GB/T 50082-2024 Standard for test methods of long-term performance and durability of concrete
1 General provisions
1.0.1 This standard is formulated with a view to standardizing and unifying the test methods for long-term performance and durability of concrete, and to improving the technical level of concrete tests and inspections.
1.0.2 This standard is applicable to tests of long-term performance and durability of concrete in construction projects.
1.0.3 In addition to this standard, the tests of long-term performance and durability of concrete shall also meet those stipulated in the current relevant standards of China.
2 Terms and symbols
2.1 Terms
2.1.1
resistance grade to freezing-thawing of concrete
resistance class to freezing-thawing of concrete classified based on the number of maximum freeze-thaw cycles measured with the slow freezing method
2.1.2
resistance class to freezing-thawing of concrete
resistance class to freezing-thawing of concrete classified based on the number of maximum freeze-thaw cycles measured with the rapid freezing method
2.1.3
test method for coulomb electric flux
test method for measuring the coulomb electric flux through concrete specimens to reflect the resistance of concrete to chloride penetration
2.1.4
test method for rapid chloride ions migration coefficient (RCM)
test method for reflecting the resistance of concrete to chloride penetration by measuring the depth of chloride penetration in concrete and calculating the chloride ions migration coefficient. It is referred to as the RCM for short
2.1.5
resistance class to sulphate of concrete
resistance class of concrete to sulfate attack divided by the maximum number of wet-dry cycles measured with test method for resistance to sulfate attack
2.2 Symbols
c——Total cracking area per unit area of concrete specimen;
Ct——Creep of concrete during the loading period t;
d——Carbonation depth of concrete;
DRCM——Unsteady chloride ions migration coefficient of concrete;
Ed——Dynamic elastic modulus of concrete;
kp——Gas permeability of concrete;
Kf——Corrosion resistance coefficient of compressive strength of concrete;
Lw——Weight-loss ratio of corroded steel bars;
P——resistance class to permeability of concrete;
Q——Coulomb electric flux of concrete;
εct——Creep strain of concrete during the loading period t;
εst——Shrinkage ratio of concrete during the test period t;
εsst——Autogenous shrinkage ratio of concrete during the test period t;
φt——Creep coefficient of concrete during the loading period t.
3 Basic requirements
3.1 Sampling
3.1.1 The sampling of concrete shall meet the relevant requirements of the current national standard of China GB/T 50080 Standard for test method of performance on ordinary fresh concrete.
3.1.2 The mixture used for each group of specimens shall be sampled from the concrete of the same tray or the same truck.
3.1.3 The test instruments and equipment shall have a certificate of metrological verification or calibration within the validity period.
3.2 Fabrication and curing of specimen
3.2.1 The fabrication and curing of specimen shall meet the requirements of the current national standard of China GB/T 50081 Standard for test methods of concrete physical and mechanical properties.
3.2.2 The specimen shall be made using the test mould that meets the requirements of the current professional standard of China JG/T 237 Mould for concrete specimens; the test mould shall be accurately installed in case of preparing the specimen, and it shall be ensured that the dimensional tolerance of the specimen meets the requirements of 3.3 in this standard.
3.2.3 In case of preparing the specimen for tests of long-term performance and durability of concrete, the specimen for test of compressive strength of concrete cubes corresponding to the corresponding durability test age shall be fabricated at the same time.
3.2.4 In case of preparing the specimen for tests of long-term performance and durability of concrete, the shaking table and mixer used shall meet the requirements of the current professional standards of China JG/T 245 Vibrating table for concrete test and JG/T 244 Mixers for concrete test respectively.
3.3 Test report
3.3.1 The content provided by the unit commissioned shall include the following items:
1 Name of the unit commissioned and the witness unit;
2 Project name and construction position;
3 Name of items required to be inspected;
4 Other contents needed to be explained.
3.3.2 The content provided by the specimen fabrication unit shall include the following items:
1 Specimen No.;
2 Specimen fabrication date;
3 Concrete strength grade;
4 Shape and dimensions of the specimen;
5 The variety, specification and place of origin of the raw materials and the mix ratio of concrete;
6 Curing conditions;
7 Test age;
8 Other contents needed to be explained.
3.3.3 The contents provided by the test or inspection unit shall include the following items:
1 Receipt date of the specimen;
2 Shape and dimensions of the specimen;
3 Test No.;
4 Test date;
5 The name, model and number of the instruments and equipment;
6 Test room temperature (humidity);
7 Curing conditions and test age;
8 Actual concrete strength;
9 Test results;
10 Other contents needed to be explained.
Contents 1 General provisions 2 Terms and symbols 2.1 Terms 2.2 Symbols 3 Basic requirements 3.1 Sampling 3.2 Fabrication and curing of specimen 3.3 Test report 4 Test methods for resistance of concrete to freezing and thawing 4.1 Slow freezing method 4.2 Rapid freezing method 4.3 Single-side freezing and thawing method (salt freezing method) 5 Test method for dynamic modulus of elasticity 6 Test methods for resistance of concrete to water penetration 6.1 Test method for depth of water penetration 6.2 Test method for gradual pressure loading 7 Test methods for resistance of concrete to chloride penetration 7.1 Test method for rapid chloride ions migration (RCM) 7.2 Test method for coulomb electric flux 8 Test method for shrinkage of concrete 8.1 Non-contact method 8.2 Contact method 8.3 Corrugated tubes method 9 Test method for early cracking of concrete 10 Test method for creep of concrete in compression 11 Test method for carbonization of concrete 12 Test method for corrosion of embedded steel reinforcement in concrete 13 Test method for fatigue deformation of concrete in compression 14 Test method for resistance of concrete to sulphate attack 15 Test method for alkali-aggregate reaction 16 Test method for gas permeability of concrete Explanation of wording in this standard List of quoted standards Addition: Explanation of provisions
