9 2 abutment and pier

SECURITY AND SAFENESS NH91 1 CONSTRUCTION OF TRA NOC BRIDGE; SANG TRANG 1 BRIDGE; SANG TRANG 2 BRIDGE CONSTRUCTION METHOD STATEMENT FOR ABUTMENTS AND PIERS TABLE OF CONTENTS CHAPTER I PREPARATION WORK[.]

CONSTRUCTION METHOD STATEMENT FOR

ABUTMENTS AND PIERS

TABLE OF CONTENTS

CHAPTER I: PREPARATION WORKS

I CONSTRUCTION LAYOUT

II ARRANGEMENT OF WORKING TEAMS

III MOBILIZATION OF EQUIPMENT FOR CONSTRUCTION OF

ABUTMENTS AND PIERS

CHAPTER II: CONCRETE WORK, REINFORCEMENT, FORMWORK

I FORMWORK

II REINFORCEMENT

III CONCRETE WORK

IV INSPECTION AND ACCEPTANCE

CHAPTER III: CONSTRUCTION METHODS FOR ABUTMENTS AND PIERS

I BASES FOR MAKING OF TECHNNICAL PROPOSAL AND

CONSTRUCTION TECHNOLOGY FOR CONSTRUCTION OF ABUTMENTS AND PIERS

II SELECTION OF TECHNICAL SOLUTIONS AND CONSTRUCTION TECHNOLOGIES

III THE GENERAL REGULATIONS FOR CONCRETE WORKS

IV CONSTRUCTION SEQUENCES FOR ABUTMENTS AND PIERS

CHAPTER I: PREPARATION WORKS

I CONSTRUCTION LAYOUT

1 Tra Noc Bridge

machinery at the positions of apporach roads on the left side , facilitatethe movement of machinery or supply equipment to two bridgebranches

Noc bridge

m high

- Details of construction plan show in the drawings of constructionmethod

2 Sang Trang 1 Bridge

and machinery at the positions of apporach roads on the left side ,facilitate the movement of machinery or supply equipment to twobridge branches

Trang 1 bridge

m high

- Details of construction plan show in the drawings of constructionmethod

3 Sang Trang 2 Bridge

and machinery at the positions of apporach roads on the right side ,facilitate the movement of machinery or supply equipment to twobridge branches

- Carry out thhe demolition works within the construction range of SangTrang 2 bridge.

m high

- Details of construction plan show in the drawings of constructionmethod

II ARRANGEMENT OF WORKING TEAMS

1 Ba Dai bridge

Arranging 04 construction teams for execution of Ba Dai bridge

retaining wall

2 Sang Trang 1 bridge

Arranging 04 construction teams for execution:

retaining wall

3 Sang Trang 2 bridge

Arranging 04 construction teams for execution:

retaining wall

Note: Actually, in the Site, the Contractor will gather 3 teams of “Castingbeams and launching and installation of beams” into one big team to beincharge of those works

III MOBILIZATION OF EQUIPMENT FOR CONSTRUCTION OF ABUTMENTS AND PIERS

The contractor will mobilize the entire construction equipment andmachinery needed for construction of 3 bridges Detailed mobilization as inthe under statics table:

CHAPTER II: CONCRETE WORK, REINFORCEMENT, FORMWORK

I FORMWORK

submit to the Supervision Consultant detailed construction method ofwork items, which will clearly state the type of formwork, scaffolding,

as well as calculation sheets of applied load (if required)

- Formwork shall be made of steel to ensure rigidity, stability andremovable, and will not cause difficulties for installation ofreinforcement steel, placing and compacting concrete

vertical load in accordance with ACI 347 standards In addition, theformwork must be designed to create the finished concrete surface inaccordance with the tolerances specified

poured and compacted cement concrete, at the same time protect thefresh concrete from weather influences

- Fabricating and installation of formwork must be accurate as inaccodance with the correct shape and size Formwork will be theappropriate design and durable construction The contractor will adjust

to get the exact concrete structures to ensure small chamfer, camber,etc

- It is neccessary to limit formwork joints, the joints should not bearranged on the same cross section and at the position of big loads.The bracing, strut and supports should be calculated and arrangedappropriately to the overall stability of formwork

non-stick oil The anti-adhesive oil is applied according to themanufacturer's instructions and do not touch either reinforcingsteel or prestressed strand and anchors The Contractor shall useonly one type of anti-adhesive oil for the concrete structure toensure uniformity of color concrete

formwork without affecting to the quality

smooth, non-slip and no deformation when the bearing the loadand the impact of the construction process

points or the appropriate measures to check the centre line

 Tolerances for installing formwork must be in compliance withproject standards

strengths of each type of structures indicated by the technicalinstructions of the project (Sub-clause 5.1.9.3 of the Specifications)

- Removal of formwork should be avoided without causing sudden stress

size in the same works, but different physical properties

accordance with the requirements TCVN 6284-1: 1997 or AASHTOM164M for bolts, and hot-dip galvanized according to AASHTO M232,Type C The bolts must be tested after plating as required in AASHTOM164M

2 Cutting and bending of reinforcing steel.

- The fabrication of reinforcing steel is in compliance with projectstandards, Manufacturing tolerances comply with ACI 315

- Cutting and bending reinforcing steel shall be conducted only bymechanical methods

- Reinforcing steel is bent to fit the shape, size of the design Steelproducts to be cut and bent must be inspected and approved by theEngineer

the working drawings When the size of the hook or bending diametersnot shown, we will comply with Section I, Article 8.23 or ACI 318, "Thebuilding codes requirements for reinforced concrete."

3 Reinforcement Joints.

Welding Joints:

Welding Joints are permitted only when approved by Consulting Engineer orspecified in the drawings

quality of welding seams as in accordance with design requirements

- When febricating the reinforcing steel grid by welded points, if nospecial instructions, comply with the following provisions:

rows of outer perimeters, the remaining points in between by awelding alternating order;

than 8 mm

 Welding all the in-situ details, the component structures andbonding of joints in the assembly

Mechanical fitting connection:

- Joints with mechanical connection is only used when there is priorapproval or detailed in the Drawings or Consulting Engineer allow tosubstitute for the weld joint The fitting connection must be tested toget requirements of at least 125% of the yield strength of steel bars

III CONCRETE WORK

1 General requirement

the current standards

contamination or mixed grain sizes and types When encountering suchcases, it should be immediately remedied to ensure the stability ofquality

2 Material for concrete

2.1 Portland cement

4033-1995 or other types of cement approved by the Engineer On lyapproved Cement shall be used for all concrete works throughout theProject unless otherwise authorized by the Engineer

- The source of supply of cement shall be submitted to the Engineer forapproval The Cement deliveried to the site shall include manufacturer

‘s test certificates, and shall be carried out frequency tests

- Cement shall be delivered to the Site in sealed bags or in bulk byspecialized trucks with bulk cement in large quantities

cement storage All handling shall be by methods that preventcontamination of the cement The silos shall be provided with interiormoisture control devices that keep the cement dry and preventpremature hydration The silos shall be provided with access laddersand access points to enable samples to be taken from various levels ofeach silo for testing purposes

level Storage capacity shall be sufficient to hold enough cement for thelargest units to be cast Bags shall not be stored more than 8 high and

a free passage of at least one meter shall be left between the cementand the side walls of the sheds

permanently in each shed for checking the weight of the bags

2.2 Water for Concrete Mixing and Curing

- The Contractor’s proposed water source shall be submitted to theEngineer for his approval together with test results confirming thatwater from the source complies with this specification

containing cement shall be clean water free from oil, salt, acid, sugar,vegetable or any other substance injurious to the concrete unlessotherwise authorized in by the Engineer

Specification and as required by the Engineer

2.3 Aggregates

alkali in the cement sufficiently to cause unacceptable expansion of theconcrete The Engineer’s approval of aggregate sources will be based

on satisfactory evidence furnished by the Contractor that the aggregate

is free from such materials This evidence shall include certified records

of tests by a testing laboratory that the aggregates meet therequirements of the Specifications

The Contractor shall be responsible for processing aggregates to meetthe requirements of this specification The Contractor’s proposedsources of aggregates shall be submitted to the Engineer for hisapproval Samples shall be taken in the presence of a representative ofthe Engineer and the Contractor for testing and approval beforematerials are brought to the Site

- Aggregates shall be stored in stockpiles that ensure the materialsremain free draining and are adequately separated to prevent crosscontamination Stockpiles shall be placed on a properly preparedsurface to ensure no contamination occurs when materials are re-

handled Materials shall be handled in a manner which avoidssegregation All stockpiles are to be labelled with markers indicatingthe material type in the stockpile Aggregates shall be stored insufficient quantity to ensure that there is no interruption of concretingwork at any time Aggregates shall be stock near mixing plant, beforemixing aggregates shall be comply enough moisture, aggregates shall

be checked and approved by the engineer

- Fine and coarse aggregates shall be tested in accordance with thestandards below

Fine aggregates

sand or other inert materials with similar characteristics, having hard,strong, durable particles Fine aggregate shall be clean and free fromextraneous materials, clay balls, organic matter or other detrimentalmaterial in accordance with AASHTO M6 The maximum combinedquantity of soluble chlorides and sulphates in the fine aggregate shallnot exceed 1000 ppm fine aggregate

grading requirements contained in Table 1

Table No 1- Grading Requirements of Fine Aggregate

Sieve Size(mm)

Percent Passing by weight

- If required by the Engineer and in order to meet specificationrequirements, fine aggregates for use in reinforced concrete shall bewashed with fresh potable water.

Coarse aggregate

works and unreinforced concrete works and shall be homogeneous,clean, free from extraneous materials, clay lumps, organic matter, andalkaline and detrimental material Coarse aggregate for structuralconcrete shall meet the requirements of TCVN 7570:2006 TheEngineer may order that the coarse aggregate be washed if it isunclean, or may reject any material that does not comply with thisSpecification

approved by the Engineer before material is delivered to the Site of theWorks

grading requirements in Table 2

Table No 2 Grading Requirements of Coarse AggregatesSieve

Size(mm)

Percent Passing by WeightConcrete

Class A, B, Cand D

Concrete Class Eand F

Concrete

Class Gand P

as determined by TCVN 7572-12:2006 The coarse aggregate shallwithstand at least five cycles of immersion and drying in both sodiumsulphate and magnesium sulphate solutions, as prescribed in thesoundness test, and shall show an average weight loss of not morethan 15 percent

2.4 Admixtures

Each type and each location or purpose shall be approved individually.Approval will be dependent upon the submission of mix designs andsatisfactory trial mixes to demonstrate the function of the admixture

- To avoid cold joints the Contractor shall provide sufficiently largecapacity in his concrete producing plant and concrete transportingarrangements and use an appropriate retarder when deemednecessary by the Engineer The retarder shall be of a type approved bythe Engineer and shall comply with the requirements of TCXDVN325:2004 The Contractor shall be entirely responsible for the use ofany approved retarder in strict accordance with the manufacturer’sinstructions, and previously tested to receive the approval of theEngineer.

mix unless approved by the Engineer The fluid content of admixturesshall be considered in the determination of water/cement ratios of themix-design

- Preliminary tests of cylinder strength and any other tests shall becarried out for all concrete with admixtures When the Engineerapproves changing the brand or type of cement, the Contractor will berequired to carry out further tests and establish a relative mix design

accordance with TCXDVN 325:2004 and plasticizing and plasticizingand retarding admixtures in accordance with 22 TCN 202-1998 may beused with written permission of the Engineer in accordance with mixdesigns and slump requirements as approved by the Engineer

permitted

3 Concrete work

- The contractor will submit the Consulting Engineer for approval ofposition and qualifications of batching plant, and collected yards.Contractor shall also submit details on the type of mixer and mixingplant and transportation plan from concrete batching plant to the Site

Engineer for testing and such samples shall be tested in the sitelaboratories as directed by the Engineer No materials forming any part

of this mix shall be delivered to the Site before the Contractor receivesprior approval of the Engineer for such materials

the Engineer, for approval 14 days before production (covering twopossible trials for sampling and testing of concrete at 28 days), or atleast within a period of time enough to allow the Engineer to checktwice the proposed mix design before approval according to theprocedure specified in sub-section 3.1.2, “Approved Mix Design” of thisSpecification

transported to the construction location by agitators Prior to delivery ofconcrete, the quality control and testing of concrete must be conductedalong with delivery records

- At construction sites quantities of concrete are not so big andscattered, the Contractor propose to use small concrete mixer 500lit or

750 lit