2 bvt thuyetminh abutment and pierok

SECURITY AND SAFENESS GMS Ben Luc Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 CONSTRUCTION METHOD STATEMENT FOR ABUTMENTS AND PIERS TABLE OF CONTENTS I PREPARATION WORK[.]

CONSTRUCTION METHOD STATEMENT FOR

ABUTMENTS AND PIERS

TABLE OF CONTENTS

III CONSTRUCTION METHODS FOR ABUTMENTS AND PIERS

I PREPARATION WORKS

1 Arrangement of working teams

1.1 Ong Keo bridge

Arranging 04 construction teams:

- Team 1: Construction of bored piles

- Team 2: Construction of abutments, pier

- Team 3: Cantiver formwork

- Team 4: Casting beams, installation of beams and superstructure

1.2 Bau Sen bridge

Arranging 03 construction teams for execution:

- Team 1: Construction of bored piles

- Team 2: Construction of abutments

- Team 3: Casting beams, installation of beams and superstructure

2 Mobilization of equipment for construction of abutments and piers

The contractor will mobilize the entire construction equipment and machinery neededfor construction of piers and abutments Detailed mobilization as in the under staticstable:

Bulldozer ≥110hp Nos 3

Excavators 1.25m3 Nos 6

Crawler or Moblie Cranes ≥40T Nos 4

Crawler or Mobile Cranes ≥15T Nos 10

Concrete truck mixer 8m3 Nos 6

Concrete pump 60m3/h Nos 4

Welding machine 23kw Nos 25

Generator 200KVA Nos 4

Dump Truck 10-12 tons Nos 12

Description Unit Quantities Remarks

Rebar bending and cutting machine Nos 10

Electromechanical poker vibrators D70 Nos 30

Concrete Mixing Plant Nos 2

Transformer Station Nos 2

Concrete Bucket ≥1m3 Nos 8

Front Loader ≥2,4m3 Nos 2

Vibration hammer machine 60kW Nos 8

1 Reference standards

The following Standards in their latest edition shall be particularly applied to the works covered by this Specification:

TCVN141-08 Portland cement- Methods of chemical analysis

TCVN5438-04 Cements - Standard Specification for Terminology

and definitionsTCVN5439-04 Cements-Standard Specification for ClassificationTCVN4029-85 Cements -Technical requirement procedure for

physical contents testingTCVN4030-03 Cement Test method for determination of finenessTCVN4031-85 Cements-Method for determination of standard work

ability setting time and volume stabilityTCVN4032-85 Cements - Methods for determination of bending

and compressive strengthTCVN4453-95 Concrete & integral Steel concrete structure -

Code of Construction and acceptance standardTCVN6016-01 Cements-Test methods- Determination of strengthTCVN6017-95 Cements-Test methods- Determination of setting time

and soundness

TCXDVN302-04 Water for mixing concrete and mortar– Technical

requirementsTCXDVN305-04 Mass concrete-Code of Construction and acceptance

procedure AASHTO M6 Fine Aggregate forPortland cement Concrete;

AASHTOM33 Preformed Expansion Joint Filler for Concrete

(Bituminous Type)AASHTOM80 Coarse Aggregate for Portland Cement

Concrete;

AASHTOM85 Portland Cement;

AASHTOM115 Asphalt for Damp-proofing and Waterproofing;

AASHTOM116 Primer for Use with Asphalt in Damp-proofing and

Waterproofing;

AASHTOM148 Liquid Membrane- Forming Compounds for Curing

Concrete;

AASHTOM153 Preformed Sponge Rubber and Cork Expansion Joint

Fillers for Concrete Paving and StructuralConstruction;

AASHTOT22 Compressive Strength of Cylindrical Concrete

Specimens;

AASHTOT23 Making and Curing Concrete Test Specimens in the

Field;

AASHTOT96 Resistance to Abrasion of Small Size Coarse

Aggregate by Use of the LosAngeles Machine;

AASHTOT119 Slump of Portland cement Concrete;

AASHTOT121 Massper Cubic Meter, Yield, and Air Content

(Gravimetric) of Concrete;

AASHTOT141 Sampling Freshly Mixed Concrete;

AASHTOT224 Correction for Coarse Particles in the Soil

Compaction Test; ACI347 Guide to Formwork forConcrete, American Concrete Institute-ACICommittee 347

ASTMC31 Making and Curing Concrete Test Specimens in

the Field;

ASTMC33 Concrete Aggreates;

ASTMC39 Compressive Strength of Cylindrical Concrete

ASTMC91 Masonry cement;

ASTMC94 Standard Specification for Ready-Mixed Concrete;ASTMC109 Compressive Strength of Hydraulic Cement Mortars

(Using2-in or 50-mm Cube Specimens);

ASTMC123 Light weight Pieces in Aggregate;

ASTMC136 Sieve Analysis of Fine and Coarse Aggregates;

ASTMC138 Unit Weight, Yield, and Air Content (Gravimetric) of

Concrete;

ASTMC143 Slump of Portland cement concrete;

ASTMC144 Aggregate for Masonry Mortar;

ASTMC150 Portland Cement;

ASTMC227 Potential Alkali Reactivity of Cement-Aggregate

Combinations (Mortar-Bar Method);

ASTMC294 Constituents of Natural Mineral Aggregates;

ASTMC295 Petrography Examination of Aggregate for

Concrete;

ASTMC494 Chemical Admixtures for concrete;

ASTMC827 Change in Height at Early Ages of Cylindrical

Specimens of Cementations Mixtures;

ASTMC1017 Chemical Admixtures for Use in Producing Flowing

Concrete;

ASTMC1077 Laboratories Testing Concrete and Concrete

Aggregates for Use in Construction and Criteria forLaboratory Evaluation

2 Cementitious material

Cement shall be Portland cement type I complying in all respects with ASTM C150(AASHTO M85) or Portland cement blend complying in all respects with ASTMC1157-GU However the Contractor may submit to the Engineer for his approvalfully supported proposals for the use of other types of cement All cement shall bemanufacturer’s standard cement unless otherwise specified on the drawings Onlyone brand of cement shall be used for all concrete works throughout the Projectunless otherwise authorized by the Engineer

Cement shall be delivered to the Site in sealed bags or in bulk The Contractorproposed source of supply of cement shall be submitted to the Engineer for hisapproval All deliveries of cement to site shall include appropriate test certificates,certified by an independent agency in the country of origin, confirming that thematerial delivered complies with the specification

Bagged cement shall bear the manufacturer’s name, cement type and the date ofmanufacture and shall be stored in waterproof sheds or other such temporarybuildings used exclusively for the storage of cement Cement shall be stored in dryconditions on areas raised above ground level Storage capacity shall be sufficient tohold enough cement for the largest units to be cast Bags shall not be stored morethan 8 high and a free passage of at least one meter shall be left between the cementand the side walls of the sheds

Cement delivered by bulk carriers shall be stored in silos made for cement storage.All handling shall be by methods that prevent contamination of the cement The silosshall beprovided with interior moisture control devices that keep the cement dry and

prevent premature hydration The silos shall be provided with access ladders andaccess points to enable samples to be taken from various levels of each silo fortesting purposes.

Access ways shall be provided between storage containers such that every containercan be visually inspected Each delivery shall be stored separately from previousdeliveries Deliveries shall be used in the order in which they were delivered Anydelivery which has become caked or otherwise adversely affected shall be removedfrom the Site at the Contractor’s expense

The Contractor shall provide weighing machines which shall be kept permanently ineach shed for checking the weight of the bags

3 Water for concrete mixing and curing

The Contractor’s proposed water source shall be submitted to the Engineer for hisapproval together with test results confirming that water from the source complieswith TCXDVN-302-2004 Periodic testing of the water source shall be made at leastmonthly

Water for concrete mixes, curing concrete and other products containing cement shall

be clean water free from oil, salt, acid, sugar, vegetable or any other substanceinjurious to the concrete unless otherwise authorized by the Engineer

4 Aggregates

Aggregates shall be free of substances that react deleteriously with alkali in thecement sufficiently to cause unacceptable expansion of the concrete The Engineer’sapproval of aggregate sources will be based on satisfactory evidence furnished by theContractor that the aggregate is free from such materials This evidence shall includecertified records of tests by a testing laboratory that the aggregates meet therequirements of ASTM-C227 and may include service records of concrete ofcomparable properties placed under similar conditions of exposure Tests shall bemade in accordance with ASTM-C287 and ASTM-C295 ASTM C1077 orequivalent test standards in TCVN 7570-2006

4.1 FineAggregate

Fine aggregate shall consist of natural sand with hard, strong, durable particles orother inert materials with similar characteristics Fine aggregate shall be clean andfree from extraneous materials, clay balls, organic matter or other detrimentalmaterial in accordance with AASHTO M6 The maximum combined quantity ofsoluble chloride and sulphate in fine aggregate shall not exceed 1,000 ppm

Fine aggregate shall be reasonably graded and shall meet the grading requirementsmentioned in Table 1

Fine aggregate shall be of such uniformity that the fineness modulus as defined inAASHTO M6 shall not vary more than 0.20 in either way from the fineness modulus

of the representative samples used in the mix designs

Table1Grading Requirements of Fine Aggregate

Sieve Size(mm) Percentage Passing byWeight (%)

Coarse aggregate shall be reason ably graded and shall meet the gradingrequirements

The percentage wear of the aggregate shall not be greater than 50 as determined byAASHTO-T96 Coarse aggregate shall with stand at least five cycles of immersionand drying in both sodium sulphate and magnesium sulphate solutions, as prescribed

in the soundness test, and shall show an average weight loss of not more than 15percent

4.3 Admixtrures

Inprinciple, water-reducing admixtures to ASTMC494/C494M shall be used for allconcrete on the project Admixture complying with TCVN 8826:2011 are alsopermitted

The use of any admixtures will require the approval of the Engineer Each type andeach location or purpose shall be approved individually Approval will be dependentupon the submission of mix designs and satisfactory trial mixes to demonstrate thefunction of the admixture

4.4 Approved mix design

The Contractor shall follow ACI (American Concrete Institute) method of concretemix design or similar internationally acceptable mix design procedure The mixdesign shall include mass of dry aggregates, mass of absorbed water in the aggregate

sand mass of free water per cubic metre of wet concrete mix Separate concrete mixdesigns shall be prepared if pozzalonic material such as microsilica, GGBS (groundgranulated blast furnaceslag), PFA ( pulverised fuelash) isused.

In principle the concrete shall be proportioned in order to reliably meet the criteriafor acceptance through use of a target mean strength as follows

Where the standard deviation is not more than 3.5MPa:

Target strength= specified strength+(1.4standard deviation) Where the standarddeviation is more than 3.5Mpa

Where the standard deviation is more than 3.5MPa:

Target strength=specified strength+(2.4x standard deviation –3.5)

No concrete work will be allowed to commence until the Engineer approves theContractor’s proposed mix design(s)

A new mix design shall be submitted to the Engineer for his approval if there are anychanges in characteristics or source of supply of any of the component parts of themix Any delay due to such changes shall be entirely the responsibility of theContractor

During the execution of the Works, the Engineer may require additional tests to bemade on the work mix to check compliance with the approved Mix Design

4.5 Water – cement ratio

The Contractor’s proposed water content and water cement ratio shall be included inthe mix designs, supported by trial mixes, submitted to the Engineer for his approval.The water content shall be the least amount that shall produce a workablehomogeneous plastic mixture Excess water shall not be permitted and any batchcontaining such excess shall be rejected

The total water content for any batch of concrete shall include an allowance for watercontained in the aggregates The Contractor shall determine the water content of theaggregates before concrete batching begins and admixture (if any) The water added

to the mix shall be adjusted for the water contained in the aggregates

Frequent slump tests shall be carried out to ensure that the workability of the concreteremains consistent

4.6 Adjustments during progress of work

After a mix design has been approved, the mix shall not be changed during theprogress of the work except as follows:

If it is found impossible to obtain concrete of the desired workability with the mixproportions originally determined, changes in aggregate weights may be madesubject to the approval of the Engineer

If it is found impossible to produce concrete of the minimum compressive strengthspecified, the cement content may be increased subject to the approval of theEngineer.

4.7 Contents of chloride and sulphate

The amount of chloride in the concrete mass shall not exceed 1,000 ppm of the totalconcrete mass, or 6,000 ppm of the amount of cement in the mix

The amount of sulphate in the concrete shall not exceed 3,500 ppm of the totalconcrete mass to TCVN141:1998

The amounts of chloride and sulphate shall be determined by recognized methods oflaboratory analyses of the cement ,aggregates, water and admixtures

5 Formwork and falsework

5.1 Design

For cast-in-place concrete structures, the calculated deflection of falsework flexuralmembers shall not exceed 1/240 of their span irrespective of the fact that thedeflection may be compensated by camber strips

Formwork and falsework shall be designed for vertical load and lateral pressures

in accordance with ACI 347 and, where appropriate, any increased or re-adjustedloading that may result from pre-stressing forces If retarding admixtures are used,their effect shall be duly considered during the calculation of the lateral pressures ofthe fresh concrete The formwork and falsework shall be designed and constructed toensure completed concrete surfaces comply with the tolerances specified in ACI 347

or elsewhere in this specification

Falsework which cannot be founded on a satisfactory footing shall be supported onpiles which shall be spaced, installed, and remove din an appropriate manner

5.2 Construction of formwork

The formwork shall be constructed accurately to represent the shape of the structure

as detailed on the drawings It shall be of suitable design and appropriate constructionand shall have been approved by the Engineer The Contractor shall make anynecessary adjustments to allow for shrinkage, settlement or deflection which mayoccur during construction so that the finished concrete sections conform accurately tothe specified dimensions true to line, level, location and camber

Wooden boards shall be cut accurately to shape and fixed such that there are noopening safter the wetting of the formwork prior to placing concrete

Forms shall be sufficiently rigid that undulation of the concrete surface shall notexceed 3mm when checked with a 1500 mm straightedge or template

No concrete shall be placed in the formwork until construction of the formwork and