【法规名称】
【法规编号】 79807 什么是编号？
【正 文】
第10页 CAP 123B BUILDING (CONSTRUCTION) REGULATIONS
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[接上页] (a) moderate exposure conditions, which are those conditions experienced by surfaces protected by adequate permanent finishes or otherwise sheltered from driving rain, surfaces of buried concrete in contact with the ground and concrete continuously under fresh water; or (b) severe exposure conditions, which are those conditions experienced by surfaces exposed to driving rain or alternate wetting and drying, surfaces subject to heavy condensation or corrosive fumes, and surfaces in contact with flowing aqueous solutions including sea-water. (Enacted 1990) Cap 123B reg 57 Designed mix concrete strengths (1) Designed mix concrete shall have the specified grade strength in accordance with Table 5 for the particular application of the concrete except for marine works or where the concrete is exposed to particularly corrosive conditions a higher grade strength than that specified may be required. TABLE 5 DESIGNED MIX CONCRETE GRADE STRENGTHS AND APPLICATIONS Application Lowest specified grade strength of concrete permissible Plain concrete except in carriageways 15D Reinforced concrete made with light weight aggregate (moderate exposure condition) Piles Bond courses in masonry retaining walls Footpaths 20D Reinforced concrete made with light weight aggregate (severe exposure condition) Reinforced concrete made with normal weight aggregate (moderate exposure condition) Carriageways 25D Liquid-retaining structures (moderate exposure condition) Reinforced concrete made with normal weight aggregate (severe exposure condition) Pre-stressed concrete with post-tensioned tendons (moderate exposure condition) 30D Pre-stressed concrete with post-tensioned tendons (severe exposure condition) Liquid-retaining structures (severe exposure condition) 35D Liquid-retaining structures (severe exposure condition) including those retaining salt water Pre-stressed concrete with pre-tensioned tendons (moderate exposure condition) 40D Pre-stressed concrete with post-tensioned tendons (severe exposure condition) 45D (2) The cement content of concrete shall be not less than the appropriate amount given in Table 6. TABLE 6 MINIMUM CEMENT CONTENT KG/M3 OF FINISHED CONCRETE MADE WITH NORMAL WEIGHT AGGREGATES 40 mm maximum aggregates 20 mm maximum aggregates 10 mm maximum aggregates Reinforced concrete 260 290 340 Pre-stressed concrete 300 300 360 (3) Concrete shall be tested in accordance with regulation 58 for compliance with the specified grade strength set out in regulation 59. (Enacted 1990) Cap 123B reg 58 Concrete cubes (1) The compressive strength of concrete shall be determined by testing standard 150 mm cubes 28 days after mixing. (2) A representative sample shall be taken from the fresh concrete to make test cubes and each sample shall be taken from a single batch. (3) The rate of sampling fresh concrete shall be at least that specified in Table 7 and at least one sample shall be taken from each grade of concrete produced on any one day. (4) From each sample of concrete taken 2 cubes shall be made by a suitable method. (5) Each concrete cube shall be given a number in serial sequence and no serial number shall be duplicated or omitted. (6) All cubes shall be adequately cured on site or in the laboratory until ready for testing. (7) 28 days after mixing, all cubes shall be tested for compressive strength by a recognized method and the average compressive strength of each pair of cubes made from the same sample shall be taken as the test result. TABLE 7 SAMPLING RATES Type or part of building, building works or street Quantity of concrete to be represented by each sample Masts, cantilevers more than 3 m in length, columns, shear walls, prestressed and other critical elements 10 m3 or 10 batches whichever is the smaller volumn Solid rafts, pile caps, caisson caps and mass concrete retaining walls 100 m3 or 100 batches whichever is the smaller volumn All other types or parts 25 m3 or 25 batches whichever is the smaller volumn (Enacted 1990) Cap 123B reg 59 Acceptance criteria (1) The specified grade strength for concrete shall be deemed to have been attained if the individual test results and the average results of all overlapping sets of 4 consecutive test results comply with the criteria specified in Table 8. (2) When there are more than 4 test results the average of each set of 4 consecutive test results shall be calculated and checked for compliance each time a new test result is produced, using that test result and the immediately preceding 3 test results. (3) Where there are only 2 or 3 test results available, those results shall be treated for the purposes of this regulation as if they were 4 consecutive test results. TABLE 8 COMPRESSIVE STRENGTH COMPLIANCE CRITERIA Column A Column B Specified grade strength Average of 4 consecutive test results shall exceed the specified grade strength by at least Any individual test result shall not be less than the specified grade strength minus |
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