S-900-3120-001_2_0001 ( Concreate Building )

8/19/2019 S-900-3120-001_2_0001 ( Concreate Building )

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DSLNG Project Job No. : 0-5151-20Doc. No. : S-900-3120-001

CONSTRUCTION SPECIFICATION FOR CONCRETE WORK SHEET 2 OF 23

CONTENTS

CONSTRUCTION SPECIFICATION ......................................................................................................1

FOR .........................................................................................................................................................1

CONCRETE WORK................................................................................................................................1

DONGGI SENORO LNG PROJECT ......................................................................................................1

1 GENERAL........................................................................................................................................4

1.1 Scope........................................................................................................................................41.2 Definitions .................................................................................................................................4

1.3 References................................................................................................................................41.3.1 Codes and Standards........................................................................................................41.3.2 Project Specifications and Drawings.................................................................................5

1.4 Conflicts in Requirements.........................................................................................................5

2. INGREDIENTS OF CONCRETE.....................................................................................................5

2.1 Cement......................................................................................................................................52.1.1 Material Description...........................................................................................................5 2.1.2 Storage ..............................................................................................................................6 2.1.3 Rejection of Cement Material............................................................................................6

2.2 Aggregates................................................................................................................................62.2.1 Material Description...........................................................................................................6

2.2.2 Storage ..............................................................................................................................6 2.3 Mixing Water.............................................................................................................................62.4 Admixtures................................................................................................................................6

2.4.1 Material Description...........................................................................................................6 2.4.2 Storage ..............................................................................................................................7 2.4.3 Usage ................................................................................................................................7

3. CONCRETE MIXING.......................................................................................................................8

3.1 Production by Batch Plant ........................................................................................................83.1.1 General Requirement ........................................................................................................8 3.1.2 Facility Requirements........................................................................................................93.1.3 Measuring and Batching....................................................................................................9

3.2 Ready-Mixed Concrete...........................................................................................................103.3 Production by In-Situ Concrete Mixer.....................................................................................103.4 Durability .................................................................................................................................103.5 Slump......................................................................................................................................113.6 Air Contents ............................................................................................................................11

4. REINFORCEMENT........................................................................................................................11

4.1 Materials..................................................................................................................................114.2 Fabrication and Placing of Rebars .........................................................................................11

4.2.1 General ............................................................................................................................114.2.2 Fabrication.......................................................................................................................114.2.3 Placing of Rebars ............................................................................................................12 4.2.4 Mechanical Splices..........................................................................................................12

5 CONCRETING...............................................................................................................................12


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5.1 Blinding Concrete....................................................................................................................125.2 Formwork................................................................................................................................12

5.2.1 General ............................................................................................................................12 5.2.2 Design and Installation of Formwork...............................................................................12 5.2.3 Preparation of Form Surface...........................................................................................135.2.4 Removal of Forms ...........................................................................................................13

5.3 Anchor Bolts and Embedded Items........................................................................................145.4 Waterstops..............................................................................................................................145.5 Joints.......................................................................................................................................14

5.5.1 Construction Joints..........................................................................................................145.5.2 Expansion Joints .............................................................................................................15 5.5.3 Contraction Joints............................................................................................................15

5.6 Placing of Concrete ................................................................................................................155.6.1 Transportation .................................................................................................................15 5.6.2 Placing.............................................................................................................................15

5.7 Finishing..................................................................................................................................16

5.8 Curing......................................................................................................................................175.8.1 General ............................................................................................................................17 5.8.2 Moisture Retention ..........................................................................................................17 5.8.3 Protection from Mechanical Injury...................................................................................17

6. REPAIR OF SURFACE DEFECTS...............................................................................................17

7. HOT WEATHER CONCRETE.......................................................................................................18

8. MASS CONCRETE........................................................................................................................18

9. PRECASTING FOR CATCH BASINS, MANHOLES, PITS, AND OTHER FOUNDATIONS......19

10. INSPECTION AND TEST ..........................................................................................................19

10.1 Construction Tolerance...........................................................................................................1910.1.1 General ............................................................................................................................1910.1.2 Concrete..........................................................................................................................1910.1.3 Reinforcement .................................................................................................................20 10.1.4 Anchor Bolts & Embedded Items ....................................................................................21

TABLE-5: TOLERANCE OF ANCHOR BOLT GROUPS....................................................................21

TABLE-6: TOLERANCE FOR EMBEDDED ITEMS............................................................................21

10.2 Inspection and Test ................................................................................................................21

10.2.1 General ............................................................................................................................2110.2.2 Sampling for Test ............................................................................................................2110.2.3 Slump Test.......................................................................................................................2110.2.4 Compressive Strength Test.............................................................................................22 10.2.5 Water Filling Test for Concrete Ponds/Pits .....................................................................22

10.3 Test Reports ...........................................................................................................................23


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1 GENERAL

1.1 Scope

This specification describes the construction requirements for Concrete Works, includingmaterials, proportioning, mixing, placing, testing and curing of plain and reinforced concretefor Donggi Senoro LNG Project, Indonesia.

ACI 301-05, Specifications for Structural Concrete, shall be applied as the generalspecification for concrete supply and construction, except as specified herein or elsewherein the Contract Documents.

1.2 Definitions

The following terminologies are used in this specification.

(1) The OWNER is PT. Donggi-Senoro LNG

(2) The CONTRACTOR is PT. JGC Indonesia and JGC Corporation Consortium.

(3) The SUBCONTRACTOR is the party appointed by CONTRACTOR which carries out

the activities of the Work.

1.3 References

1.3.1 Codes and Standards

ACI American Concrete Institute

117/117R Standard Specifications for Tolerances for Concrete Construction andMaterials

211.1 Standard Practice for Selecting Proportions for Normal, Heavyweight, andMass Concrete

301 Specification for Structural Concrete

302.1R Guide for Concrete Floor and Slab Construction

304R Guide for Measuring, Mixing, Transporting, and Placing Concrete

304.2R Placing Concrete by Pumping Methods

305R Hot Weather Concreting

308/308R Standard Practice for Curing Concrete

318 Building Code Requirements for Structural Concrete

347R Guide to Formwork for Concrete

350 Code Requirements for Environmental Engineering Concrete Structuresand Commentary

504R Guide to Joint Sealants for Concrete Structures

SP2 ACI Manual of Concrete Inspection

SP17 ACI Design Handbook

SP-66 ACI Detailing Manual

SP-78 Foundation for Equipment and Machinery


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ASTM American Standards for Test and Materials

A185/A185M Standard Specification for Steel Welded Wire Fabric, Plain, forConcrete Reinforcement

A307 Standard Specification for Carbon Steel Bolts and Studs

A615/A615M Standard Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement

C31 Standard Practice for Making and Curing Concrete Test Specimens inthe Field

C39 Standard Test Method for Compressive Strength of CylindricalConcrete Specimens

C94/C94M Standard Specification for Ready Mixed ConcreteC143/C143M Standard Test Method for Slump of Hydraulic-Cement ConcreteC150/C150M Standard Specification for Portland CementC172/C172M Standard Practice for Sampling Freshly Mixed Concrete

And other standards and specifications related to works described hereinafter.

1.3.2 Project Specifications and Drawings

S-900-1358-015 Application for Grouting of Rotating Equipment

D-900-1310-001 Standard Drawing for Civil General Notes

D-900-1320-001 Standard Drawing for Hooks, Development Length and Splice of Rebar

D-900-1320-002 Standard Drawing for Anchor Bolts

D-900-1320-011 Standard Drawing for Rebar Arrangement (1/2)

D-900-1320-012 Standard Drawing for Rebar Arrangement (2/2)

1.4 Conflicts in Requirements

Conflicts among different codes and standards as well as project specifications anddrawings shall be notified to OWNER/CONTRACTOR for resolution. However, in the eventof conflicts, order of priority shall be as follows:

1. Design drawings

2. Standard drawings and specifications

3. International codes and standards as ACI, ASCE, ASTM, etc.

2. INGREDIENTS OF CONCRETE

2.1 Cement

2.1.1 Material Description

Cement shall conform to Ordinary Portland Cement ASTM C150 Type I, Blended HydraulicCements ASTM C595 or Portland Composite Cement SNI 15-7064-2004, unless otherwisespecified.

Manufacturer’s Test Certificate shall be submitted to OWNER/CONTRACTOR for each

delivery.


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2.1.2 Storage

Cement shall be stored in weather-tight sheds, bins or silos which will provide protectionfrom moisture and contamination. Cement bags shall be stored at a height of minimum 0.3m

above floor that shall be concrete paved.

Consignment of cement shall be stored as received and shall be consumed in the order ofdelivery.

2.1.3 Rejection of Cement Material

Cement remaining in weather-tight bulk storage for more than 6 months, or cement in bagsin local storage in the custody of a vendor for more than 3 months after completion of testsshall not be used. Cement that has become caked or partially set also shall not be used.

2.2 Aggregates


Both Fine and Coarse Aggregate shall meet the requirements of ASTM C33. Fine Aggregateshall consist of clean, washed, natural or crushed sand of uniform gradation. Coarse Aggregate shall consist of washed gravels or washed crushed stones that are hard, strong,durable, and free from adherent coating, other weak and deleterious substances.

Maximum size of coarse aggregate for structural concrete shall be 20 mm, except thatfireproofing concrete that shall be 10 mm.

The source of materials shall be approved by OWNER/CONTRACTOR, and not be changedwithout OWNER/CONTRACTOR’s approval.

2.2.2 Storage

Aggregate stockpiles shall be arranged and used in a manner to avoid excessivesegregation and to prevent contamination with other materials or with other sizes of similar aggregates. To ensure that this condition is met, test for determining conformance torequirements for cleanness and grading shall be performed on samples secured from theaggregates at the point of batching. The stockpiles shall be kept to have uniform moisturecontent throughout the stockpile.

2.3 Mixing Water

Mixing water for concrete shall meet the requirements of ASTM C94 and ASTMC1602/C1602M and free from injurious amounts of oil, acid, salt, alkali, organic matter, andother deleterious substances. Seawater shall not be used for mixing concrete.

Water shall have a pH between 6.0 and 8.0.

2.4 Admixtures


Admixtures shall conform to the requirements given in ACI 212.3R, 212.4R, ASTM C260, ASTM C494, ASTM C618 or ASTM C1017 and shall not contain chloride nor any corrosiveagents.


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2.4.2 Storage

Admixtures shall be stored in a manner that will avoid contamination, evaporation, ordamage, conforming to the recommendations and instructions given by the manufacturer.

2.4.3 Usage

Careful attention should be given to the manufacturer’s instruction.

When more than one admixture is used, the combination of such admixtures shall not haveany harmful effects on the concrete. SUBCONTRACTOR shall submit written statement toprove no harmful effects and test of trial mixtures prior to the commencement of work.


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3. CONCRETE MIXING

Requirements for concrete are summarized in the following Table,

ItemsSpecified

CompressiveStrength

MaximumWater

CementRatio

MaximumCoarse

AggregateSlump

AirContents

(MPa) (mm) (mm) （%）

Beams, Columns, Walls 28 0.50 20 100±25 3.5±1.5

Foundations Walls andFootings, Duct Banks,Sleepers, Culverts,Pavements, Floors andSlabs

28 0.50 20 75±25 3.5±1.5

Watertight concrete 28 0.45 20 75±25 3.5±1.5

Exposed to sea water 28 0.40 20 75±25 3.5±1.5

Lean Concrete 10 0.60 20 75±25 3.5±1.5

Fireproofing Concrete 21 0.50 10 75±25 3.5±1.5

3.1 Production by Batch Plant

3.1.1 General Requirement

The plant shall have functions capable for continuous concrete supply and for testing

requested in the specifications during construction work. The plant shall be located withinthe plant fence. This batch plant is installed as a temporary facility, thus, all facility shall beremoved and cleared after the construction work is completed.

The batch plant and associated facilities shall include, but not limited to:

• Batching and mixing units

• Aggregate bins/weighing hopper

• Cement weighing hopper

• Cement silos

• Operator cabin

•Conveyors

• Water chilling system

• Insulated water storage tanks and water pump.

• Cement & admixture storage warehouse

• Aggregate storage bins/shelters/yard

• Laboratory and office with toilet

• Curing pool for compression test cylinder

• Washing basin for truck mixers

• Drainage facilities including siltation pits.

• Generator with electrical distribution system

• Mixer trucks

• Lighting system

SUBCONTRACTOR shall submit his complete plan to meet the requirement herein and


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hereunder for OWNER/CONTRACTOR’s approval before commencing related works.

3.1.2 Facility Requirements

(1) The batch plant shall be a full-automated wet mixing type, and be designed to havecapacity to produce the appropriate and sufficient quantity of concrete. The capacity ofbatch plant shall fulfill maximum construction requirement. At least two batch plants ormixers shall be installed for a back-up purpose.

(2) The batch plant should be painted white to reflect the sun and be directly shaded fromthe sun.

(3) Aggregate storage bins shall have partitions to separate fine and coarse aggregate anddifferent size/type of aggregate. The floor of the bins shall be concrete to preventcontamination with soils. The storage bins shall have roofs for sunshade and equippedwith water spray system.

(4) The cement silos shall be an adequate size to store sufficient cement to ensurecontinuity of work. The silos shall be equipped with thermometers to check temperatureof cement. Ventilation system shall be provided for cement storage.

(5) The laboratory shall have equipment for the field testing of concrete and concretematerials.

(6) Temporary drainage system including siltation pits shall be provided and drains from thebatch plant area shall be treated prior to discharge to the surface water drainagesystem.

3.1.3 Measuring and Batching

(1) Concrete Production

The weighing and mixing shall be a fully automated.Quality of concrete produced in the plant shall meet the standard stipulated in relevantProject specification including:

- Material for concrete: cements, admixtures, mixing water, aggregates.

- Proportioning: concrete strength, durability, slump, maximum size of coarseaggregate, determination of standard deviation.

- Production of concrete: temperature control of concrete materials including mixingwater and weather conditions.

(2) Accuracy of Scales

The accuracy of weighing scales shall be within ± 0.4 percent of their total capacities.Standard test weights shall be kept available on site for checking the accuracy of allscales.

(3) Accuracy of Batching

Batching equipment shall be operated within the tolerances conforming to ACI 304 R.

(4) Mixing

The concrete shall be mixed in a batch mixer capable of thoroughly combining theaggregates, cement, and water into a uniform mass within the specified mixing time,

and of discharging the concrete without harmful segregation.


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(5) Control of Admixtures

Separate containers and measuring devices shall be used for admixtures. Admixturesshall be charged into the mixer as solutions. The liquid shall be considered a part of the

mixing water. Admixtures that cannot be added in solution may be weighed ormeasured by volume if so recommended by the manufacturer. If two or moreadmixtures are used in the concrete, they shall be added separately to avoid possibleinteraction that might interfere with the efficiency of either admixture or adversely affectthe concrete.

(6) Calibration

All laboratory equipment and batch plant equipment shall be calibrated regularly inaccordance with Indonesian Regulation and ACI 304R.

3.2 Ready-Mixed Concrete

When ready-mixed concrete is to be used, requirements of ASTM C94/C94M shall besatisfied.

Subject to OWNER/CONTRACTOR’s approval, truck-mixing may be allowed for drybatching, where all mix ingredients are pre-batched in a batch plant. Water and liquidadmixtures are added at site. In this case, discharge of the concrete shall be achieved within90 minutes after introduction of the mixing water to the cement and aggregates, and beforethe drum of the truck has revolved 300 revolutions. Each truck delivering concrete shall havean operable water system with an accurate water measuring device of one of the followingtypes:

- automatic cut off siphon type

- water meter of the automatic shut off type

- sight gage

The final concrete shall satisfy the requirements of this specification. Consistency anduniformity tests shall be performed as per the requirements of ASTM C94/C94M. Test shallbe witnessed by representative from OWNER/CONTRACTOR.

3.3 Production by In-Situ Concrete Mixer

In-Situ Concrete Mixer may be used for concreting work for small items that can becompleted with one batch.

In-Situ Concrete Mixer shall not be used without OWNER/CONTRACTOR’s approval.

3.4 Durability

(1) Normal weight concrete shall have a maximum water cement ratio of 0.50 for structuralconcrete including fireproofing concrete, and 0.60 for non-structural concrete.

(2) Normal weight concrete required being watertight shall have a water-cement ratio notexceeding 0.45 if exposed to fresh water, or 0.40 if exposed to seawater.

(3) The maximum concentration of water soluble chloride ions (Cl-) accumulated in theconcrete by all of the ingredients including water, aggregates, cement and admixturesshall not exceed the values (percent by weight of cement) stipulated in ACI 318, Table

4.4.1.

(4) The total water-soluble sulfate content of the concrete mix expressed as SO3 should not


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exceed 4% by mass of the cement in the mix and ACI 318 requirement.

3.5 Slump

ACI 211.1 shall be referred for recommended slumps for various types of construction. Theslump shall be determined in accordance with ASTM C143. Unless otherwise specified, thefollowing slumps shall apply.

Slabs, beams, columns and walls : 100mm±25mm

Foundations walls, footings, slabs, etc : 75mm±25mm

Fireproofing concrete : 75mm±25mm

The slump ranges shown apply when vibration is used to consolidate the concrete. Theslumps may be increased 25mm for method of consolidation other than vibration.

Slump may be increased when chemical admixtures are used, provided that theadmixture-treated concrete has the same or lower water-cement or water-cementitiousmaterial ratio and does not exhibit segregation potential or excessive bleeding.

3.6 Air Contents

Air content tests shall be in accordance with the requirements of either ASTM C138 or C173,or C231.

4. REINFORCEMENT

4.1 Materials

Steel reinforcement shall conform to the requirements of SNI-07-2052-2002 Grade BJTS40,yield strength fy=390 N/mm

2, or ASTM A615 Grade 60 or equivalent. Steel welded wire

fabric shall conform to the requirements of SNI 07-0663-1995, ASTM A185 or equivalent.

Reinforcement shall satisfy the followings as per Section 21.2.5 of ACI 318:

(a) The actual yield strength based on mill tests does not exceed the specified yield strengthby more than 120MPa (retests shall not exceed this value by more than an additional20MPa); and

(b) The ratio of the actual ultimate tensile strength to the actual tensile yield strength is notless than 1.25.

4.2 Fabrication and Placing of Rebars

4.2.1 General

Details of concrete reinforcement and accessories not covered herein shall be inaccordance with ACI 315.

4.2.2 Fabrication

(1) Welding of reinforcing bar shall be avoided.

(2) General construction details and workmanship relative to reinforcement, including barbends, lap splices and installation shall be in accordance with ACI 318, Chapters 7 and


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12. Unless otherwise noted, all lap splices of deformed bars and deformed wire intension shall be Class B.

4.2.3 Placing of Rebars

(1) Reinforcing bars shall be free from mud, dirt, loose rust, loose mill scale, oil, grease, andany other foreign matter that may reduce the bond between bars and concrete.

(2) All reinforcement shall be supported and fastened together to prevent displacementbeyond the required tolerances due to construction loads or the placing of concrete.Reinforcing bars shall be supported by pre-cast concrete/mortar blocks having acompressive strength not less than the specified compressive strength of the concrete,or by other acceptable spacers made of metal, plastic, etc.

(3) Splices in reinforcement shall be made and located as required by design drawings, inthe construction notes, or as otherwise approved. Splices in adjacent bars shall be

staggered.(4) Lap splices shall not be used at the following locations as per ACI 318 Para.21.5.2.3.

(a) within the joints

(b) within a distance of twice the member depth from the face of the joints

4.2.4 Mechanical Splices

Mechanical splices shall be Type 2 conforming to ACI 318 Sec.21.1.6.1 (b).

Mechanical splices of beam reinforcement shall be located not closer than half of the beamheight from the joint face. Splice sleeves, filling mortar and all other associated materialsshall be installed in accordance with manufacturer’s instructions and manuals.

5 CONCRETING

5.1 Blinding Concrete

All reinforced concrete foundations shall be constructed on plain concrete blinding. Minimumthickness of blinding shall be 50 mm, and it shall be extended to at least 50 mm outside thefoundation perimeters in all directions.

5.2 Formwork

5.2.1 General

(1) Requirements for formwork not covered herein shall be in accordance with ACI 347R.

(2) Forms shall have sufficient strength to withstand the pressure resulting from placementof concrete and vibration during concrete pouring, and shall have sufficient rigidity tomeet specified tolerances.

(3) The forms material shall produce smooth, hard and uniform texture on the concretesurface unless different texture requirement shown on the drawings.

5.2.2 Design and Installation of Formwork

(1) Forms shall be sufficiently tight to prevent loss of mortar from the concrete. Chamfer


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strips shall be placed in the corners of forms to produce 25 mm chamfer beveled edgeson permanently exposed surfaces. Chamfer strips are not required on interior cornersfor edges of formed joints, tops of piers supporting horizontal vessels, and concreteedges providing direct support for flooring, or to which steel will be attached for flooringsupport.

(2) Temporary openings shall be provided at the base of column forms and wall forms andat other points where necessary to facilitate cleaning and inspection immediately prior toconcreting.

(3) Positive means of adjustment (wedges, jacks, etc.) of shores and struts shall beprovided and all settlement shall be taken up during concrete placing operation. Formsshall be securely braced against lateral deflections.

(4) Earth cuts shall not be used as forms for lateral surfaces unless required or permitted.

5.2.3 Preparation of Form Surface(1) All surfaces of forms and embedded materials shall be cleaned of all accumulated

mortar or grout from previous concreting and of all other foreign material beforeconcrete is placed.

(2) Before placing the reinforcing steel or the concrete, the surfaces of the forms shall becovered with an acceptable coating material that will effectively prevent absorption ofmoisture, prevent bond with the concrete, and not stain the concrete surfaces. A fieldapplied form release agent or sealer of acceptable type or factory appliednon-absorptive liner may be used. Care shall be taken that the parting agent does notget on concrete or reinforcement, which is to bond with new concrete.

5.2.4 Removal of Forms

(1) Removal of forms and supports shall be in accordance with ACI 347.

(2) When repair of surface defects or finishing is required at an early age, forms shall beremoved as soon as the concrete has hardened sufficiently to sustain the load andresist damage from removal operations.

(3) Formwork for columns, walls, sides of beams and other parts not supporting the weightof the concrete may be removed as soon as the concrete has hardened sufficiently toresist damage from removal operations.

Forms and shoring in the formwork used to support the weight of concrete in beams,slabs and other structural members shall remain in place until the concrete has reached

the required strength to support the weight of concrete and anticipated imposed loads.Field-cured specimens shall be used to estimate the strength of concrete. When field-cured specimens can not be used to determine the time of the form removal, forms andshoring shall be remain in place for a period of time not less than that specified in ACI347R.

• Walls :12 hours (Note 1)

• Columns and Pedestals :12 hours (Note 1)

• Sides of Beams, Girders and Footings :12 hours (Note 1)

• Joist, Beam or Girder Soffits:

- Beams perpendicular to piperacks

or equipment supporting structures :14 days (Note 2, 3)


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- Other Beams :21 days (Note 2, 3)

Note 1: Where such support formwork for slab or beam soffits, the removal times of thelatter should govern.

Note 2: In the case when design strength of concrete is confirmed by crushing test at 7days, formworks may be removed.

Note 3: Where forms may be removed without disturbing shores, use half values shown.

(4) When forms are removed before the end of the required curing period, the concrete shallbe cured after removal of the forms by suitable methods.

5.3 Anchor Bolts and Embedded Items

(1) All sleeves, inserts, anchors and embedded items shall be placed and properly fixedprior to concrete pouring. Voids in those embedded items shall be filled temporarily withreadily removable material to prevent the entry of concrete into the voids.

(2) Anchor bolts and other embedded items shall be cleaned of undesirable coatings, suchas scale, grease, or dirt that would be detrimental to bonding with concrete.

(3) Anchor bolts shall be placed inside the "cages" of reinforcing bars.

(4) Other embedded items shall be installed as shown on design drawings and they shall besupported against displacement during placement and consolidation of concrete.

(5) Top of anchor bolt sleeves, if any, shall be cut off flush with rough concrete just prior togrout or equipment installation.

(6) Embedded plates shall be flush with concrete surface, and shall be visible after formsare removed.

5.4 Waterstops

PVC water-stop shall be used. (Minimum width 150mm unless noted otherwise).

The location of water-stops in joints shall be in accordance with the construction drawings.

Water-stops shall be installed per ACI 301, Section 2.2.

5.5 Joints

5.5.1 Construction Joints

(1) Construction joints shall be made as shown on the drawings and per ACI 301.Construction Joints not indicated on the construction drawings may be provide atSUBCONTRACTOR's option, except that they must meet the requirements of ACI 301.Joints shall be perpendicular to the main reinforcement.

(2) Construction joints shall not be made in horizontal framing members unless called for onthe drawings. Construction joints in elevated slabs should be located preferably wihtinmiddle third of the span between adjacent supporting members.

(3) The surface of the concrete at all joints shall be rough, thoroughly cleaned and alllaitance shall be removed prior to placing adjoining concrete. The laitance shall beremoved by brushing, chipping, wet sandblasting or high pressure water-blasting down


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to sound mortar matrix, leaving clean, sound aggregate exposed over the entire jointsurface, but not undercutting the large aggregate particles. The surface of the concreteshall then be washed thoroughly to remove all loose material.

(4) All concrete joint surfaces to receive new concrete shall be free of surface water butshall be in a saturated surface dry condition. Construction joints of which strength iscritical against shear, or which requires water-tightness should be covered with 12mmmortar immediately before the concrete placing, or provided with keys having 1/3 widthof the smallest joined member and 50mm depth.

5.5.2 Expansion Joints

Expansion joints shall be made as shown on the drawings and per ACI 301.

Expansion joints shall extend to the full width and depth of the concrete section.

Expansion joint filler material shall conform to ASTM D994 or ASTM D1751.

5.5.3 Contraction Joints

Contraction Joint shall be made straight and uniform by forming, tooling or sawing. Thesealer material and their application shall confirm to ASTM D2628.

5.6 Placing of Concrete

5.6.1 Transportation

(1) Concrete shall be transported from Batch Plant to the construction site by methodswhich prevent segregation, loss, or contamination of concrete ingredients so as toassure that the required quality of the concrete is maintained.

(2) A time for transportation from the time of adding cement till the final pouring shall notexceed good concrete setting time determined during trial mixing

(3) Aluminum and aluminum alloy material shall not be used in conveying equipment,including trucks, pump lines, tremies, chutes, etc. Short pump lines, tremies and chutesto remove concrete from transit truck mixers are excluded.

5.6.2 Placing

(1) Hardened concrete parts and foreign materials shall be removed from the inner surfacesof the conveying equipment.

(2) All below ground concrete should be placed on a layer of blinding concrete. In dryweather, any soil on which concrete is to be placed shall be moistened immediatelybefore placing the concrete. Concrete shall not be placed in standing water.

(3) Prior to placing concrete the reinforcement shall be secured in place, the embeddeditems shall be positioned and the interior of all forms shall be thoroughly cleaned andmade free from all foreign matter and accumulated water. The interior of wooden formsshall be wetted prior to concrete placing. The entire preparation shall be accepted byOWNER/CONTRACTOR.

(4) To minimize segregation, the concrete shall be deposited at a position as near aspossible to its final position.

(5) The placement rate shall be such that the concrete will remain plastic at all times, and

will flow readily into all spaces between the reinforcing bars, etc.

(6) Concrete that has partially hardened or has been contaminated by foreign matter shall


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not be used.

(7) Once placement has started, it must be carried out continuously until the placing of theconcrete for that panel or section is completed.

(8) The drop height for the concrete shall not exceed 1.5 meters. Temporary openings shallbe provided for tall forms to reduce the drop height and to enable easy vibration. Toensure sufficient vibration, concrete shall be placed in horizontal layers not exceeding0.6 m in depth; care must be taken to ensure that the top surface of each layer ishorizontal.

(9) Unless otherwise specified, all concrete shall be thoroughly consolidated by vibratorsduring placing. The vibrators shall be inserted in a vertical direction into the concrete,and care shall be taken to ensure that the concrete is thoroughly worked around thereinforcement, anchor bolts and other embedded fixtures, and into the comers of theforms. A proper number of spare vibrators shall always be kept at the site during allconcrete placing operations. Vibration equipment shall not be used to move concrete

within the forms.(10) Concrete placing for large or lengthy foundations and structures shall be so performed

as to avoid cold joints.

(11) Concrete shall not be placed during rain unless the adequate protection of the concreteis provided until it has hardened sufficiently so that it will not be damaged and theacceptance from OWNER/CONTRACTOR is obtained.

5.7 Finishing

(1) All finished concrete shall be as stated below, unless otherwise specified elsewhere inthe drawings. The specified surface finish and correlating tolerance requirements shallbe as defined in ACI 301, unless noted otherwise.

(2) Equipment bases shall be finished with a floated finish. Float finish shall be provided byscreeding to the required level with a straight edge and finished with a hand float, abladed power float equipped with float shoes, or a powered disk float.

(3) Interior floor slabs shall be finished with a trowel finish. Trowel finish shall be finished bytamping the concrete with a wire mesh tamper to depress the coarse aggregatesufficiently to bring the matrix fines to the surface, then screeding and striking withstraight edges to bring the surface to the required finished level. While the concrete isstill green, but sufficiently hardened to bear a man's weight without excessive imprint, itshall be floated either by hand or mechanical means to a true, even plane, with nocoarse aggregate visible. Sufficient pressure shall be used on the float to bring

moisture to the surface. After surface moisture has disappeared, the surface shall bemachine or hand troweled to a smooth, even finish.

(4) Heavy broomed finish for vehicular traffic is to have a float finish, followed by broomingwith a heavy broom, producing patterns perpendicular to traffic.

(5) Surfaces designated for foot traffic are to receive a light broomed finish. They are toreceive a steel trowel finish, followed by brooming after completion of the troweling witha horsehair bristle brush or light broom in a direction perpendicular to the main line oftraffic.

(6) Unless otherwise specified on drawings, top surfaces of concrete foundations on whichgrout will be installed shall be rough-finished to an elevation of 25 mm to 50 mm belowfinished elevation.


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5.8 Curing

5.8.1 General

(1) Requirements for curing and protection of concrete not covered herein shall be inaccordance with ACI 308.

(2) Beginning immediately after placement, concrete shall be protected from prematuredrying, excessively hot temperatures, and mechanical injury, and shall be maintainedwith minimal moisture loss at a relatively constant temperature for the period necessaryfor hydration of the cement and hardening of the concrete.

5.8.2 Moisture Retention

(1) For concrete surfaces not in contact with forms, one of the following procedures shall beapplied immediately after completion of placement and finishing:

• Ponding or continuous sprinkling.

• Application of absorptive mats or fabric kept continuously wet.

• Application of sand kept continuously wet.

• Application of sheet materials conforming to ASTM C171. The sheets shall be lappednot less than 100 mm at edges and ends and be sealed with adhesive or pressuresensitive tape no less than 40 mm in width. The membrane shall be weighted toprevent displacement. Holes appearing in the membrane during curing period shallbe immediately patched. The membrane shall remain intact for not less than thecuring period in 5.8.2(3).

• Application of other acceptable moisture-retaining covering.

• Application of a curing compound conforming to ASTM C309.

• The curing water used in the above methods shall be clean and free of contaminatingsubstances that will discolor the concrete.

(2) Moisture loss from surfaces placed against wooden forms or metal forms exposed toheating by the sun shall be minimized by keeping the forms wet until they can be safelyremoved. After form removal the concrete shall be cured until the end of the timeprescribed in Section 5.8.2 (3) by one of the methods of Section 5.8.2 (1).

(3) Curing in accordance with this section shall be continued for at least 7 days in the caseof all concrete except high-early-strength concrete, for which the period shall be at least3 days.

(4) Abrupt changes in the temperature of the concrete shall be prevented.

5.8.3 Protection from Mechanical Injury

The concrete shall be protected from damaging mechanical disturbances, such as loadstresses, heavy shock, and excessive vibration. All finished concrete surfaces shall beprotected from damage by construction equipment, materials, or methods, by application ofcuring procedures, and by rain or running water. Self-supporting structures shall not beloaded in such a way as to overstress the concrete.

6. REPAIR OF SURFACE DEFECTS

(1) Defects of concrete such as honeycombs, cracking or other conditions that are


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detrimental to strength, stability, durability and water tightness of the concrete shall berepaired immediately after form removal per ACI 301 Section 5.3.7 or by approvedrepair procedure. All defects shall be removed down to a sound surface. Curingprocedures shall not be delayed or interrupted while making repairs. Prior to repair ofdefects, it shall be notified to OWNER/CONTRACTOR.

(2) Holes left by the withdrawal of tie-rods shall be filled solid with cement mortar and theends made flush with the surrounding surface area. It is recommended to refrain fromusing hole-through tie rods for liquid retaining structures.

7. HOT WEATHER CONCRETE

Concrete work is significantly affected by high temperatures in the concrete and in the air, orby a low relative humidity, or by a high wind velocity. If these conditions are prevalent, theconcrete work shall be carried out in accordance with the requirements of ACI 305R, and the

following:

Where the concrete temperature exceeds 32 °C, necessary preventive measures, as notedbelow, shall be taken. However, if the rate of evaporation from the concrete surface asdetermined by ACI 305R is less than 1.0 kgf/m

2/h that no preventive measures are required

even when the concrete temperature exceeds 32 °C. In no case shall the concretetemperature exceed 38 °C. Exceeding the limiting water -cement ratio in order to havesufficient slump for placing at concrete temperatures between 32 °C and 38 °C shall not bepermitted. Instead, the preventive measures noted below will be used to increase the slump.

The following preventive measures shall be taken to avoid the adverse effects of hot weather

(a) Adding water-reducing and retarding admixture to concrete.(b) Using chilled water for mixing.(c) Painting storage facilities, batching plants, pipes, and agitating trucks white or silver

and/or insulating the same.(d) Keeping the transportation time to a minimum.(e) Checking mixer drums and blades frequently during hot weather, and ensuring that the

interior of the mixer is free of any accumulated matter that will interfere with the mixingaction.

(f) Providing sufficient equipment and workers to ensure quick placing and finishing, andso as to avoid cold jointing and plastic shrinkage cracking. All plans for the arrangementof the equipment and workers shall be submitted to OWNER/CONTRACTOR forapproval.

(g) Using a white pigmented material when a curing compound is applied.(h) Shading materials and facilities from the direct rays of the sun.

When the measures given above are considered insufficient to avoid the adverse effects ofhot weather, the following additional measures may be taken:

(a) Carrying out concrete placing in the evening, at night, or in the early morning.(b) Spraying water onto the aggregate and considering new w/c ratio on design mix.

(Any water in the aggregate must be accounted for in the water-cement ratio.)(c) Providing wind breaks during concrete placing.(d) Using flaked ice as a part of the mixing water.

8. MASS CONCRETE

When the concrete is considered as massive concrete in accordance with ACI 207.1R, therequirements of ACI 207.1R should be referred to.


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9. PRECASTING FOR CATCH BASINS, MANHOLES, PITS, AND OTHER FOUNDATIONS

The catch basin, manholes, foundations, etc. may also be precast concrete. TheSUBCONTRACTOR shall submit the items to be precast, showing the causes and merits ofsuch construction methods, with the procedure of the work for the approval ofCONTRACTOR.

(1) Attention shall be paid to the location, elevation and plane alignment in setting.

(2) SUBCONTRACTOR shall submit their method statement of setting work forCONTRACTOR’s prior approval.

(3) When groundwater appears during excavation, replacement or improvement of subsoilunder the structures is required, and dewatering shall be carried out.

10. INSPECTION AND TEST

10.1 Construction Tolerance

10.1.1 General

Tolerance shall conform to ACI 117, ACI 315 and ACI 347 in the case neither specified inthis section, nor in the design drawings.

10.1.2 Concrete

Table-1: Tolerance for Concrete Construction

Items to be measured Tolerance

Variation from the plumb:

(In the lines and surface of columns, piersand walls.)

± 6mm in any 3m.

±25mm for entire length.

Variation of the finishing level of ElevatedSlab.


Variation of the finishing level of Surfaces tobe grouted.

± 6mm.

Variation of the finishing level of Floors. ± 6mm in any 3m.

±10mm in any bay or in any 6m of length.


Variation in the thickness of slabs and wallsand in the cross-sectional dimensions ofbeams and columns.

- 6mm

+12mm

Misplacement of eccentricity of Footing. 2% of width in the direction ofmisplacement but not more then 50mm.

Decrease of specified thickness of Footing. Less than 5% of specified thickness.


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10.1.3 Reinforcement

Table-2: Tolerance of Clear Distance from form surfaces (as defined in ACI 117 Sec.2.2.1)

Member Depth or Thickness Tolerance of Reinforcement Locations

101mm or less ±6 mm

over 101mm and not over 305mm ±10 mm

over 305mm and not over 610mm ±13 mm

over 610mm ±25 mm

Table-3: Concrete Cover measured perpendicular to concrete surface (ACI 117 Sec.2.2.2)

Member Depth or Thickness Tolerance of Concrete Cover

305mm or less - 10mm

Over 305mm - 13mm

Tolerance of distance between reinforcements shall be 1/4 of the specified but not largerthan 25mm.

The minimum clear spacing between parallel bars in the same layer shall be the farthestamong,

• 2 times of nominal diameter of rebar

• 4/3 times of nominal maximum size of coarse aggregate

• 25mm


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10.1.4 Anchor Bolts & Embedded Items

Table-4: Tolerance of Anchor Bolt Locations

Item to be measured. Tolerance

Bolt Projection + 7mm

- 0mm

Bolt Location (without sleeves) ± 3mm

Bolt Location (with sleeves) ± 5mm

Table-5: Tolerance of Anchor Bolt Groups

Item to be measured. Tolerance

Steel Structure (Shelters, Buildings, Piperacks

and the like)Deviation of Group Anchor Bolts from the Alignment shown on the drawings.

Columns/Posts in 5m

Columns/Posts in more than 5m

± 5mm

± 10mm

Equipment and Vessels

Misplacement of Anchor Bolts centroid fromthe position shown on the drawings.

± 5mm

Table-6: Tolerance for Embedded ItemsItem to be measured Tolerance

Inclination from true in any direction 1/200

Offset ± 5mm

Elevation ± 5mm

10.2 Inspection and Test

10.2.1 General

Inspection and test shall confirm to ACI 311 if not specified in this section. Also please refer to related QC inspection and test plan for concrete work.

10.2.2 Sampling for Test

The sampling and slump test of freshly mixed concrete shall be performed at the point ofdelivery.

10.2.3 Slump Test

The slump tests shall be carried out in accordance with the following:

• All slump test shall be carried out in accordance with the requirement of ASTM C143.


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• Slump test shall be performed at each delivery of concrete.

• The result of the tests shall show that the slump is within the range specified in the

construction drawing, or the concrete shall not be placed.The temperature of fresh concrete shall also be checked at the time of slump test.

10.2.4 Compressive Strength Test

Compressive strength tests shall be carried out for each class of concrete, in accordancewith the following procedures:

(1) Samples of concrete for compressive strength test specimens shall be obtained inaccordance with the requirements of ASTM C172.

(2) A minimum of 4 specimens shall be molded and cured in accordance with therequirements of ASTM C31.

(3) Compressive strength tests of cylinders shall be carried out in accordance with therequirements of ASTM C39. These cylinders shall be tested as follows:

• one at 7 days for information

• Three at 28 days for determining acceptability of concrete strength

Evaluation and acceptance of concrete shall be in accordance with ACI 318.

Samples shall be taken from each complete pour for individual foundations or structuressupporting main processing units, heavy mechanical equipment, buildings, storage tanks,and from other important concrete structures. At least two samples shall be taken from eachfull days concreting or not less than required by the following.

Cubic Meters in Any Samples to be TakenIndividual Foundation or Structure (4 Cylinders per Sample)

0-38 One sample for each 20 cubic meters

39 -150 One sample for each 40 cubic meters

151 - 270 One sample for each 60 cubic meters

Greater than 270 One sample for each 75 cubic meters

10.2.5 Water Filling Test for Concrete Ponds/Pits

For concrete ponds/pits that are designed to retain contaminated water such as oil andchemicals, a water-filling test shall be carried out before back filling of the pond. Water-fillingtest is not required for seawater or clean water ponds unless the high water level is higherthan ground elevation. Water shall be filled to the design high water level, a minimum of 24hours is required before inspection. Concrete ponds shall be back filled only after approval ofOWNER/CONTRACTOR.

The acceptance criterion for water filling test is that no water leak is observed on the externalsurface of the concrete pit. If the leakage is found, the defected parts shall be repairedaccording to the section 6 above, then inspect the parts again until no leakage is observed.

The use of sea water and storm water is not permitted for the test.


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10.3 Test Reports

All test reports shall be submitted to OWNER/CONTRACTOR upon completion of tests.