1 General provisions
1.0.1 This standard is formulated with a view to standardizing and unifying the test methods of concrete physical and mechanical properties, and improving the technical level of concrete test.
1.0.2 This standard is applicable to tests of concrete physical and mechanical properties in construction projects. This standard is not applicable to fully-graded concrete and roller-compacted concrete in water conservancy and hydropower projects.
1.0.3 In addition to this standard, the test methods of concrete physical and mechanical properties shall also comply with those stipulated in the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1 concrete
a kind of engineering material produced by mixing, forming, curing and other processes from the main raw materials such as cement, aggregate and water as well as the mineral admixtures and other admixtures as required according to a certain mix ratio, which has strength after hardening
2.1.2 compressive strength
the maximum pressure a cubic specimen can withstand per unit area
2.1.3 axial compressive strength
the maximum pressure a prismatic specimen can axially withstand per unit area
2.1.4 elastic modulus under static compressive stress
stress required for generation of unit deformation when a prismatic specimen or a cylinder specimen is subjected to a certain axial pressure
2.1.5 poisson's ratio
ratio of the absolute value of the transverse normal strain to that of the axial normal strain of the concrete specimen under axial compression
2.1.6 splitting tensile strength
approximately uniformly distributed ultimate tensile stress generated in the vertical plane under the action of pressure when the middle of the upper and lower surfaces of a cubic specimen or a cylinder specimen is subjected to splitting failure under uniformly distributed pressure
2.1.7 flexural tensile strength
ultimate tensile stress on the surface of concrete specimen when its small beam is subjected to fracture failure under the action of bending moment
2.1.8 axial tensile strength
the maximum tensile force that a concrete specimen can bear per unit area in the axial direction
2.1.9 bond strength
bond stress between new and old concrete materials measured by splitting tensile test
2.1.10 thermal diffusivity
a representation of the rate at which the temperature of each part tends to be consistent when the concrete material is heated or cooled
2.1.11 thermal conductivity
heat flow though concrete material per unit thickness and per unit area under a stable heat transfer state and the action of unit temperature difference
2.1.12 specific heat capacity
heat capacity of unit mass concrete, i.e., the heat absorbed or released by the unit mass concrete at the time of changing the unit temperature
2.1.13 linear expansion coefficient
elongation per unit length of concrete specimen when the concrete temperature rises by 1℃
2.1.14 apparent density
ratio of mass to apparent volume of a dried hardened concrete specimen, with the latter being the sum of the solid volume and the closed pore volume of hardened concrete
2.1.15 as-received density
ratio of mass to total volume of an as-received hardened concrete specimen, with the latter being the sum of solid volume, internal closed pore volume and open pore volume of concrete
2.1.16 water saturated density
ratio of surface dry mass to total volume of a water-saturated hardened concrete specimen, with the latter being the sum of solid volume, internal closed pore volume and open pore volume of concrete
2.1.17 oven-dried density
ratio of mass to total volume of an oven-dried hardened concrete specimen, with the latter being the sum of solid volume, internal closed pore volume and open pore volume of concrete
2.2 Symbols
a——the thermal diffusivity of concrete;
c——the specific heat capacity of concrete;
Ec——the elastic modulus of concrete under static compressive stress;
Et——the elastic tensile modulus of concrete;
fcc——the compressive strength of cubic concrete specimen;
fcp——the axial compressive strength of concrete;
fts——the splitting tensile strength of concrete;
ff——the flexural tensile strength of concrete;

1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements
3.1 General requirements
3.2 Cross-sectional dimensions of specimen
3.3 Dimensional measurement and tolerance of specimen
3.4 Test report
4 Preparation and curing of specimen
4.1 Instrument equipment
4.2 Sampling and preparation of specimen
4.3 Preparation of specimen
4.4 Curing of specimen
5 Test of compressive strength
6 Test of axial compressive strength
7 Test of elastic modulus under static compressive stress
8 Test of poisson's ratio
9 Test of splitting tensile strength
10 Test of flexural tensile strength
11 Test of axial tensile strength
12 Test of the bond strength between concrete and steel bars
13 Test of concrete bond strength
14 Test of abrasion resistance
14.1 Test of abrasion loss
14.2 Test of grinding pit length
15 Test of thermal diffusivity
16 Test of thermal conductivity
17 Test of specific heat capacity
18 Test of linear expansion coefficient
19 Test of density of hardened concrete
20 Test of water absorption
Annex A Sample forms of test or inspection report
Annex B Preparation of cylinder specimen
Annex C Test of compressive strength of cylinder specimen
Annex D Test of elastic modulus under static compressive stress of cylinder specimen
Annex E Test of splitting tensile strength of cylinder specimen
Annex F Table of relation between θ/θ0 value and at/D2 value
Explanation of wording in this standard

1 General provisions
1.0.1 This standard is formulated with a view to standardizing and unifying the test methods of concrete physical and mechanical properties, and improving the technical level of concrete test.
1.0.2 This standard is applicable to tests of concrete physical and mechanical properties in construction projects. This standard is not applicable to fully-graded concrete and roller-compacted concrete in water conservancy and hydropower projects.
1.0.3 In addition to this standard, the test methods of concrete physical and mechanical properties shall also comply with those stipulated in the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1 concrete
a kind of engineering material produced by mixing, forming, curing and other processes from the main raw materials such as cement, aggregate and water as well as the mineral admixtures and other admixtures as required according to a certain mix ratio, which has strength after hardening
2.1.2 compressive strength
the maximum pressure a cubic specimen can withstand per unit area
2.1.3 axial compressive strength
the maximum pressure a prismatic specimen can axially withstand per unit area
2.1.4 elastic modulus under static compressive stress
stress required for generation of unit deformation when a prismatic specimen or a cylinder specimen is subjected to a certain axial pressure
2.1.5 poisson's ratio
ratio of the absolute value of the transverse normal strain to that of the axial normal strain of the concrete specimen under axial compression
2.1.6 splitting tensile strength
approximately uniformly distributed ultimate tensile stress generated in the vertical plane under the action of pressure when the middle of the upper and lower surfaces of a cubic specimen or a cylinder specimen is subjected to splitting failure under uniformly distributed pressure
2.1.7 flexural tensile strength
ultimate tensile stress on the surface of concrete specimen when its small beam is subjected to fracture failure under the action of bending moment
2.1.8 axial tensile strength
the maximum tensile force that a concrete specimen can bear per unit area in the axial direction
2.1.9 bond strength
bond stress between new and old concrete materials measured by splitting tensile test
2.1.10 thermal diffusivity
a representation of the rate at which the temperature of each part tends to be consistent when the concrete material is heated or cooled
2.1.11 thermal conductivity
heat flow though concrete material per unit thickness and per unit area under a stable heat transfer state and the action of unit temperature difference
2.1.12 specific heat capacity
heat capacity of unit mass concrete, i.e., the heat absorbed or released by the unit mass concrete at the time of changing the unit temperature
2.1.13 linear expansion coefficient
elongation per unit length of concrete specimen when the concrete temperature rises by 1℃
2.1.14 apparent density
ratio of mass to apparent volume of a dried hardened concrete specimen, with the latter being the sum of the solid volume and the closed pore volume of hardened concrete
2.1.15 as-received density
ratio of mass to total volume of an as-received hardened concrete specimen, with the latter being the sum of solid volume, internal closed pore volume and open pore volume of concrete
2.1.16 water saturated density
ratio of surface dry mass to total volume of a water-saturated hardened concrete specimen, with the latter being the sum of solid volume, internal closed pore volume and open pore volume of concrete
2.1.17 oven-dried density
ratio of mass to total volume of an oven-dried hardened concrete specimen, with the latter being the sum of solid volume, internal closed pore volume and open pore volume of concrete
2.2 Symbols
a——the thermal diffusivity of concrete;
c——the specific heat capacity of concrete;
Ec——the elastic modulus of concrete under static compressive stress;
Et——the elastic tensile modulus of concrete;
fcc——the compressive strength of cubic concrete specimen;
fcp——the axial compressive strength of concrete;
fts——the splitting tensile strength of concrete;
ff——the flexural tensile strength of concrete;

Contents of GB/T 50081-2019

1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements
3.1 General requirements
3.2 Cross-sectional dimensions of specimen
3.3 Dimensional measurement and tolerance of specimen
3.4 Test report
4 Preparation and curing of specimen
4.1 Instrument equipment
4.2 Sampling and preparation of specimen
4.3 Preparation of specimen
4.4 Curing of specimen
5 Test of compressive strength
6 Test of axial compressive strength
7 Test of elastic modulus under static compressive stress
8 Test of poisson's ratio
9 Test of splitting tensile strength
10 Test of flexural tensile strength
11 Test of axial tensile strength
12 Test of the bond strength between concrete and steel bars
13 Test of concrete bond strength
14 Test of abrasion resistance
14.1 Test of abrasion loss
14.2 Test of grinding pit length
15 Test of thermal diffusivity
16 Test of thermal conductivity
17 Test of specific heat capacity
18 Test of linear expansion coefficient
19 Test of density of hardened concrete
20 Test of water absorption
Annex A Sample forms of test or inspection report
Annex B Preparation of cylinder specimen
Annex C Test of compressive strength of cylinder specimen
Annex D Test of elastic modulus under static compressive stress of cylinder specimen
Annex E Test of splitting tensile strength of cylinder specimen
Annex F Table of relation between θ/θ0 value and at/D2 value
Explanation of wording in this standard