Tổng quát : Biện pháp này trình bày các chỉ tiêu kỹ thuật vật liệu được sử dụng; kỹ thuật công tác xây, trát; chống thấm tường; kế hoạch kiểm soát chất lượng, an toàn và môi trường trong thi công. Biện pháp này sẽ được áp dụng cho toàn bộ công tác xây, trát tại công trình khách sạn và căn hộ cao cấp Crowne Nha Trang. 2 Những tài liệu và tiêu chuẩn tham khảo: Chỉ tiêu kỹ thuật công tác xây gạch phần 04210, 09200 của dự án Tiêu chuẩn việt nam 40851985: kết cấu gạch đá – quy phạm thi công và nghiệm thu Tiêu chuẩn việt nam 14501986, 14511986: Gạch rỗng, gạch đặt đất sét nung. Tiêu chuẩn việt nam 17701986: Cát xây dựng yêu cầu kỹ thuật. Tiêu chuẩn việt nam 45061987: Nước cho bê tông và vữa yêu cầu kỹ thuật Tiêu chuẩn việt nam 40331985: Xi măng pooclăng – puzolan. Tiêu chuẩn việt nam 44591987; 4314 2003: Hướng dẫn pha trộn và sử dụng vữa xây dựng Tiêu chuẩn xây dựng việt nam 3032006 : công tác hoàn thiện trong xây dựng – thi công và nghiệm thu, phần II Công tác trát trong xây dựng Tiêu chuẩn xây dựng việt nam 56741992: công tác hoàn thiện trong xây dựng – thi công và nghiệm thu.
COFICO 1- GENERAL : This method includes specification of material; brick works and plastering works procedure; moistureproofing for brick wall; plan for quality control, safety and environment conservation This method to be applied to all brick works, plastering works in the Crowne Plaza Nha Trang Hotel & Residences 2- REFERENCE: Specifications of MAPS section 04210: block work and brick work, section 09200: lath and plaster TCVN 4085-1985: masonry structures – codes for construction, check and acceptance TCVN 1450-1986, 1451-1986: Clay hollow brick, Clay burnt brick TCVN 1770-1986: Sand for construction- technical requirements TCVN 4506-1987: Water for concrets and mortars - Technical requirments TCVN 4033-1985: Cement portland–puzolan TCVN 4459-1987; 4314 - 2003: Guidance for mixing and using of building mortars TCVN 303-2006: Finishing works in construction – execution and acceptance, part II TCVN 5674-1992: Finishing works in construction – execution and acceptance 3- MATERIAL: All kind of materials for brick works and platering works should be approved first: Sand: local cleaning yellow sand (Dien Tho) Cement: Portland PC40 cement from Luks or Holcim Water: from public water supply system Dowel: plain round rebar diameterr 6mm Epoxy to embed dowel into RC column: Epoxy with components (samples to be submitted later) Trellis: with stitch 10x10mm (samples to be submtted later) Method of brick works and plastering works COFICO Mortar: grade 75 (7.5 MPa), with flowability 165-205mm as per approved mix design Mortar grade Cemnet type Cement (kg) River sand (m3) Water (kg) Luks (PCB40) 285 0.96 275 Holcim PCB40) 313 0.98 274 Luks (PCB40) 309 0.99 297 Holcim (PCB40) 322 0.99 287 75 75 Remark Using for brickwork (flow: 165-195 mm) Using for plastering work (flow: 175-205 mm) Brick: Tunnel clay brick from Hoa Khanh or Khanh Hoa Co Strength: >= MPa, absorbsion < 25% by mass Types of bricks: hole hollow brick: 80 x 80 x 180mm hole hollow brick: 115x80x180mm Solid brick: 40 x 80 x 180 mm HOLLOW BRICK HOLLOW BRICK SOLID BRICK 4- Technical specification: Method of brick works and plastering works COFICO 4.1 For brickworks: Brick wall should be flat in horizontal, plumb in vertical, perpendicular in corrner, full, equal and alternate in mortar joint, thickness of mortar joint should not exceed 12mm The location of the brick wall should follow the marking line which has been specified in slab, column, beam or corewall as per construction drawings 4.2 For plastering works: Surface should be smooth and flat, without partially roughness, deviation is < 3mm when checked with 3m ruler Surface should be without scratch, without mortar drops, without indentation caused by plastering tools 5- Mock-up of brick wall: Before proceeding brick works, plastering works on a large scale, contractor should build mock ups for all types of brick walls, show out all connections between brick wall with concrete structure, lintels and piers The mock-ups should be built on site with dimension of 2x1.5m and these mock-ups will show out requirements of the designer and will be the basic comparative samples for approval to actual on site brick works and plastering works 6- Preparation: Preparing shop drawings for approval As soon as formwork of R.C structure taken off, clearing all unnessarry things to install barricade, safety mesh for the areas of construction Mobilizing enough cement, sand, brick to the site to ensure works can be carried out continuously without interruption Maintain, arrange, and cover material in storage carefully; especially, cement should be stored in dry areas to prevent contact with moisture and water; sand and brick should be stored on strong and clean areas Distribute enough material to each floor or each working area as scheduled Arrange enough workers and suitable safety device for the working areas to ensure works can be carried out continuously Arrange areas to store material, mortar mixing, walkway for workers and material carry to working areas for convenience Install temporarily water supply system for mortar mixing, power supply system to each floor or each working area Arrange mortar mixers 150 – 350 litters, material gauge box and mortar tray to working areas Method of brick works and plastering works Mechanical mixer MORTAR TRAY COFICO Arrange enough equipment and tool to working areas: hand trowel, hand float, level ruler, ruler 2m, 3m, plumb, tape, scaffoldings, wheel barrow, mortar tray and drilling tool 45° Mixing yard plan Section A-A Mortar mixes A Slab floor 45° Method of brick works and plastering works A Mortar tray Mortar tray 45° COFICO 7- Sequence of brick works: Method of brick works and plastering works COFICO Level Column At first, setting out guide lines which are parallel and offset from the grid line on the slab, columns and beams; Next setting out the boundery of the wall, location of the doors, windows and other openings (if any) based on these guide lines Carrying brick and other material to the right locations to build brick wall and soak the brick into water for minimum 30 minutes before using to build the wall Installing the scaffoldings if necessarry, the scaffolding is 0.1-0.2m apart from the wall Drilling hole and embed dowel at the connection between brick wall and R.C structure by Epoxy, Dowel is plain round rebar with 6mm diameter @ 0.6m, Dowel is 360mm long with the length 300mm in the brick wall and 60mm remaining in concrete structure (column, pier or core wall) as the sketches for typical detail of brick wall attached Cleaning and then plastering cement slurry as bonding agent on the surface between brick wall and concrete structure to increase adhesive and moistureproofing future Well-mixed mortar with flowability 165-195mm to be carried to the working areas and stored in mortar tray; mortar mixed with water over hour must not be applicable Proceeding brick works from bottom to top, main wall first, secondary wall later, external wall first, internal wall later Maximum height of each building stage is 1.5m Method of brick works and plastering works COFICO Checking at least times the flatness, straightness, and angle of wall within each height of 0.50.6m, correcting if leaning detected Bonding of brick walls 100mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm shown in the attached drawings of typical detail for brick wall Where the wall contacts the soffit of beam, the top course brick must be placed slanted and filled mortar to void in order to prevent cracks caused by concrete shrinkage Get touch to top And bottom surface Beam/slab bottom surface Top of wall to be placed and get fill settlement Installing rebar and formwoks and then concrete for lintel on top of door and window openings with the both ends embedded 300mm into brick wall Installing door frame (if available) Installing rebar and formworks for vertical stiffener and horizontal beam and then concreting Method of brick works and plastering works COFICO For brick wall 100mm, 200mm with span >3m, 4m, there should be vertical stiffener, distance between vertical stiffeners is 3-4m Detail of vertical stiffeners as shown in construction drawing S-003 For brick wall 100mm, 200mm with height >3,5m, 4m there should be horizontal beam, distance between horizontal is 3.5m, 4m Detail of horizontal beam as shown in construction drawing S-003 When finished, soft broom should be used for cleaning Covering carefully or installing barricade to stop any movement can affect to fresh-built brick wall For curing after finished, using water to keep the wall damp in day Internal checking and correcting defects (if any) Request AIC engineer to check and accept 8- Sequence of plastering works: days after brick works finished, and after AIC’s engineer approved the wall as well as installation of embeded system (electrical, communication, phone cable, internet, water supply, waste water…) then the plastering works can start Cleaning dirt (if any) on the plastering surface, filling all the gaps with mortar and then flattening smoothening, applying cement slurry to increase adhesive feature for the concrete Making the plastering surface damp Installing the scaffoldings, working platform (if any) Fixing datum point made by broken brick with mortar, datum point has the square shape 50x50mm and the thickness is equal to the thickness of plastering layer Fixing the datum points at the top and wall end first, and then the points in the middle later, plumbing from the upper points to fix the middle and lower points, Distance between these datum points is around 1.5-1.8m Brickwall Plumb line Datum point Slab level Method of brick works and plastering works 10 COFICO Fixing trellis with the stitch 10x10 mm to cover the joint between brickwall and concrete structure, each side 125mm Mixing mortar with the flowability 175-205 mm then carry to working area and stored in the tray Plastering from top down to bottom; plastering the ceiling, beam and wall first then column later with 5-8mm thickness for each plastering coat Firstly rendering mortar on the surface, waiting until the mortar layer becomes dry then rendering the finish coat, lastly using ruler and hand float to make the surface flat and smooth In case the plastering layer is too thick then we can separate it into some coats, each coat is about 5-8 cm and after finishing the first coat, the surface must be roughened to increase adhesive ability for the next coat, if the surface is too dry it must be watered before rendering the next coat 24 hours after finishing, start curing by watering or keeping it damp in day Internal checking and correcting defects (if any) Request AIC engineer to check and accept 9- Quality control: All materials come to the site should be checked by eye and have material delivery inspection Periodically, samples should be taken to testing at laboratory with the witness of AIC engineer Quality of brick works and plastering works should be checked and inspected as specification and approved drawings 10- Safety and environment conservation: Everybody on site should be well- equipped with safety devices: helmet, shoes, clothes, safety glass and gloves (if necessary) Further, safety belt should be equipped when working at high level Every workers should conform to safety measures when building wall, especially when working on scaffoldings, working at high level there must be safety corridor; working with external wall there must be safety mesh to prevent falling objects Cleaning mortar dropped on floor at the end of working time Absolutely conform to site regulations for safety and environment conservation.further, safety officials and staffs regularly check and popularize regulations for safety and environment conservation to everybody 11- Inspection and acceptance: Document for appoval: Material Delivery Inspection Form (attached in appendix1) Minutes of check and inspection (attached in appendix1) Appendix1: Document for approval Appendix 2: Drawings for typical details of brick wall Appendix 3: Site organization chart Appendix 4: Site plan Method of brick works and plastering works 11