07 3 iok a1 SUPERSTRUCTURE

CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION CONSTRUCTION METHOD STATEMENT FOR SUPERSTRUCTURE TABLE OF CONTENTS CHAPTER I: CONSTRUCTION TECHNOLOGY OF PRESTRESSED RC BEAM I MATERIALS II CASTING YARD AND FORMWORK III CONCRETE WORKS IV TENSIONING PRESTRESSING STEEL V QUALITY ASSESSMENT AND INSPECTION OF I BEAM VI CONSTRUCTION OF I33M BEAM VII CONSTRUCTION OF I24, I40M BEAMS VIII CONSTRUCTION OF PC VOID SLAB GIRDER - CASTING ON SCAFFOLDING CHAPTER II: INSTALLATION OF I BEAMS I CONSTRUCTION REQUIREMENTS II INSPECTION OF QUALITY III THE SEQUENCE CONSTRUCTION OF THE SUPERSTRUCTURE FOR EACH BRIDGE CHAPTER III: CONSTRUCTION METHOD OF OTHER WORK ITEMS I BEARINGS II CONSTRUCTION OF CROSS BEAMS III CONSTRUCTION OF PARAPET IV CONSTRUCTION OF EXPANSION JOINTS V BRIDGE DECK WATERPROOFING MEMBRANE VII CONSTRUCTION OF BRIDGE DRAINAGE 1/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION CHAPTER I: CONSTRUCTION TECHNOLOGY OF PRESTRESSED RC BEAM All works of this items must be complied with “SPECIFICATION SECTION 07400 - PRESTRESSED CONCRETE AND PRESTRESSING” The contractor will provide skilled technicians in the construction of prestressed structures, monitoring work and supporting the Engineer if needed The Contractor shall provide all types of machinery and equipment necessary for construction and pre-stressed tensioning Prestressed tensioning must be carried out by appropriate jacking equipment system, which has been approved If hydraulic jacks are used they shall be equipped with accurate pressure gauges The combination of jack and gauge shall be calibrated and a graph or table showing the calibration shall be provided to the Engineer I Materials General Requirements The materials must ensure technical requirements in accordance with current standards During storage, transportation, materials must be stored to avoid contamination or mixed grain size and type When the above cases happen, solutions must be carried out to to ensure the stability of quality Table reference standards:  22TCN 272-05 Specification Standard for Bridge Design  22TCN 247-98 Specification for Construction and Acceptance of Prestressed Girder  TCVN 9114:2010 Precast Prestressed Requirements and Acceptance Concrete Products - Technical  22TCN 267-2000: Anchor for Prestressed Concrete T13; T15 & D13; D15 International Standard:  ASTMA416M Steel Strand, Un-coated Seven Wire Stress Relieved  Grade270 Strand for Pre-stressed Concrete  AASHTO M235 Epoxy Resin Adhesives Material Requirements 2.1 Prestressing Steel Reinforcement must comply with article 2.2.2 “Reinforcing Steel” of “Specification section 07400 - Prestressed Concrete and Prestressing” High tensile steel strand with low relaxation shall be weld free and stress relieved after stranding and shall conform to the requirements of ASTM A416M-Grade 270 or equivalent steel strand, uncoated seven wire stress relieved strand for Prestressed Concrete 2/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Testing of prestressing reinforcement shall be in accordance with the requirements of the ASTM Specifications for the type of system intended to be used or subject to approval by the Engineer 2.2 Anchorages All anchorage assemblies shall be subject to the approval of the Engineer in according with Vietnamese Standard 22TCN267-2000 All post tensioned prestressing steel shall be secured at the ends by means of approved permanent type anchoring devices The Contractor shall submit information and details, including test certifications for by the Engineer End anchorage devices (stress and dead anchors) shall be designed and manufactured for the types of tendons to be used They shall have a previous service record of performance and durability when used on similar type work All anchorage devices for post tensioning shall be capable of holding the prestressing steel at a load of not less than 95 percent of the guaranteed minimum tensile strength of the prestressing steel It is the responsibility of the Contractor to design reinforcement, which takes cognisance of the bursting force produced by the particular shape and design of the anchorages All exposed steel parts shall be protected from corrosion All threaded parts and fittings shall be protected by greased wrappings or plugs until used Anchorages shall be kept free from dirt, mortar, loose rust or other deleterious materials Damaged anchorage parts shall not be used 2.3 Ducts for internal Tendons Ducting for internal tendons shall be fully compatible with the proposed prestressing system Ducting for internal tendons shall be fully compatible with the proposed prestressing system The ducts shall be fabricated from corrugated galvanized sheet steel or semi rigid conduit Minimum duct thickness shall be as follows:  0.45mm for duct diameter less than or equal to 67 mm  0.6mm for duct diameter greater than 67 mm  0.25mm for bar tendons Ducts shall have grouting connections at each end and shall have vent/drains at all intermediate high and low points, subject to the approval of the Engineer 2.4 Grout for Ducts Unless otherwise specified in other prevailing Specification Sections or subject to approval by the Engineer as a result of grouting trials the grout shall:  3/ 38 Consist only of ordinary Portland cement (PC40,PC50 with chloride and sulphate contents of less than 0.5%) water and expansive admixtures approved by the Engineer and used in accordance with the manufacturer’s instructions, PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION  Have a water to cement ratio as low as possible consistent with the necessary workability, and under no circumstances shall the water/cement ratio 0.34 - 0.38 (without admixture < 0.4; with admixture < 0.38)  Contain no admixtures containing chlorides, nitrates or similar electrolytic conducting materials 2.5 Concrete Concrete shall be of the class indicated on the Drawings and shall conform with the requirements of Specification Section 07100 Concrete and Concrete Structures and the requirements specified below unless otherwise stated on the Drawings or as may be required by the Engineer The maximum size of aggregate for use in the manufacture of Prestressed Concrete shall be 25 millimeters The main properties of concrete such as compressive strength at 28 days, Modulus of Elasticity (Young Modulus), and other properties that were used for the detailed design shall be confirmed by testing of samples of the approved mix design The Contractor shall perform the tests in accordance with the appropriate standards, or as may be required by the Engineer 3.1 Storage of materials High tensile strength steel The High tensile strength steel shall be carefully packaged to avoid moisture rust, during transportation to use the tight canvas, not to stick to oil, grease, salt, chemical fertilizers Transportation of high strenth steel shall not be associated other cargos While loading and unloading from vehicles to the stock yard or otherwise, it is not permitted to throw down from above, not to be twisted and scratched Any defect that damages the high tensile strength steel wire shall be the reason to check and it may be rejected The High tensile strength steel must be stored in the tall warehouse, ventilation, not wet, when high tensile strength steel is pilied up, the steel must be placed on the even platform at least 0.2 m high from the ground and should not pile up exceed 1.50 m 3.2 Reinforcement and built-in structures All the steel before using must be checked including the documents for labels, codes and categories Steel must be separated in each type of diameter for easy use and checked as needed, not to adhere oil, grease, paint or other chemicals Steel must stored on the timber shelf so that the entire bars is higher than the ground at least 0.3 m Prior to installation, the fabricated built-in items must be inspected for correction of marks, steel code, drawings and specifications During storing, materials must be separated, absolutely not adhere greasy, asphalt, if adhering contaminants, materials must be cleaned 4/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION 3.3 Storage of cement When transporting cement to the storage, canvas must be used to cover to avoid rain If the cement be moistured, put these cement bags aside and have plan to use in advance Cement placed in the storage, the storage ground must be tall, no stagnancy, no leaking from all directions around Cement storage shall be at least 0.2 m higher than the background and placed on the airy floor The cement bags pile no more than layers, the bags are stored away from a wall about 0.3 m, between the rows of cement bags must have walkway to transport To ensure no degradation of cement, the time from production to use ≤ 70 days 3.4 Storage of aggregates Aggregate for concrete of beam must be stored separately, not mixing with aggregate of other concrete components Sand, stone storage areas must meet the requirement hereunder:  There is no stagnant water, have drainage ditch around  There are layers of compacted crushed stones so as separate with mud  During use, the damaged surface must be remedied in time The amount of sand and rock must be stored enough quantities for production of the beam Each delivery of sand, stone must be checked for the dirt, flatness grain content, and weathering rock content 3.5 Storage of additives Additives must be contained in the sealed barrel, labeled outside, and production time, meet requirements of the Specifications The closed additive barrel may be stored outdoor or indoor, others must be kept in covered storage Additives used in concrete batch shall be calculated in dose II Casting yard and formwork Casting bed and formwork I beams are the post-tensioning concrete beams The Contractor will organize casting beds and concrete mixing plants to supply concrete Service road will be provided for transportation of concrete  The Contractor will fabricate enough formworks for construction; Design of casting bed and formworks 2.1 Casting bed Structure of casting bed must ensure convenience for placing reinforcing steel and pre-stressing steel to get enough space for the erection and 5/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION removal of formwork, concrete supply, placing concrete and lifting casted beams then transport to the storage yard The position of the casting yard must be in high places to ensure good drainage, absolutely no settlement 2.2 Formwork Fabrication and erection of formwork shall be in the correct position It should be easy to erect and remove the formwork The joints must be parallel or perpendicular to the beam axis and to be sealed tight enough to prevent cement motar from leakage Formwork consists of two parts: bottom and side formworks  Bottom formwork is made plate steel of mm thickness, having the vertical and horizontal stiffeners made of steel Bottom formwork is divided into small plates After installing into the casting bed, the plates will be connected by bolts  Side formwork: made of steel plate thickness mm, reinforced with V shaped steel Vibrators attach outside at even distance to be used when concreting  After the completion of installing vibrator into the side formwork, trial operation is needed to check the stiffness of the formwork, status of vibrator and stability  Technical requirements of formwork: * * * The firmness, durability, watertightness The evenness Tolerance of dimensions within the allowable range Construction 3.1 Casting bed  3.2 3.3 6/ 38 As shown in construction method drawings Bottom formwork  Install bottom formwork plates of 3m length and connect by bolts  After welding done, detailed dimensions and flatness of each plate will be checked, fix the error before starting next works Side formwork  Side formwork will be fabricated by plates of 3m length Connections of plate will be made by bolts;  Before casting the first beam, side formwork will be erected with bottom formwork to generally check all formwork of I beam  Installing the vibrators to the side form by bolts  Turnbuckle will be used for closing on the top of side formwork  Turnbuckle will be installed in the two sides for supporting side formwork;  Side formwork will be installed only when completion of reinforcing PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION steel and ducts Installation of bottom formwork with casting bed Each plate of the bottom formwork is linked with casting yard, may place and pump cement grouting linking for each section before the joint welding and then pumping cement grouting for the next section, or put the entirely then pumping cement grouting The sequence of construction as follows:  After fabrication of the bottom formwork plate meets the requirements then each plate will be installed on the casting yard Link all bottom formwork plates by butt weld then grinding welds smoothly Use the turnbuckles to tighten the bottom formwork with the casting yard Check the overall size of the bottom formwork installed  Pumping cement mortar M100 into the gap between the bottom formwork and the casting yard  Repeat the above sequence of construction for the next segment  Set and associate support structures for wall wing together with casting yard  Set and associate jacking beam with the casting yard  Check the overall size of the entire bottom formwork with casting yard Beam storage yard Fabrication yard should have a suitable length The yard is compacted to K95 20cm of crushed stone will be placed on the top The beams are chocked with concrete sleepers, dimensions 90x40x40 cm or equivalent at the location 150 cm from the beam head Moving or transfering beams from casting bed to storage yard by gate gantry I CONCRETE WORKS Concrete is produced by batching plant at construction sites and transported to the construction site by truck agitators Prior to delivery of concrete, the quality control and testing of concrete must be conducted along with delivery records With different structures: measures for placing concrete are shown in the drawings of the construction methods Components of concrete The concrete beams are designed as specified in the Specification Adjusting concrete mix design at the site will be conducted on the principle that water / cement ratios will no be changed When aggregates is moist, it should reduce the amount of mixing water, keep the required slump Manufacture of concrete mix Manufacturing concrete mix by batching plant Mixing concrete process shall comply with the following provisions: 7/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION  When mixing concrete, materials must be weighted accurately Moisture content of sand and stones must be conducted inspection regularly to adjust the amount of aggregates and water use  Allowed tolerance when weighing shall not exceed the allowed values  The accuracy of measuring equipment must be calibrated During weighing, regular monitoring to detect and correct promptly Transportation of concrete mix Batching plant is located next to casting yard so the transportation is very convenient and initiative in any situation Placing concrete Placing concrete must meet the following requirements:  Closely monitor the status of formwork during the construction process to settle in time if problems occur  When it rains, covering to prevent concrete from raining  The placing concrete must follow instructions of the Engineer Compacting concrete Different kind of vibrators may be used, but to ensure that after the concrete is compacted the surface free from honeycombing Compaction time for each location must ensure that the concrete is thoroughly compacted when compacting concrete:  When using poker vibrators, moving distance not exceeding 1.5 times the radius of the vibrator effects Distance to side formwork from 510cm, penetrating into the under concrete layer 5-10cm, when finishing each vibration of a place just to withdraw vibrator up, avoid colision of vibrator into formwork, reinforcing steel and right in place buried parts  When using the vibrator must base on the figure and shape of the structure and vibrator functions, through testing to determine the distance of the vibrators  When the concrete stop subsidence, no air bubbles, surface wellcompacted, then stop vibrating  The placing concrete must be conducted continuously If interruption occurs, the interupption time must be less than the time of initial setting, or less than the allowable time for re-vibrating the earlier placed concrete Curing concrete After placing conrette, concrete must be cured in conditions of humidity and needed temperature for curing and preventing the harmful effects during curing of the concrete 8/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Moisture curing: is the process for keeping concrete with moisture necessary to the setting and hardening after shaping During curing, the concrete shall be protected against mechanical impacts such as vibration, shock forces, loads and impacts, which are likely to cause other damage Checking of the concrete samples The limit compressive strength of concrete must be taken through testing samples Each casted beam takes 09 samples, 03 samples tested after 72 hours (3 days), 03 following samples is tested after days, 03 remaing samples to determine the 28-day strength The testing sample is cylinder 150x300 mm or cube 150x150x150 mm The quality of materials used for mixing concrete must be tested, the test methods must conform to the relevant regulations II Tensioning Prestressing Steel Preparation works 1.1 Quality Ceritificates The Contractor shall provide sufficient anchorage certification of the manufacturer Check the anchor system before stressing 1.2 1.3 Preparation work before stressing - Check test result of concrete - Check the test results of PC strand - Check the manufacture certifications - Check the tolerance when placing high tensile strength tendon - Check and calibration of the jack, the pressure gauge will be used If beyond the time limit must be re-calibrated - Determination of friction coefficient of the jack and anchorage ring (determined separately for each jack) - Check the threaded hole for high tensile strength steel tendon (cleanness, the space) - Check the operation and safety procedures - The contractor will establish mark points to measure the elongation and demand pressures as required by Consulting Engineer Installation of PC strand PC strand is prepared on the casting yard, tie one end of strand by tied wire and pass through duct The strands need to be free from rust, oil, grease, and dirt, deformation All steel reinforcement shall be accurately placed in the position shown on the Drawings and rigidly held in place during placing and setting of the concrete Distance from the forms shall be maintained by stays, formwork spacers, ties, hangers, or other approved support Formwork spacers for holding units from contact with the forms shall be of approved material, 9/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION shape and dimensions Layers of reinforcement shall be separated by suitable wire spacers Wooden blocks shall not be used 1.4 Threading anchorage ring Cleaning ring and strand before installation Jack and sequences for tensioning: - Jacks used to stress the tendon is Pre-stressing jack ≥ 290 Tons - Use anchorage type of OVM or equivalent - Jacks and anchorage must be tested before being put into use - Tensioning sequence as in accordance with design method Tensioning method: - Jacks are on the support by the chain hoist Insert the jack in the manner that the jack head leans against anchorage of beam - Firstly apply jacking forces 10% of design capacity - Then use the ruler to measure metric length of the jack piston corresponding to each pressure level - After jack achieves the design pressure, measuring the total elongation compared with the actual elongation allowed by design - Return the jack from design pressure to pressure to close the wedge and measuring wedge slip (if any) - Calculation the elongation of the strand through linear interpolation method (taking into account the slip in the two ends of jacks) Technical requirements of the process of tensioning prestressed tendons Post tensioning shall be carried out in accordance with an approved method and in the presence of the Engineer unless permission has been obtained to the contrary Immediately before tensioning the Contractor shall prove that all tendons are free to move in the ducts Each anchorage device shall be set square to the line of action of the corresponding post tensioning tendon and shall be securely fixed in position and gradient to prevent movement during the placing and compaction of concrete Except where dead end anchorages are cast in the concrete, tendons shall not be installed until just prior to stressing Tendons shall be pulled or pushed through the duct in such a manner as to avoid damage to either the tendon or the duct Unless approved otherwise concrete shall not be stressed until test cylinders taken from it have attained a compressive strength of not less than 80% of the specified 28 day strength as shown by standard specimens cured in a similar fashion to the element unless specifically noted otherwise on the 10/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION  To be inspected in accordance with by the Engineer to satisfy the Specifications Concrete  To be inspected in accordance with by the Engineer to satisfy th Specifications Pre-stressing  To be inspected in accordance with by the Engineer to satisfy the Specifications Dimension and position of Structure  To be inspected in accordance with by the Engineer to satisfy the Specifications  (Summary of Inspection Item) inspection sheet and as required requirements in the Technical inspection sheet and as required requirements in the Technical inspection sheet and as required requirements in the Technical inspection sheet and as required requirements in the Technical Item Form work Dimension /position / straightness Stains Rebar works Number/ size/interval / lap length of joints / concrete cover Concrete works Pre-stressing works Dimension and Position of structure Slump, Temperature Concrete compressive tests Pressure / extensile Position in – Plan view/ elevation/ length at joint points Time / Frequency - Before concrete - Before install inner formwork - Before concrete - - During concreting/ As Specifications - After concreting /every lift Environmental Protection Plan Industrial hygiene on site shall be strictly observed and regularly checked after each working shift Production area at Casting yard factory shall be always cleaned up Hygiene shall be done after every working shift Different kinds of products shall be stored separated to facilitate inspection and transport Layout arrangement (office, accommodation and construction area) shall be kept dry, free of water, and ventilated All requirements on fire protection shall be strictly observed All site wastes shall be collected and discharged at required place Fuel area shall be kept separately and strictly controlled to prevent fire or lost Safety Plan Safety shall be in first priority during construction, safety staff shall be present on site all the time to supervise and to remind workers to observe safety requirements Any work not meeting safety requirements shall be stopped immediately 24/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Safety shall be strictly observed All workers and staff on site shall pass a course on safety requirements All safety equipment such as clothes, shoes, hat, gloves, safety belt, etc shall be provided and regularly checked during construction V Construction of I24, I40 m beams The construction method is the same with I33m 25/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Some images in manufacturing site Bottom of formwork 26/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Side formwork Reinforcement on the bottom formwork 27/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Concrete transport & Concrete placing method Installing the prestressed strands in duct Stressing strands 28/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Cover Concrete The storage yard 29/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION VI CONSTRUCTION OF CONSTRUCTION OF PC VOID SLAB GIRDER CASTING ON SCAFFOLDING Work Flow Work flow chart ins t al l s c af o l ding Lo ad t es t f o r s c af o l ding No Ins pec t io n Yes ins t al l f o r mw o r k ins t al l Reinf o r c ement No Ins pec t io n Yes pOURING c o nc r et e Cur ing c o nc r et e No Co nc r et e r eac h t o r eq uir ement s t r eng t h Yes s t r eSSING STRANDS & g r o ut ing Co mpl et io n Erection of scaffolding system The details are shown in the construction method drawings Load test of scaffolding system 30/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION A crane is used to lift concrete blocks for load test of scaffolding system Readjust the scaffolding system The details are shown in the construction method drawings Concreting Erect formwork, Adjust exactly elevation, longitudinal centerline, cross centerline of formwork Erect formwork of external wall: it must be ensured geometric dimensions of casting segment Formwork plates of external wall are fixed into external scaffolding system Concrete curing: curing work is begun since redundant water on concrete surface has already completed evaporating Time for continuous curing is within days Stretching of pre-stressing tendon Pre-stressing tendon is carried out stretching when concrete strength met 90% of design strength Before stretching pre-stressing tendon, formworks of external wall and internal wall must be removed from concrete surface 31/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION CHAPTER II: INSTALLATION OF I BEAMS I Construction Requirements Prior to the erection of the beams the Contractor shall survey the positions of the supporting columns and confirm with the Engineer on the positions, both horizontal and vertical, of the supports The Contractor shall submit a full method statement for his proposed methods for lifting and placing girders in their permanent position The method statement shall be submitted to the Engineer for his approval within one month of the commencement date of the Works The method statement shall particularly include but not be limited to the use of lifting and transfer gantries supported on the new structure and particular locations such as the start of erection from the embankment The method statement shall include full details of the equipment to be used to handle girders and to incorporate them into the structure The method statement shall be accompanied by full structural calculations and appropriate Working Drawings for each stage of the procedure The calculation shall be consistent with the trial construction and shall be considered for all the combinations of loads arising during construction and actual conditions at the Site, particularly the wind load and the conditions of natural ground The Contractor shall carry out all additional soils investigation necessary to confirm his assumptions concerning the nature of the existing ground The calculations and drawings shall be certified and stamped by a qualified structural engineer experienced in the preparation of such details The details shall include consideration of the effect of each stage of the procedure on the completed Permanent Works on which the gantry is to be mounted and operated The procedures for lifting and transferring the beams into position and the order of erection of the beams be appropriate for the eccentricity of loading on the completed permanent works (supporting piers and the foundations) is minimized Girders shall be firmly secured from moving laterally during the placing of insitu concrete at a later stage The lifting and placing of girders will not be permitted to commence until such time as the Contractor’s method statement, calculations and Shop and Working Drawings have been reviewed and approved by the Engineer Complete details covering the equipment to be used to handle beams and to incorporate them into the structure together with a step by step erection procedure shall be submitted to the Engineer for his approval The order of erection of the beams and the casting of top slabs shall be such that the eccentricity of loading on the supporting columns and the foundations is minimized Transportation and erection of beams shall be carried out in such a manner that there is minimal interference to road traffic When beams are being placed in position they shall be braced against overturning before being released by the crane or other lifting devices Beams shall be prevented from moving laterally during the placing of the insitu concrete 32/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Launching and erecting girders done by suitable mechanical equipment, which adapts the weight and size of the beams Erection of beams is done by cranes and Launching Girder Road for beam transport must be guaranteed flatness, stability to withstand the pulling force of the beam, the weights of the beam together with the auxiliary equipment in construction After construction of the transport road, it will be inspected by the Engineer in writing prior to transporting beams Before erecting requirements: beams, the Contractor shall perform the following  Carry out trial erection to observe If it is safe for workers and equipments, the official erection will be conducted  Inspection of the bearing pads  In the process of moving beams the stable bracing must be taken to ensure no overturning and upturning during movement After completion of beam installation, the completion of inspection sheets, records for quality shall be made then move to next items II Inspection of quality Inspect the flatness of the geometric dimensions, cracks, warping, camber of the beams prior to construction After installation is complete, the following criteria should be checked: III  The alternation between the center lines of the beams on the piers and abutments  Tolerance of vertical alignment of beams  Difference of heights between surfaces of the beams on a pier  Difference of heights between surface of the beams on the adjacent piers The sequence construction of the superstructure for each bridge Suppersutructure construction will follow orders as shown on attached drawings 33/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION CHAPTER IV: CONSTRUCTION METHOD OF OTHER WORK ITEMS I Bearings Elastomeric Bearings The Standard Specifications for Highway Bridges and the most recent edition of the following Standards shall be applied to this Work (in accordance with Section 07600 - BRIDGE BEARINGS of the Specifications) Elastomeric bearings shall consist of laminated elastomeric pads or assemblies of laminated elastomeric pads as indicated on the Drawings and as specified herein Variation in thickness of an individual elastomer lamination shall not exceed mm within the width or length of a bearing pad and the variation in thickness of all elastomer laminations within a bearing pad shall be such that each metal or fabric lamination will not vary by more than mm from a plane parallel to the top or bottom surface of the bearing pad The total thickness of a bearing pad shall not be less than the thickness indicated on the Drawings nor more than mm greater than that thickness Variation of total thickness within an individual bearing pad shall not exceed mm The length and width of a bearing pad shall not vary more than mm from the dimensions indicated on the Drawings The bond between the elastomer and the steel laminate shall be such that, when a sample is tested for separation, failure shall occur within the elastomer and not between the elastomer and the steel All materials used in the manufacture of the bearing assemblies shall be new and unused with no reclaimed material incorporated into the finished assembly All bonding of components shall be done under heat and pressure during the vulcanizing process The bond shall be continuous throughout the plan area with no air spaces greater than 0.25 mm within the bonding material The bearing assemblies shall be furnished as complete units from one manufacturing source The materials for the elastomeric bearings and assemblies shall comply with the following requirements: Elastomeric Materials The elastomeric materials of the compounds shall be 100% virgin polychloroprene synthetic rubber meeting the requirements of Table No.1 The properties of the elastomeric compounds shall be determined from test specimens complying with ASTM D3182 through D3190 inclusive and D3192 A variation of ± 10% in tensile strength and ultimate elongation under “physical properties” will be permitted when test specimens are cut from the finished product Internal Steel Laminates The internal steel laminates for the laminated elastomeric bearing pads shall be rolled carbon steel sheets complying with AASHTO M183 Laminated Elastomeric Bearing Pads 34/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Laminated elastomeric bearing pads shall be individually moulded to the required size Corners and edges may be rounded with a radius at the corners not exceeding mm and a radius at the edges not exceeding mm All edges of the steel laminations shall be covered with not less than mm and not more than mm of elastomer MECHANICAL BEARINGS a) Mechanical Bearings shall be pot type bearings Movement bearings will normally have sliding surfaces of stainless steel and polytetrafluoroethylene and may also have been fitted with guide bars or keyways b) All structural steel except stainless steel which is used for the manufacture of bearings shall comply with ASTM A709M Stainless steel which is used for manufacture of sliding surfaces shall comply with ASTM A240M, type 304, 2B; for surface finishing and sliding surfaces, then polished as mirror surface with a roughness of under 0.4 micro C.L.A If anchor steel for pot bearings is used it must comply with the requirements in AS 2074 Grade Type A, or BS 3100 Grade A Anchor of carbon steel is not warping and cohesive with cast seam, foam, cracking, blistered or other damages at positions where affect to the aesthetics or strength of steel Packaging, Handling, and Storage of Mechanical Bearings a) Prior to shipment from the point of manufacture bearings shall be packaged in such a manner to ensure that during shipment and storage the bearings will be protected against damage from handling, weather or any normal hazard b) Each completed bearing shall have its components clearly identified, be securely bolted, strapped or otherwise fastened to prevent any relative movement, and marked on its top as to location and orientation in each structure in the project in conformity with the plans c) Dismantling at the Site shall not be done unless absolutely necessary for inspection or installation d) All bearing devices and components shall be stored at the Site in an area that provides protection from environmental and physical damage e) When installed bearings shall be clean and free of all foreign substances DOWELS a) Steel dowels shall be provided and installed in accordance with requirements and with accessories noted on the Drawings b) Dowels shall be smooth plain billet steel bars conforming to requirements of ASTM A615, 400 MPa and shall be zinc (hot dip galvanized) in accordance with ASTM A123 c) Dowels may be cast insitu as shown on the Drawings or drilled and grouted with an approved epoxy compound d) If dowels are drilled and grouted: e) Holes shall provide at least 10 mm in diameter greater than the largest diameter of the dowel; f) Holes shall be thoroughly cleaned with compressed air and water prior to grouting of dowels so as to remove all loose or extraneous materials; 35/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION g) The epoxy compound used shall be ASTM C881, Type IV or approved equivalent and mixed and placed in accordance with manufacture’s requirements Bearing Installation The bearings shall be clearly marked with their longitudinal and transverse axes, their type number and their intended locations in the Works Unless otherwise approved by the Engineer bearing beds shall be of non shrink grout conforming to ASTM C1107, Grade A Proposals for the thickness and type of bearing plinths and beds shall be submitted by the Contractor and approved by the Engineer in advance of bearing installation Bearings shall not be dismantled Any transit bolts, straps or other temporary fixing shall not be removed until the bearing is fixed in its final position and the structure immediately above the bearing is in place Care shall be taken to ensure that all transit bolts, straps or other temporary fixings are finally removed All bearings shall be set horizontal in both directions and shall be positioned so that the inscribed longitudinal axis is parallel to the structure axis at the point of support, unless otherwise noted on the Drawings Any devices such as steel packs used to hold bearings level whilst being fixed, must be removed so that the bearing seats only on its mortar bedding Where pre-cast beams and segments are placed on elastomeric bearings, immediately prior to the placing of each beam and segment the top of the bearing shall be coated with a sufficient thickness of approved mortar to take up any irregularities between the surface of the beams and segment and the bearings The characteristics of all bearing shall be within both the manufacturer’s tolerances and the following tolerances as shown on Table Tolerances Alignment, maximum departure from required vertical or horizontal plane: Entire assembly 1:400 Lower part of bearing 1:1000 relative to upper Plan position II Laterally mm Longitudinally 6mm Center/Center Spacing mm Construction of cross beams Materials for construction of cross beam, deck slab as described in other concrete structures The Contractor shall submit construction method to the Consulting Engineer prior to commencement 36/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Cross beams and deck slab will be constructed in accordance with the size of working drawing III Construction of parapet Using a total station and level to determine vertical and horizontal position and elevation of parapet, make roughness and clean the contact surface to ensure the consistency of concrete Carry out erection of reinforcement, formwork of parapet and lighting post (compliance with the design and regulation of reinforcement and formwork as mentioned above) After getting approval of the Engineer, carry out casting concrete When concrete reachs required strength, formwork will be removed Complete inspection sheets and carry out construction of next item When getting approval of the Engineer, survey and install steel rail on the span and abutment Completion of installation IV Construction of Expansion joints This work must be complied with SPECIFICATION SECTION 07800 EXPANSION JOINT of the Specifications Expansion Joint Material No materials shall be used or installed until they have been approved by the Engineer Method of Construction and Installation Concrete on which expansion joints are to be set shall be; dry, clean and free from dirt, grease, laitance and contaminants and shall be level and sound with no broken or spilled concrete No joint shall be placed until the Engineer has inspected and approved the seat conditions After coating the seat area with the specified sealant adhesive the joint shall be positioned over the anchor bolts and the nuts securely tightened All loose or long anchor bolts shall be corrected in a manner approved by the Engineer All joints between units around connecting bolts and cavity plugs shall be carefully sealed with sealant in a neat workmanlike manner to keep out water and protect against corrosion Neoprene surfaces in contact with sealant shall be buffed at the plant or wire brushed prior to installation to provide a bonding surface for the sealant Prior to filling the space in the bolt wells, the Engineer shall inspect the anchor bolts and check the tightening of the nuts to the manufacturer’s specified torque Any wells sealed without the Engineer’s approval shall be opened and resealed after approval at the Contractor’s expense The expansion joint shall be installed after completion of the final layer of the pavement to ensure an even joint, true to line and level, between the expansion joint and the pavement The finished joint shall present a smooth, neat appearance with no protruding bolts or rough joints Excess sealant shall be wiped or scraped away before it becomes hard 37/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION The Contractor shall use a non shrink 40 MPa grout conforming with ASTM C1107, Grade A in the transition section between the expansion joint and the pavement; as described in the expansion joint Drawings V Bridge Deck Waterproofing Membrane All the materials to be used for furnishing and installing the deck waterproofing membrane shall be certified by the manufacturer and shall be approved by the Engineer before they are used in the Works The concrete of bridge deck prior to application of Deck Waterproofing Membrane must remove all loose and foreign materials, grind and make flat surface to achieve designed level Use air compressor combined waterwashing to clean the surface of concrete deck then proceed Acetylene lamps to heat the waterproofing membrane and paste on the concrete deck, which has been cleaned This work is carried out by the “step by step“ method VI Construction of bridge drainage Contractor shall ensure full preparation in quantity and quality and drainage pipes on the bridge Using manpower to carry out the installation of drainage devices on the bridge 38/ 38 PHUONG THANH TRANCONSIN – GRBCC JV ... the allowable range Construction 3. 1 Casting bed  3. 2 3. 3 6/ 38 As shown in construction method drawings Bottom formwork  Install bottom formwork plates of 3m length and connect by bolts ... samples, 03 samples tested after 72 hours (3 days), 03 following samples is tested after days, 03 remaing samples to determine the 28-day strength The testing sample is cylinder 150x300 mm or... with I33m 25/ 38 PHUONG THANH TRANCONSIN – GRBCC JV CIVIL WORKS CONTRACT PACKAGE A1 (KM 65+000-KM81+150)- DA NANG – QUANG NGAI SECTION Some images in manufacturing site Bottom of formwork 26/ 38