01 method for sika v1

CONSTRUCTION METHOD STATEMENT CONTENT CHAPTER TEMPORARY WORK & PREPARATION 1.1 GENERAL 1.2 SITE INSPECTION, ATTACHING BATTER BOARDS, SCAFFOLDING, Etc 1.3 TEMPORARY ACCESS ROAD 1.4 MATERIAL STORAGE YARDS, CONSTRUCTION SHEDS AND OTHER TEMPORARY WORKS 1.5 REMOVAL OF TEMPORARY UNITS AND OTHERS CHAPTER PRESSING PILE METHOD STATEMENT 2.1 FABRICATION OF PC PILE SEGMENTS 2.2 PILE MAINTAINING AT SITE 2.3 SURVEYING OF PILE LOCATION 2.4 PREPARATION WORKS BEFORE DRIVING PILE 2.5 PILE PRESSING EXECUTION 2.6 STATIC LOADING TEST 10 CHAPTER EARTH WORK 13 3.1 GENERAL REQUIREMENT 13 3.2 EARTH WORK SUPPORT 14 3.3 METHOD OF EXECUTION .14 CHAPTER REINFORCEMENT WORKS 18 4.1 MATERIALS 18 4.2 PROCESSING AND ASSEMBLY .18 4.3 ARRANGEMENT OF BARS .19 4.4 HOLES IN BEAMS AND OTHER CASE 19 CHAPTER FORMWORKS 20 5.1 MATERIALS AND CONSTRUCTION 20 5.2 ASSEMBLY .20 SEQUENCE OF CONSTRUCTION FOR COLUMN & WALL 20 5.3 FORMWORK INSTALLATION 21 5.4 FORMWORK REMOVAL 22 5.5 HEAD TREATMENT FOR FORM TIGHTENING PARTS 22 CHAPTER CONCRETE WORK 23 6.1 GENERAL .23 SEQUENCE OF CONSTRUCTION OF BUILDING FLOOR SLAB 23 6.2 CONCRETE CASTING PLAN 23 6.3 MATERIALS FOR NORMAL WEIGHT CONCRETE 24 6.4 MIX PROPORTION OF ORDINARY CONCRETE .24 6.5 PRODUCTION, TRANSPORT AND PLACEMENT OF CONCRETE .25 6.6 TESTING 28 6.7 TROWEL FINISH FOR FLOOR CONCRETE .29 CHAPTER STRUCTURAL STEEL WORK 31 7.1 GENERAL .31 7.2 MATERIALS REQUIREMENTS .31 7.3 GENERAL SHOP DRAWINGS 32 7.4 ANCHOR BOLT SETTING 36 7.5 WELDED JOINTS 37 7.6 PAINTING .42 7.7 OTHER NOTICES ON FABRICATING STEEL STRUCTURES 42 CHAPTER FINISHING WORKS 44 8.1 WATERPROOFING 44 8.2 BRICK WORK .45 8.3 DOOR FRAMES INSTALLATION 45 8.4 PLASTER WORK 47 8.5 TILE WORK 49 8.6 PAINTING WORKS 52 8.7 CEILING WORK 54 8.8 METAL WORK 54 CHAPTER INTERNAL ROAD 56 9.1 ROADWAY EXCAVATION 56 9.2 METHOD APPLIED FOR CONSTRUCTION OF SUB-GRADE 56 9.3 THE METHOD APPLIED FOR CONSTRUCTION OF BASE AND SUB-BASE COURSE 57 9.4 THE CONSTRUCTION METHOD OF ROAD STRUCTURE .59 CHAPTER 1.1 TEMPORARY WORK & PREPARATION GENERAL Site clearing shall consist of clearing, grubbing, removing of top soil, and removing and disposal of all vegetation and debris within the limits except such objects as are designated to remain in place or are to be removed in accordance with specifications or instruction of the Engineer MAJOR SEQUENCE AND PLAN FOR CONSTRUCTION Temporary Access road Construction of piling Construction of foundation Construction of superstructure Finishing works M&E works 1.2 SITE INSPECTION, ATTACHING BATTER BOARDS, SCAFFOLDING, Etc 1.2.1 Checking Site Conditions and Staking Out After verifying the conditions on site, the location of the building shall be indicated by staking out or other suitable method and this shall be inspected by the Engineer 1.2.2 Benchmarks Firmly install wooden or concrete stakes as benchmarks so as to prevent any movement, and provide curing around them A fixed non-moving object may be used as a substitute Benchmarks shall be inspected by the Engineer 1.2.3 Attaching Batter Boards After staking out the site, install batter boards at the corners and other important points of the building, and provide temporary making for setting line at a place where the work will not be affected The top of the batter board shall be planed using a planer and attached horizontally to the ground stakes with nails When attaching batter boards clearly indicate the location of the building and horizontal reference and ask the Engineer to inspect the batter boards 1.2.4 Scaffolding Scaffolding, landing stages, temporary enclosures etc shall be built with appropriate materials and structures in accordance with the labor law, building standard law, requirements for public disaster prevention in construction and other relevant laws 1.3 TEMPORARY ACCESS ROAD Clearing and Grubbing and Tree Removal The Contractor shall clear and/or grub, including disposal as required all surface objects and all trees, down timber, rotten wood, stumps, roots, snags, brush, other vegetation, rubbish, and other protruding obstructions not designated to remain In area under roadway embankments, from which the topsoil or unsuitable materials are to be removed or which are designated to be compacted, the Contractor shall remove all stumps and roots to a depth at least 20 cm below the original ground surface and at least 15 cm below the bottom of the lowest pavement layer In roadway cut area, all stumps and roots shall be remove to a depth of not less than 30 cm below the finished sub-grade level Voids left after removal of roots shall be filled with suitable compacted materials as approved by the Engineer Topsoil Stripping The Contractor shall remove the topsoil in area under roadway embankment or where designated by the Engineer, and stockpile / dispose of it to the approved area as directed by the Engineer When the topsoil will be used for dressing of the slopes of the embankment or other area as directed by the Engineer or as indicated on the drawings, the Contractor shall place and spread the stockpiled topsoil in such designated area After spreading, the topsoil shall be raked to form a smooth surface free from weeds, roots, sods and large stones Removal of topsoil shall be executed to the depth as directed by the Engineer, and the topsoil shall be kept separate from other excavated materials Disposal of Cleared Materials All cleared material is the property of the Engineer and shall be used or disposed of as the Employer sees fit The Contractor shall haul all cleared material from the clearing and grubbing operation to locations designated by the Engineer No accumulation of debris shall remain on or adjacent to the right-of-way 1.4 MATERIAL STORAGE YARDS, CONSTRUCTION SHEDS AND OTHER TEMPORARY WORKS 1.4.1 Materials storage yards Material storage yards or construction sheds, etc shall be allocated and constructed to suit the stored material and depend on site organizing plan 1.4.2 Storehouses for explosives Storehouses for flammable materials such as paints and oil shall conform to the relevant laws and be situated as far as possible from buildings, construction sheds, material storage yards etc The roof and interior and exterior walls and ceilings shall be of fire-preventive construction or be covered with a fire protection material; each door shall be lockable, and provided with a "CAUTION: FLAMMABLES" notice and fire extinguisher 1.4.3 Contractor's Offices and other rooms The contractor's office, toilet, etc shall be provided Signboards displaying the name of the construction work, name of owner and other details shall be installed at a suitable location on the construction site 1.5 REMOVAL OF TEMPORARY UNITS AND OTHERS If a temporary construction is disturbing the progress of work or the use of other buildings within the premises, then the contractor shall negotiate with the Engineer for its removal In the event that there is no place to move the temporary construction, then part of the construction may be used if approved by the Engineer The temporary constructions should be removed, the construction area as well nearby areas cleared and cleaned and the ground surface leveled before the formal completion of the construction work CHAPTER 2.1 PRESSING PILE METHOD STATEMENT FABRICATION OF PC PILE SEGMENTS PC, PHC piles that will be used in the project shall be approved by the Owner, and made by contract between the Contractor and the Supplier(s) Pile document includes pile catalogue, all pile quality certificates and material testing reports 2.2 PILE MAINTAINING AT SITE All storage piles at site keep in good condition carefully Be specific to comply with regulations as follows: - Piles comply with number of layers exactly (non exceeded 03 layers) - Supporters must be put in the correct handling positions marked on pile body Piles are not put on the ground directly which maybe generate particular stresses to crack or break pile to effect on quality of pile - Absolutely not put any heavy objects on the pile body as well as preventing to hit beside of pile body - Do not put piles which have the differ lengths together - While transporting, loading to truck-trailer as well as unloading storage or installing into locations, hooks and cables must be good; and when workers wear the cable into handling points, they should be careful to prevent slipping and breaking - The previous fabrication piles should be driven first, the next pile will be driven later unless having the other requirements from the Client or the Supervising Consultant Maintaining methods at site must be done strictly, any violations must be penalized adequately to ensure the strictness and safety for all works 2.3 SURVEYING OF PILE LOCATION The work will be done immediately after completion of site plan preparation and having full of designed pile drawings They includes works as follows: - Locating standard level is obtained from the National standard level It should be done and handed-over with Supervising Consultant and the Client because it will be base on cutting pile head after completion - Locating points of co-ordinate standard in piling location gridline - Locating points of pile is obtained from locations of points of co-ordinate standard The surveying work are done by theodolites and checked in two perpendicular directions, also constructing fixed intermediate survey-marker to perhaps check promptly the co-ordinate system of pile driving 2.4 PREPARATION WORKS BEFORE DRIVING PILE Gathering full of pile quantity of adjacent driven pile positions Checking the number of pile, diameter, length, pile location, hammer type, drop height of hammer to record on pile driven record sheet Marking each 25cm for final piece of combination pile no to determine the depth of driven pile Preparation equipment use for recording pile set such as pile set recording form, drawing pencil and supporters etc… If execution at area recorded to have obstructers, it should be removed out which is near the nature ground level or boring in advance if it is more deeper Prepared dolly is soft wood such as fir or plywood with 5-10cm thickness The wood dolly is used one time for a driven pile only; it is not used for the next pile although it still be in good status Should use cover and dolly suitable with pile cross section The slits between pile hip to each of the edge of cover should not exceed 1cm 2.5 PILE PRESSING EXECUTION 2.5.1 Pile driving execution at SIKA VIETNAM factory located in VSIP Bac Ninh Based on the fact of site and construction plan, to shorten and to ensure the execution in comformity with the schedule, a robot pile pressing machine shall be used for piling work It has greatly increased the piling speed which could reach the maximum capacity in 6m pile per minute While handling, should pay attention to points of wearing hook is necessary exactitude, especially dragging pile into the rig at one point must be complied with Engineer’s instructions Piles are checked the vertical degree in two perpendicular directions by theodolites and it is careful continuously during pressing procedure When jointing pile, the joint is the welding joint, height and width welding is done as shown in design detailed pile drawing and welding rod On the other hand, alignment of under piece must be line to the upper piece and centric axis of under piece is line to the upper piece When pressing, follow and check frequently as well as counting the blows of 100cm penetration length to record in the pile driven record sheet To friction piles, driving pile will be stopped when pile tip reach the designed level or bearing capacity of pile is over the designed bearing capacity While pile pressing procedure, if any strange phenomenon are happened is to stop to inform to the Engineer to be instructed treatment method complied with “Some of cautions” clause bellow 2.5.2 Checking Checking before pile driving procedure: Checking slits on the pile body, bending degree, perpendicular degree to site plan Checking certification of calibration of rig and pile driving equipment whether met allowable calibration criterions Checking pile installation position suitable for design While pile driving procedure, perpendicular of pile need to be checked frequently in two directions as well as center of both of piece when jointing, especially appeared deformations 2.5.3 Some of cautions While pile driving procedure, some of phenomena often happen and treatment methods are to be done: - Pile was reached to the required pile set before reaching the designed depth: in this case, the driving team should stop driving and re-drive after 03-07 days from the stopping day to prevent pretending refusal by gathering stresses phenomena at pile tip or hard obstructers If the pile set still be not changed then, it should be to inform to Supervising Consultant or the Client to approve whether accepted or not - Pile reached at the designed depth before reaching the required pile set: in this case, it should be to inform to Supervising Consultant or the Engineer immediately to consider treatment methods or connect the second pile to drive the pile until reaching the required pile set or stopping to drive to cancel it and adding the other - Pile is broken at the pile head in driving: if happened, it should be to inform to Supervising Consultant or the Client and Manufacturer to consider the grade of destroyed pile head together - If the pile head is damage slightly such as appearing the slits around the hook or peeling off concrete outside the pile head, it is done to cut off damage part of 0.3-0.5m from the end of slits, then pasted the end plate other by Epoxy glue and it is driven continuously after 30 minutes - If the pile head is damaged strictly such as collapsing on side or the length of breaking completion concrete to expose reinforcements are large, at that time, it should be approved by Supervising Consultant or the Client to permit to treat as the above or add the pile other 2.6 STATIC LOADING TEST 2.6.1 General Must be performed before driving pile in mass This is the canonical testing method and regarded reliable method to test the loading capacity of pile Number & tested piles are shown in design drawings 2.6.2 Sequence of work Install equipment and settling measure instruments Loading for pile is divided to several levels, increases for each level with value 1/15-1/10 of estimated loading (in normal each level increase about 1,25; 2,5; 5; or 10 ton) At the first stage each level shall be added about 1/5-1/25 of ultimate loading At following stages, the added loading shall be reduced gradually about 10 Prior to laying tiles give adequate moisture to the backing mortar Make all necessary preparations for tiling Give adequate moisture to tiles with water absorbing properties 8.5.3 Laying floor tiles Stretch leveling string throughout in accordance with joint layout, fix corners, angle and other important points, stretch the string straight and flat, and clean the surface and bottom of joints from time to time For larger laying areas laying of tiles shall be based on joint layout of about 2.5m as reference, and lay time shall use this as a ruler Clean joint sections prior to filling pointed joints Fill joints at an early stage by checking the hardening of mortar after laying Give adequate moisture depending on drying state at joint sections Pointed joints: 8.5.4 - Joints shall be flat in shape - Except for large floor tiles, place and press down the joint mortar using a joint trowel and finish without creating irregularities or leaving traces of the trowel - For large joint widths of ordinary floor tiles, fill joints with mortar using a rubber trowel and press the joint down with a joint trowel in accordance with clause above - For small joint widths of ordinary floor tiles and unit tiles make rubbed joints - After filling joints clean the tile surface Laying wall tiles Tight adhesion laying: Limit of area for each coating of laying mortar shall be about 2m2 This may be increased or reduced slightly depending on weather conditions etc if approved by the Engineer The quantity of mortar to be mixed shall be required for one coating Mortar shall not be used after more than 30 minutes following mixing Use water retaining agents as required when laying mortar, but not exceed the predetermined quantity The correct laying sequence is :stretch leveling strings throughout in accordance with joint layout and lay tile accessories first at window, near entrance, corner and angle After coating with laying mortar, immediately press tiles against mortar, vibrate tile surface using tile vibrator (vibrato and lay tiles without creating irregularities using the vibrator until the laying mortar spreads over the entire rear surface of the tiles and further comes out at the edges (joint depth shall be less than half of tile thickness) Finish pointed joints to the designated shape with joint trowels at the correct time, when the mortar has set sufficiently After forming the joints clean the tile surface Improved laying by stacking: Lay tile accessories in accordance with the joint layout, stretch leveling strings 50 throughout and lay tiles upward from the bottom Apply laying mortar flat to the entire rear surface of the tiles, lay tiles, strike all over with wooden hammer for compaction until mortar oozes out from the edges, and correct the tile position to make it perfectly flat and in alignment with others Tiles coated with mortar shall be laid within minutes Mortar shall not be used after more than 30 minutes following mixing Limit of laying height per day shall be less than 1.5m After filling joints was surface of tiles Improved pressure laying: Limit of the coating area for laying mortar at one time shall be the area in which tiles can be laid within 60 minutes The quantity for mixing shall be that of coating plus laying at one time Prior to laying applying mortar to back sides uniformly Apply laying mortar flat over the entire rear surface of the tiles, lay tiles, hit all over with wooden hammer for compaction until mortar oozes out from the edges, and correct the tile arrangement to make it perfectly flat and in alignment with other tiles When tile laying at one time is completed on mortar surface, remove mortar out from the edges of already laid tiles, coat mortar correctly and begin re-laying tiles After filling joints wash the surface of the tiles Laying by stacking: Fit tiles with mortar, avoiding gaps on the rear surface of the tiles, and place flat in alignment with other tiles The quantity of laying mortar to be mixed with water shall as a rule be only as much as can be used up within 30 minutes Do not use mortar more than one hour after mixing Supplement laying mortar where insufficient or where gaps have arisen Use water retaining agents for laying mortar Apply and press laying mortar with trowel over the entire rear surface of the unit tiles using masks for unit tiles, lay tiles by aligning vertically and horizontally and with the joint widths, and hit tiles with a hitting board for compaction until mortar comes out at the joint sections Apply tiles within minutes after coating mortar Do not use mortar after more than 30 minutes following mixing Paper on the font side shall be peeled off after a suitable period from laying Wet the paper, peel off and correct tile alignment After filling joints wash the surface of the tiles Laying mosaic tiles (tile under 25mm): Limit of coating area for laying mortar at a time shall be about 3m2 After applying laying mortar lay the tiles, adjust the alignment vertically, horizontally and for joint width, and hit tiles for compaction with a hitting board until the laying mortar comes out at the joint portion Remove laying mortar at connections between tiles and re-coat 51 After filling joints wash the surface of the tiles Laying wall tiles with adhesive: Prior to tile laying verify the accuracy of the backing surface and the dryness Remove impurities from the surface of backing; for backing made of boards, apply primer The maximum area for coating adhesive at one time shall be the area over which tile laying can be finished within 30 minutes The quantity mixed shall be only that required for coating at one time Adhesives shall be applied flat using trowels or the like, and traces of combs shall be made using a special comb trowel Stretch leveling strings based on joint layout, lay ruler tile as reference, and lay tiles upward, carefully checking tile alignment at vertical and horizontal joints When laying tiles singly, press each by hand and give a twist For unit tile laying, correct joint alignment by hand while lightly padding the whole surface, and then hit tile with a hitting board for tight adhesion After filling joints clean the surface of the tiles 8.5.5 Tile laying for lintels, window sills, etc For the backing, create the required shape and water gradient according to the design documents When laying tiles larger than ceramic mosaics on lintel or the bottom tip of eaves, attach pulling metal parts described in Paragraph above to the mortar and support the structure with supporting wood attached for at least 24 hours Window sill tiles shall be inserted at the rear side of window frames or water drip sheets and the rear gap filled with mortar 8.6 PAINTING WORKS 8.6.1 General Mix ratio for finish shall be to the color and gloss specified by the manufacturer For small quantities color may be adjusted on -site using paints from the same manufacturer Paints shall be delivered to the site with the seals unbroken Mixed paints should be used as they are, although they may be readjusted slightly depending on base coarseness and density, degree of absorption and outside air temperature Avoid contamination and damage of painted surfaces and floors, and provide adequate curing for painted sections and surrounding areas Finish color shall be approved by the Engineer from submitted sample books or coated sample boards Any factory-painted components found to be damages upon delivery to the construction site shall be immediately repaired Standing time for each painting process shall be determined according to the type of material and weather conditions Second and finish coats shall be different colors whenever possible 52 Doors or windows which are visible and exposed to water, and which cannot be painted after assembly, installation or tie-in work, should be painted with finish coat in advance Painting shall not take place if dew condensation is considered likely due to air temperature under 5oC, humidity higher than 85% or poor ventilation, since the paint will not dry properly Where this cannot be avoided curing by heating and ventilation shall be provided instead Outdoor painting shall not be performed as a rule during rainfall or strong winds Coating quantity shall be the standard amount of paint adhering to flat surfaces, and shall be measured before thinning Ventilation is required during painting to prevent solvent poisoning Avoid fires and/ or explosions Cloths used for wiping paints can spontaneously ignite and should be quickly disposed of after use 8.6.2 Techniques Paints should be well mixed immediately before using and divided in several containers if required Polishing : (1) Polishing paper shall be abrasive cloth, and waterproof abrasive paper shall be (Waterproof abrasive paper) (2) Rubbing with abrasive paper and wet rubbing shall be performed after lower layer and putty coats have hardened and dried Rub in longitudinal direction of raw material with abrasive paper or waterproof abrasive paper, taking care not to remove lower layer coats Puttying and putty squeezing : (1) Fill deep holes and large gaps with putty by pressing with trowel or spatula (2) Spread putty thinly with trowel or spatula in depressions, gaps and uneven places (3) Following (1) and (2) above, rub with abrasive, coat putty with spatula over entire surface, then rub and fully remove putty until base surface appears, taking care not to leave too much putty on the surface (4) After puttying and rubbing with abrasive paper, apply putty over entire surface to make it flat; after drying, repeat the process of rubbing with abrasive paper Coating method shall be suited to the paint used Use one of the methods described below Do not damage color boundaries, corners or recessed sections, and clearly delineate division lines (1) When using brush make that brush lines are straight uniform (2) When using spray gun, select type, aperture, and air pressure according to the type of paint Uniform coating of paint is important (3) When using roller brushes, switch to a small brush or special roller for corners and recessed sections to obtain uniform coating (4) Apply rustproof paint by dip coating 53 8.7 CEILING WORK Start to set up ceiling frame following design drawing and technical specify for ceiling frame: - Ceiling board shall be applied when mechanical and electrical works have been joint together - Ceiling must be flat and frame must be straight after finished Intervals for furring strips holders, hanger bolts and inserts shall be approximately 900 mm, and within 150 mm from the end in peripheral sections The inserts shall be laid during form assembling work Attach the top portion of each hanger bolt to the buried insert (for steel framed reinforced concrete structure) or by an appropriate method such as welding (for steel frame structures) Hanger bolts shall have furring strips-holding hangers at the bottom, to which furring strips holders shall be attached The furring strips and furring strips holders shall be attached with clips, which shall be attached alternately Interval for indoor furring strips: - Approximately 360 mm when there is backing material and/or formed metal panels have been laid - Approximately 300 mm when finish material, wall paper or backing for paint is going to be laid directly; under 455/2 mm when the length of one side of board is under 455 mm - Under 455/2 mm when slitting process has been used for furring strips Interval of outdoor furring strips - Interval of furring strips shall be about 300 mm Clips shall be attached to furring strips holders by folding inside the groove in the furring strips holder Ceiling joints with no backing and furring strips butting to a wall or similar place shall be installed by inserting ] channel shaped or [ angle- shaped zinc coated steel sheeting at least 0.5 mm thick to butt end portion of furring strips or splicing Where furring strips run parallel to a wall double furring strips should be used at the end portion of the furring strips Openings indicated in the Design Documents shall be reinforced as follows : - Furring strips cut off at openings such as for lighting fixtures or air diffusers from ducts shall be reinforced with furring strips, furring strips holders or the like - Openings to be used as access holes to attic spaces shall be reinforced with members the same as for furring strips holder 8.8 METAL WORK 8.8.1 Handrail and ladders Handrails Tie-in between handrail and balusters shall be done by small screws or welding Handrail parts shall as far as possible be assembled in factory Expansion adjusting joints shall be installed as required Butt end of handrail shall be closed using a lid made of the same material 54 Weld balusters to pre-attached anchors and attach firmly Ladders When fabricating into ladder shape using shape steel joints of longitudinal frames shall be made using splices tightened with bolts, rungs shall be attached to longitudinal frame with caulking, and leg brackets shall be welded or tightened to longitudinal frame using mm diameter bolts and double nuts For round steel the legs shall be fixed with concrete and shape steel firmly attached by welding leg brackets to reinforcing bars 8.8.2 Formed metal paneling The small installation screws shall be suitable the type of material used Layout is required prior to installation Chips stuck while cutting material shall be immediately removed Install by nailing to the working surface on backing For long-size panels install expansion adjusting joints against temperature changes 55 CHAPTER 9.1 INTERNAL ROAD ROADWAY EXCAVATION For ensuring that roadway excavation is undertaken in condition of free water, the proper drainage shall be arranged and depending on the actual site conditions, the canal, ditch or berm may be arranged for drainage The roadway shall be excavated by Bulldozer, excavator in combination with manual in accordance with the level, line, dimensions, cross section shown on Drawings /or as required by the Engineer In the case the thickness of ground to be excavated and removed is bigger than design thickness, our Contractor shall stop the work and make and submit report to Employer and Engineer for their instruction For ensuring the excavated roadway is free of water, the cofferdam may be constructed The culverts used for drainage for maintaining traffic control shall be not removed until the work is completed or other proper solution is applied for The structures below the existing works (if are not remained) shall be removed completely to the bed of natural flown The hole or foundations arisen from excavation of existing structures shall be replaced with material suitable to material of adjacent areas and compacted to level of adjacent areas or undertaken under the Engineer's instruction In the case the excavated material is good quality and suitable for embankment construction, our Contractor shall propose Engineer to permit re-use after testing such material in accordance with the Technical Specification and upon approval of Engineer This material shall be transported to proper areas to protect carefully until re-use In the case the excavated material is not suitable fur embankment construction but is suitable for top soil for planting trees or grass, which shall made free of sand, stone, rubbish and other foreign matters and then transported to required places for re-used later, if approved by Engineer The excavated surplus material, unsuitable material shall be disposed to disposal areas upon Engineer's approval Upon completion of road bed excavation to design level and cleaning excavated ground, Engineer shall undertake to check and review and approve 9.2 METHOD APPLIED FOR CONSTRUCTION OF SUB-GRADE The material used for sub-grade construction shall be selected carefully and meet the requirements of Technical Specification Prior undertaking sub grade construction at the site, the line, level, gradient, cross section, density etc of completed shall be checked and adjusted in accordance with the design and approve by Engineer The sub-grade material shall be transported to the site and dumped into the pits with proper distance for leveling into regular layer The placed sub-grade material shall be leveled by bulldozer in regular layer and over the both edges of embankment about 20 cm of each for ensuring enough material to 56 compact After that sub-grade shall be trimmed and removed the surplus material The rolling shall be undertaken from low point to high point; the next rolling trip shall overlap the previous rolling trip at least 20-25cm If the rolling is undertaken in quadrate with centerline, so overlap of two rolling trips shall be at least 50-100cm For ensuring sub grade density to 98MDD, the moisture of sub grade material shall be adjusted at the proper moisture by adding water or removing surplus water dung undertaking compaction The water truck shall be used for sprinkling water of sub grade material, if necessary Upon completion of sub grade construction, its level, dimensions, gradient, cross section shall be checked and adjusted in accordance with Drawings and Technical Specification and approved by Engineer 9.3 THE METHOD APPLIED FOR CONSTRUCTION OF BASE AND SUB-BASE COURSE The construction of sub-base course and base course shall be undertaken in accordance with the requirements of Technical Specification and Engineer’s instruction and supervision 9.3.1 Sub-base Aggregate Course Construction The sub-base aggregate used fur construction of sub-base course should be tested and checked in compliance with the criteria and approved by Engineer before putting into permanence works Any sub-base aggregate which are not responded these requirement shall be removed from the site Preparing and mobilizing to the site enough and necessary construction plant and equipment used for construction such as motor grader, rollers, dump truck and water truck and other instruments used for adjusting proper moisture, measurement of level, thickness, density etc Preparation: Completion of surface of sub grade layer to 98MDD and in accordance with the design gradient, level, centerline, thickness and geometrical dimensions, cross section etc., after that installing states of centerline, shoulders and remarking the thickness of paved aggregate (uncompaction) of trial section The sub-base aggregate material shall be transported and dumped into pits in proper distance by dump truck so that it can be leveled and compacted to design level and specified density The laid sub-base aggregate shall be leveled in layer in specified geometrical dimensions by motor grader The moisture of laid sub-base aggregate shall be adjusted at proper moisture by sprinkling water, if dry or dried, if so wet so that it can be leveled and compacted to specified density If the segregation between laid sub-base aggregate layers arisen during construction, such aggregate shall be removed from the site and replaced with new other in compliance with requirements of Technical Specification and under Engineer's 57 instruction and approval The surface of laid previous sub-base aggregate shall be prepared and sprinkled with water to specified moisture prior construction of next sub-base aggregate layer Prior construction of next sub-base aggregate trip, straight ending of pervious trip shall be trimmed correctly fur ensuring rolling the match of two trips to specified density Compaction: Prior undertaking rolling, the laid sub-base aggregate layer may be sprinkled lightly water in order maintain it moisture in range less than 3% and more than 2% in comparison with optimum moisture and approved by Engineer The base aggregate layer shall be compacted by rollers with following steps: Preliminary rolling: by Roller 4t-6t running 04 time/point and then placing additional aggregate and trimming surface Density rolling: by Vib Roller 14T (its capacity is reached to 25T under vibrating force), next rolling by tire wheel roller with 2.5T - 40T/wheel Finishing rolling: by Steel Wheel Roller 8T - 10T The official Sequence and rolling numbers shall be determined through result of trial work Due to evaporating of laid aggregate during rolling, therefore water shall be added by sprinkling lightly the surface for remaining the moisture at the proper level for density compaction 9.3.2 Base Aggregate Course Construction The base aggregate used fur construction of base course should be tested and checked in compliance with the criteria of two above tables and approved by Engineer before putting into permanence works Any base aggregate which are not responded these requirement shall be removed from the site The construction of base aggregate course shall undertaken only when the sub-base course has been completed and approved by Engineer and the trial work has been done in accordance with the requirements of Technical Specification and satisfied to Engineer The sequence of base aggregate course construction is as follows: Preparation: Completion of sub-base aggregate course in compliance with the design gradient, level, centerline, thickness and geometrical dimensions, cross section etc., after that installing states of centerline, shoulders and remarking the thickness of paved aggregate (uncompaction) of trial section The base aggregate material shall be transported by dump truck to site and dump into spreader The laid base aggregate shall be leveled in layer in specified geometrical dimensions and thickness by spreader The moisture of laid base aggregate shall be adjusted at proper moisture by sprinkling water, if dry or dried 58 Compaction: The base aggregate layer shall be compacted by rollers with following steps: - Preliminary rolling: by Roller 4t-6t running 04 time/point and then placing additional aggregate and trimming surface - Density rolling: by Vib Roller 14T (its capacity is reached to 25T under vibrating force), next rolling by tire wheel roller with 2.5T - 4.0T/wheel - Finishing rolling: by Steel Wheel Roller 8T - 10T Pay attention that the next rolling trip should over-run the previous rolling trip at least 20cm and over-run the edges at least 20cm of each Due to evaporating of laid aggregate during rolling, therefore water shall be added by sprinkling lightly the surface fur remaining the moisture at the proper level for density compaction Maintenance of base aggregate course: The traffic shall not be permitted to operate on the new constructed base course, when the prime coat is not sprinkled yet Keeping moisture of base course surface at proper level in order that the fine particles are removed from the surface The prime coat shall be sprayed as soon as possible upon completion of base aggregate course for avoiding its damage by traffic operation 9.4 THE CONSTRUCTION METHOD OF ROAD STRUCTURE 9.4.1 Construction of Prime coat and tack coat Material: The emulsified or cut back asphalt used for construction of prime coat and tack coat shall be tested for checking its quantity in compliance with the material requirements Specified in Technical Specification and approved by Engineer before undertaking construction at the site The emulsified or cut back asphalt used for construction of prime coat and tack coat should respond the following requirements: - The materials shall be either AC-20 grade asphalt cement (which is approximately equivalent to 60/70 Pen.) diluted with kerosene - The materials fur Tack Coat to be used in the prepared A/C Binder Course for Rough Surface Course shall satisfy the requirements of liquid bitumen RC-70 (ASTM D2028-97) with proportion (volume of bitumen of emulsified asphalt will be liter/m2) : o Finished Asphalt Surface Course which has not been put into operation yet: o Bitumen RC-70, proportion 0.2-0.3 litre/m2; o Finished Asphalt Surface Course which has not been put into operation: o Bitumen RC-70, proportion 0.3-0.4 litre/m2; 59 o Spraying temperature: For RC-70 is 110oC-10oC - When AC-20 is to be diluted with kerosene, the proportion of kerosene diluents to be used previously approved by the Engineer Construction sequence: Site Preparation: - Prior to the application of the bitumen, loose dirty and other objectionable materials shall be removed from the surface by means of power broom of blower or both If this does not provide a uniformly clean surface, additional sweeping shall be done by hand using stiff brooms Sweeping shall extend at least 20 centimeters beyond each edge of the area to be sprayed - The Contractor shall be responsible for all the consequences of traffic being admitted too early to newly laid Prime Coat, and he shall prohibit such traffic when necessary by providing a detour or by half- width construction - Bituminous material shall not be discharged into any side ditch or drain The transverse distribution of bitumen application rates produced by the distributor shall be tested by passing the spray bar over a test area laid with 25cmx25cm sheets of absorbent material with a binder-proof backing, which are weighed before and after the spray application The difference in weight shall be used in determining the spraying rate actually applied to each sheet and the variation from the mean rate for any sheet across the full width sprayed shall not exceed 15 percent The distributor having rubber wheels and has a minimum capacity of 1,000 liters The distributor shall be so designed, equipped, maintained and operated that Bitumen at even heat may be applied uniform on variable widths of surface, at a controlled rate of transverse and longitudinal spread within ±10 percent of the required rate of application The distributor equipment shall be include a tachometer ,pressure gausses, a calibrated tank dipstick, a thermometer for measuring the temperature of the tank contents, and an instrument fur measuring the speed of travel at low speed All measuring e equipment on the distributor shall have been recently calibrated and an accurate and satisfactory record if such calibration shall be supplied to the Engineer When so directed by the Engineer, the Contractor shall make equipment and operators Available for field testing and shall supply any other assistance required for this purpose The areas, prime coat and tack coat of which cannot be sprayed by Distributor shall be applied by sprinkling can: The construction of prime coat shall not be permitted to under while the outside temperature under 15oC Traffic shall not be permitted on the coated surface until the Bitumen has penetrated and dried and, in the opinion of the Engineer, will not pick up under traffic In exceptional circumstances where it becomes necessary to permit traffic on prime coat prior to that time, but in no case sooner than hours after the application of the prime coat, clean cover aggregate shall be applied as directed by the Engineer and traffic may be permitted to use the lanes so treated Cover aggregate shall be spread from trucks in such a manner that no wheel will travel 60 on uncovered wet bitumen When applying cover aggregate to a treated lane that adjoins a lane yet to be treated, a strip at least 20 cm wide along the adjoining edge shall be left uncovered, or if covered shall be uncovered when the second lane is being prepared for treatment, in order to permit an overlap of Bitumen as required above The cover aggregate shall be used to the minimum extent possible 9.4.2 Construction Method of Asphalt Concrete Pavement Construction work The paving plant, rolling equipment, dump truck and other necessaries instruments shall be prepared in good conditions and mobilized already and satisfied to Engineer at the site prior starting undertaking AC mixture paving AC mixing method Prior staring AC mixing, all materials used for mixing AC mixture shall be tested for checking their quality in compliance with the requirements of Technical Specification under Engineer's instruction and supervision and recording the checking the weight of coarse and fine aggregate, bitumen temperature and properties of AC mixture etc also shall be undertaken regularly at the plant Coarse and fine aggregate will be crushed store and supplied separately and sampling test for materials from every materials resource will be carried out and approved by the engineer Every gauge aggregate, mineral powder and bitumen will be measured accurately in accordance with approved manufacturing mixing proportion with the measurement en or controlled within stipulation During the mixture mixing gradation will be strictly controlled within the stipulation and be closed to medium value of required gradation Mixing temperature and duration of bitumen mixture are two basic factors of even mixture and after they are confirmed they must not be changed at will during the construction The appearance and color of the mixture after mixing will be same without grizzled granular and the distribution of coarse and fine granular When separation occurs mixing temperature will be adjusted in time and mixing duration will be prolonged The entire over heated mixtures or the discharge of temperature of the mixture exceeding the upper bound of normal temperature must not be used Transporting AC mixture: The dump trucks 12T which are used for transporting AC mixture to the site shall be clean and tidily and covered with canvas, except sunny weather and approved by Engineer The truck transporting AC mixture shall be accompanied with its record when leaving from AC mixing plant Basing on the operation productivity of paving plant and rolling equipments and capacity of AC mixing plants, dump trucks using for AC mixture shall be arranged in enough number For avoiding cohesive of AC mixture, the tank of dump truck shall be coated with soap or oil think layer prior dumping AC mixture into 61 Paving AC mixture: The temperature of AC mixture dumped from the truck into Paver shall be > 1200C The paving AC mixture is permitted to carry out when the outside temperature not less than + 50C The hot laid AC mixture shall be paved by paver In addition the narrow areas, paving AC mixture of which cannot be undertaken by paver, so it shall be carried out by manuals and should meet the following requirements: − Manuals using shovel to place lightly AC mixture over the surface of such area so that AC mixture shall not be segregated − The overlaid AC mixture shall be leveled in specified gradient and layer in 1.35 1.45 time of design thickness for ensuring rolling hot 1aid AC mixture to design thickness − The matching of AC mixture paved by Paver and AC mixture placed by manuals shall be done carefully in order that the surface of such area shall be rolled smoothly to specified density and without joint − Because the width of one lane of carriage way is in 9m and for ensuring the quality of work and construction schedule, therefore two (02) AC mixture Pavers shall be used at the same time for undertaking AC mixture paving Two pavers will be used to make up an echelon for combination spreading with the foreand-aft distance within 10~20m and the track of two paver will be overlapped 30~60mm Prior staring paving AC mixture, the paver shall operate without loading AC mixture within 10- 15 minutes for checking its spiral axis, conveyor, heating plate in good conditions A pair dice or wood piece in 1.2 - 1.3 times of design thickness of AC layer to be hanged under the heating plate Accurate coefficient shall be determined through trial paving Before the start of paving operations the heating plate of the paver shall be heated The paver shall be operated at a speed which does not cause surface cracks, tearing, or any other irregularities in the surface After finishing working shipment, the paver shall run without loading AC mixture far from the last paving trip about 5-7m and stop The edge at end of paving trip shall be trimmed and corrected in specified thickness in right manner Cutting off a part of hot laid AC mixture at the edges of previous paving trip after completion of rolling to specified density and while temperature of AC mixture in < + 700C in order to joint with the next paving trip and create good joint between two paving trips and then surplus material shall be removed from the site Prior paving the next trip the longitudinal and cross joints shall be trim-med in correct manner and coated with thin emulsion layer or heated by heater for ensuring good matching of existing paving trip and new paving trip The longitudinal joints of under and above layers and previous and next construction sections shall be unmatched at least 20cm The cross joints of under and above layers shall be unmatched at least 1m 62 AC mixture rolling: The compaction of hot laid AC mixture shall be undertaken as soon as possible by rolling equipments after paving The most effective of compaction that the hot laid AC mixture is rolled while its temperature in 1300C - 1400C range and the rolling AC mixture to specified density shall be finished and completed before temperature of laid AC mixture is downed to > 700C During undertaking rolling hot laid AC mixture for avoiding cohesive of AC mixture on the roller's wheels, special steel wheel roller, the wheels shall be wetted by sprinkling water If the AC mixture is cohesive on the wheels, that shall be removed by steel brush and wetted wheels with water Adding AC mixture to the places, where a part of AC mixture is removed by roller The tire wheels of roller shall be coated with the oil for avoiding cohesive of AC mixture Rolling Sequence: The rolling hot laid AC mixture to density is undertaken in condition of AC mixture in high temperate and sunny conditions: − Preliminary rolling by steel roller 8T: rolling 04 times/point, arrangement of manuals for adding AC mixture and repairing the defective places − Density rolling by tire roller 16-25T : rolling 12 times/point for coarse AC mixture and rolling 10 times/point for fine AC mixture Rolling First 6-8 times is in 2km/h speed and then in 3-5km/h − Finishing rolling by steel roller 10T The rolling hot laid AC mixture to design density is undertaken in condition of AC mixture in minimum temperate and winter conditions: − Firstly rolling by tire roller: rolling 12- 14 times/point − Next rolling by steel wheel roller 10T: Rolling 04 times/point Speed of each roller is similar to above The rolling AC mixture to required density shall be finished and completed before the temperature of AC mixture is downed to ≤ 70oC Construction sequence: Gathering all necessaries materials in enough quantity at the site before starting the work − Construction materials consisting of crushed stone in 0.5 – 1.0cm size and in 1.01,6cm size and bitumen The main construction equipment used for this work are as follows: − Bitumen Distributor: 01 unit − Aggregate Spreader: 01 unit − Air Compressor: 01 unit 63 ... .20 SEQUENCE OF CONSTRUCTION FOR COLUMN & WALL 20 5.3 FORMWORK INSTALLATION 21 5.4 FORMWORK REMOVAL 22 5.5 HEAD TREATMENT FOR FORM TIGHTENING PARTS 22 CHAPTER... for reinforcing bars Reinforcing bars, however, is spot-welded after preheating if approved by the Engineer Hooks at each end of the reinforcing bars shall be provided where: - The main reinforcements... concrete used for the processing of reinforcing bars for column and beam specifications shall be the sum of the minimum thickness of cover concrete plus 10mm as standards For steel frame reinforced