QUALITY STANDARDS FOR STRUCTURAL WORKS

 Part 1 : Reinforced Concrete Structures Item* Standards 1 1a 1b 1c Formwork Formwork dimensions and openings for services Alignment, plumb and level Condition of formwork, props & bracing 1) Tolerance for cross-sectional dimensions of cast in-situ & precast elements: +10mm / -5mm 2) Tolerance for penetration / opening for services: +10mm for size and ±25mm for location 3) Tolerance for length of precast members (major dimension of unit): • Up to 3m: ±6mm • 3m to 4.5m: ±9mm • 4.5m to 6m: ±12mm • Additional deviation for every subsequent 6m: ±6mm 1) Tolerance for departure of any point from its position: 10mm 2) Tolerance for plumb: 3mm / m, maximum 20mm 3) Maximum deviation of mean level of staircase thread to temporary bench mark: ±5mm 4) For cast in-situ elements, the deviation of level of any point from the intended level: ±10mm 1) Formwork must be free from defects 2) Before concreting, the interior must be free from debris 3) All formwork joints must not have gaps to prevent leakage 4) There must be adequate support, bracing and tie-back for the formwork to prevent bulging or displacement of structural elements 2 2a Reinforcement (cast in-situ & Precast) Main & Secondary rebars 1) According to structural drawings (numbers / sizes) 2) Spacing of bars not more than that specified Effective date: 1st Jan 2005 Item* Standards 2b 2c 2d 2e Anchorages & lap lengths Cover provision Links, stirrups and trimming bars Rebar Condition 1) Required lap length not less than that specified 1) According to specifications with tolerance of +5mm 1) According to structural drawings (numbers / sizes) 2) Spacing of links not more than specified 1) Rebars must be securely and properly tied in place 2) Rebars must be freed from concrete dropping, corrosion etc 3 3a Finished Concrete (cast in-situ & Precast) Dimension for elements / opening for services 1) Tolerance for cross-sectional dimension of cast in-situ and precast elements: +10mm / -5mm 2) Tolerance for opening: +10 for size and ±25mm for location 3) Tolerance for length of precast members (major dimension of unit): • Up to 3m: ±6mm • 3m to 4.5m: ±9mm • 4.5m to 6m: ±12mm • Additional deviation for every subsequent 6m: ±6mm 4) Straightness or bow (deviation from intended line) of precast member: • Up to 3m: 6mm • 3m to 6m: 9mm • 4.5m to 6m: 12mm • Additional deviation for every subsequent 6m: 6mm 5) Squareness of precast member – Difference between the greatest and shortest dimensions should not exceed the following: Length of shorter sides • Up to and including 1.2m: 6mm • Over 1.2m but less than 1.8m: 9mm • 1.8m and over: 12mm