EXPERIMENTAL STUDY OF FIBER REINFORCED SELF …ijset.in/wp-content/uploads/2014/08/IJSET.0720140248.1011.2507... · EXPERIMENTAL STUDY OF FIBER REINFORCED SELF COMPACTING CONCRETE

EXPERIMENTALSTUDYOFFIBERREINFORCEDSELF

COMPACTINGCONCRETE

1K.S.JOHNSIRANI,2DR.A.JAGANNATHAN

1AssociateProfessor,DepartmentofCivilEngineering,MailamEngineeringCollege,

Email:[email protected]

2AssociateProfessor,DepartmentofCivilEngineering,PondicherryEngineeringCollege,

Puducherry,INDIA,605014

ABSTRACT

SelfCompacting concrete gets compacteddue to its ownweightwithout anyexternal

vibration. The trial mix whish satisfies the fresh concrete properties as per EFNARC

guidelinesandtheonewhichgivesmaximumcompressivestrengthisusedinthework.

The proposed experimental program is aimed to evaluate performance of SCC with

varying percentage of polypropylene fibers. An attempt has beenmade to study the

freshandhardenedpropertiesofselfcompactingconcretewith10%ofclassFflyashto

theweight of cement and super plasticizer. The self compacting concretewith

0.01% of polypropylene fiber satisfies EFNARC guidelines and showed better results

whencomparedtoothertrialmixes.

KEYWORDS:SCC,VMA,Polypropylene,Flyash,Superplasticizer.

1. INTRODUCTION

Self‐compacting concrete (SCC) is considered as a concrete which can be placed and

compactedunder its selfweightwith little or no vibration effort, andwhich is at the

same time cohesive enough to be handled without segregation or bleeding of fresh

concrete. SCC mixes usually contain superplasticizer, high content of fines and/or

viscosity modifying additive (VMA). Whilst the use of superplasticizer maintains the

fluidity, the fine content provides stability of the mix resulting in resistance against

bleedingandsegregation.Theuseof flyashandblast furnaceslag inSCCreducesthe

dosageof superplasticizerneeded toobtain similar slump flowcompared to concrete

mixesmadewithonlyPortlandcement.ItisestimatedthatSCCmayresultinupto40%

K. S. JOHNSIRANI et al. DATE OF PUBLICATION: AUGUST 03, 2014

ISSN: 2348-4098 VOLUME 02 ISSUE 06 JULY 2014

INTRNATIONAL JOURNAL OF SCIENCE, ENGINEERING AND TECHNOLOGY- www.ijset.in 1006

faster construction than using normal concrete. The special rheological properties of

SCCcouldbeachieved,throughtheuseofchemicalandmineraladmixturesandmixture

modifications,including:

•Superplasticizer(SP)

•ViscosityModifyingAgent(VMA)

•Flyash(FA),silicafume(SF),ormicro‐silicaparticles

•Reducedwater/powderratio(powder=cement+FA+SF)

•Limitedcoarseaggregatesizeandcontent

Significant water reduction ability of SPs is essential to provide the necessary

workability; high fluidity, however, can increase the tendency of a mix to segregate.

ThereforemaintaininghomogeneityisanimportantissueforthequalitycontrolofSCC.

PolycarboxylateEther(PCE)basedsuperplasticizersrepresentamajorbreakthroughin

concretetechnologyastheycanreducethewaterrequirementbyasmuchas40%and

impartveryhighworkabilitythatcanbeextendedupto60minutesforgoodflowability

(thediameterof slump flow is larger than600mm)without theundesirableeffectsof

postponement and segregation. With proper use of viscosity modifying agents, SCC

could achieve higher flowability and higher slump without segregation, and also

maintainbetterslumpretention,thusmakingconcretealsomoredurable.

Polypropylene (PP), also known aspolypropene, is athermoplasticpolymerused in a

wide variety of applications includingpackaging and labeling,textiles(e.g.,ropes,

thermal underwear and carpets),stationery, plastic parts and reusable containers of

various types, laboratory equipment,loudspeakers, automotive components,

andpolymerbanknotes.Anadditionpolymermade fromthemonomerpropylene, it is

ruggedandunusuallyresistanttomanychemicalsolvents,basesandacids.




PolypropyleneFibersinconcretecontrolsthecrackingduetoplasticshrinkageanddry

shrinkage. They also reduce thepermeabilityof concrete and thus reduce bleeding

ofwater.Sometypesoffibersproducegreaterimpact,abrasion,andshatterresistance

in concrete. Generally fibers do not increase the flexuralstrengthof concrete, and so

cannotreplacemoment–resistingorstructuralsteelreinforcement.Indeed,somefibers

actuallyreducethestrengthofconcrete.

2. PREVIOUSSTUDY

Zoran grdic et al (2008)[1] studied the properties of self compacting concrte with

defferent types of additives and thisworkpresents the properties of self compacting

concrete,mixedwithdifferenttypesofadditives:flyash,silicafume,hydrauliclimeand

amixtureofflyashandhydrauliclime.

C. Selvamony et al [2] in his investigations on self ‐compacted self –curing concrete

using lime stone powder and clinkers indicated the use of silica fume in concrete

significantly increased the dosage of Superplasticizer (SP). Silica fume can better

reducingeffecton totalwaterabsorptionwhilequarrydustand limepowderwillnot

havethesameeffect,at28days

Kazumasa Ozawa [3] carried out an research on the development of self compacting

concrete. Ozawa (1989) completed the first prototype of self‐compacting concrete

usingmaterialsalreadyonthemarket. Byusingdifferenttypesofsuperplasticizer,he

studiedtheworkabilityofconcreteanddevelopedaconcretewhichwasveryworkable.

S. Deepa shri et al [4] carried out a research on the development of self compacting

concrete, in their study they analyzed the mechanical properties of SCC with

polypropylene fibers at different ratios and found the optimum percentage of 0.3

percentageofcementandtheyalsoutilizedthesiliconfumeasapartialreplacementof

cement.Accordingtotheirstudiestheymadethefollowingconclusion.

The mix (1:1.2:0.8) satisfies the fresh concrete properties as per EFNARC

Guidelineswiththeaveragecompressivestrengthof27.2N/mm2.

Asthepercentageofpolypropylenefiberincreases,thestrengthcharacteristicof

concretealsoincreases

Addition of 0.3% polypropylene fiber and 25% silica fume increases the cube

compressivestrengthby19%,splittingtensilestrengthby61%andflexuralstrengthby

54%.




3. PROPERTIESOFMATERIALSUSED

3.1 CEMENT

OrdinaryPortlandcementof53grade from the localmarketwasusedand tested for

physicalandchemicalpropertiesasperIS:4031–1988andfoundtobeconformingto

variousspecificationsasperIS:12269‐1987.

1.Normalconsistency: 30%

2.Initialsettingtime: 95min

3.Finalsettingtime: 155min

4.Specificgravity:3.01

5.Compressivestrength

7days: 37N/mm2

14 days: 47N/mm2

28days: 53N/mm2

3.2FLYASH

Class F fly ash is designated in ASTM C 618 and originates from anthracite and

bituminous coals. It consistsmainly of alumina and silica and has a higher LOI than

ClassCflyash.ClassFflyashalsohasalowercalciumcontentthanClassCflyash.

TypicalOxideCompositionofFlyAsh

S.No Characteristics Percentage

1 Silica,Sio2 49‐67

2 AluminaAl2O3 16‐28

3 IronOxideFe2O3 10‐Apr

4 LimeCaO 0.7‐3.6

5 MagnesiaMgO 0.3‐2.6

6 SulphurTrioxideSO3 0.1‐2.1

7 LossOnIgnition 0.4‐1.9

8 SurfaceAreaM2/Kg 230‐600




3.3 SUPERPLASTICIZER

Superplasticizer isessential for thecreationofSCC.The jobofSP is to impartahigh

degreeofflowabilityanddeformability,howeverthehighdosagesgenerallyassociate

with SCC can lead to a high degree of segregation. CON XL – PCE (VMA blended) is

utilizedinthisproject,whichisaproductofDonChemicalshavingaspecificgravityof

1.222. Super plasticizer is a chemical compound used to increase the workability

withoutaddingmorewateri.e.spreadsthegivenwaterintheconcretethroughoutthe

concrete mix resulting to form a uniformmix. SP improves better surface expose of

aggregatestothecementgel.Thepropertyofthespusedisshownbelow.

3.4 POLYPROPYLENEFIBER

Polypropylenefiberisauniquetechnologythatcreatesadditionalmicrofibrilsthatare

attachedtotheprinciple fibrillatednetwork.Theseadditionalanchoragesitesprovide

increased bonding between the mortar matrix and the fiber network. The increased

performanceattributabletoMasterFiberF100productmakesitanexcellentcandidate

asashrinkageandtemperature(secondary)reinforcement.Additionally,MasterFiber

F100 product exhibits excellent finishing properties, which is atypical for fibrillated

polypropylene fibers. It also provides reinforcement against cracking due to plastic

shrinkageandsettlement.

PROPERTIESOFSUPERPLASTICIZER

Name CONXL8860PCE(VMABlended)

FormOrState Liquid

Type PolycarboxylateEther

Color Darkambientcolor

SpecificGravity 1.14

Solidcontent 40%

Chlorinecontent Nil

WaterReduction ReducesUpto40%OfW/CRatioAndOtherMixParameters

P[H] 8.0




3.5FINEAGGREGATE

InthepresentinvestigationfineaggregateisnaturalsandfromlocalQuarryisused.The

physicalpropertiesoffineaggregate,specificgravityandfinenessmodulusaretestedin

accordancewithIS:2386.

Property Result

Fineness

modulus2.72

Specificgravity 2.69

3.6 COARSEAGGREGATE

The crushed coarse aggregate of 12.5mmmaximum size roundedobtained from the

local crushing plant, Mailam is used in the present study. The physical properties of

coarseaggregatelikespecificgravity,bulkdensity,gradationandfinenessmodulusare

testedinaccordancewithIS;2386.

PROPERTIES VALUES

Absorption Nil

SpecificGravity 0.91

FiberLength 6mm– 10mm

ThermalConductivity Low

ModulusofElasticity 5.52GPa

MeltPoint 320°F(160°C)

IgnitionPoint 1,094°F(590°C)

ElectricalConductivity Low

AlkaliResistance Excellent

AspectRatio 29

TensileStrength 415MPa




Physicalpropertiesofcoarseaggregate

ConventionalMixRatio=0.4:1:1.173:2.42

Cement Flyash Fineaggregate CoarseAggregate waterSuper

plasticizer

Kg/m3 Kg/m3 Kg/m3 Kg/m3 Lit/m3 %ofcement

431.05 47.89 561.96 1158.68 191.6 Upto5%

SCCisnotachievedbytheaboveproportion

3.7MODIFICATIONACCORDINGTOEFNARCGUIDELINES

Usingtheconventionalmixproportion= 1:1:2:0.4

Cement Flyash Fineaggregate Coarse Aggregate water Superplasticizer


490.5 54.5 545 1090 216 Upto5%

SCCconditionisnotachieved

AftermanytrailmixSCCconditionisachievedbythefollowingproportion

Cement Flyash Fineaggregate Coarse Aggregate water Superplasticizer


540 60 840 720 216 4

22.5% 2.5% 35% 30% 9% 4%ofcement

1 0.11 1.56 1.33 0.4 4%

SCCmixproportion=0.4::1:0.11:1.56:1.33

Properties Result

Finenessmodulus 6.15

Specificgravity 2.72




TRAILMIXES

S.

No.Mix

Cement Flyash FineAgg. CoarseAgg. Water PPFiberSuper

plasticizer

Kg/m3 Kg/m3 Kg/m3 Kg/m3 Lit/m3 %ofcement% of

cement

1 SCC0 540 60 840 720 216 Nil 4

2 SCC1 540 60 840 720 216 0.05% 4

3 SCC2 540 60 840 720 216 0.10% 4

4 SCC3 540 60 840 720 216 0.15% 4

5 SCC4 540 60 840 720 216 0.2% 4

4. TESTINGANDRESULTS

4.1SLUMPFLOW&T50TEST

Slumpflow isoneof themostcommonlyusedSCCtestsat thecurrent time.This test

involvestheuseofslumpconeusedwithconventionalconcretesasdescribedinASTM

C143(2002).ThemaindifferencebetweentheslumpflowtestandASTMC143isthat

the slump flow testmeasures the “spread” or “flow”of the concrete sample once the

coneisliftedratherthanthetraditional“slump”(dropinheight)oftheconcretesample.

TheT50testisdeterminedduringtheslumpflowtest.Itissimplytheamountoftime

theconcretetakestoflowtoadiameterof50centimeters.Typically,slumpflowvalues

ofapproximately24to30inchesarewithintheacceptablerange;acceptableT50times

rangefrom2to5sec.




4.2L‐BOXTEST

TheL‐boxvalueistheratiooflevelsofconcreteateachendoftheboxafterthetestis

complete at each end of the box after the test is complete. The L‐box consists of a

“chimney“sectionanda“trough“sectionafterthetestiscomplete,thelevelofconcrete

in the chimney is recorded as H1,the level of concrete in the trough is recorded as

H2.TheL‐boxvalue(alsoreferredtoasthe“L‐boxratio”,“blockingvalue”,or“blocking

ratio”)issimplyH2/H1.TypicalacceptablevaluesfortheL‐boxvalueareintherangeof

0.8to1.0.If theconcretewasperfectly levelafterthetest iscomplete, theL‐boxvalue

wouldbeequalto1.0.Conversely,iftheconcretewastoostiff toflowtotheendofthe

troughtheL‐boxvaluewouldbeequaltozero.

4.3V‐FUNNELTEST&FUNNELTESTATT5MINUTES

V‐funneltestisusedtodeterminethefillingability(flowability)oftheconcretewitha

maximumaggregatesizeof20mm.Thefunnelisfilledwithabout12litersofconcrete

andthetimetakenforittoflowthroughtheapparatusismeasured.Afterthisthefunnel

can be refilled concrete and left for 5 minutes to settle .If the concrete shows

segregationthentheflowtimewillincreasesignificantly.




AcceptanceCriteriaForSCC

(Typicalrangeofvalues)

S.No. Method Unit Mini. Maxi.

1. Slumpflowtest Mm 650 800

2. T50cmslumpflow Sec 2 5

3. V‐funneltest Sec 6 12

4. V‐funnelat T5 minutes Sec 6 15

5. L‐Boxtest H2/H1 0.8 1.0

4.4PREPARATIONOFSCCSPECIMENS

4.4.1Proportioning

Thequantityofcement,fineandcoarseaggregates,flyash,waterandSPforeachbatch

ofproportionispreparedasmentionedindesignofSCC.

4.4.2MixingofConcrete

Mixing of the SCC is carried out by themanualmixing; the best homogeneousmix is

achieved by 5minutes continuousmixing after placing all thematerials. Initially the

trayismoisturewithacloth.Cement,flyashandsandaremixedthoroughlytoformthe




drymixturewiththegravel.Andthe50%ofthewaterisaddedwithitandthenmixed

well,afterthatevery10%ofthewater,whichismixedwithsuperplasticizerisadded

withit.SCCisachievedbyincreasingtheSPcontent.

4.4.3MOULDS

Theconcrete iscastedintocubemouldsofsize100mm×100mm,beammouldsofsize

100×100×500mmandcylindricalmouldsof200mmheight×150mmdia.Themoulds

usedforthepurposearefabricatedwithsteelseat.Itiseasyforassemblingandremoval

ofthemouldspecimenwithoutdamage.Mouldsareprovidedwithbaseplates,having

smooth to support.Themould is filledwithout leakage .Inassembling themoulds for

usejointsbetweenthesectionofthemouldareappliedwithathincoatmouldoiland

similarcoatingofmouldoilisappliedbetweenthecontactfacesofmouldandthebase

plate to ensure that no water escape during filling .The interior surfaces of the

assembledmouldshallbethinlycoatedwithmouldoiltopreventadhesionofconcrete.

4.4.4PLACINGOFMIXINMOULDS

Aftermixingtheproportionsinthemixingmachine,itistakenoutintothebucket.The

concreteisplacedintothemoulds(cubes,beams&cylinders),whicharealreadyoiled

simplybymeansofhandsonlywithoutusinganycompactingdevises. Itisimportant

that the concrete should be poured at aminimumheight of 50cm from themould to

avoidtheairentertainmentandgoodfinish.

4.4.5CURING

After 24 hours the specimens were removed from the moulds and immediately

submergedincleanfreshwaterandkeptthereuntiltakenoutjustpriortotesting.

4.5 TESTSONHARDENEDSCCSPECIMENS

4.5.1COMPRESSIVESTRENGTHOFCONCRETE

Compressive strengthof concrete isdefinedas the load,which causes the failureof a

standard specimen. (Ex 100 mm cube according to ISI) divided by the area of

crossection in uniaxial compression under a given rate of loading. The test of

compressivestrengthshouldbemadeon150mmsizecubes.




Placethecubeinthecompression‐testingmachine.Thegreenbuttonispressedtostart

theelectricmotor.Whentheloadisappliedgradually,thepistonisliftedupalongwith

the lower plate and thus the specimen application of the load should be 300KNper

minuteandcanbecontrolledbyloadratecontrolknob.Ultimateloadisnotedforeach

specimen. The release valve is operated and the piston is allowed to go down. The

valuesaretabulatedandcalculationsaredone.

TestingofCompressivestrengthofconcrete

4.5.2TENSILESTRENGTHOFCONCRETE

Aconcretecylinderofsize150mmdia×200mmheightissubjectedtotheactionofthe

compressiveforcealongtwooppositeedges,byapplyingtheforceinthismanner.The

cylinder is subjected to compression near the loaded region and the length of the

cylinderaresubjectedtouniformtensilestress.

Horizontaltensilestress=2P/πDL

Where

P=thecompressiveloadonthecylinder.

L=lengthofthecylinder

D=diaofcylinder




4.6RESULTSFORFRESHCONCRETETESTS

TRAIL

MIX

Slumpflow T50CM VfunnelT0mins VfunnelT5mins H2/H1

Value

obtained

(mm)

Value

obtained

(sec)

Value obtained

(sec)

Value obtained

(sec)Valueobtained

SCC0 680 3 9 11.8 0.9

SCC1 680 3 11.22 13.5 0.9

SCC2 670 4 12.78 32 0.89

SCC3 650 5 13.5 38 0.8

SCC4 620 6.5 18.5 45 0.75

4.7PROPERTIESOFHARDENEDCONCRETE

COMPRESSIVESTRENGTHOFCONCRETE

TRAILMIX

NOOFDAYS

3 7 28

N/mm2 N/mm2 N/mm2

SCC0 9.95 18.78 31.29

SCC1 12.27 22.75 37.91

SCC2 13.62 25.15 41.78

SCC3 13.85 25.81 42.44




5. CONCLUSION

Based on the experiment of the study of polypropylene reinforced self compacting

concretethefollowingconclusionsarearrived.

AsnospecificmixdesignproceduresforSCCareavailablemixdesigncanbedone

with conventional BIS method and suitable adjustments can be done as per the

guidelinesprovidedbydifferentagencies.

Selfcompactingconditionisachievedbythe1:0.11:1.56:1.33mixproportionwitha

water‐cementratioof0.4

Increasing the percentage of polypropylene fiber increases the strength of the

concrete

But increasing of percentage of fiber decreases the flow of the fresh concrete,

especiallyinV‐FunnelT5mintesttheflowpropertyisgreatlyaffected.

TheMixSCC1(0.01%)satisfiesEFNARCguidelinesandalsoshowsbetterstrengthin

bothcompressionandtension.

Furthertheadditionofsuperplasticizerincreasestheflowbutleadstothebleeding

andadditionofexcessivecost.

REFERENCES

TheEuropeanGuidelinesforSelfCompactingConcreteMay2005.

SPLITTENSILESTRENGTHOFCONCRETE

TRAILMIX

NOOFDAYS

3 7 28

N/mm2 N/mm2 N/mm2

SCC0 0.69 1.48 2.48

SCC1 0.78 1.67 2.8

SCC2 0.83 1.78 2.97

SCC3 0.94 2.00 3.34




GuidelinesforViscosityModifyingAdmixturesForConcreteSeptember2006.

IS 3812‐2003, Pulverized FuelAsh specification, part 1 for use as pozzolana in

cement,cementmortarandconcrete.

N.Bhanumathidas&N.Kalidas2002‐FlyAshforSustainableDevelopment.

V.M.MalhotraandAARamezanianpourMarch1994,FlyAshInConcrete

Hajime Okamura and Masahiro Ochi “Self‐Compacting Concrete” journal of

advancedconcretetechnologyVol.1,No1.5‐15.April2003.

Hashimoto. C., Maruyama.k. and Shimizu.k, „Study on visualization technique for

blockingfreshconcreteflowinginpipe‟,Concretelibraryinternational,JSCE,No.12,

pp.139‐153,March1989.

IS269‐1958, Indianstandardspecification forordinary,RapidhardeningandLow

heatPortlandcement,revisedandreprinted,Aug1965.

IS269‐1989,IndianstandardspecificationforordinaryPortlandcement,33grade,

4threvision,1streprint,June1991,BIS19901




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EXPERIMENTAL STUDY OF FIBER REINFORCED SELF …ijset.in/wp-content/uploads/2014/08/IJSET.0720140248.1011.2507... · EXPERIMENTAL STUDY OF FIBER REINFORCED SELF COMPACTING CONCRETE