be mixed for 3 minutes with a slow speed

400-600rpm - electric drill with a Jiffy mixer, The stirrer shall bemoved up and down andalong the sides until an even streakfree colouris obtained.Whipping in an excessiveamount of air shall be avoided.If no power is available, a flat putty knife may be used to reachinto the corners of the can andhandmixing done for at least 5 minutes.

2804.3. Surface Preparation

Surface upon which epoxy is to be placed shall be free of rust,

606


grease, oil, paint, asphalt,loosematerial, unsound concrete,dust or anyother deleterious material.

Since cured epoxy does not provide adequate bond with anymaterial, all overlay, whether epoxy or cementbased, shall be donewithin pot life of the base epoxy layer.

2804.4. Contaminants, such as oil, grease,tar, asphalt,paint, wax,curing compounds or surface impregnantslike linseed oil or silicons,including laitance and weak or loose concrete shall be removed. Whenbonding to asphalt, the surface should be roughened so that cleanaggregateis exposed.Epoxy bonding agents shall not be applied whenii rains, or in standing water. The surface must be dry.

Two general methodsof surface preparationshall be followeda) Mechanical that includes grinding, grit blasting, water blastingand scarification.

b) Chemical that includes acid etching with 15 per cent by weight of hydrochloric

solution, followed by repeatedflushing with high pressure streamof water.

2804.5. Application

Epoxy primer coat shall be applied with the help of stiff nylonbristle brushes or hard rubber rollers or spray gun depending uponthe nature of surface and extent of work area. As far as possible,the coating shall be uniformly thick.

Before the primer coat is fully cured, epoxy mortar shall beapplied by means of !rowels and floats. The interval between theapplication of primer coat 3nd epoxy mortar shall be approximate-ly 15/30 minutes depending upon the ambient temperature.

Seat Coat shall be applied after 24 hours curing, after mildroughening of the surface of the mortar,

2804.6. Coverage

The coverage of resin mix would depend on the system of resinused. However, as a general guideline the coveragearea shall be asunder

a) PrimerCoat. Onekg of resin-hardener mix coversan area of 3-6 square metresper coal depending on the fmish of the concrete.

b) Epoxy Mortar. One square metre of surface requiresapproximately 20-24 kg of epoxy mortar when laid to a thicknest of 10mm.

c) Seal Coal. 4 to 6 square metres per kg of mix depending on thetemperanireof application.

607


2804.7. Cleaning and Maintenance of Equipment

Tools and equipment arebest cleaned immediately after use sincethe removal of cured resin is difficult and time consuming. The bulkof resin shall be removed using a scraper and remainder washedaway completely using solvents such as toluene, xylene or acetone.Equipments used for epoxy shall always be cleanedbefore it hardens.Solventsusedfor this purposemay be Acetone(flammable), Methyl EthylKethone(flammable), Methyl Chloride (non-flammable). Cured epoxiesmay be removed using Methylene Chloride.

2804.8. Testing

Epoxy used for making mortar shall conform to all requirementsand testing proceduresas laid down in Clause2803.9.

2804.9. Handling Precautions

Epoxy resinscan cause irritation of skin in sensitive persons if in~correctlyhandled.The resin andhardenershould not be allowed to comeinto direct contactwith skin. The most effectiveprotectionis achievedby wearing rubber or polythene gloves.

2804.10.Personnel and Environment ,Safety

Any skin contactwith epOxy materials, solvents andepoxy strippersshould be avoided. Epoxy resins and particularly epoxy hardeners (Bcomponent) may cause a rash on the skin. The official toxicityclassification on the containerlabels may be looked for before startingwork.

Rubber gloves,with a cloth liner, and protectiveclothing shall beworn. Bather creams are recommended but are not substitutes forprotective clothing. Eyes shall be protectedwhere splashingcould occurwhile spraying or mixing. Good ventilation shall be ensured andinhalation of vapours avoided. If materials are sprayed, a respiratorshall be used.

If skin contactoccurs,it shall be immediately washedwith a cleaner,followed by soap andwater.Shouldeye contact occur, it shall be flushedimmediately with plenty of water for 15 minutes and a doctor calledfor.

If contact occurswith the clothing, it shall be immediately changedto prevent further skin contact,and if thecontactoccurswith componentsA or B, the clothing shall be thrown away. Hardened epoxy is not harmfulbut will break the clothing.

608


All emptied, used buckets,rags and containersshall be removedfrom site. These shall be stored in waste disposal bags and suitablydisposed.

2805. EPOXY BONDING OF NEW CONCRETE TOOLD CONCRETE

2805.1. Epoxy resin used for bonding shall be obtained from areputed manufacturer. The pot life of such bonding epoxy shall notbe less than 60-90 minutes at normal temperature.

2805.2.The entire surfaceof the existing concrete member shouldbe thoroughly cleaned by wire brush and then with compressedair toremove dust and looseparticles from the surface. Any crack or spallingof concrete shalt be sealedby epoxy injection/epoxymortar/groutingas decided by the Engineer. A coating of suitable epoxy resin at therate of 0.8 kg/sq.m.(minimum) should then be applied on the surfaceof the existing cOncrete members. Fresh concrete shall then be placedwithin the pot life of the resin system.

2805.3. Testing2805.3.1.Epoxy used for bonding work Shall satisfy the criteria

mentioned in Clause 28019.

2805.3.2. Two concrete cubes 150 mm size cast as per approveddesign mix shall be placed, as shown in Fig. 2800/3 at a distanceof 150 mm from each other. Epoxy resin system suggestedfor bondingnew to old concreteshall be applied on the opposite facesof the cubes.

Fresh cementconcrete cubeof gradeas per approved design mixshall be cast with water cement ratio of 0.4 or less in the mannershown in Fig. 2800/3. The assembly shall be cured in water for 28days and steel spacer removed thereafter.

The cube assemblyshall .be subjected to compression load after 28days of curing, thereby subjecting the bond to shearing load. Failuremust not occur at this joint.

2806. CEMENT GROUTING

2806.1. Material

Grouting shall normally be performed with a mixture of neat PortlandCement and water. Other additives and admixtures may be added toimprove the Impermeability, strength, etc. on the approval of theEngineer. The size of the particles and the consistency of the groutmust be suited to the passagewaysit must follow. Neat grout will not

609

Section2800

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Repairof Structures Section2800

flow freely into holes smallerthan about three timesthe largestcementparticle. Except in large cavities where thick mortar can be placed,the sand shouldall passthe 28-meshsieveand have a large portionpassingthe 50- and the 100-meshsieves.The proportions of OrdinaryPortland Cement to sand Will dependupon the size of the spacestobe filled andwill vary from a neatgrouttoabout 1:1 mix. The amountof water to be added depends upon the consistencyrequired.Oroutswith as little as 16 litres of water per bag of cementcouldbe handledand it should’seldom be necessaryto use more than 35 to 40 litresof water per bag of cement.

Where necessary and approvedby the Engineer, admixtures toPortland Cement groutmixturesmay be added for delaying thesettingtime, increasing flow ability, minimising segregation~andshrinkage.

2806.2. Preparation

The surface shall be cleanedwith wire brushand compressedair.15 mm din and 150 to 200 mm deep hoLes along the length ofthe cracks at a spacingof 500 mm may bedrifted by wetdrilling usingrotary percussiondrills and nipples.inserted in theseboles.

2806.3. Proportioning,MixIng, and Equipmentfor Grouting

The cement grout shall be mechanicallymixed using a systemof power-driven paddlesof high speedcentrifugalpump. The groutpump to be usedshall permit closecontrol of pressurestoallow aflexiblerateof injectionwith minimum cloggingof valvesand ports The mostsatisfactoryequipmentfor injectinggrout is a pump of the double-actingflexible reciprocatingtype giving a steady flow. The groutpump shallbe so placedasto reduce the waste in cleaninglines. It is preferableto add 50 percent or mOre of the mixing water into the mixer beforeadding thedry ingredientsandthen the remaining water. A continuoussupply of grout is preferable to an intermittent one. Consistencyofthegroutmay be determined by trials startingwith thin grout i.e. about40 litres of water per bag of cementand progressively decreasingthe water content to about 15 litres per bag of cemenL

Where the mixer andpump arecombinedin one unit1 the drymaterial shall be screenedbefore mixing. if the mixer and pump arein separateuwis, the grout shall passthrough ascreenbefore it entersthe pump.

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Section2800 Repair of Structures

2806.4. Application

Highest practical pressure within the limits 100-400kPashould beusedin order to force thesurpluswaterfrom the grout. As thb pressuremay be distributedhydraulicallyover considerableareas,vigilance mustbe exercisedtopreventdamageor,the needlesswasteof grout.Oroutingis ~obe done by attaching a pscker (consistingof expansibletubeof rubber) to the end of the groutsupply pump throughthe holesandnipples.

Pressureshall be steady to ensurea continuousflow of grout.Groutingshall not be continuedtill the holeconsumesmix at the rateof not lessthan 30 litres in 20 minutesor until refusalat the groutingpressureof 400kPaat any hole until iefhsaL Should the groutescapefrom an adjacent nipple,it should be plugged or capped. Any seam,crack or joint throughwhich grout escapesshallbecaulkedwith epoxyffiortar as soon as thick grout appears.

2806.& Cleaning o~Equipment

After completionof eachgrouting operationor temporaryshutdown,it is advisableto force dearwaterthrough the pumpuntil the dischargeline showsno colour,aflCr which the pumpcovers shall be removedand the valve chambers thoroughly cleaned.

2S06.6~Testing

Percolationtest done at the end of grouting operation shall give avalue of less than 2 lugions.NOTE: For specialisedtrea~ntentlike polymermodified cemenu*iour grom injection.

manufactumr’s htemuneand specification shall be followed.

2807. GUNIT1NG/SHOTCRETE

2807.1. The gunite is a mixture of cement, sand and water. Itcomprises 100 parts by weight of cement, 300 parts by weight quartzsand, 35-50parts by weight water and2 parts by weight approved quicksetting compound. In general, dry mix shotcreteshall be used.

2807.2. Ordinary Poillandcementconforming to IS:269 shaft be usedin guniting.

28073.Sand for guniting shall comply with the requirements stipu-lated in IS:383. In general,sandshould neither be zoocoarse to increasethe rebound nor too fine to increasethe slump. Sandshould preferablyhave a moisture content between 3 to 6 per cent.

612

Repair of Stmctures Scc~ion2800

The grading of sand shall lie within the limits given belowIS SieveDesignation

per centPassingthe sieve

4.75mm 95. 1002.36mm 65.901,18mm 45.75

600 microns 30 - 50

300 microns 10 - 22150 microns 2 8

2807.4. For thick sections it may be advantageousto incorporatecoarse aggregate in the mix provided adequate guniting equipment isavailable. Coarse aggregate,when used,shall conform to grading givenin Table I of IS:9012.The percentageof coarse aggregatemay normallybe kept as 20 to 40 per cent of the total aggregateand the mix shallbe suitably designed.

2807.5. Water/cement ratio for guniting shall fall within the range0.35 to 0.50 by mass, wet enough to reduce the rebound. Dryingshrinkage may be between0.06 per cent to 0.10 per cent. The quicksetting compound shall be added at the nozzle with water just beforeguniting.

2807.6. Workrnansh~p

The cement and sand shall be batched and mixed and conveyedthrough a hose pipe with the help of compressedair. A separatelineshall bring the water under pressure. The cement, sand and water mixshall be passed through and intimately mixed in a special manifoldand then projected at high velocity to the surface being repaired.The densityof gunite shall not be lessthan 2000 kg/cu.m.The strengthof gunite shall not be less than 25 MPa. For effective guniting, thenozzle shall be kept 60 to l50~cm away from the surface, preferablynormal to that surface. While enclosing reinforcement bars duringrepairs the nozzle shall be held~closer at a slight angle and themix shall be wetter than the normal.

2807.7. Test panels simulating actual field conditions shall befabricated for conducting preconstruction testing. The procedure fortesting the cubes or cylinders taken from the panels stipulated inclause 6 of lS:90l2 shall be followed.

2807.8. It should be ensured from tests that a strength of about25 MPa at 28 days is available for the mortar/concrete mix.

2807.9. The defective concrete shall be cut out to the full depth

613


till sound concrete surface is reached. Under no circumstances shouldthe thickness of concrete to be removedbe less than clear cover tothe main reinforcement. No squareshouldersshall be left at the perimeterof the cut-off portion and all edges shall be tapered.Thereafter, alllooseand foreign materials should be removed andthe surfacebe sand~blasted to make it rough to receive shotcreteafter applying a coatof bonding epoxy as per recommendation of the manufacturer@ 1.0kg per 1.5 sq.m. of surface area.

2807.10.The exposed reinforcement shall be thoroughly cleanedfree of rust, scalesetc. by wire brushing. Wherever the reinforcementshave been corroded, the sameshall be removed and replaced byadditional reinforcement. Before application of gunite, a coat of nearcement slurry should be applied on the surface of the reinforcement.

2807.11. Sufficient clearanceshall be provided around the rein-forcement to permit encasementwith sound gunite.Careshall be takento avoid sand pocketsbehind the reinforcement.

2807.12.A thickness of 25 to 40 mm of gunite can normally bedeposited in one operation. If, for some reason,the total thickness is’to be built up in successiveoperations, the previous layer should beallowed to set but not become hard before the applicati&n of thesubsequent layer. It would always be necessaryto apply guniting ona damp concrete surface.

2807.13.Where required, welded wire fabrics Scm x 5 cm x No.10 gaugeshall be providedin the first layer of guniting. The fabricshall be tied properly. In case the damage to the concrete memberis too deep,the specificationsfor guniting as well as requirement ofplacement of wire mesh has to be decidedas per field conditions.

2807.14.The stipulations given in IS:9012 regardingapplication ofgunite should be followed soas to keep the reboundto the minimum.The quality of guniting and workmanship shall be such that thepercentage of rebound mentioned in IS:9012 can be adheredto. In nocircumstances shall the reboundmaterial be re-used in the work.

2807.15. It would be desirsble that green gunite is moistened forat least 7 days. Guniting work shall not be doneduring windy or rainyconditions.

2808. REPLACEMENT/RECTIFICATION OF BEARINGS

2808.1. The replacement/rectification of bearings shall be carriedout in accordance.with approved repairplan or as approvedby the Engi-neer.

614


2808.2. Lifting of superstructure spansmay be carried out by jackingup from below or by lifting the span from top. Where jacks areemployed, their location/number and size shall be selected in sucha manner so that there are no undue stressescreated in the structure.Jacks may be placed on piers/pier caps or specially erected trestlesin accordancewith the approved methodology for lifting of superstruc.ture. All jacks shall be operated from one control panel by a singlecontrol lever. The system will have provision for manual over rideto control the loads of any particular jack. The jacks should beso synchronised that differential lift between individual jacks shallnot exceed 1 mm

2808.3. Necessaryrepair/replacementof bearings shall be carriedout as indicated in the repair plan or as directed by the Engineer. Careshall be taken to plan the execution of repair in the shortest possibleperiod.

2808.4. Precautions during Lifting of Girders for Rectification ofBearings

Walkie talkies system.or similar audio arrangements should beavailable for communicating instructions regarding lifting, stopping,starting etc. The operator shall have a clear view of the jacks andthe lifting of each girder controlled by reading the dial gauges.

2809. DISMANTLING OF CONCRETE WEARING COAT

2809.1. Commencement of Dismantlingi) Before commencing dismantling, the nature and condition of concrete, the

condition and position of reinforcementshould be ascestained. The Contractorshall familiarise himself with the structural design and ensurethat the overallstability of the bridge is not affected,

ii). The existing expansion joint assemblies shall be removed carefully along theentirewidth of the carriageway. The deck slab for a width of 400 mm on eitherside should be removed for placing of reinforcement., anchor rods, anchorboltsand other fixing assemblies for the new expansion joints and pouring of freshconcrete.The gapbetweenthe girders over thepiersshould be clearedof all debris.A temporary platform in the gap at the end of girders shall be erectedto collectthe materials falling down during concreting and fixing of expansionjoints

iii) The service lines, if any, shall be disconnected/diverted beforethedismantlingwork starts.

2809.2. Dismantling of concrete wearing coat shall be carried outusing jack hammers or suitable manual methods as approved by theEngineer. Care should be taken to avoid any damage to the existingstructure including reinforcement or prestressinganchoragesfor cables,

615

Section2800 Rcpairof Structures

if any, located in the deck slab.

2809,3. Precautions During Dismantling Work

For general guidelines, referencemay be made to Section 100.

Dismantling work shall not be carriedout at night, or during stormor heavyrain. A warningdevice shall be installedin the areato be usedto warn the workers in caseof mishaplemergency.

Safety helmets conforming to IS:2925 shall be usedby the workmenengaged in dismantlingwork, The shedsand tool boxes should belocatedaway from thework site.Gogglespreferably madeup of celluloidsand gas masks shall be worn at the time of dismantling, especiallywhere tools like jack hammersare deployed to protect eyes frominjuries from flying pieces,dirt, dust etc. Leather or rubberglovesshallbe worn by the workers during the demolition of RCC work. Screensmade up of GI sheetsshall be placedwherever necessaryto preventthe flying pieces from injuring the workers.

Water should be sprayed to reduce the dust while removingconcrete wearing course with jack hammer. No work shall be takenup under the span when dismantling work is in progress.

2810. EXTERNAL PRESTRESSING2810.1. Various components constituting the system of external

prestressingare as followsH.T. Strands/Wires, HDPE Sheathing, Deviator Blocks, Anchor

Plates, Anchoragesand grouting material.2810.2. MaterialH,T. Strands/ WiresH.T.Strandswires shall conform to Section 1000.HDPE SheathingHDPE Sheathing shall conform to IS:4984 suitable for a working

pressure of 6 bars. Its density shall be 955 kg/cum, shore hardnessD63, yield stress24 MPa and ultimate tensile strength 35 MPa.

Deviator BlocksAs necessitatedby the profile of the external cable, suitable stranW

wire deviator block fabricated from M.S.Sectionsshall be provided. Thedeviator block shall be given a coat of suitable paint (preferably epoxybased)after sand blasting.

616


Anchorages

Depending upon the prestressing force, suitable anchoragesandwedges shall be usedconforming to relevant codes and section 1800.

28103, Workmanshipa) Stressing of cablesshalt be earnedout as per instructionsgiven in the drawing,

and conforming to Section 1800.

b) Care should be taken to avoid any damageto the existing sisucture,by way ofstressconcentrationor’any other reason during fixing of the deviator blocks andafter stressing of cable.The deviator blocks shall be sofixed as not to allow anymovement due to prestressing forces. Radius of corvatureof the surfaceof thedeviator block interfacing with the cable shall be minimum one metre.

c) The anchoragesshall be sealedwith suitable epoxy mortarsystem after thestressing of cables, A minimum coverof 50mm shall be providedfor the anchorplates and anchorages.

d) Suitable grouting inlet pointsand ventpoints shall be providedby way of HDPE‘1” vent connectionsto the sheathing.

e) Grouting of cablesshall be carried out as per provisions made in Section 1800.

2810.4. It shall be ensured that no part of the existing structureis damaged/distressed due to the externalprestressing.

The behaviour of the girder shall be monitored by measurementofdeflection so that only required amount of external presiressing isimparted to the girder. Care shall be taken to avoid excessprestressingand impairment to the girders.


The materials shall be tested in accordancewith theseSpecifica-tions and shall meet the prescribedcriteria.

The work shall conform to these Specifications and shall meet theprescribed standardsof accepthnce.

2812, MEASUREMENTS FOR PAYMENTa) Measurement for sealingof cracks and injection shalt be made by weighs

of epoxy consumed in kg for epoxy grouting. For provisionof nipples requiredfor grouting, the payment shalt be for number of nipples inserted.

b) Measurement for sealing of cracks and injection shall bemade by weightof cement consumed in kg for cement grouting.

c) Measurement for applicationof epoxy mortar for specifiedthicknessshalt beper square metre of surface areaof application.

d) Measurement for bonding of old and new concrete by epoxy mortar shallbe measured in square metre surface area of interface.

617


e) Measurement for guniting/shoicreting,shall be per squaremetreof surface areaof application.

f) Payment for replacemenUrectificationof bearingsshall be for eachnumberofbearing assembl~replaced/rectified.

g) Dismantling of wearing coat shall be measured in square metre of area ofwearingcoursedismantled.

h) Provision of external prestressing shall be measuredin tonnes of FIT. ste&strand/wiremeasured from anchorage to anchorage before stressing.

2813. RATEThe contract unit rate for sealingof cracks and injection of cement

grout shall include costof all materials, labour, toots and plant, placingin position, testing, curing and other incidental expensesfor thesatisfactorycompletion of the work as per these specifications.

The contract unit rate for application of epoxy mortar forspecifiedthickness shall include cost of all materials, labour, tools andplant, placing in position, testingandother incidentalexpensesincludingsurface preparationfor the satisfactQry completion of the work as perthese specificationsand as shown on the drawings.

The contract unit rate for gunitinglshotcreting shall include costof all materials,labour, tools and plant, placing in position, testing,curing, surface preparation and other incidental expensesincludingthe provision of nipples for the satisfactory completion of the work asper these specifications.

The contractunit rate for replacement/rectification of bearingsshallinclude costof all materials, labour, tools and plant, placing in position,site welding/riveting/bolt connections,operation of jacks and otherincidental expenses for the satisfactory completion of the work as perthese specificationsand as shown on the drawings.

Thecontract unit rate for dismantling of wearing coat shallincludecost of all jirnterials, labour, tools and plant, traffic management,signages, safetyprecautions and other incidental expenses includingremovalof existing expansionjoints for the satisfactorycompletion ofthe work as per these specifications.

The contract unit rate for external prest.ressing shall include costof all materials,labour,tools andplant, temporary works, testing, curingand other incidental expensesincluding the careful monitoring of thedeflection of girders being externally prestressed for the satisfactorycompletion of the work as per these specificationsand as shown onthe drawings.

618

Pipe Culverts

2900

Pipe Culverts

Pipe Culverts Section 2900.

2901.SCOPE

This work shall consistof furnishing and installing reinforced cementconcretepipes, of the type, diameter and length required at the locationsshownon thedrawingsor asorderedby theEngineer andin accordancewiththe requirementsof theseSpecifications,

2902.MATERIALS

All materials usedin the constructionof pipe culvertsshall conform tothe requirementsof Section1000.

Eachconsignmentofcementconcretepipesshall be inspected,tested,if necessary,andapprovedby theEngineereither at theplaceofmanufactureor at the site before their incorporation in the works.

2903.EXCAVATION FOR PIPE

Thefoundation bedfor pipe culverts shall be excavatedtrue tothe linesand gradesshown on the drawings or as directed by the Engineer, Thepipes shall be placed in shallow excavation of the natural ground or inopen trenchescut in existingenibankments,takendown to levelsasshownon the drawings.In caseof high embankmentswhere the height of fill ismore than three times the externaldiameterof the pipe, the embankmentshall first be built to an elevationabovethe top of the pipe equal to theexternaldiameterof thepipe, andto width oneachsideof the pipe of not lessthan five times thediameter of pipe,afterwhich atrench shall be excavatedand the pipe shall be laid.

Where trenching is involved, its width on either sideof the pipe shallbe aminimum of 150mmorone~fourthofthediameterbfthe~ipewhicheveris moreand shall not be more than one-third thediameterof the pipe.The sidesof thetrenchshall beasnearlyverticalaspossible.

The pipe shall be placedwhere the ground for the foundation isreasonablyfirm. Installation of pipesunder existing bridges or culvertsshall be avoided as far as possible.When during excavationthe materialencountered is soft, spongy or other unstable soil, andunlessother specialconstruction methods are called for on the drawings or in specialprovisions,suchunsuitablematerialshall beremovedto suchdepth,widthand length as directedby the Engineer.The excavation shall then bebacklilled with approved granular material which shall beproperly shapedand thoroughly compactedupto the specifiedlevel.

Wherebed-rock or boulder strataare encountered,excavationshall be

621

Section2900 Pipe Culverts

taken down to atleast200 mm below the bottom level of the pipe withprior permission of the Engineerand all rock/boulders in this area beremoved and the spacefilled with approved earth, free from stone orfragmented material, shaped to the requirements and thoroughlycompactedto provide adequatesupport for thepipe.

Trenchesshall be keptfree from wateruntil the pipes are installedand thejoints have hardened.

2904.BEDDING FOR PIPE

The bedding surface shall provide a firm foundation of uniformdensity throughoutthelengthof the culvert, shall conform to thespecifiedlevelsand grade,and shall be of oneof thefollowing two typesasspecifiedon the drawings:

(i) First Class bedding: Under firstclassbedding, the pipe shall be evenly beddedon a continuous layer of well compacted approved granular material, shapedconcentrically to fit the lower part ofthe pipeexterior for atleast tenper cent of i t.soverall heightor as otherwiseshownon thedrawings. The bedding material shall bewell graded sand or another granular material passing5,6 mm sieve suitablycompacted/rammed.The compactedthicknessof thebedding~ yershall be asshownon the drawings andin nocase shall it be less than 75 mm,

~ii) Concrete cradle bedding: When indicated on the drawings or directed t~,theEngineer,the pipeshall be bedded in a cradle constructedof concretehaving a mixnot leanerthanM 15 confomiing to Section1700,The shapeanddimensionsof the -

cradle shall be as indicatedon the drawings. The pipesthafibelaid on theconere~ebeddingbeforetheconéretehas set,

2905.LAYING OF PIPE

Nopipeshall belaid in positionuntil the foundation has been approvedby the Engineer. Where two or morepipesare to be laid adjacent to eachother, theyshallbe separatedby adistanceequal to at leasthalf the diameterof the pipe subject to a minimum of 450 mm.

The arrangement for lifting, loading and unloading concretepipes from factory/yard and at siteshall besuchthat the pipes donot sufferany undue structural strain, any damage due to fall or impact. Thearrangement may be gotapproved by the Engineer.

Similarly, the arrangement for lowering the pipe in the bedshall begot approved by the Engineer. Tt, may be with tripod-pulley arrangementor simply by manual labour in a manner that the pipe is placed in theproperpositionwithoutdamage.

The laying of pipeson theprepared foundation shall start from the outletand proceedtowards the inlet and be completed to the specified linesandgrades.In caseof use of pipes with bell-mouth, the belied end shall face

622

Pipe Culverts Section2900

upstream.Thepipesshall be fitted andmatched sothat when laidinwork,they form aculvert with a smoothuniform invert.

Any pipe found defectiveor damagedduring laying shall be removedat the costof the Contractor.

290tJOINTING

The pipesshall bejointed either by collarjoint or by flushjoint. In theformer case,thecollars shall beof RCC 150to 200 mm wide and having thesamestrength asthe pipesto bejointed. Caulking spaceshall be between13and20 mm accordingto the diameter of thepipe. Caulking materialshall beslightly wetmix ofcementand sandin theratio of 1:2rammedwith caulkingirons. Before caulking, the collar shall be soplaced that itscentre coincideswith thejoint andan evenannular spaceis leftbetweenthecollarandthepipe.

flush joint may be internal flush joint or externalflush joint. In eithercase,theendsof thepipesshallbespeciallyshapedto form aselfcenteringjointwith ajointingspace13 mm wide.Thejointing spaceshallbefilled withcementmortar, 1 cementto 2 sand,mixed sufficiently dry to remain inposition when forcedwith a trowel or rammer. Care shall be taken to fill allvoidsand excess mortarshallberemoved.

For jointing pipe linesunder light hydraulic pressure, therecessat theendof thepipe shallbefilled with jute braidingdippedin hotbitumen orother suitable approvedcompound.Pipesshallbe so jointed that thebitumenring of onepipe shallset into therecessofthenextpipe. Thering shall bethoroughly compressedby jacking or by any other suitable method.

All joints shall be madewith care so that their interior surface issmoothandconsistentwith theinterior surface of thepipes. After finishing,thejoint shall be kept coveredand damp for at least four days.

- 2907.BACKFILLING

Trenches shall bebackfilled immediatelyafterthe pipes havebeenlaidand thejointing material hashardened.The backfill soil shall be clean,freefrom boulders,largeroots,excessiveamounts of sodsor other vegetablematter, andlumpsandshall be approved by theEngineer. Backfilling upto300 mm above the top of the pipe shall be carefully done and the soilthoroughly rammed, tampedor vthrated in layers not exceeding150 mm,particularcarebeingtakento thordughlyconsolidatethe materialsunderthehaunchesof the pipe. Approved pneumatic or light mechanical tampingequipment can be used.

623

Section2900 Pipe Culverts

Filling of thetrenchshallbecarriedout simultaneouslyonboth sidesof thepipein sucha mannerthatunequalpressuresdo not occur.

In caseofhighemba*rnent,afterfilling thetrenchupto thetop of thepipe in the abovesaidmanner,aloose fill of a depthequal to externaldiameterof the pipe shall be placedover the pipebeforefurther layers areaddedandcompacted.

2908.HEADWALLS AND OTHER ANCILLARY WORKS

Headwalls, wing walls, aprons and other ancillary works shall beconstructedin accordancewith the details shown on the drawings or asdirected by theEngineer. Masonryfor the walls shall conform to Section1300,1400or 1700asapplicable.Apronsshaltconform to Section2500.

2909.OPENING TO TRAFFIC

No traffic shallbe permittedtocrossthe pipe line unlessheight offilling abovethe top of the pipe line isatleast600mm.

2910.MEASUREMENTS FOR PAYMENT

R.C.C. pipe culverts shall be measuredalong their centrebetweentheinlet andoutlet endsin linearmetres.

Selectedgranularmaterial andcementconcretefor pipe bedding shallbe measuredas laid in cubic metres. Ancillary works like headwalls, etc.,shall be measuredas provided for under the respectiveSections.

2911.RATE

The Contract unit rate for the pipes shall include the cost of pipesincluding loading,unloading, hauling, handling, storing, laying in positionandjointing complete andall incidental coststo completethe work aspertheseSpecifications.

Ancillary works such as excavation including backfiiling, concretearid masonryshall be paid for separately,asprovided under the respectiveClauses.

624

Maintenanceof Road

3000

Maintenance of Road

Maintenanceof Road Section3000

3001.GENERALThe Specificationsshall apply to all itemsofroadmaintenanceworksas

required to becarriedout under theContract or asdirected by the Engineer.Theworks shallbecarriedout in conformity with therelevantSpecificationsto therequired level,gradeandlines using approvM materials.Theworksshall be carriedout using light duty machineryor manualmeansprovidedthe quality of the end product doesnot suffer. In executionof maintenanceworks,areferenceismadetotheIRC publications: “Manualfor Maintenanceof Roads” and“Code of Practicefor Maintenancefor Bituminous Surfacesof Highways, IRC 82-1982” for guidance andcompliancewhereverappli-cable. Wherever the Specification is not clear,goodengineering practiceshall be adoptedin theconstruction to thesatisfactionof the Engineer.

3002.RESTORATION OF RAIN CUTS

3002.1.Scope

The work shall consistof earthworkfor restorationof rain cuts in theembankment and shoulders, using suitable material, andcompactingthesame.

3002,2.MaterialsThe material used for restoration of rain cutsshall consist of soil

conforming to Clause305.2.

3002.3.Construction Operation

The area affectedby rain cutsshall be clearedof all loosesoil andbenched.Thewidth of thebenchesshall be at least 300 mm andtheyshallextendcontinuouslyfor asufficient length.Theheightof thebenchesshallbein the rangeof 150-300mm.

Freshmaterial shall bedepositedin layers notexceeding250mm loosethicknessandcompactedso as to match with the benching at a moisturecontentcloseto theoptimum. Compactionshall becarried out using suitableequipmentsuchasplatecompactorsandrammersor by suitableimplementshandled manually. Thefinished work shall conformtoaligmnent,levelsandslopesasindicatedin thedrawing.


The earthwork foi~restorationof rain cutsshalt be measured in cubicmetres.

627

Section3000 Maintenanceof Road

3002.5.Rate

The Contractrate for theitem of earthworkfor restorationof rain cutsshall be paymentin full forcarrying out the requiredoperationincludingfull compensationfor:

(i) Supplyofmaterial including all leadsand lifu andthecostof arrangementof land;

(ii) Setlingout;

(iii) Removal ofloosematerial from the cain cuts;

(iv) Benchingofold earthwork;and

(v) Compactingafteraddingrequiredquantityof water.

3003.MAINTENANCE OF EARTHEN SHOULDER

3003.1.Scope

Theworkof maintenanceofearthenshouldershallincludemakinguptheirregularities/lossof materialonshoulderto the designlevelby adding freshapprovedsoil andcompactingit with appropriateequipments or to stripexcesssoil from the shouldersurface as per the requirementof thisSpecification.

3003.2.Material -

Thematerialtobeaddedto theshoulder,if required,shallbeaselectsoilconformingto Clause305.

3003.3.Construction Procedure

This work shallinvolve:(i) Making up ofthe earthen thoulderby adding extra soilandcompactingrhesame;andl

or,

(ii) Stripping a layerof soil to achievethe requiredgradeandlevel.

Wherever extra earth is requiredto be added,theearthen shouldershall be strippedandloosenedto receivefresh soil. The deficiencyofthicknessshallbemadeup in layersof loose thicknessnot exceeding250mm.Watershallbeadded,if required,to attaintheoptimumamountandthelayercompactedby 80to lOOkN smoothwheelroller,vibratoryroller, handroller, plate vibrator or hand rammerto obtain atleast94 per centof themaximumdry densityin accordancewith IS: 2720 (Part 8).The finishedsurfaceshallhave the specifiedcross.slopeandline in accordancewith thedrawing.Thesideslopesshall be trimmedtotherequiredslopewith thehelpof grader or manualmethodsusinghandtools.

Whereverthe earthis requiredto beexcavatedfrom theshoulder,thisshallbe doneeither usingequipmentlike graderor by inanualmeansusing

628


handtools.The resultingsurfaceshallbe uniform and haveafield densityof atleast94 perCentof maximumdensityobtainedin accorthnce withIS : 2720(Part 8). If the surfaceis not uniformly compacted,it shall beexcavatedto adepthof 150 mm andthe soil mixedwith water if requiredandcompactedat amoisturecontentcloseto theoptimumtoachieve94percentof maximumdensity as statedabove.

3003,4.Measurementsfor Payment

Maintenanceof earthenshouldershallbe measuredin sq.metres.

3003.5.Rate

The Contractunit rate for maintenanceof earthenshoulder shall bepaymentin full compensationfor:

(i) furnishing earth required formaking up of shouldersincluding all leadsand lifts,costof land andcompaction;

(ii) excavationof earth asrequired anddisposalof theearthat the locationapproved;and

(iii) all tools, equipments andincidentalsto complete the work in accordancewith theaboveSpecification.

3004.BiTUMINOUS WORK IN CONNECTION WITHMAINTENANCE AND REPAIRS

3004.1.Filling Pot-holesand Patch Repairs

3004.1.!.Scope : This work shall include repair of pot-holes andpatchingof all typesof bituminoussurfaceswith abituminousmix eitherproducedatplant siteoratthesiteitself with manualmethodof mixing andplacedatsite in thepot holesor in patchesafter trimming the pot-holeordepressionto proper shapeand depth,sidepainting with tack coat andcompactingthelayerto the levelsspecifiedin thedrawing.

3004.1.2.Materials The materials used for the pot-hole and patchrepairof bituminoussurfaceshall be asper theContractandshallbeof thesametypeasusedfor theexistingbituminoussurface.A mix superiorto theoneonexistingsurfacecanalsobeconsideredappropriatefor repair work.An emulsifiedbitumenmix compatiblewith the existinglayerShall alsobeconsideredappropriate.

The gradingofaggregatesandbitumencontentof the mix usedforsuchpatchrepairshallbein accordancewith Clause501.

3004.13.Preparationoftheareafor pot-holeand patch repair Eachpot-holeandpatch repairareashall be inspectedand all loose materialremoved.Theareashall becut/trimmed eitherwith jack hammeror handtools like chisels,pick-axesetc., such that the areais in the shapeof a

629

I - I ~


rectangleorsquare.Theedgesshallbe cutvertically uptothelevelwherethelowerlayerisstablewithout anyloosematerial,Theareashallbethoroughlycleanedwith compressedair or any appropriate method approvedby theEngineerto removeall dust andloS particles.Theareashallbetackedorprimed with cutbackor emulsiondependingupon whetherthelower layeris bituminousor granularin nature.Thesides,however,are to bepaintedwith hottackcoatmaterialusingabrush.Theprimecoal andtack coat shallconform to Clauses502 and503of theseSpecifications,respectively.

3004.1.4.Backfilling operation : The mix to be filled shall beeitherahot mix or a coldstorablemix (usingbituminousemulsion).Mixing shallbedonein aplantof suitablecapacity.It shallbeplacedin thicknessesnotmore than100mm (loose).It shallbe compactedin layerswith roller/platecompactor/handroller/ rammer.While placingthefinal layer,themix shallbespreadslightly proudof thesurfacesothatafter rolling, thesurfaceshallbe flush with the adjoiningsurface.If the area is large,the spreadingandlevelling shallbedoneusinghandshovelandwoodenstraightedge.Duringtheprocessof compactionwith roller or othermeans,thesurfacelevel shallbe checkedusinga3 m straightedge.

3004.1.5.Measurementsfor payment: Filling of pot-holesandpatchrepairshall be measuredin sq.m.

3004.1.6.Rate:TheContractunit rate for filling of pot-holesandpatchrepairshall bein full compensationfor

(i) fumi thing all materials required;

(ii) works involved in trimming, tacking, priming with cutback or emulsion;

(iii) all labour, tools,equipmentsand incidentalsto completethework inaccordancewiththeSpecifications.

3004.2.Sealingof Cracks with FogSeal

3004.2.1.Scope:Fog seal shall consistof anapplicationof emulsifiedbitumen,withoulany aggregatecover for sealing fine hair-cracks likeshrinkagecracksandalligator cracksor rejuvenating oxidisedbituminoussurfaces.Areashavingcrackswith lessthan 3 mm width shallbeconsideredfor this treatment.

3004.2.2.Material : Bituminous emulsion for FogSealshallbeof aslow settingtype.

3004.2.3.Application : The areato be appliedwith fog sealshall bethoroughlycleanedwith compressedair, scrubbers,etc. Thecracksshallbecleanedwith pressureairjet to remove all dirt, dust,etc.The fog sealshallbeapplied at the rateof 0.5-1.0litre/sq.m.using equipment like apressure

630


tank, flexible hoseandsprayingbaror lance.Traffic shall be allowedon thesurface after the sealhassetto a non-tacky and firm condition sothat if isnot picked up by the traffic.

3004.2.4.Measurementsfor payment: The fog sealwork shall bemeasuredin sq.metres.

3004.2.5.Rate: The Contract unit rate for application of fog sealshallbe in full compensationfor:

(i) supplying of fog sealmaterialand all the operations for applying it; and

(ii) all thelabour,tools,equipmentsand incidentalsto completethe work in accordancewith this Specification.

3004.3.Slurry Seals

Clause516shall apply, with the modification that simple implementsand toolsamenableto manual methodsshall beused.

3004.4. Premix Carpetfor Renewal of SurfaceThe work shall consistof laying a 20 mm thick open-gradedpremix

carpetfor renewal of surface.The stipulations contained in Clause 509shallgovern as regards scopeand materials. A tack coat shall be appliedconforming to Clause503,but manual methodsor useof relatively smallcapacityequipmentshallbepermitted.The premix shall be preparedin hot-mix plants of suitable capacity or small portable mixers, approved by theEngineer. Rolling shall be done as per Clause 509.1.3.5. A seal coatconforming to Clause513 shall be applied after laying the carpet.

The work shall bemeasuredin sq.rnetresand the Contract unit rate shallcover supply of all materials, labour and equipment and carrying out thework to Specifications.

3004.5.SurfaceDressingfor MaintenanceWork

The work shall bedonein conformity with Clause508, exceptthat theuseof small and portable equipment shall be permitted.

3005.MAINTENANCE OF CEMENT CONCRETE ROAD

3005.1. Repair of Joint (hooveswith Epoxy Mortar or EpoxyConcrete

3005,1.1.Scope: The work shall consistof repairof spalled jointgrooves of contraction joints, longitudinal joints and expansionjoints inaconcretepavementusingepoxymortar or epoxy concrete.

3005.1.2. Materials: The type/gradeof epoxy compatible with thecoefficient of thermal expansion of concrete shall be used with either

631


processedfine aggregateor fine stonechipsto produceadrymix forrepairingspalledor damagededges.

3005.1.3. RepairingProcedure: Spalledor broken edges shall beshapedneatlywith a vertical cut with chiselsinto the shapeof rectangle.Smallpneumaticchiselsalsomay be used,provided thecutting depthcanbecontrolled.The depthof thecut shall be the minimumto effect repair.After shapingthe spalledarea,it shall be cleaned andprimed.Theepoxymortar/concreteis then applied usinghand toolslike trowels,straightedges,brushesetc. Therepairededgeshallbein linewith thejoint grooveandshallbeflush with theconcreteslabs.Duringtherepairwork,anydamagenoticedto thejoint sealantshall bemadegood by rakingOut the affected portionandresealiag.

3005.1,4.Traffic: Althoughtheepoxymixessetin 2-3hourstime, it isdesirableto divertthetraffic for12hoursor aspertherecommendationofthemanufacturers.

3005,1.5.Measurementsfor payment: Repair of joint grooves shallbemeasuredin linearmetres.

3005.1.6.Rate: TheContractunit ratefor repairof joint grooveswithepoxymortaror epoxyconcreteshall be in full compensationfor~

(i) supply and applicationof epoxyprimer, epoxymortaror epoxyconcrete;

(ii) all tools,equipmentandincidentalsto completethework in accor-dancewith theabove Specification.

3005.2. Repair Involving Removalof OldJoint SealantandSealingwith FreshSealantin Cement ConcretePavements

3005.2.1.Scope:The repairof sealantof contraction,longitudinalorexpansionjoints shallincluderemovalof the existingsealantandresealingthejoint with freshsealantmaterial.

3005,2,2.Material: Sealant material to bereplacedshallbeeitherhotpouredrubberisedbitumenor polysulphidetypeof sealantas perClause602.2.8.As pertherecommendationof themanufacturer,appropriatetypeofprimeralsoshallbeapplied.

3005.2,3.Repairing procedure: The existing sealantshallberakedoutwith the help of a metal rakersuchthat mostof the sealantis removed.Subsequently,thesealantstucktothesidesof thegroovesshallbe removedthoroughly eitherby usingsaw cutting machine so thatgroovesmay bewidenedby onemm or by sandblasting. In no casethe old sealantshallbe

632


presentduringresealingoperation,If joint groovesare found inadequateindepth,they shall be deepenedas directedby theEngineer.

Beforecommencingthesealingoperation,compressedairshallbe usedto cleanthejoint groovestocleanthejoint groove.A heatresistant,paperbackedcompressibledebondingstripor tapeshouldbe inserted in accor-dancewith the requirementof Clause602.11.2.Sealantmay be pouredeither using hand held pourer or usingmechanisedsealingmachines.Sealantsshouldnot be heateddirectlybut in doublejacketedmachine.Allprecautionsandarrangementsshall betaken not tospill thesealanton theconcrete pavement.Thesealantmay be poured to adepthof 5±2 mmfrom the pavementsurface.

3005,2,4.Measurementsforpayment:Repairofjoint sealantshall bemeasuredin linearmetres.

3005.2.5.Rate: Contract unit rate for repair~of joint sealantshallbe infull compensationfor~

(i) removal of old sealant,regrooving or sandblasting thesealinggrooveandplacing ofdebondmgstripor tape.

(ii) all tools, equipmentsand incidentals to compkte the work in accordancewith theaboveSpecification.

633

Appendices

Appendices

Appendices

Appendsxl

LIST OF IRC PUBLICATIONS REFERRED TO IN THE

SPECIFICATIONS, CODES & STANDARDS

NumbeTDesignation TItle

IRC : 21965 RouteMaskqSignsforNanonalHighways (FiratRevision)

IRC : 5-1985 StandardSpecifications& Codeof Practicefor Road Bridges, Section1-GeneralFeawresofDesign(SixthRevisiou)

[RC :6-1966 StandardSpecifications&CodeofPracticeforRoad Bridges,SectionH-Loads and Stresses(Third Reviston)

IRC : 8-1980 Type Designsfor Highway Kilometre Stones(SecondRevision)

IRC 10-1961 RecommendedPractice for Borrowpiis for RoadF.mbankmentsConstnKtedby ManualOperation

LRC : 14-1977 RecommendedPracticefor2anThickBitumen andTarCarpets (ThirdRevision)

IRC : 16-1989 TentativeSpecificationfor Printing of BaseCoursewith BituminousPrimers

IRC : 17-1965 TentativeSpecification for Single Coat BituminoqsSurfaceDressing

IRC : 18-1985 Design Criteria for PrestiessedConcrete Road Bridges (Post-Tensioned Concrete) (SecondRevision)

IRC : 19-1977 StandardSpecificationsand Codeof Practicefor Water Bound Mac-adam(SecondRevision)

IRC : 20-1966 RecommendedPracticefor Bituminous Penetration Macadam(FullGan~)

IRC : 21-1987 StandardSpecificationsandCodeofPracticefor Road Bridges,SectionHI-CementConcrete(PLain andReinforcec~(First Revision)

[RC : 22-1986 StandardSpecificationsandCodeofPracticefor RoadBridges,SectionVI- CompositeConstructionfor RoadBridges(FirstRevision)

1RC : 23-1966 TentativeSpecificationfor Two Coat BituminousSurfaceDressing

IRC : 24-1967 StandardSpecificationsandCodeofPracticeforRoadBridges,SectionV-SteelRoadBridges

IRC : 25-1967 TypeDesignsfor BoundaryStones

[RC :26-1967 TypeDesignsfor 200-metreStones

mc : 27-1967 Tentative Specificationfor Bituminous Macadam(Base& BinderCourse)

IRC : 29-1968 TentativeSpecificationfor 4 cm AsphalticConcreteSurfaceCourse

IRC :30-1968 Standard Letters and Numerals of Different Heightsfor Use onHighway Signs

637

Appendices

Number Designation Title

IRC : 35-1970 CodeofPracticefor Road Markings (withPaints)

IRC :36-1970 RecommendedPractice for the ConstructionofEarthEmbankmentsfor RoadWorks

IRC : 37-1984 GuidelinesfortheDesignofFlexible Pavements(FirstRevision)

IRC : 40-1970 Standard SpecificationsandCodeof PracticeforRoadBridges,Section1V-(Brick,StoneandBlock Masonry)

IRC : 45-1972 Recommendationsfor Estimatingthe Resistanceof Soil below theMaximum ScourLevel in theDesignofWell Foundationsof Bridges.

IRC : 47-1972 TentativeSpecificationfor Built-upSprayGrout

IRC 48-1972 Tentative Specificationfor Bituminous Surface DressingusingPre-coatedAggregates

IRC : 49-1973 RecommendedPracticefor thePulverixationofBlack Cotton Soils forLime &abilisation

1RC : 50-1970 RecommendedDesignCriteria for the UseofCementModified Soilin RoadConstruction

IRC :51-1973 Re~ommendedDesIgnCritcriafortheLJseof Sol’ LimeMixesin RoadConstruction

IRC : 56-1974 RecommendedPractice for Treatment of EmbankmentSlopesfor Ero-sionControl

IRC : 63-1976 Tentative Guidelines for theUseof Law GradeAggregatesandSoilAggregateMixturesin RoadPavementConstruction

IRC :67-1977 CodeofPracticefor Road Signs

IRC 72-1978 RecommendedPracticefor Useand UpkeepofEquipment, ToolsandAppliancesfor Bituminous PavementConstruction

IRC : 75-1979 Guidelinesfor the Designof High Embankments

IRC : 78-1983 StandardSpecificationsand CodeofPractice forRoad Bridges, SectionVII -EoundationofSubstructure(First Revision)

IRC : 79-1981 RecommendedPracticefor RoadDelineators

IRC : 82-1982 Codeof Practicefor Maintenanceof Bituminous SurfaceofHighways

IRC : 83-1982 StandardSpecificationsandCodeofPracticefor Road Bridges, SectionIX-Bearings, Part I: Metallic Bearings

IRC : 83-1987 StandardSpecificationandCodeofPracticefor Road Bridges, SectionLX, Bearings,Part IhElattomericBoarings

IRC : 87-1981 Guidelines for theDesign& Erection of FalseWork forRoad Bridges

1RC : 89-1985 Guidelinesfor DesignandConstruction of River Training andControl

Works for RoadBridgesIRC : 90-1985 Guidelines for Selectiçm,Operation andMaintenanceof Bituminous

Hot Mix Plant

IRC : 93-1985 Guidelines on Designamid Installation of RoadTraffic Signals

638

Appendices

Number Designation

IRC :94-1986

IRC:SP:1l-1977

IRC : SP :31-1986

Title

Specificationsfor DenseBituminous Macadam

HandbookofQuality Controlfor Coesuuction.ofRoadsandRunways(First Revision)

NewTraffic SignsMiniatty of Shipping& Transport(RoadsWing) Handbook on goadConstruction Machinery(1985)

IRC Highway ResearchBoard,StateoftheArt: Granular andBoundBasesandSub-Bases

IRC : SpecialReport 11, 1992

639

Appendices

Appendix2

LIST OF INDIAN AND FOREIGN STANDARDS REFERREDTO IN THE SPECIFICATIONS

(A) INDIAN STANDARDS

Number Designation Title

IS : 5-1978 Colourfor readymixedpaints andenamels

IS : 73-1992 Paving bitumen

IS : 164-1981 Readymixed paints,brushing, for road masking,to Indian StandardColour No. 356 Goldenyellow, white andblack

IS : 210-1978 Grey iron castings

IS : 215-1961 Road tar

IS : 217-1988 CUtbaCkbitumen

IS : 226-1975 Structural steel (standardquality)

IS 269-1989 33 grade ordinary portland cement (fourth revision)

IS : 278-1978 Galvanizedsteelbarbedwire for fencing

IS : 280-1978 Mild steel wire for general engineeringpurposes

IS : 334-1982 Glossaryof terms relating to bitumen and tar

IS : 383-1970 Coarseand fine aggregatesfrom natural sourcesfor concrete

IS : 432-1982 Mild steelandmedium tensilesteelbars andhard-drawnsteelwire forconcretereinforcement

(PartI) Mild steelandmedium tensilesteelbars

(Part11) Hard-drawnsteelwire

IS : 443-1975 Methods of sampling and test for rubberhoses

IS = 454-1961 Digboi typecutback bitumen

IS : 455-1989 Portland stag cement(fourth revision)

IS : 456-1978 Code of practice for plain and reinforcedconcrete(third revision)

IS : 458-1988 Concrete pipes (with andwithout reinforcement)

IS : 460-1985 Test sieves

IS : 508-1973 Specification greasegraphited (secondrevision)

IS : 516-1959 Methods oftestfor strength of concrete

IS : 702-1988 Industrial bitumen (secondrevision)

IS ~:736 -1986 Wrought aluminium andaluminium alloys, plate~for general engineer-i:ng purposes

IS : 814-1974 Coveredelectrodesfor metalarc welding of miki steel

640

Appendices

NumberDesignation

IS : 823-1964

IS : 961-1975

IS : 1002-1956

IS : 1030-1974

IS :1077-1976

IS :1124-1974

IS :1129-1972

IS :1139-1966

IS : 1148-1973

IS :1149-1973

IS :1195-1968

IS: 1199-1959

IS : 1201 to

1220- 1978iS : 1239-1979

(PartI)IS : 1239-1979

(PartII)

IS : 1364-1967

IS : 1367-1984

IS : 1387-1967

IS : 1398-1960

15: 1442-1964

1St: 1448

IS : 1477

(PanI)-1971

IS : 1489-1991

IS : 1498-1970

IS : 1514-1959

IS : 1732-1971

IS :1785

(PartI)-1966

Title

Codeofprocedurefor manualmetalarcweldtugofmild steel

Stnmcturalsteel(High tensile)

MultipurposegreaseNo. 1, No.2andNo.3

Steelcastingsfor generalengineeringpurposes

Commonburntdaybuildingbrides

Method oftestfor water*bsosptiovsci naturalbuilding stones

Dressingofnaturalbuilding stones

Hot rolledmild steel and medium tensilesleetdeformedbarsforconcretereinforcement

Rivetbars for structural purposes

High tensilerivet banfor structuralpurposesProcedure for restingfor hardnessnumberof bitumenmastic

Methodof samplingandanalysisof concreteindianstandardmethodsfor resting tar andbituminousmaterials

Mild steeltubes(fourth revision)

Mild steel tubular and other wroughtsteelpipe fittings(secondrevi-sion)Precisionandsemi-precisionhesagonboks,sctnwa,nutsandlocknsts

(diameterrange6 to S9tnm)(first revision)

Technicalsupplyconditionsfor threadedsteelfarmers

General requirementsfor the supply ofmetallurgicalmaterials

Packingpaper,waterproof,bitumen-laminated

Covered electrodes for metal arc weldingofhigh tensilestructuralsteel

Method of testsforpetroleumandits products

Code of practice for finishing of it-on and steeWferiousmetalinbuildings: painting and allied finishes

Operationsandworkmanship

Portland-pozzolanacement

Qassificationand identification of soils for general engineering

purposesMethodsof samplingand testfor quick lime andhydratedlime

Dimensionsfor roundand squaresteelbars for structuralandgeneralengineeringpwposes

Plain hard-drawn steel wire for pretuessedconcrete

Cold-twisted steel bars for concretereinforcement

641

Appendices

NumberDesignation Title

(Part1)- 1983

IS : 1888-1982

IS :2004-1978

15 :2062-1980

IS :2116-1980

IS 2131-1981

IS :2250-1965

15 :2386-1963

(Paul)

(Part2)

(Part3)

(Part4)

(Part5)

(Past6)

(Part7)

(Part8)

IS : 2720

(Part2)4973

(Part3)-I980

Section1

SectionIl

(Past4)-1985

(Part5)-1985

(Part7)4980

(Part10)-1973

(Part13)-1985

(PartI4)-l983

(Part16)-1987

High ttrengthdeformedsteelbarsandwires for concretereinforcement

Prefonnedfiller forexpansionjointin concretepavementandstructures(non extntding andresilienttype)

Bitumen impregnatedfibre (first revision)

Methodof loadtestsonsoils

Carbon steel forgingfor generalengineering purposes

Stnicturaisteel(fusionweldingquality)

Sand for masonry mortars

Methods for standardpenetration testfor soils

Code of practice for preparationand use of masonrymortars

Methodsof test for aggregatesfor concrete

Particle sizeand shape

Estimation of deleteriousmaterialsand organic impurities

Specificgravity,density,voids,absorptionandbullring

Mechanicalproperties

Soundness

Measuriig mortarmaking propertiesof fineaggregates

Alkali - Aggregate reactivity

Petrographicexamination

Methodsof test for soils

Determination of water content

Detenninationofspecificgravity

Pinegrained soils

Medium andcoarsegrainedsoils

Grain sizeanalysis

IS : 1786-1985

IS : 1838

Determinationofliquid andplasticlimits

Determination of moisture content/dry density relation using lightcompaction

(Pan 8)-I983 Determination of water content-dry density relationusing heavycompaction

Determinationofunconfinedcompressivestrength

Direct sheartest

Determinationof density index (relativedensity)ofcobesionlesssoils

Laboratorydeterminationof CBR

(Part27)-1977 De~rminationof totalsolublesuliihates

642

Appendices

(Part28)-1974 Determinationofdrydensityofsoils in-placeby the sandreplacementmethod

(Part29)-1975 Determination ofdiy densityof soils in-placeby corecuttermethod

(Part37)-1976 Determinationof sandequivalentvaluesof soilsandfine aggregates

(Part40)-1977 Determinationof freeswellindexof soils

IS :3117-1965 Specification for bitumen emulsion for roads(cationictype)

IS : 3466-1967 Masonry cement

iS : 3764-1992 Codeof safesyfor excavationwork

IS : 4138-1977 Safetycodefor workingin compressedair

ES : 4332 Methodoftest for stabilizeds#iLs

(Part1)4967 Method ofsamplingandpreparationof stabilized soils for testing

(Part3)4967 Test for detemnnarionof moisture content-dry density relation forstabilizedsoilmixtures

(Part4)4968 Wettinganddryingand,freezingandthawingtestsforcosnpactedsoil-cementmixtures

Detemiinationofunconfsnedcompressivestrengthof stabilizedsoil

Determination of cementcontentof cementstabilizedsoils

Determinationoflime contentof lime stabilizedsoils

Codeofpracticefor in-situ vanesheartest for soils

Hotdippedgalvaniaedcoatingon sound scaledwires

Specificationfor bitumen mastic for bridgedeckingand roads

Generalrequirementsfor old asphaltmacadammixing plant

Method for determiningthe aggregate impactvalueof soft coarseaggregate

IJncoaxed stressrelieved strandsfor prestrcs~cdconcrete

Methodoftenfor determination of strippingvalueof road aggregates

Supersulpbatedcement

Methods of test for determination of waxer soluble chlorides inconcreteadmixtures

Road traffic signals

Rapid hardening portland cement

43 gradeordinaryportlandcement

Specificationfor bitumen emulsion for roads(cationictype)

Admixturesfor concrete

Guidelinesfor concretemix design

NumberDesignation Title

(Part 5)-I 970

(Part7)4973

(Part8)-1969

IS 4434-1978

IS 4826

IS :5317-1969

IS : 5435 (Revised)

IS : 5640-1970

IS :6006-1970

IS :6241-1971

IS :6909-1991

IS :6925-1973

IS : 7537-1974

IS :8041-1978

IS :8112-1989

ES : 8887-1978

IS :9103-1979

IS : 10262-1982

643

Appendices

Number DesIgnation

iS: 12269-1987

IS: 12330-1988

IS : 13321(Part1)-1992

IS: 13325-1992

iS : 13326(Partl)-l992

IS: SP23-1982

ASTM :D-36

ASTM : D-395

ASTM :D-412

ASTM : D-429

ASTM : D-573

ASTM : D-624

ASTM : D-664

ASTM : D-797

ASTM : D-4533

ASTM : fl-li

ASTM:E-S10

AASFETO: DM283

AASHTO: DM 294-70

AASHTO : DM 288-82

AASI-ITO : DM 17-77

AASHTO: DR 5-80

TItle

Specificationfor 53 gradeordinary poillandcement

Specificationfor sulphateresistingpon~heidcement

Glossaryoftermsfor geosynthesicspats1: lennausedin materialsandpropetties

Determinationof tensile properties of extruded polymer geogridsusing the wide strip-testmethod

Evaluation of interface friction betweengeo-syntheticsand soil-methodof test part 1: Modified threctsheartechnique

Handbookon concretemixes (basedon indianstandards)

(B) FOREIGNSTANDARDS

Thennoplastiematerial

Compressionsetof vulcanizedrubber

Tensiontestingof vulcanizedtubber

Adhesionof vulcanizedrubberto metal

Acceleratedagingof vulcanizedrobberby theovenmethod

Tearresistanceof vulcanizedrubber

Testmethodfor neutralisation numberfor potentiomerrictitration

Young’s modulusin flexure of elastomerat normal andsubnormaltemperature

Effect of water on cohesionof compactedbituminousmixtures

Acceleratedozonecracking of vulcanizedrubber

Test for resistanceto plastic flow of bituminousmixturesusingMarshallapparatus

Extraction,quantitativeof bitumen frombituminouspaving mixtures

indentationhardnessof rubberand plastic by meansof a Durometer

Test method for effect of water on bitumencoatedaggregate usingboiling water,

Testmethodfor trapezoidtearingstrengthofgeolextiles.

Specificationfor wire cloth sievesfor testingpurposes-

Testmethodfor coefficientofretro-reflectión or retro-reflectionsheet-ing.

Coarseaggregatefor highway andaixportconstruction

Fineaggregateforbituminouspavingmixtures

Geotextilesusedfor subsurfacedrainage pu~oses

Mineral filler for bituminouspavingmixtures

Selectionanduseofemulsifiedasphaits

ASTM

ASThI

ASTM

ASThI

ASTM

ASTM

1075

D-1149

D-1559

D-2172

D-2240

D-3625

644

Appendices

NumberDesignation

AASHTO: DM 81-75

AASHTO : Dlv! 82-75

AASHTO: DM 140-80

AASHTO: DM 7-10

AASHTO : DM147-65(1980)

AASIITO : OM216-68

AASHTO : DM 249-79

AASHTO: DM268-77

AASHTO:DM282.80

BS ~‘~10-1969

BS 729-1971

ES 812-1975

Part2-

Part3 -

Part lii -

Part 114-

BS : 1047.1952

BS 1154-1970

BS : 1377-1975

ES : 1447-1973

BS : 1449-1956

Part1-1972

Part 2-1967

BS : 1470-1972

IS :2630

BS : 2870

BS : 3262

Part-i

Part-2

Part-3

BS : 5212Part 2-1975

Title

Cut-backasphalt (rapid-curing type)

Cut-backasphalt(medium~curingtype)

Emulsifiedasphalt

Materials for embankmentsandsubgrades

Materials for aggregateandsoil-aggregate

sub-base,baseandsurfacecoursesLimefor soil stabilisation

Whiteandyeliowreflectivethermoplasticstripingmaterials(solidform)

Weatherometer

Joint sealants,hotpoured,elastometictype. (or ASTM : D3406) for

portlandcementconcretepavementsTestsieves

Hot dip galvanizedcoatingson iron and steelarticles

Testing aggregates

Methodsfor determinationofphysicalproperties

Methodsfor determinationofmechanicalproperties

Method for determinationoftenpercentfines value(TFV)

MethOd for detenninationof’ thepolished-stonevalue

Air-cooledblastfumaceslagcoarseaggregatefor concrete

Vulcanizednatural rubbercompounds

Methodsof rest for soilsfor civil engineeringpur~p~scs

Masticasphah(limestonefineaggregates)for roadsandfootways

Steelplate,sheetandstrip

Carbonsteel plate, sheetandstrip

Stainlessandheat resistingplate, sheetand strip

Wrought alinninimn and aluminium alloys for general engineeringpurposes- plate,sheetandstrip

Preformedjoint filler

Rolled copperandcopperalloys : sheet,strip andfoil

Hot-applied thermoplasticroad marking materials

Specificationfor constituentmaterialsandmi,uus’es

Specificationfor madperformance

Specificationfor applicationof materialto road surface

Cold poured joint sealantsfor concretepavements

645

Appendices

Title

Specificationfor pavementmarkingpaints

Specificationforsolidglassbeadaforusewith roadmaikingcompoundsand for otherindustrial uses

Methodsof teatfor geotextiles

Determinationof the tensile propertiesusinga wide widthstrip

Determinationof the apparentporesizedistributionby drysieving

Determinationof waterfiownormalto theplaneofthegeotearileunder

a constantheadDetermination ofthe puncture resistance(CBRpunctureteat)

Determinationof in-plane waterfiow

Method at test for curing compoundfor concrete

Bituminous RoadConstructionHandBook

The asphalthan&took,manual

seriesNo.4 (MS-4) 1989 edition

GRI-GGI Geogrid rib tensilestrength

GRI-GG2 Geogrid junctionstrength

GRU3G3 TensilecreeptestingofGeogrids

(GRI denotesstandardsfor testpreparedby GeosyntheticResearchInstitute atDrexelUniversity Philaddphia, USA)

NumberDesignation

BS : 6044

B.S : 6088

ES : 6906

Past I

Part2

Pail 3

Part4

Part7

ES : 7542CR111andICC,NewDelhi

Asphalt institute

646

Appendices

Appendix3

(Clause4023.2and 403.3.2)

METHOD OF SIEVING FOR WET SOILS TO

DETERMINE THE DEGREE OF PULVERISATION

I. Asample of pulverisedsoil approximately1kg in weight should be takenand weighed(W1).

2.. It should be spreadon thesieveandshakengently, carebeing taken to breakthe lumpsofsoils as little as possible.Weightof soil retainedon the sieveshould be recorded (Wi).Lumps offiner soils in the retainedmaterial should be brokenuntil all the individualparticulars finer than the aperturesizeof the sieveareseparated.

3. The soil shouldagainbeplacedon the sieve and shakenuntil sievingis complete. The

retainedmaterial shouldbeweighed(W,).

4. WeIght of roil by percentpassingthesievecan than hecalculatedfrom theexpression:

(W1—W2)x 100

(W1-W,)

647

Appendices

Appendix4

GUIDELINES ON SELECTiON OF THE GRADE OF BITUMEN

(Source BituminousRoadConstructionHandbook,Indian Oil CotporationandCentralRoadResearchInstitute)

A Forbituminouspremixcarpet,choiceis governedby climaticconditionsand intensity oftraffic.

(I) Grade 30/40 for areas where difference betweenmaxtrnutn and minimumairnospherictemperaturesis less than 25 C and traffic intensityis greaterthan150(1commercialvehiclesper day.For traffic intensityteasthan1500 commercialvehiclesper day,Grade 50/60is preferred.

(ii) Where the differencebetweenmaximum and minimumatmospherictemperatureismorethan25~Candtrafficintensity is greaterthanl500conmrercialvehiclesperday, Grade 50/60maybeused.For traffic intensity of less than1500commercialvehiclesperday,Grade 8OflOOmaybeused.Forroadswithveryheavytraffic greaterthan 4500 commercial vehiclesper clay, such asmetropolitancity roads,Grade30/40is preferred.

(iii) Grade80/100may be usedin high altitudeandsnow-boundregions,irrespectiveoftraffic intensity cotlaideration.

B For bituminous macadamandpenetrationmacadamas alsobuilt-up spraygrout,Grade30/40(for hotclimates) and60/70or 801100for otherclimatesaresuggested.

C For a dense-gradedbituminousconcrete,a more viscousgradelike 60170canwithstandstressesof heavier wheel loads better than a less viscous grade of 80/100.Similarlypavingbitumengrade60/70isrnoreadvantageousfor roadswith largenumberofrepetitionsofwheelloadslike expressways,urbanroads,factory roads etc.High stabilityrequirementcannot be meteffectively by lessviscousbitumen.

D A more viscous gradeof bitumen is advantageousinreducing strippingofbitumen filmfrom aggregatesin the presenceof water.~

E With roundedriver shingles,amoreviscousgrade ofbitumencompensatestosomeextentfor poormechanicalinterlock. A comparisonof penetrationgradesandviscositygrades(AC-23toAC-40)ofasphaltcementandAR grades(basedonRolling Thin Film OvenTestresidue)is shownbelow.

648

Appendices

tt~

C,0

>4

100

SO

10

5

AC. LU

t

;c. 2.5

AR.

AR.

2000

~1ooo

Coniparision of per~etrationgrades and viscosity

grades of bitumert

649

Appendices

Appendix5

ANTI-STRIPPING AGENTS USED FOR BITUMINOUSMATERIALS AND MIXES

I. Scope

1.1.Anti-strippingagentsareusedfor bituminous materials andmixes to ensure adhesionbetweenaggregates(hydrophilic in nature) and bitumen, evenunder submergencein water.Prior approval of the Engineershall be taken in respectof both qualitative andquantitativeuseof a particular product.

2. MaterIals

2.1. The anti-stripping agents shall be fatty acid amines having a long hydrocarbonchain.

2.2.PhysIcaland ChemicalRequirements: The anri.stripping agents shall conformtothe physical andchemicalrequirements asdetailedin TableAS-I.

2.3,Storageand Handling : Anti-stripping agents shall be properly stored in closedcontainersmadeof steel or aluminium. Containersmadeof zinc, copper, polythenePVC andmosttypesofrubberarenot suitable for use.A~mostof theanti-strippingagentscause irritationwhen in contact with humanskin and are also irritating to the eyes,protective glovesforhands andgogglesforthe eyesshall be usedwhilehandlingthem, speciallyin caseofliquid anti-strippingagents.

3. Usein SprayedWork

3.1. AdditIve Dosage: The dosage shall be determined depending on the nature(stripping value)ofthe aggregateandthe size of aggregate. While the recommendedminimumdoseof anti-strippingagentfor sprayed work is given in TableA5-2, the actual dosageshall bedetermined in the laboratory as directedby the Engineer.

3.2. MixIng ProcedureDuring Construction: The anti-stripping agent supplied inliquid, solid or concentrateform shall be thoroughly mixedwith liquid bituminousmaterial orwith straight rim bitumen. Whenusedwith straight runbitumen, the correctdoseof anristrippingagent shall be mixed in a hot bitumen tankboiler.

The two constituentsshallbe agitatedtill the anti-strippingagentis thoroughly mixed.Thedoseofanti-strippingagenishall suitably be increased ifthe binder is to remain in bitumenboilertots longerperiod.

4. Usein Premix Work

4.1. Additive Dosage: The dosage shall be determineddepending on the nature(stripping value)oftheaggregateand the percentvoids in the mix~While the recommendedminimum dosesfordifferent typesof bituminous premix materials in termsof voidscontentaregiven in TableA5-3, theactualdosageshall be determined irs the laboratoryasdirected by theEngineer.

650

Appendices

TABLE A5.1,SPECIFICATION FOR ANTISTRIPPINGCOMPOUND

S~No. Test Method - Litelt

1. Appearance Visual Liquid/Solid

2. Odour Smelling Agreeable

3. Specific gravity27’C IS: 1202-1978 0.860-1.03

4. Pour point‘C Maximum IS: 1448 42

5. Flashpoint (COC~ IS 1448 150Minimum

6. WaterContentper cent Vol. IS: 1448 1.0Maximum

7. Solubility in diesel Asgivenat Completeoil (HDOorLDO) in end oftheraiioof298at Appendix50’C

8. Total basevaluemg ASTM 1)664 200KOHIgminimum

9. Nitrogencontentpercent Elemental 7,0Wt. minimum Analyser

10. Stripping value with IS : 6241 No strippingbitumencontaining As givenatlpercentWLantiatripping theendofcompoundat 40’ C Appendix24 hours

11. Under water coating - do - Completetest Coating

12. Thermal stabilityat - do - Shouldnot163’C 5hours loseitsefficacy

13. Boiling water lestpercent ASTM D 3625 95minimum coating

14. RetainedMarshall Asgivenat 75Stability per centminimum theendof

appendix

651

Appendices

TABLE A5.2. TENTATIVE RECOMMENDED MINIMUM DOSEOFANTISTRIPPING AGENT FOR SPRAYEDWORK

Aggregatestrippingvalue

Doseofantlatrippiweightofbitumen

Surfacedressingwithprecoatedaggregate

ng agent In per

PenetrationMacadam!Built upspraygrout

centby

SurfaceDressingwithuncoatedaggregate

Liquidsealcoat

0-25 0,5 0.6 0.7 08

25-50 0.6 0.7 0.8 1.0

50-100 0.75 1.0 1.0 1.0

4.2. Mixing Procedure During Construction: The required doseof theanti-strippingagent shall be pouredinto th~hot bitumen tankand allowed 15 to 30 minutes of circulationor stirred to ensure a homogeneousmix. It is necessaryto use a stableantismrippingagent orincreasethedose according to expecteddegradation. Alternatively, thecorrectdoseshalibeinjected intothe bitumen line by means of a pump. The agent isfed intothebitumenfirst beforeit is sprayedon the aggregate inthemix; thus,no separatemixing time for mixing the agentwith bitumen is required. In rolled asphalt and bitumen mastic surfacing works, precoatedchippingsare pressedinto the hardsurfacewhile themix isstill hot to makethenewly laid surfaceskid resistant.These chippings shall be precoated with bitumen treatedwith antistrippingcompound. -

TABLE AS-3. TENTATIVE RECOMMENDED MINIMUM DOSE OFANTISTRIPPING COMPOUNDIN BITUMEN PREMIX WORKS

Strippingvalueolaggregate

Doseof antistrippingagentin per centby weightofbitumen

Voidscontent3-5percent

VoIds content5.10percent

Voids content10-15percent

0-25

25.50

50-100

0.3

0.4

0.6

0.4

0.5

0.8

0.5

0.6

1.0

652

— .. .. —.———.—. . .. .

Appendices

Annexw’etotheAppendixS

TESTING PROCEDURE FOR SOLUBILITY OFANTISTRIPPING AGENT IN DIESELOIL

Procedure:98m1ofdieseloil (HDO orLDO)and2m1ofantistrij~ingagentshall betakeninameasuringcylinderwith stopper. The cylinderalongwithita contentsshallbe keptin waterbath,maintainedas5O°+l°Cforhalfanhour.Issball thenbetalcenoutfromwaterbath and shakenvigorously for 10 minutes, The ssoppershall be removed andthe cylinderkeç* in waterbath forhalf an hour and examinedfor separationursettlemenL

Reportingofresults:An antistripping agentis repoited to becompletely solublein dieseloil if no separationor settlement is observedfor halfanhour.

TESTING STRIPPING VALUE OF AGGREGATES USING BITUMEN WITHVARYING PERCENTAGESOF AWI’ISTRIPPING AGENT.

Procedure:Coarseaggregatepassing19mmsieveand retainedon 13.2 mmsieveshallbe washedand driedin an ovenfor 24 hours at 110°C. Suchdried200gmsofcoarse aggregatesshall be heatedat 149°Cand thenmixed with 801100 penetrationgradebitumen5percentbyweightof coarseaggregateheatedupso 163°C. The mixture shall be mixed thoroughly foruniform coating of aggregatesby bitumen.The mix shall thenbe transferredto a 500ml beakerandallowedto coolto roomtemperature.Distilled water shallbe addedin thebeaker,which shallbe placed in a water bathmaintained at40°~1°Cfor 24hours.Thepercentagedegreeof strippingshall be assessedvisually. The test shall also beconductedwith watercontaining 1 per centSodium Chloride, as a precautionary measure to eliminate water contamination. The test isrepeated using bitumen containingupto one per centofantisirippingagentin stagesof0.25percent.

TESTING EFFICACY OF ANTISTRIPPING AGENT TO COAT AGGREGATESWITH BITUMEN IN PRESENCEOF WATER

Procedure:The antistrippingageteshailbeadded in percentcontentsof 00,0,25,0.50.,035, l.O0and 1.25 to cutbackbitumen MC3(4partsofbiuunen&WlOOand 1 part of keroseneoil). The blends shall be used for testing their ability to coattheroad aggregatesunderwater,

(a) 100gm of cleananddry stonedussconforsningto followinggradation shallbetaken:

SteveSize percentpassing

236mm 1001.18mm 80600mic. 75300mic. 45

The bottle shall be Filled to3~’4of its volume with distilled water at 40°C. The

bitumen-antistrippingagentblend shall be addedin thebottle at the rateof 7.5 per centbyweightof stone dust. The stopper shall be replacedandthe bottle shall be vigorously shakenfor two minutes.The water shall be then drained off and the stone dust shall be transferred to apiece of paper and examined visually for satisfyingcompletecoating. The minimusn per centcontent of antistrippingagentat which the stone dustsample is thoroughly coatedshall berecorded. The test shall be repeated at 60°Cin water aswell as 1 per cent solution of SodiumChloridein waterfor both the testing temperatures.

653

Appendices

(b) The under water coating test shall further beconductedwith coarseaggregate,passing19 mm sieveandretainedon 13.2 mm sieve. In this casetheper centcontentof shecuthack-antistrippingagesnblendshall bekept at 5 per centby weightof coarseaggregate.In orderto take careof contaminationin water, the test shallalsobecarriedout in the I percentSodiumChloride in water.

The minimum per cent content of antistripping agent atwhichstonedust/coarseaggregate

is thoroughlycoatedasper (a) and ~i) shall be taken asthedoseofantistrippingagent.TESTING FOR THERMAL STABILITY OF ANTISTRIPPING AGENT

Procedure:Blendsof antistrippingagentandbitumenof 80/100grade shall be preparedwith 0.00,0.25,0.50,0.75and 1.00per cent consentsof antistmipping agentandkept in oven at163°Cfor five hours. After the heatexposure,sheblend samplesare fluxed with keroseneoilso obtain the consistencyof MC 3 andtestedfor under water coating test

Reportingoftestresults: An antistripping agent ahall bedeemedto be beatresistantif thedoserequirement before and after beatexposureremains unchanged.

QUANTITATIVE EVALUATION OF RETAINED MARSHALL STABILITYVALUES AFTER IMMERSION IN WATER

Procedure: For quantitative evaluation, the tests shall be carried out as stipulated inASTM D1075(Effect ofWater on CohesionofcompactedBisuminousMixtures). Thegradasionof aggregatesshall be such as to givesufficientvoidsin thecompactedbituminousmix to bringout the effectsof stripping. The gradationof aggregatesshall be asunder:

SteveSize per centPassing

19.00mm . 10013.20mm 75-1009.50mm 60-804.75mm 35-552.36mm 20-35600 mic 10-22300mic 6-16lSOmic 4-12

75 mic 2-8

The Marshall testspecimensshall be preparedusing Sper centbitumen of80/100 grade byweight of aggregatesblended with varying percentagesof anristripping agentsfrom 0 to I perient in stepsof 0.25percent The testsamplesshall givea void contentof about 6’per cent. Atleast8 standard Marshall specimensfor eachof the varying antistripping agentpercentagesshallbe prepared.Bath setof 8 test specimensshall be sortedout in two groupsof4 eachsothat theaveragespecificgravity of thespecimenin group I shall be essentially the sameasin group ILGroup-I shall be testedfor Marshall Stability in the usualprocedureASTM D1559.Group-Ilspecimens shall be immersed in water for 24 hours at 60°C±1°C.and then shall be teasedimmediately for Marshall stability as per ASTM D 1559.

CalculatIon: The numerical indexof resistanceof bituminous mixtures to thedetrimentaleffectof water shall be expressedasthe index of retainedstability: -

AverageMarshall Stability ofGroup-Ilx 100percent

AverageMarshall Stability ofGroup-i

RequIrement for acceptance:A minimum of 75 per centof resaiisedMarshall strengthshall be requiredfor acceptance.

654

Appendices

Appendix1000-1DRAFT DOCUMENT ON IS : 9077-1979CODEOF PRACTICE

FOR CORROSION PROTECTION OF STEEL REINFORCEMENTIN RB AND RCC CONSTRUCTION (REVISED)

FOREWORD

This Indian Standardhasbeen revised taking into considerationtheexperiencegainedover the years, developments thote have taken place subsequentlyand also considering theneed for evolving suitableacceptancetestsfor qualitycontrol. In thisregard,theelectrochernicaltestsdevelopedattheCentralElectrochemicalResearchInstitute,Karaikudi,andalso the tensspecifiedin ASTMA775(A775M-90 for powderepoxycoating havebeen considered.

Thisrevised standardsupersedesearlierstandardnamely15:9077-1979.While revisingthis standard, is wasdecided socoverthe varioustest proceduresrequiredto ensurethe qualityof individual product aswell asthe finished products. Is wasalso decidedthat this standardshould include very stringent testprocedures particularly for finished productsso that theseprocedurescan be usedto evaluatenot only the corrosionresistanceof a particular finishedproduct covered by this standard but also any otherfinished product suchas galvanising,powderepoxyetc.

1. SCOPE;

1.1. This standard(revised)specifiesthe recommendedpracticefor surfacepreparation,surfacepretreatmentandanti-corrosivetreatmentbasedoninhibited andsealedcementslurryasanin-situprocessforcorrosionprotectionofmild steelreinforcesnent/ IIYSD bars in conventionalreinforced concretestructures and conventional reinforcedbrickwork,constructions Thispracticeis altoapplicablefor non-prestressingsteels(mild steelreinforcement/HYSI)bart)usedin prestressedConcretessmcture.

1.2. This standard applies only for in-situ corrosion pmtecsicn of rn:ild steelreinforcement)HYSD bars after all bending and shaping operations arecompleted. However, this doesnotprecludethepossibility of usingthis practiceasafactoryprocess.

2. ANT1CORROSIVETREATMENT PROCFSSSEQUENCES

Theanticorrosivetreatmentshouldnecessarilyincludethe following sequentialsteps~

(a) Surfacepreparation(dc-rusting)

Sincepresenceof oil, grease,dirt, heavyscaleandrust will adverselyaffecttheperformanceof any anticorrosivetreatment,it is essentialto adoptsuitablesurfacepreparationtechnique,Surfacepreparationcanbeeitherby acidpickling orby sandblasting.

(b) Surfacepretreatment

Surfacepreparation should be immediately followed by a surface treatmentsteptoensuretemporary protection during the time lag betweenthe dc-rusting and finish coating.Thispretreatsnentshouldnotadverselyaffecteithertbeadhesionofthefinish coatorcorrosionperformance.

(c) InhibitedCementSlurry coating

A minimum of2 coatsshouldbeappliedto ensurefull coverage.

(d) Sealingtreatment

Sealingtreatment shouldmakethecoatingharder and lesspermeable.

655

Appendices

A typical flow diagramis shownin Fig. 1000/1.

3. PROCEDUREFOR SURFACE PREPARATION

3.1.SandBlasting

Sandblasting of the steel surfaceto SAE 2 1/2 standardscanbe done

3.2.De-rustingby Pickling

The pickling weld should bepreferablybasedon hydrochloric acid andshouldincludeanefficient inhibitorsopreventbasemetalattack.

A typical dc-mating solution shouldhave thefollowing characteristics:

(a) inhibitorefficiency shouldnotbe lessthan97 per cent.

(b) weighs loss of a polished standard mild steel reinforcerrsesst / HYSD barsspecimenwhendippedin thesolution for 10 minutes shouldnot be more than 2 g persq. metre.

(c) Specific gravity when testedusingastandardspecificgravitybottle shouldbearound1.12.

4. PROCEDURE FOR SURFACE PRE-TREATMENT

De:in.stedsurfaceshould be immediately convertedby using phosphating treatment. Itshould be ensured by a suitable rinsing process that no residual acid is remaissingon thesurfaceatthe timeofpisosphating. A typical phosphatingcompositionofbnsahableconsistencyshouldhave the following characteristics:

(a) Coating weighswhen testedasper testprocedure A given hereunder shouldbe around4.5gsns./sq.m.

(b) Density ofthe productshould be in therangeof 1.22 to 1.4 kg/litre.

(c) Presenceof fungicideshall be testedby dissolvingthe jelly in deionizedwater,theresultingsolution shall be yellow incolour.

(d) Presenceof phospisasingchesnicalin jelly shall beensuredwith ammonia molybdatetest

(e) pH of thecomposition when testedin a standardspecificgravity bottle should beasound2.5 0.1

(I) Nail scratchtest should clearly leave a mark on thespecimen. This indicatesthe

existenceofthe coating.

5. PROCEDUREFOR INHIBITED CEMENT SLURRY COATING

5.1. A typical inhibitoradmixtureusedshouldhavethefollowing characteristics:-

(i) It should in liquid form ready for mixing with theordinary portland cement

(ii) Specific gravity when testedusing a standard specificgravity bottle shouldbe 1.04+0.02

(iii) pH when testedusing a pH metershouldbe 12.75~0.25

(iv) Tolerablelimit for chloride in inhibitor - admixturewhen testedusinganodicpolari-sation technique(asper testprocedureH) shouldbe 300±25 ppm

5.2. OrdInaryPortland Cement

This shouldconform to lS:269andshould be sievedtopaaa through 75 microns IS sievc.

656

STEPS

STORAGE YARD

PICKLING

RINSING

PHOSPHATING (brushing)

REACTION TIME

RINSING

“A” SOLUTION (Brushing)

INHIBITED CEMENT SLSJRRYFIRST COAT (Brushing)AIR DRYING

“B’ SOLSYTION (Brushing)

INHIBITED CEMENT SLURRYSECONDCOAT (Brushing)AIR DRYING

“B” SOLUTION (Brushing)

AIR DRYING


AIR DRYING


AIR DRYING

STACKING YARD

[ TANK

-fF’

~-Ii~~IiIII]~ii’iiixiii’ii~

~iiiiiiiiii~~i~ixiiiiiiiii~

[I~I~~1

DURATION(For iOns lengthRebar)

15 — 30 stirs

2 — 3 sin

3 — 4 sin

40 sin

2 — 3 main

2 — 3 sin

3 — 4 rain

12 — 24 rain

2 — 3 sin

3 - 4 sin

12 — 24 h

2 — 3 sin

2-4 h

2 - 3 sin

2-4 h

2 — 3 sin

2-4 h

Fig. 10O~W1: Flow Diagram for Anti-Corrosive Treatment ofReinforcementBars

657

Appendices

5.3.Cementandinhibitoradmixtureshouldbemixed inspecifiedproportionsohavesuitableconsissency.Coating should be appliedpreferably by brushing. However, underspecificcircurn~stancessprayingor dipping is alsoallowable.

5.4. Sufficient time lag shouldbe allowed in betweensuccessivecoatingsto ensurefinalsetting of theundercoat. A minimum of6 to 12 hoursmay be necessary.

5.5 A minimum oftwo coatswith sufficient time lag in betweenshould be applied.

6. SEALING TREATMENT

Thesealingtreatmentshould be performedover thecoated surfaceimmediatelyafter finalsetting of thesopcoat. Sealingtreatmentcan beappliedby brushing.sprayingor dipping.

6.1. A typical sealingsolution should havethefollowing characteristics:-

(a) Specificgravity when testedusing a standardspecific gravity bottle shouldbe 1.09+0.02

(b) pH whenmeasuredusinga pHmeter shouldbe42.25±0.25

(c) Tolerable limit for chloride in sealingsolution using anodicpolarisation techniqueshouldbe 450±25ppm(asper test procedureB).

7. SPECIFICATIONS FOR FINISHED END PRODUCT

7.1. Finished coating when visually examinedshould be fairly uniform in thicknessandshould be devoidof any defectssuchas cracks,pinholes,peeling,bulgingetc. No surfaceareashou’dbe left uncoated.No rustspotshouldbe visiblesothe nakedeye.

7.2. Thicknessof theCoating

The minimum thickness of shecoatingshall be200microns.Preferablerangeis 200so400microns.

7.3.Bond Strengthof the CoatedRebar

The bond strength of shecoatedrebarandconcreteshall notbeless than that specified inIS:456 at per clauseNo, 0,2, 5, ii and 44.1.2andtestedasper IS:2770(Part1).

7.4.Hardnessofthecoatingwhen measuredusing a pencil hardnesstestershall be around5 IIto7H.

7.5. Tolerablelimit for chloridein 0.04Normal NaOH medium using anodicpolarisasiontechnique (aspertestprocedureB) shall be around4500to 5000 ppm.

7.6. No film failure as evidenced by evolution of hydrogen gas at the cathodeorappearanceof corrosionproductsat the anodeshall takeplaceduringonehour oftesting (aspertest procedureC).

8. GENERALREMARKS:

Is is advisable that severelyrusted and heavily pitted reinforcementsarenot acceptedfortreatment.

TEST PROCEDUREA

Determinationofphosphatecoatingweight

7.5 cm a 2.5 cm or 7.5 cm a 5 cm mild steelpolishedanddegreasedspecimensare to beusedfor this test. First the blank lossof unphospbatedspecimenis to be found out. For this,the initial weighs (W,) is accurately weighed. The specimen is kept immersed in the Clark’ssolution or patentedinhibitedde-russing solution for 1 minute. The specimenis removed,rinsed

658

Appendices

in distilledwateranddriedusinghotairblower. The specimenis immediatelyweighed(W2) The

differencebetweenW1 andW2 is termedasblank loss.

Anotherspecimen(polishedarid degreased)is brushedwith phosphatingjelly andkeptfor 45 minutes. Then the specimen is washed free ofjelly, rinsedin clean waterand driedusing hot air blower. The phosphatedspecimen(Vi’,) is accurately weighed. After weighing,the specimenis keptimmersedin Ouk’s solutionor patentedinhibited dc-rustingsolution foroneminute. Then the specimenis removed,rinsed in distilled water and dried using hot airblower. The specimenis immediatelyweighed(W4). Coatingweight= W3- W4 - blank loss.

TEST PROCEDUREB

Anodic Polarisasion Technique

Mild steel reinforcement / HYSD Bar testspecimensof size10mm in dia and 100 mmin length wish stemsof size5mmindiaand50mm in length is polished,degreasedandsealedat bottomedgeand as the stem with suitablescalerslike wax, lacquer. Then test specimen iskept immersed in tess solution and potential is momtoredusing high impedancemulsimeteragainst suitable reference electmdesuch as saturated calomel electrodel copper-coppersulphateelecsrode. Aftergettingstabilisedpotential using appropriatecurrent regulator (0-100mA), the test specimenis anodically polarisedat a constantcurrentdensity of 290 ~.tAcmusing a platinum/stainlesssteel/TSIA/polishedmild steelreinforcement/HYSDBar as cathode.Potential with tirefé is followed for 5 minusesaftercurrentis applied. The maximwn chlorideconcentrationupto whichthepotential remainsconstantfor 5 minutesis takenasameasureoftolerablelimit,

TEST PROCEDUREC

Resistanceto Applied.Vol cageTest

Twomild steelreinforcement/ HYSD bars of sizenot lessthan 10mmindia and800mmin length shall be givenanti-corrosive treatment as per specified procedure.The end of therebarsshall be solderedwith insulated copperelecsricalconnectingwire (14gauge)to serveaselectrical contact poinL Coatedrebus at the two ends shall be sealedwith an insulatingmaterial to a length of 25 mm as eachend, Test areashall be theareabetweenthe edge of thebottom sealedendandimmersionline which shallnot be lessthan250mmin this case.

The coated rebus shall be suspendedvertically in a non-conductiveplastic container ofsize not less than 150 mm x 150 mm squareand 850 mm high. The rebarsshall be sosuspendedas so haveaclearanceof25 mm at bottom, 45 mm at the sidesand40mm in betweenthe rods.

Thecontainershall thenberifled toa heightof800mmwith an aqueoussolution of7 percentNaCI, A potentialof2 Yin betweenthecoated rods shall be impressedfor a period of60 minutesusing a high resistancevolt meterfor direct currenthavingan internal resistanceofnot lessthan10 mega Ohms and having a rangeupto S V (minimum). Storage batseriesmay be usedforimpressingthevoltage.

During this 60 minusesoftesting,thereshall not be any coatingfailure as evidencedbyevolution of hydrogengasat thecathodeor by appearanceof corrosion products of iron at theanode.

659

H~TORVOF SINKING OF WELL NO - AIPENJ)JX - 120041-I

LOWEST BED LEVEL — L0WESr WATER LEVEL, HIGHEST FLOOD LEVEL _____________ FOUNDING LEVEL

HEIGHTOF CURB __________ HEIGHT OF (~UT~INGEDGE _______

SThINING SINKING

— DEPTHOFSTJMP

Bit OWCLTIING

EDGE

METRE

STRATAMI ~‘

\\ Ii H

KENTLEDGE

QUANTITYOF [MU [Xii I)MAIl RIM

~ METRE

REPORTRIG \RDINC

OBS I I S ORSA’JI) I~I1 ()\V

DURING SINKING

REPORTANY SPU( tAtMI tHUD 01

SINKINGEMPLOYED

REMARKS SIGNATURE01

SUPFR\~ISINGOil ICLR

REDUCED RI. OFTCPLVI I ~RI ) OF SlEININU

I3UTIDM BEIORIt UI UNG CASTINGEDGE

RI. OFTOPOF STFINING

Al [I RLASTING

HEIGHTOF511 INING

C \S1(CCII 4 CCII 3)

MEFRE

TOTALHFICH1 UISF1 INING

(IN(I I DING)CURB ANI)CUFFING

EDGE-(COI~$..C0L3)

METRE

RL. OF.RI Fl RI N( I

LI VII(Al WHICHCUllING

EDGE ISPt ACE1))

INITI,\1,GAUGE

RI Al )1N

MUIRI-.

FINAL(,AU( I

RI ADIM

MEIRE

SINKINGDL RIMI UI DM

~LUI 9 LU] ~

MITRE

RI. OFBOFIOM

UI C I I I IL’.(I IX,1

(COI..7 C )E.K~

.

METRE

wEIGHT

TONNF

ECCENTRI-CIIY

Al UNG XAXIS

METRE

ECUEN]RI~

Al ONGY AXJ~

MEfl~E

3 4 c 7 9 10 II 12 Ii 14 I~ 17 IS E) 20 21

~____-_

660

APPENDIX 1200/1-2

(PLACE) (PLACE)

0%0-~

PLAN OF WELL NOC)CD

WELL ELO -

PLAN SHOWING WELL NOS.

U’s

- TftAHC DW5~

TILT ANt) SHIFT IN WELL NO~-

APP ENLEX 1200/Il

DATE

—

TOTALSmINING

MFFRF

TOTALSINKING

Mfl1~I

REDUCEDLEVELS (RL~S)OFGAUGFMAt KSTILT ALONG TILT ALONG

X~AXIS YAXISCOLUMN COLUMN

6 9DIVIDED BY DIVIDEF) 1WWLLLDIA WI] I )I~

RESULTANTTiLT

•J(COL, l0’+COL,

.H~ACTION

TAKEN FORREC11FICAT1ON

REMARKS SIGNATURE

OFSUPERVISING

OFFICER

ALONGX~AXlS ALON(JY-AXIS AJONGX-AXISWITH

DIRECTh)N\•U RI

ALONGY-AXISWITH

DIRECTIONMFIRJ

1.~ThNT‘~S(COL. I3)~*RCOL, 1~jV~

MI FRF

(PLACE)ENI)

(PLACE)ENI)

DIFFERFNCE(COL.5

~

(U!S) (1)15> DIFFERENCE(COL.8 -

COL;)

I 2 3 4 5 6 7 8 9 II) Ii 12 13 II 15

-_________.~_________

652

Appendices

Appea4fr - 15%/f

INFORMATION TO BE SUPPLIED BY THEMANUFACTURERS OF PROPRIETARY SYSTEMS

L GENERAL

LI. The ifonnation ‘atidi the manufactureris requiredso supply shall be in suchdesail as to obviate 1515515useof the equipnensdue to Ut intention of the manufacturernot hawing been snideclear or disc to wn~gassumptionson Ut past of the user.

Li. The user shall refer unusual problem or çaoblesnsof erection/assemblynotin keqir!g with the Seededuseof Ut equipom too shemanufacturerof theequipment.

2. INFORMAl ION REQUIRED

ii, The masssiifaetusenof Ivopsiesarysyssonsshall sqçiy thefollowing information:

a) E)eacripaionof basic fsascsiestsof equ.ipmera

b) List of kansof equ~pmu*svailable,giving singeof sizes,spansand such like,with the snassufacusser’sidasti1~casionnusnbersor other references.

c) The basis on whkls Ut safe wosking loads have beetsdetermined andwhetherthe factor of safety given ~pp4ies so collapse or yield.

d) Whether Ut ss!c&r’s data ia based on calcnlEions or teats, ml shallbe dearlyssased as there may be wide variasieassbetweenresultso&ainedby eithermethod.

e) [nstnscaionsfor useandmaintenance,includingany points whAck requirespecialattention during ‘eressioss,especsallywhere safety is concerned.

I) l~aik4Idisnensionalinformation, as follows:

(i) Overall dimensionsand depth and wifls of members

(ii) Line drawing, including perspectivesandphotographashowingnormal uses.

(iii) Self ntight~

(iv) Full dimensionsof connecsiassand any special positioningarrangements.

(v) Sizes of mats, including tube diamesersandthicknessesof materials,

(vi) Any pennaneracamberbuils into Ut ecpsipnens

(vii) Sizesof holesand dimensionsgiving their positions.

g) Data relating to strengthof equipnens as foLlows

0) Avengefaibre loads as detenninedby tests

(ii) Recorntnasdedsnasinsumnworking loads for various conditionsof usc,

(iii) Working resistancemomentsderived from rests,

(iv) Working tar capacitiesderivedfrom reset

fr) Recosnmendcslfacrossof safety usedin assessingrecommendedloadsanddellecsionsbasedcm teas results,.

663

Appendices

(vi) Deflectionsunder load togetherwith recommendedpm-camberand limitingdellectiona,

(xii) If working loadsdependon calculations,,working stressesshouldbe stared,U’ deflectionsdependon theoreticalmomentsofio,rtia orequivalentmomentsof inertia rather than tests, this should S noted,

(viii) information on the designof sway bracingagainstwind and otherhorizon-tal loadings.

(ix) Ailowahlc loading relating to maximum ntension of basesand/or heads.

664

Appendices

Appendix - 1700/i

SPECIFICATION FOR CONSTRUCTION JOINTS

Location

The location of consft’uction joints shall be as shownon the drawingor as approvedby the Engineer. If addilionalfnewjoints are approvedby the Engineer,the following considerationsfor their location shall hetaken into account

(i) Joints shall he provided in non-aggressivezonesor in noo-splashzones, If notfeasible.,the joints shall he sealed.

(ii) Joints should be positioned where they are readily accessiblefor preparationandconcreting, such as location where the crosssection is relatively small, and wherereinforcementis not congested.

(iii) In beams and slabs, joints should not be near the supports. Constructionjointsbetweenslabs and ribs in compositebeamsshould be avoided,

(iv) For box girders, it ia preferableso cast the sofiasod the webs without any joint.

(v) location of joints shall minimise theeffects of thediscontinuity on the dunsbility,structural integrity and the ar..arsnceof the stnicture.

Preparation of Surface of the Joint

I...,aitanceshall be removedbe,fore. freshconcreteis cast.The surfaceshall he roughened.~Care shall be taken that they should not dislodgeihe coarseaggregates,Concretemay he brushedwith a stiff brush soonafter casting while the concrete is still fresh,

if the concretehas partially hardened,it shall he treatedby wirebrushing or with a stiff water jet followed by drying with air jeti rnmediateiy.

Fully hardenedconcreteshafi be treatedwith mechanicalhand toolsor grit blasting, hIking care not to split or crack aggregateparticles.

Before further concrete is cast, the surface should be thorot~ghlycleanedto removedebrisand accumulatedntbbish, oneeffective methodbeing by air jet.

Where there is likely to he a delaybefore placing the next concretelit’l, protruding reinforcementshall be protected. Before the next lift isplaced,rust, lose mortar or othercontaminationshall he removedfromthe reinforcements,In aggressiveenvironment,the concteleshall he cutbackto exposethe reinforcementsfor a lengthof about50 mm to ensurethat contaminatedconcrete is removed,

665

Appendices

The joint surfaceshall not be contaminatedwith releaseagents,dustor curing membrane.,

Concretingof Joints

The old surfaceshall be thoroughly cleanedandsoakedwith water,Standingwatershall heremovedshortlybeforethenew concreteis placed.iui.d the new concreteshall be thoroughly compacted.Concreting shallbe carried out continuouslyupto the constructionjoints.

Surfaceretardersmay be usedto improve thequality of constructionjoints.

For a verticalconstructionjoint, astoppingboard shall be fixed pre-viously at the predeterminedposition and shall be properly stayed topreventits displacementor bulging when concreteis compactedagainstit, Concreting shall be continued right upto the board,

666

Ap

pe

nd

ice

s

z (it

‘ii

,r) 0 z

rn I rn w -~ n rn

C m at ‘0 ‘0 m

x z D rn

667

AppendicesAppendix- 1800/I

TESTS ON SHEATHING DUCTSAll tests specifiedbelow shall be carried out on thesamesamplein the order given

below.

At least 3 samplesfor one lot of supply (not exceeding 7000 metre length) shallbe tested.

The tests are applicablefor sheathingtransportedto site in straight lengths wherethe pressressingcableis threaded inside the sheathingprior to concreting.Thesetestsarenot applicablefor sheathingtsar for coiled cableand transportedto site as an assembledunit, nor for sheathing ducts placed in position without threadingof prestressingcableprior to concreting.

(A) WORKABILITY TEST

A tett sample 1100mm long is solderedto a fixed baseplate with a soft solder (Fig.1800(1-I). The sample is then bent so a radius of 1800 mm alternatelyon either tide tocomplete 3 cycles.

Thereafter, the sealingjoints will be visually inspected to verify that no failurelopeninghas taken place.

(B) TRANSVERSELOAD RATING TEST

The lest ensuresthat stiffness of the sheathingis sufficient to prevent permanentdistortion during site handling.

The sample i~placedon a horizontal support500 mm long so that the sample issupportedat all points of outward comagations.

A load as specifiedin Table I is applied gradually at the centre of the supportedportion through a contact surface12 mm long. It shall beensuredthatthe load is appliedapproximatelyat the centre of two corrugations,Fig. 1800/1-2. The load as specified isapplied in increments.

dia (mm) 25.35 35-45

TABLE

45-55

1

55-65 65-75 75-85 85-90

load (N) 250 400 500 600 700 800 1000

The sampleis consideredacceptableif the permanent defonnationis less than 5 percent of the diameter of the sheathing.

(C) TENSION LOAD TEST

A testspecimen is subjectedto a tensileloact The hollow core is filled with a woodencircular piecehaving a diasfleterof 95 per cent of the inner dia of the sample to ensurecircular profile during test loading, Fig. 180(W[-3.

A coupler is screwedon and the sample loaded in increments,till reaching the loadspecifiedin Table 2. If no deformationof the joints nor slippage of couplers is noticed,the rest shall be consideredsatisfactory.

TABLE 2

dia (mm) 25-35 35-45 45-55 55-65 65-75 75-85 85-90

load (N) 300 500 800 1100 1400 1600 1800

668

Appendices

(D) WATER LOSS TEST

The sampleis sealedat one end. The sample is filled with waler and after sealing,the end is connected to a system capable of applying a pressureof 0.05 MPa, Fig. 180W1-4, andkept constant for 5 minutes using a hand pumpwith pressure gauge or stand pipesystem can be used.

The sampleis acceptable if the water loss does not exceed 1.5% of the volume.

669

App

endi

ces

“1 as-o

~ ~ ‘I

0 C)

e —I z 0 tø

np

670

AppendicesI~S PLATE 153 ~53

l5O~15C)a()tr.m

— -... - — —--.~ L—25s25a4 Cd~L~.)

1

PIg. llIOWL-2 : Dimensionsarein nun,

4

ELEVATION

I. --••• ... 500TIMB ERPAC KING

A

A

PLAN

L—FRAME25 x 25 x 4

VIEW A-A

671

Appendices

SOLDERED JOINT

M.SPLATE 100*100*10mm

fig. 1890/1—3 flin1cn~ionsare in mm.

672

SPLATE ISO x!50x~0mm

SOFT SOLDERED JOINT

-SHEATHING PIPE 1100mm LONG

WOODEN CYLINDRICAL MEMBEROF 95% INNER DiAMETER OFSHEATHING

1WUn I 0~

—

49

PAN

Appendices

PVC TUBE ~0rn.m~ SUBJECTEDTO A PRE5SURE OFO.O5 MPaBt PUMP/ WATER HE.AD FORS MONUTES

H S FL. ATE

so oso~0mm

~OL.DERNO

k --- 100

NI 5 pEAT LlOOxlOOx 3 mm~

I SHEATHING SAMPLE LENGTH I

Fig 1800/1 4 F)imcnsionsare in mm.

673

NUMIIER OR NAME OF THE BRIDGE:

Ave. Cube Strength at the time of stressing kglcni2

High Tensile Steel(UTS)—~ kg/cm2

Cube Strength: at 28 days kg/cm’

PJ.~STRESSINGREPORT:

SPAN No. ___________________________

ELEMENT/GIRDERNo.__________________

LAST DAlE OF CONCRETING____________

DATh OF PRESTRESSING______________

Max-JackPressurenot to exceedunderanycircumstances kg/cm2

StressingSequenceDrg. No.

MarksofPlant UsedJacks

Pumps:

Gauges

APPEN[)JX I 800/U

Left endof Cable= ARight endof C~bk.= UISpecified(Jau~ePressureduringJacking

COLUMNSI 2 3 4 5 4 6 7 9 0 11 12 13 14 15 16 17 18 19 ~20~211 22 23 24 25 26

CableStressingSecjuence

CalculatedElongation

mm

GaugeMark Readingsof extension in mm atthepressureof 100kg/cm

~< *~1

GaugeMarkReadingscii extens~on

in mm it thepressureof200k~/cm —~

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Readingat ~nstanmotI.x,ckiog

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SLIP(Draw~in>mm

Inisnediatelyafter kiter Totallocking 24Ht~ Drawmn

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Client

674

Appendices

Appendix - 1800/Ill

SPECIFICATIONS FOR GROUTING OF POST-TENSiONEDCABLES IN PRESTRESSED CONCRETE

1. GENERAL1,1, The recommendations cover thecement grouting of post-

tensioned tendonsof prestressedconcretemembers of bridges. This’also covers some of the essential protective measuresto be adoptedfor minimising corrosion in PSC bridges.

1.2. The purposeof grouting is to provide permanent protectionto thepost-tensionedsteel against corrosionandto developbond betweenthe prestressingsteelandthe surrounding structural concrete.Thegroutensuresencasementof steel in an alkaline environment for corrosionprotectionandby filling the ductspace,it prevents watercollection andfreezing..

2. MATERIALS2.1. Water

Only cle.anpotablewaterfree from impuritiesconforming to section10(X) shall bepermitted. No sea or creek water is to he. used at all.

2.2. Cement

Ordinary Portland cementshould heused for preparation of thegrout. it should heas freshas possibleand free of anylumps. Pozzolanacement shallnot be used.

23. Sand

it is not recommendedto use sand for growing of prestress-lug, tendons. in casethe internaldiameterof the ductsexceeds:150 mm,,use of sand may be considered. Sand, used, shall conform to 15:383and shall passthrough !S Sieve. No. 156. The weight of sand in thegrout shall not he. more than 10 per cent of the weight of cement,unlessprope.r workability can be ensure.dby addition of suitable plasticizers.

2,4. Admixtures

Acceptable admixturesconforming to 15:9102may be used if testshaveshownthat their useimprovesthe propertiesof grout, i.e. increasingfluidity, reducing bleeding, entraining air or expanding the grout.Admixtures must not containchlorides,nitrates, sulphides,sulphitesorany olhe.rproductswhich arelikely to damagethesteelor grout. Whenan expanding agent is used, the total unrestrainedexpansionshould

675

Appendices

not exceedlO per cent. Aluminum powderas an expandingagentis notrecommendedfor grouting be..causeits long term effectsare not freefrom doubt.

2.5. Sheathing

2,5,1.For specificationsof sheathing,section 1800 may bereferred

2.5.2. Grout openingsor ventsa) All ducts should have grout openingsat bnt.h ends. For this porpose special

openingsshould be provided where such openingsare not availableat end an-chorages. For draped (curved) cablesventsshall be provided at all crown andvalley points. 0 is a good practice so provideadditions] air vents at suitableintervalsnot exceeding20 m. All groutopeningsorventsshouldincludeprovisionsfor preventinggrout leakage.

h) Standard details of fixing couplers, inlets, outlets and air vents to the duct!anchorageshall be followed as recommendedby the supplierof theprestressingsystetn.

23,3. Ducts should be securelyfastenedatclose intervals. All un-intended holesor openingsin th’e duct must herepairedprior to concreteplacing. The jointsof the couplers and the. .s’heathing shouldbe made‘water proof by use of adhesivetape or similar suitable sy~itemcapableof giving leak proof joints. Groin openingsandventsmust be securelyanchoredto the duct and to either the forms or to reinforchig steelto prevent displacementduring concreting operationsdue to weight,buoyancy and vibrations.

2.5.4.Ducts require very ‘careful handling as, beingof thin metal,they are susceptibleto leakage due to corrosion in transitor storage,by It lnng/nppLno in handl ng parttctil irl) ~slu_n p1 KL d adjotntng toreinforcing steel, by pulling apart at j.oints while insertin,g tendonsprior to concreting,or by accidental p’unctur~ngwhile drilling for formties/inserts. Duels are also liable to damageby rough use of internalvibrator and sparks from welding being done. close by.

3. EQuIPMENT

3.1, Grout Mixer and Agitator

It is ~ssentialthat the. grout is maintainedin a homogeneousstateand of uniform consistencyso that there is no separationof cement.Use of grout niixers to obtain a colloidal grout is essential. The mixershould ha.ve an additional storagedevice, with an agitator to keep thegroifi moving continuouslybefore it is pumped in the duct. Positivereciprocating type grout pumps should be used.

676

Appendices

3.2. Grout Pump

The pump shouldhe a positive displacementtype. and should becapable of ejecting the grout in a continuous operation and not. byway of pulses. The grout pump iii ust he fitted with a pressure gauge.to enablepressureof injection to be controlled. The minimum pressure.at which grout shouldbe pumpedshall he 0.3 M’Pa and the grout pumpmust have arelie.f arrangement. for bypass of the grout. in case of buildup ctt’ pressurebeyond 1 MPa, The capacity of the grout pump shouldhe such as to achieve forward speed of grout of around 5 to 10 metresper minute.. The slower rates are referable as they reduce the possibilityof occurrence of voids. If th.e capacity of the pump is large, it isusual to grout two or more cables simultaneously through a comtnonmanifold.

Use of hand pumps for ,grouting, is not recommended. Use of com-rresse.d air operated equipment for injection is prohibited, as it is likelythat there. will he some air trapped itt grout.

3.3. Water Pump

Before comrnenten’ientof grouting, a stand by direct feed highpressure water pump should he available at site for an emergency. Incase of any problem in growing the. ducts, such pump shall immediatelybe connected to the duct and all grout flushed by use .of high pressure.water flushing. it is, therefore, necessary to have adequate storage~ ofcleanpotablewater for operationof the water pump for such eaergencies.

3.4. Grout Screen

The grouting equipmentshouldcontain a screenhavinga meshsizeof 106 micron sizeof 150 micronsif sandis used.). Prior to introductioninto the grout pump,the grout should he passed through such screen.‘This screen should he easily accessible for inspection and cleaning.

3,5. Connections and Air Venls

Standarddetailsof fixing inlets, outlets andair ventsto the sheathingand! or anchorageshould he followed as recommended by specialistsupplier of the system of prestressing. In general,all connections.are to he of the “Quick couple” type and at change of diameters suitablereducers are to be provided.

4. PROPERTIES OF THE GROUT

4.1. Water/cementratio should be as low as possible, consistent withworkability. This ral.io should not normally exceed 0.45.

‘677

44.nendice.s

4.2. Before grouting, the properties of the grout mix should hetested in a laboratory depending on the facilities available.Tests shouldbe. conducted for each job periodically. The recommended test is.described beLow.

4.3. Compressive Strength: The. compressive strength of 100 mmcubes of the grout shall not be les.s than 17 MPaat 7 days. Cube.s.shallbe cured in a moist atmosphere for the first 24 hottrs and subsequentlyin water, These tests shall be conducted in advance to ascertain thesuitability of the grout mix.

5. MIXING OF GROUT

5.l. Proportions of materials should be based on field trials madeon the grout belore commencement of grouting’, but subject to the limitsspecified above. The materials should be measured by ‘weight.

5.2. Water should h, added lo the mixer, first, followed by Port-land ccitt ent and s~mnd, if used. Admixture if any, may be addt’,.d asrecommended by the manufacturer.

5.3. Mixing time depends upon the type of the tnixer, but willnormally be betwee.n 2. and 3 niinutes. However, mixing should he forsuch a duration as to obtain uniform and thoroughly blended grout,without excessive tempe.rature. increase or loss of expansive propertiesof the. admixuires. The g’rout should he continuously agitated until itis injected.

5.4. Once mixed, no water shall he addedto the grout to increaseus fluidity.

5.5. ‘Hand mixing is not permitted.

6. 6ROUTING OPERATIONS

6.1. Generala) Grouting shall be carried out as early aspossiblehut not later than 2 weeks

of stressing a tendon. Wheneverthis stipulation cannotbe complied with ‘forunavoidable reasons,adequate temporaryprotect~onof the steel againstcorrosionby methods or products which will not impair the tsltintate adherenceof theiejected grout shouldhe ensuredtill grooting. The sealingof the anchorageendsafter concreting is considered to he a good practiceto preventingressof water.For structores in aggressivc environment, sealingof the anchorage ends ismandatory.

Notes

i) Application of some patented water soluble oils ‘for coating of sieel/VPI powderinjection! sending in of hot, dry, oil—free compressedair throughthe vents at frequentintervals have shown some good results.

67’:.

Appendices

ii) Some of themethod.t recommendedfor sealing of anchoragesare to seal theopenings‘with h:itstmen impregnatedgunny bag or water proof pape:ror by building a brick

l:)edestal plastered on all faces enclosingthe exposedwirea outside the anchorages.

iii) Aey traces of oil if applied to steel for presentingcorrosionshould he removedbefore grouting operation..

iv) Ducts shall be flushed with ‘water for cleaning as well as for wtttiog the surfacesof the duct walls. Water used for flushing should be of samecitsslity as usedforgrousing. Is may, however, contain about I per cent of stakedlime or quick lime.All water shouldhedrained‘thorough thelowestvent pipe or by blowing compressedair through the duet

v) The water in the duct shoukl he blown out with oil free compressedair.

Blowing out waterfrom duct for cables longer than 50 m draped up at bothendsby compressedair is not effective,outlet! ventprovided at or near the lowestpoint shall be usedto drain out ‘water from duct

vi) ‘l’he connectionbetweenthenoxateof the injection pipe andduct should be suchthatair cannot he ssteked in.

vii) All outlet points includingventopeningsshould be keptopenprior so commencementof injection grout

‘viii) Before grousing, all air in thepump and hose tlsould be expelled.. i’he suctioncircuit of the pump should be air-tight

6.2. Injection of Grouta) After mixing the grout ~shouldbe ke

1* in continuous‘movement.

h) Injection of grout must be continuousand should not be interrupted.

c) For vertical cable or cablesinclined more than 60 degreesto the hori~.,.ontal,injection should be effected from the lowest anchorageor vent of she duct

d) The method of injection should ensurecomplete filling of the ducu, To verifythis, it is advisableto comparethe volume of the spaceto be fitted by the injectedgrout with the quantity of grout actually injected.

e) Grout.ing should becommencedinitially w~tha low pressureof injection of upto0.3 .M,Pa increasingit until the grout comesout at the other end. Th.e groutshould be. allowed to flow freely from thd other enduntil the consistencyof thegrotit at this end it thesame£ that of the groutat the iniecrion end. When thegrout (Iowa at the otlter end, it should be closed off and building upof pressurecomntenced,Full injection pressureat about0.5 MPa shall be maintainedfor atleast one minute before closing the injection pipe. It is recommendedpracticeto providea standpipe at the highestpoint of thetendonprofile to hold all waterdisplacedby sedimentationorbleeding. If thereis a Stilt up of pressuremuchin excessof I MPa without flow of grout coming at theotherend, the groutingoperationshuuld be discontintted and theentireductflushed with ltigh pressurewater, Also, the bypasssystemindicatedin para3.2 above is essentialfor furthersafety.

I) In the caseof cablea drapeddownwardse.g. in cantileverconstnsctionsimul-taneousinjection from both ends may be adopted Fig. lSOO!lII- 1.

g) Grout not usedwithin 30 minutes of miaing should he rejected.

679

Appendices

~Eit’11PSPE ~ LWL’

- -~ THPDLSOH tUTH CO:MS’SsE.S.SED A~t

c~ivtLt’’ s~c:~PLUG ~ 10’~SINT

5T55 ~ ~a rwt. OUCT ~IT.H SSA’T.tFS

~AT[ S cR5.5 SLOW ‘: RAT IFS SN DUCT

c ~ ~ CROUT

5, Cossut’NCe OFSOUTLNG 5SMULT,ANE’OUSLV FROM 60TH ENDSSE.MOVE tNTLFSMt,DLATE PLODS AT SNTESFVALS ‘TO CHICK FLOW

WATER OLIN FLOW NAT sv s~DucT

~ ~4. FLUD INTISMEDIATE VENTS A~rER GFSOUT FLOWS

r COLOURED W.ATL~

050551 ~ ~ osoijr

5. WHCN WATCR FLOW OUT Of TOP LTNT ThKIS ON COL’OU~OFC�sstNT STeW PUw.S’IaO eWOUT 555GM ONE END CONTLNU5.

(~5~UT6. tF GROUT 6E5~NSTO FLOW FROM 105’ VEPeT,STOS’ PuNFPSN’G AND

PESTAST rFsoM OTpStFS END SF’ C LEAFS WATER FLOWS FROM TOPVrF~r ~ r~r,I ~i,Jn.

-.~.,,_

7 WHEN PUMS’SNO FROM BOTH CNDS tN TURN ,CAUSES GROUTTO FLOW FROP~4TOP VENT

PLUG . PLUG PLUG

- ~ GROUT

.5.. PLUG ALt.. VENTS AND tNCREASI FUASF’ PRESSURE AT 6~DTHENDS

TO o.~MP~HOLD TH’~SPRESSURE 5055 AT LEAST ONE MSNUTI

Fig. 111051/1ft.! Procedurefor (houtin,f of CablesDrapedDownwards

680

Appendices

Appendix 1800/IV

CROUTING RECORD

,loh Naistc: — —.__._._—_

Span No. ~_.._. __~_ Cable No:

Datc of Cable lrss:allation: —_____. — Date of Grouting:.—.

typeof Ccrsicnt:CPC/I 150FF

\Vcck’otd ‘5 cur of Manufactureot OP 11501k.

W!C Ratio:

Name and amotirstof admixtureused,il any —.—........ ——________________‘l”cmpcrature: Mixing waler _. Grout ...__._.~. ._ —.

‘j’isrte: Start,. ...,~ Finish ___________.~. ——__________

tLC~SJip.rtteStt (;ro’ut mixer —~ ‘Grout ptsmp

Cable dues: Diarrteter ._...... _._.... 1_englls ..._..____.

Voltime of grout .n litre’s — Regrouting ___________________—.______________

Grouting pressure

(‘~crnentconsu sp~iort:1)seoresseal._........_.. : Aetu:sl ________________________________

l5re~gtoutitigebeUks:

Free of block’aee Inlet: Yes/No : outlet : Yes/No

Vents: Yes/No Cableduct : Yes/No

f..eakageobsers’cd : Yes/No Sealed : Yes/No

11’ cable duct blocked: Remedial Measures

Grotjtirs~observ:isions:

Passaneof ,grousi.:rougls vents : Yes/No

i~s’ss~:geof grout througlt i:sutlet Yes/No

i\ny equijarnentSolute — ______________ —.————____________

Posteroutine ebeL’ks

Prohbirtgby still’ ~‘ii.e

kernarks _______________ _____________ ________

.Si,ers:stijress’sf cslt. :‘ers Ires’eItt sluitng gtcsuting:

tli’L:r’st (Tontractor SystertsSupplier

681

A1:spendiees

Li) DisconnecLion is facitiutted if a short length of tles.thie tube connectsthe ductand injection pipe. This can be squeezedandcut off aftershe grouthas hardened

7. PRECAUTIONS AND RECOMMENDATIONSFOR EFFECTIVE GROUTING

si ln cold and frosty weather, injection should be postponed, unless speciatpnTcsutionsaretaken. If frost is likely so occur aithin 48 hoursafter injection,heat must he applied to the memberastdmaintainedfor at least 48 hestirsafterinjection so that the temperatureof the grout does not fall below 5 dc.greesCclstu.s, Prior to cottunencemensof grouting,care must be taken to ensurethat the duct is completelyfree of frost/ice by flushing with warn water, butnot with steam.

h) ‘l’be temperatureof thegroutshallnot exceed 25 degreesCelsius.For increasingthe workability of grout, tts temperaturemay be lowered by useof chilled wateror by putting ice outside she grout storage container.

c) When the cahlcs are threaded after concreting, the duct must be tetnporaril~stiffenedduring cond.scting by insertmgbunch of strandt,wires or reinforcemenor a rigid PVC pipe or any other suitable method.

d) Duruig concreting,caseshall be takento ensurethat the sheathingis notdamaged.Needle vibrators shall be used with extreme care by well experiencedstaffonly, to ensure against such damage.

e) It is A gsrod prsctic:eto sstoseshe cablesin h:rsh iti rectionsdursng the c:oncretingopemations. This can easilyhe done by light hammeringshe endsof the wtresfstndndsduring concreting It ts alsoadvisablethat 3 to 4 hoursaftercdncreungthe cableshould bemovedbosh waysthrougha distanceof about 20 ems.Withsuch movement, any leakageof tnorumr svhich has taken place in spite of allprecautions,loses bond with the cables, thus reducing the chanceof blockagesThis operationcan also be clone by fit irig prestresssngjacks,at oneend pullingthe entire cableand then repeatingsheot.Teration by fixing thejack at the otheresid.

5) The cablesto he gmoutedshould be separatedh1 as much distanceaspossible

g) In ease.sif stage pmestnr ssing, cablestsTnsioncd in tbe. first stageshould not rr.mnainusigrosite.dtill all cablesare stressed Is is good pmacttce, while grouting anyduct in stageprestressing,to keep all the remainingduets filled up with watemcontainingI per cent time or by running water through such dtsetetill the gn:tuthas set. After grouting the particular cable, the water in the other cablesshould be draineit and removedwish compressedair so prevent corrosion

hi Care should he t:tkemt so avoist leaks frnm one duct to atsotherat joints of precastmetnbersin pamntettlar

i) End faceswheseanchoragesare locatedare vulnerablepoints of entry of water.‘thisy haseio henecessarilyprotectedwith aneffective harrier. Recessesshosildbe packed with mortar concreteand should preferablybepainted with waterproof paint.

.ti After grouting is completed, the projecting portion of the vents should hecut off and the face protected to prevent corrosion.

682