1 General Provisions
1.0.1 This standard is formulated in order to strengthen concrete quality control, promote concrete technical progress and ensure concrete work quality.
1.0.2 This standard is applicable to normal concrete quality control of construction engineering.
1.0.3 In addition to meeting the requirements of this standard, the concrete quality control shall also meet the requirements of the relevant national current standards.
2 Raw Material Quality Control
2.1 Cement
2.1.1 The selection of cement variety and strength grade shall be determined according to design, construction requirements and project environment. As for normal concrete for general building structure and precast member, common portland cement should be adopted; high strength concrete and the concrete with freezing resistance requirements should adopt portland cement or ordinary portland cement; as for concrete work with requirements for preventing concrete alkali-aggregate reaction should adopt the cement with alkali content less than 0.6%; mass concrete should adopt medium and low heat portland cement or low heat portland slag cement. The cement shall meet the relevant requirements of the current national standard "Common Portland Cement" GB 175 and "Moderate Heat Portland Cement-Low Heat Portland Cement-Low Heat Portland Slag Cement" GB 200.
2.1.2 Main control items for cement quality shall include setting time, stability, mortar strength, magnesium oxide and chloride ion content; the main control items for the cement with alkali content less than 0.6% shall also include alkali content; the main control items of medium and low heat portland cement or low heat portland slag cement shall also include hydration heat.
2.1.3 The application of cement shall meet the following requirements:
1 The cement produced by new dry process kiln should be adopted.
2 The variety and the mixing amount of composite materials in cement shall be indicated.
3 The temperature of the cement used for producing concrete should not exceed 60℃.
2.2 Coarse Aggregate
2.2.1 The coarse aggregate shall meet the requirements of the current professional standard "Standard for Technical Requirements and Test Method of Sand and Crushed Stone (or Gravel) for Ordinary Concrete" JGJ 52.
2.2.2 Main control items for coarse aggregate quality shall include grain composition, elongated flaky particle content, silt content, clod content, crushing strength index and solidity; the main control items of coarse aggregate used for high strength concrete shall also include compressive strength of rock.
2.2.3 The application aspect of coarse aggregate shall meet the following requirements:
1 The concrete coarse aggregate should adopt continuous gradation.
2 As for concrete structure, the maximum nominal grain size of coarse aggregate shall not be larger than 1/4 of minimum size of member section and shall not be larger than 3/4 of minimum clear spacing of steel bar; for concrete solid plate, the maximum nominal grain size of aggregate should not be larger than 1/3 of plate thickness and shall not be larger than 40mm; for mass concrete, the maximum nominal grain size of coarse aggregate should not be less than 31.5mm.
3 As for concrete with penetration resistance, freezing resistance, corrosion resistance, wear resistance requirements or other special requirements, the silt content and the clod content in coarse aggregate shall not be larger than 1.0% and 0.5% respectively; the mass loss of solidity inspection shall not be larger than 8%.
4 As for high strength concrete, the compressive strength of rock of coarse aggregate shall at least be higher 30% than concrete design strength; the maximum nominal grain size should not be larger than 25mm and the elongated flaky particle content should not be larger than 5% and shall not be larger than 8%; the silt content and clod content shall not be larger than 0.5% and 0.2% respectively.
5 As for coarse aggregate or rock used for producing coarse aggregate, the alkali activity inspection shall be carried out, including alkali-silicic acid reactivity inspection and alkali-carbonate reactivity inspection; for concrete work with the requirements for preventing concrete alkali-aggregate reaction, the coarse aggregate with alkali activity should not be adopted.
Contents
1 General Provisions
2 Raw Material Quality Control
2.1 Cement
2.2 Coarse Aggregate
2.3 Fine Aggregate
2.4 Mineral Additives
2.5 Admixtures
2.6 Water
3 Concrete Performance Requirements
3.1 Mixture Performance
3.2 Mechanical Property
3.3 Long Term Performance and Durability
4 Mix Proportion Control
5 Production Control Level
6 Production and Construction Quality Control
6.1 General Requirements
6.2 Raw Material Approaching the Construction Site
6.3 Measurement
6.4 Mixing
6.5 Transport
6.6 Shaping by Pouring
6.7 Curing
7 Concrete Quality Inspection
7.1 Quality Inspection of Raw Concrete Materials
7.2 Concrete Mixture Performance Inspection
7.3 Hardened Concrete Performance Inspection
Appendix A Slump Loss Test Method
