Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
According to the requirements of Notice on Printing (JIANBIAO [2013] No.6) of the Ministry of Housing and Urban-Rural Development, the standard drafting group revised this standard via extensive investigation, careful summarization of practical experience, reference to relevant international and foreign advanced standards, and widely soliciting for opinions.
Main technical contents of this standard: 1. General Provisions; 2. Terms and Symbols; 3. Basic Requirements; 4. Tests of Slump and Slump Loses through Time; 5. Test of Slump-flow and Slump-flow Loses through Time; 6. Test of Vebe Consistometer; 7. Test of Flow Time of Mixture from the Inverted Slump Cone; 8. Test of Passing Ability; 9. Test of Funnel; 10. Test of Slump-flow Time; 11. Test of Setting Time; 12. Test of Bleeding; 13. Test of Pressure Bleeding; 14. Test of Apparent Density; 15. Test of Air Content; 16. Test of Uniformity; 17. Test of Anti-segregating; 18. Test of Temperature; 19. Test of Adiabatic Temperature Rise.
Main technical contents revised in this standard: 1. This standard is coordinated with relevant standards issued after 2002; 2. "Terms and Symbols" is added; 3. "Basic Requirements" is added as a chapter and mixture sampling, specimen preparation, test record, test report and the like are included in this chapter; 4. Methods for test of slump loses through time and slump-flow loses through time are added; 5. Method for test of slump is revised and perfected; 6. Method for test of slump-flow is revised and perfected; 7. Test of flow time of mixture from the inverted slump cone is added; 8. Method for test of passing ability is added; 9. Method for test of funnel is added; 10. Method for test of slump-flow time is added; 11. Method for test of pressure bleeding is revised and perfected; 12. Method for analysis test of mix ratio in the former standard is deleted; 13. Method for test of apparent density is revised and perfected; 14. Method for test of air content is revised and perfected; 15. Method for test of uniformity is added; 16. Method for test of anti-segregating is added; 17. Method for test of temperature is added; 18. Method for test of adiabatic temperature rise is added.
The Ministry of Housing and Urban-Rural Development is in charge of the administration of this standard while China Academy of Building Research is responsible for the explanation of specific technical contents. During the process of implementing this standard, the relevant opinions and advice, whenever necessary, can be sent to China Academy of Building Research (Address: No.30 North 3rd Ring East Road, Beijing, 100013).
Contents
Foreword i
1 General Provisions 1
2 Terms and Symbols 1
2.1 Terms 1
2.2 Symbols 2
3 Basic Requirements 4
3.1 General Requirements 4
3.2 Sampling and Preparation of Specimen 4
4 Test of Slump and Slump Loses through Time 6
4.1 Test of Slump 6
4.2 Test of Slump Loses through Time 7
5 Test of Slump-flow and Slump-flow Loses through Time 8
5.1 Test of Slump-flow 8
5.2 Test of Slump-flow Loses through Time 9
6 Test of Vebe Consistometer 9
7 Test of Flow Time of Mixture from the Inverted Slump Cone 10
8 Test of Passing Ability 12
9 Test of Funnel 14
10 Test of Slump-flow Time 15
11 Test of Setting Time 16
12 Test of Bleeding 19
13 Test of Pressure Bleeding 22
14 Test of Apparent Density 24
15 Test of Air Content 26
16 Test of Uniformity 30
16.1 Mortar Density Method 30
16.2 Concrete Consistency Method 32
17 Test of Anti-segregating 34
18 Test of Temperature 35
19 Test of Adiabatic Temperature Rise 37
Annex A Test of Compacting Factor 40
Explanation of Wording in This Standard 44
List of Quoted Standards 45
1 General Provisions
1.0.1 This standard is formulated with a view to specifying and unifying the test method of performance on ordinary fresh concrete, enhancing the level of testing technique, ensuring the performance on fresh concrete, and meeting the quality requirement for precast concrete member and cast-in-place concrete work.
1.0.2 This standard is applicable to the test of performance on ordinary fresh concrete.
1.0.3 Test of performance on ordinary fresh concrete shall not only comply with the provisions of this standard, but also those specified in the relevant current ones of the nation.
2 Terms and Symbols
2.1 Terms
2.1.1 ordinary concrete
concrete with dry apparent density of 2,000kg/m3~2,800kg/m3
2.1.2 slump
the slumped height of fresh concrete under the action of deadweight
2.1.3 slump-flow
the extended diameter of fresh concrete after slumping
2.1.4 passing ability
the performance of fresh concrete in uniformly passing through gap
2.1.5 J-Ring
annular instrument used for determining the passing ability of fresh concrete
2.1.6 self-compacting concrete
the concrete with high fluidity, uniformity and stability and capable of flowing and filling the space of formwork under the action of deadweight without tamping by external force during pouring
2.1.7 slump-flow time
the time required for fresh concrete to expand to the diameter of 500mm after slumping
2.1.8 bleeding
the phenomenon of fresh concrete in bleeding moisture content
2.1.9 pressure bleeding
the bleeding phenomenon of fresh concrete under pressure effect
2.1.10 consistency
index characterizing the flowability of fresh concrete, which can be represented by slump, Vebe consistency or slump-flow
2.1.11 segregation resistance
performance of all kinds of components in the fresh concrete for maintaining homogeneous dispersion
2.1.12 adiabatic temperature rise
temperature rise of concrete caused by hydration of cementing material under adiabatic condition
2.2 Symbols
2.2.1 Slump
Ho——the initial slump value of fresh concrete when it comes out from mixer;
H60——the slump value of fresh concrete after standing for 60min.
2.2.2 Slump-flow
L0——the initial slump-flow value of fresh concrete when it comes out from mixer;
L60——the slump-flow value of fresh concrete after standing for 60min.
2.2.3 Flow time
tsf,m——the average value of the flow time of fresh concrete from the inverted slump cone measured in two tests;
tsf1,tsf2——the flow time of fresh concrete from the inverted slump cone measured in two tests respectively.
2.2.4 Bleeding amount
Ba——the bleeding amount of fresh concrete in unit area;
V10——the bleeding amount when pressurizing for 10s;
V140——the bleeding amount when pressurizing for 140s.
2.2.5 Bleeding rate
B——the bleeding rate;
BV——the pressure bleeding rate.
2.2.6 Air content
A——the air content of fresh concrete;
A0——the air content of uncorrected fresh concrete;
Ag——the air content of aggregate.
2.2.7 Density
ρ——the apparent density of fresh concrete;
ρw——the water density;
ρm——the apparent density of concrete mortar mixture;
ρmax——the larger apparent density of concrete mortar mixture sampled from that first and last coming out of the mixer;
Δρm——the difference of apparent densities of concrete mortar mixture sampled from that first and last coming out of the mixer.
2.2.8 Others
DRρ——the deviation rate of concrete mortar density;
SR——the separation rate of fresh concrete;
fPR——the penetration resistance in unit area;
α——the correction coefficient of adiabatic temperature rise for test equipment;
θn——the adiabatic temperature rise value of concrete of n days in age;
θ′n——the temperature rise value of concrete of n days in age recorded by instrument;
θ0——the initial temperature of fresh concrete.
3 Basic Requirements
3.1 General Requirements
3.1.1 The maximum nominal particle size of aggregate shall meet the relevant requirements of the current professional standard JGJ 52 Standard for Technical Requirements and Test Method of Sand and Crushed Stone (or Gravel) for Ordinary Concrete.
3.1.2 Relative humidity of test environment should not be less than 50% and the temperature shall be maintained at 20℃±5℃; the temperature of adopted material, test equipment, container and auxiliary equipment should keep consistent with the test room temperature.
3.1.3 If the test is carried out on site, concrete specimen shall be free from the influence of wind, rain, snow and direct sunlight.
3.1.4 When specimen is prepared for fresh concrete performance test, the adopted mixer shall meet the requirements of the current professional standard JG 244 Mixers for Concrete Test.
3.1.5 The test equipment shall be calibrated prior to use.
3.2 Sampling and Preparation of Specimen
3.2.1 As for the sampling of fresh concrete of the same group, samples shall be taken from the concrete on the same pan or same vehicle. The sampling amount shall be more than 1.5 times of the required amount, and should not be less than 20L.
3.2.2 Representative samples of fresh concrete shall be taken by the method of sampling for many times. Samples should be taken at 1/4, 1/2 and 3/4 of concrete on the same pan or same vehicle respectively, and mixed uniformly; the time interval between the first sampling and the last sampling should not exceed 15min.
3.2.3 Performance test should be carried out within 5min after sampling.
3.2.4 The mixing of the fresh concrete prepared in test room shall meet the following requirements:
1 Mixer shall be adopted for mixing the fresh concrete. Prior to mix, the mixer is washed out, a small amount of the same fresh concrete or mortar of same water-binder ratio is premixed, and the residual material shall be unloaded after back mortaring;
2 The weighted coarse aggregate, cementing material, fine aggregate and water shall be put into mixer successively; indissolvable and insoluble powdery admixture should be put into mixer together with cementing material; liquid and soluble admixture should be put into mixer together with mixing water;
3 Fresh concrete should be mixed for more than 2min until it becomes uniform;
4 The amount of fresh concrete in one mixing should not be less than 1/4 of the nominal capacity of mixer, shall not be greater than the nominal capacity of mixer and shall not be less than 20L.
3.2.5 When mixing concrete in test room, the material consumption shall be counted by mass. Weighing accuracy of aggregate shall be ±0.5%; the weighing accuracy of cement, additive, water and admixture shall be ±0.2%.
3.2.6 When sampling, the following contents shall be recorded or written in the test or inspection report:
1 Sampling date, time and person;
2 Project name and structure position;
3 Concrete watering time and mixing time;
4 Concrete mark;
5 Sampling method;
6 Specimen number;
7 Specimen quantity;
8 Environment temperature and weather condition during sampling.
9 Temperature of sampled concrete.
3.2.7 When preparing fresh concrete in test room, besides the contents required in 3.2.6, the following contents shall be recorded and written in test or test report;
1 Test environment temperature;
2 Test environment humidity;
3 Variety, specification, origin of production and performance index of all kinds of raw materials;
4 Concrete mix ratio and material consumption of concrete in each pan.
4 Test of Slump and Slump Loses through Time
4.1 Test of Slump
4.1.1 This test method should be used to determine the slump of the fresh concrete with maximum nominal particle size of aggregate not greater than 40mm and the slump not less than 10mm.
4.1.2 The equipment for test of slump shall meet the following requirements:
1 Apparatus for concrete slump test shall meet the requirements of the current professional standard JG/T 248 Apparatus for Concrete Slump Test;
2 Two steel rulers shall be equipped and the measuring range of steel ruler shall not be less than 300mm, and the division value shall not be larger than 1mm.
3 Steel plates with plane size not less than 1,500mm×1,500mm, thickness not less than 3mm and maximum deflection not greater than 3mm shall be adopted as bottom plates.
4.1.3 The test of slump shall be carried out according to the following procedures:
1 The inner wall and bottom plate of slump cone shall be moist and without visible water. Put the bottom plate on solid horizontal plane and put the slump cone at the center of the bottom plate, then stamp on the pedals of both sides; keep the slump cone at the same position when feeding;
2 Fresh concrete specimen shall be put into slump cone uniformly by three layers; after each layer of fresh concrete is put, it shall be tamped with tamping rod for 25 times uniformly from edge to center in spiral shape; after tamping, the height of each layer of fresh concrete specimen shall be 1/3 of the height of cone.
3 When the bottom layer is tamped, the tamping rod shall run through the whole depth, when the second layer and the top layer are tamped, the tamping rod shall run through this layer to the surface of next layer;
4 The fresh concrete at top layer shall be higher than the opening of cone, in the process of tamping, if the fresh concrete is lower than the opening, fresh concrete shall be added at any time.
5 After tamping the top layer, take down the feed hopper, scrape off the excessive fresh concrete and trowell the fresh concrete along the opening.
6 After removing the concrete on the bottom plate of cone side, the slump cone shall be lifted vertically and steadily and put near the specimen carefully; when the specimen stops slumping or the slump time is up to 30s, the difference between cone height and the highest point of slumping concrete specimen shall be measured with steel ruler to serve as the slump value of fresh concrete.
4.1.4 The lifting process of slump cone should be controlled in 3s~7s; the whole process from feeding to lifting slump cone shall be carried out continuously and shall be completed within 150s.
4.1.5 After lifting the slump cone, if collapse or shear failure occurs at one side of concrete, sample shall be retaken for determination; if collapse or shear failure occurs again at one side of concrete in the second test, it shall be recorded and described.
4.1.6 The measurement of slump value of fresh concrete shall be to the nearest 1mm and the result shall be rounded off to 5mm.
4.2 Test of Slump Loses through Time
4.2.1 This test method may be used to determine the variant of slump of fresh concrete along with the standing time.
4.2.2 The equipment for test of slump loses through time shall meet the requirements in 4.1.2.
4.2.3 The test of slump loses through time shall be conducted according to the following procedures:
1 The initial slump value H0 of fresh concrete flowing out from the mixer shall be measured;
2 Put all the fresh concrete specimen in plastic drum or metal drum not corroded by cement paste, and seal with drum cover or plastic film and keep it still.
3 Start timing from adding water in mixing, keep it still for 60min and pour all the fresh concrete specimen in drum into mixer and mix for 20s, then subject it to slump test to obtain the slump value H60 in at 60min.
4 Calculate the difference between initial slump value and slump value at 60min to obtain the test result of concrete slump loses through time of 60min.
4.2.4 If the engineering requires to adjust the time for keeping still, the concrete slump loses through time shall be determined and calculated according to the actual time for keeping still.
Foreword i
1 General Provisions
2 Terms and Symbols
2.1 Terms
2.2 Symbols
3 Basic Requirements
3.1 General Requirements
3.2 Sampling and Preparation of Specimen
4 Test of Slump and Slump Loses through Time
4.1 Test of Slump
4.2 Test of Slump Loses through Time
5 Test of Slump-flow and Slump-flow Loses through Time
5.1 Test of Slump-flow
5.2 Test of Slump-flow Loses through Time
6 Test of Vebe Consistometer
7 Test of Flow Time of Mixture from the Inverted Slump Cone
8 Test of Passing Ability
9 Test of Funnel
10 Test of Slump-flow Time
11 Test of Setting Time
12 Test of Bleeding
13 Test of Pressure Bleeding
14 Test of Apparent Density
15 Test of Air Content
16 Test of Uniformity
16.1 Mortar Density Method
16.2 Concrete Consistency Method
17 Test of Anti-segregating
18 Test of Temperature
19 Test of Adiabatic Temperature Rise
Annex A Test of Compacting Factor
Explanation of Wording in This Standard
List of Quoted Standards
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
According to the requirements of Notice on Printing (JIANBIAO [2013] No.6) of the Ministry of Housing and Urban-Rural Development, the standard drafting group revised this standard via extensive investigation, careful summarization of practical experience, reference to relevant international and foreign advanced standards, and widely soliciting for opinions.
Main technical contents of this standard: 1. General Provisions; 2. Terms and Symbols; 3. Basic Requirements; 4. Tests of Slump and Slump Loses through Time; 5. Test of Slump-flow and Slump-flow Loses through Time; 6. Test of Vebe Consistometer; 7. Test of Flow Time of Mixture from the Inverted Slump Cone; 8. Test of Passing Ability; 9. Test of Funnel; 10. Test of Slump-flow Time; 11. Test of Setting Time; 12. Test of Bleeding; 13. Test of Pressure Bleeding; 14. Test of Apparent Density; 15. Test of Air Content; 16. Test of Uniformity; 17. Test of Anti-segregating; 18. Test of Temperature; 19. Test of Adiabatic Temperature Rise.
Main technical contents revised in this standard: 1. This standard is coordinated with relevant standards issued after 2002; 2. "Terms and Symbols" is added; 3. "Basic Requirements" is added as a chapter and mixture sampling, specimen preparation, test record, test report and the like are included in this chapter; 4. Methods for test of slump loses through time and slump-flow loses through time are added; 5. Method for test of slump is revised and perfected; 6. Method for test of slump-flow is revised and perfected; 7. Test of flow time of mixture from the inverted slump cone is added; 8. Method for test of passing ability is added; 9. Method for test of funnel is added; 10. Method for test of slump-flow time is added; 11. Method for test of pressure bleeding is revised and perfected; 12. Method for analysis test of mix ratio in the former standard is deleted; 13. Method for test of apparent density is revised and perfected; 14. Method for test of air content is revised and perfected; 15. Method for test of uniformity is added; 16. Method for test of anti-segregating is added; 17. Method for test of temperature is added; 18. Method for test of adiabatic temperature rise is added.
The Ministry of Housing and Urban-Rural Development is in charge of the administration of this standard while China Academy of Building Research is responsible for the explanation of specific technical contents. During the process of implementing this standard, the relevant opinions and advice, whenever necessary, can be sent to China Academy of Building Research (Address: No.30 North 3rd Ring East Road, Beijing, 100013).
Contents
Foreword i
1 General Provisions 1
2 Terms and Symbols 1
2.1 Terms 1
2.2 Symbols 2
3 Basic Requirements 4
3.1 General Requirements 4
3.2 Sampling and Preparation of Specimen 4
4 Test of Slump and Slump Loses through Time 6
4.1 Test of Slump 6
4.2 Test of Slump Loses through Time 7
5 Test of Slump-flow and Slump-flow Loses through Time 8
5.1 Test of Slump-flow 8
5.2 Test of Slump-flow Loses through Time 9
6 Test of Vebe Consistometer 9
7 Test of Flow Time of Mixture from the Inverted Slump Cone 10
8 Test of Passing Ability 12
9 Test of Funnel 14
10 Test of Slump-flow Time 15
11 Test of Setting Time 16
12 Test of Bleeding 19
13 Test of Pressure Bleeding 22
14 Test of Apparent Density 24
15 Test of Air Content 26
16 Test of Uniformity 30
16.1 Mortar Density Method 30
16.2 Concrete Consistency Method 32
17 Test of Anti-segregating 34
18 Test of Temperature 35
19 Test of Adiabatic Temperature Rise 37
Annex A Test of Compacting Factor 40
Explanation of Wording in This Standard 44
List of Quoted Standards 45
1 General Provisions
1.0.1 This standard is formulated with a view to specifying and unifying the test method of performance on ordinary fresh concrete, enhancing the level of testing technique, ensuring the performance on fresh concrete, and meeting the quality requirement for precast concrete member and cast-in-place concrete work.
1.0.2 This standard is applicable to the test of performance on ordinary fresh concrete.
1.0.3 Test of performance on ordinary fresh concrete shall not only comply with the provisions of this standard, but also those specified in the relevant current ones of the nation.
2 Terms and Symbols
2.1 Terms
2.1.1 ordinary concrete
concrete with dry apparent density of 2,000kg/m3~2,800kg/m3
2.1.2 slump
the slumped height of fresh concrete under the action of deadweight
2.1.3 slump-flow
the extended diameter of fresh concrete after slumping
2.1.4 passing ability
the performance of fresh concrete in uniformly passing through gap
2.1.5 J-Ring
annular instrument used for determining the passing ability of fresh concrete
2.1.6 self-compacting concrete
the concrete with high fluidity, uniformity and stability and capable of flowing and filling the space of formwork under the action of deadweight without tamping by external force during pouring
2.1.7 slump-flow time
the time required for fresh concrete to expand to the diameter of 500mm after slumping
2.1.8 bleeding
the phenomenon of fresh concrete in bleeding moisture content
2.1.9 pressure bleeding
the bleeding phenomenon of fresh concrete under pressure effect
2.1.10 consistency
index characterizing the flowability of fresh concrete, which can be represented by slump, Vebe consistency or slump-flow
2.1.11 segregation resistance
performance of all kinds of components in the fresh concrete for maintaining homogeneous dispersion
2.1.12 adiabatic temperature rise
temperature rise of concrete caused by hydration of cementing material under adiabatic condition
2.2 Symbols
2.2.1 Slump
Ho——the initial slump value of fresh concrete when it comes out from mixer;
H60——the slump value of fresh concrete after standing for 60min.
2.2.2 Slump-flow
L0——the initial slump-flow value of fresh concrete when it comes out from mixer;
L60——the slump-flow value of fresh concrete after standing for 60min.
2.2.3 Flow time
tsf,m——the average value of the flow time of fresh concrete from the inverted slump cone measured in two tests;
tsf1,tsf2——the flow time of fresh concrete from the inverted slump cone measured in two tests respectively.
2.2.4 Bleeding amount
Ba——the bleeding amount of fresh concrete in unit area;
V10——the bleeding amount when pressurizing for 10s;
V140——the bleeding amount when pressurizing for 140s.
2.2.5 Bleeding rate
B——the bleeding rate;
BV——the pressure bleeding rate.
2.2.6 Air content
A——the air content of fresh concrete;
A0——the air content of uncorrected fresh concrete;
Ag——the air content of aggregate.
2.2.7 Density
ρ——the apparent density of fresh concrete;
ρw——the water density;
ρm——the apparent density of concrete mortar mixture;
ρmax——the larger apparent density of concrete mortar mixture sampled from that first and last coming out of the mixer;
Δρm——the difference of apparent densities of concrete mortar mixture sampled from that first and last coming out of the mixer.
2.2.8 Others
DRρ——the deviation rate of concrete mortar density;
SR——the separation rate of fresh concrete;
fPR——the penetration resistance in unit area;
α——the correction coefficient of adiabatic temperature rise for test equipment;
θn——the adiabatic temperature rise value of concrete of n days in age;
θ′n——the temperature rise value of concrete of n days in age recorded by instrument;
θ0——the initial temperature of fresh concrete.
3 Basic Requirements
3.1 General Requirements
3.1.1 The maximum nominal particle size of aggregate shall meet the relevant requirements of the current professional standard JGJ 52 Standard for Technical Requirements and Test Method of Sand and Crushed Stone (or Gravel) for Ordinary Concrete.
3.1.2 Relative humidity of test environment should not be less than 50% and the temperature shall be maintained at 20℃±5℃; the temperature of adopted material, test equipment, container and auxiliary equipment should keep consistent with the test room temperature.
3.1.3 If the test is carried out on site, concrete specimen shall be free from the influence of wind, rain, snow and direct sunlight.
3.1.4 When specimen is prepared for fresh concrete performance test, the adopted mixer shall meet the requirements of the current professional standard JG 244 Mixers for Concrete Test.
3.1.5 The test equipment shall be calibrated prior to use.
3.2 Sampling and Preparation of Specimen
3.2.1 As for the sampling of fresh concrete of the same group, samples shall be taken from the concrete on the same pan or same vehicle. The sampling amount shall be more than 1.5 times of the required amount, and should not be less than 20L.
3.2.2 Representative samples of fresh concrete shall be taken by the method of sampling for many times. Samples should be taken at 1/4, 1/2 and 3/4 of concrete on the same pan or same vehicle respectively, and mixed uniformly; the time interval between the first sampling and the last sampling should not exceed 15min.
3.2.3 Performance test should be carried out within 5min after sampling.
3.2.4 The mixing of the fresh concrete prepared in test room shall meet the following requirements:
1 Mixer shall be adopted for mixing the fresh concrete. Prior to mix, the mixer is washed out, a small amount of the same fresh concrete or mortar of same water-binder ratio is premixed, and the residual material shall be unloaded after back mortaring;
2 The weighted coarse aggregate, cementing material, fine aggregate and water shall be put into mixer successively; indissolvable and insoluble powdery admixture should be put into mixer together with cementing material; liquid and soluble admixture should be put into mixer together with mixing water;
3 Fresh concrete should be mixed for more than 2min until it becomes uniform;
4 The amount of fresh concrete in one mixing should not be less than 1/4 of the nominal capacity of mixer, shall not be greater than the nominal capacity of mixer and shall not be less than 20L.
3.2.5 When mixing concrete in test room, the material consumption shall be counted by mass. Weighing accuracy of aggregate shall be ±0.5%; the weighing accuracy of cement, additive, water and admixture shall be ±0.2%.
3.2.6 When sampling, the following contents shall be recorded or written in the test or inspection report:
1 Sampling date, time and person;
2 Project name and structure position;
3 Concrete watering time and mixing time;
4 Concrete mark;
5 Sampling method;
6 Specimen number;
7 Specimen quantity;
8 Environment temperature and weather condition during sampling.
9 Temperature of sampled concrete.
3.2.7 When preparing fresh concrete in test room, besides the contents required in 3.2.6, the following contents shall be recorded and written in test or test report;
1 Test environment temperature;
2 Test environment humidity;
3 Variety, specification, origin of production and performance index of all kinds of raw materials;
4 Concrete mix ratio and material consumption of concrete in each pan.
4 Test of Slump and Slump Loses through Time
4.1 Test of Slump
4.1.1 This test method should be used to determine the slump of the fresh concrete with maximum nominal particle size of aggregate not greater than 40mm and the slump not less than 10mm.
4.1.2 The equipment for test of slump shall meet the following requirements:
1 Apparatus for concrete slump test shall meet the requirements of the current professional standard JG/T 248 Apparatus for Concrete Slump Test;
2 Two steel rulers shall be equipped and the measuring range of steel ruler shall not be less than 300mm, and the division value shall not be larger than 1mm.
3 Steel plates with plane size not less than 1,500mm×1,500mm, thickness not less than 3mm and maximum deflection not greater than 3mm shall be adopted as bottom plates.
4.1.3 The test of slump shall be carried out according to the following procedures:
1 The inner wall and bottom plate of slump cone shall be moist and without visible water. Put the bottom plate on solid horizontal plane and put the slump cone at the center of the bottom plate, then stamp on the pedals of both sides; keep the slump cone at the same position when feeding;
2 Fresh concrete specimen shall be put into slump cone uniformly by three layers; after each layer of fresh concrete is put, it shall be tamped with tamping rod for 25 times uniformly from edge to center in spiral shape; after tamping, the height of each layer of fresh concrete specimen shall be 1/3 of the height of cone.
3 When the bottom layer is tamped, the tamping rod shall run through the whole depth, when the second layer and the top layer are tamped, the tamping rod shall run through this layer to the surface of next layer;
4 The fresh concrete at top layer shall be higher than the opening of cone, in the process of tamping, if the fresh concrete is lower than the opening, fresh concrete shall be added at any time.
5 After tamping the top layer, take down the feed hopper, scrape off the excessive fresh concrete and trowell the fresh concrete along the opening.
6 After removing the concrete on the bottom plate of cone side, the slump cone shall be lifted vertically and steadily and put near the specimen carefully; when the specimen stops slumping or the slump time is up to 30s, the difference between cone height and the highest point of slumping concrete specimen shall be measured with steel ruler to serve as the slump value of fresh concrete.
4.1.4 The lifting process of slump cone should be controlled in 3s~7s; the whole process from feeding to lifting slump cone shall be carried out continuously and shall be completed within 150s.
4.1.5 After lifting the slump cone, if collapse or shear failure occurs at one side of concrete, sample shall be retaken for determination; if collapse or shear failure occurs again at one side of concrete in the second test, it shall be recorded and described.
4.1.6 The measurement of slump value of fresh concrete shall be to the nearest 1mm and the result shall be rounded off to 5mm.
4.2 Test of Slump Loses through Time
4.2.1 This test method may be used to determine the variant of slump of fresh concrete along with the standing time.
4.2.2 The equipment for test of slump loses through time shall meet the requirements in 4.1.2.
4.2.3 The test of slump loses through time shall be conducted according to the following procedures:
1 The initial slump value H0 of fresh concrete flowing out from the mixer shall be measured;
2 Put all the fresh concrete specimen in plastic drum or metal drum not corroded by cement paste, and seal with drum cover or plastic film and keep it still.
3 Start timing from adding water in mixing, keep it still for 60min and pour all the fresh concrete specimen in drum into mixer and mix for 20s, then subject it to slump test to obtain the slump value H60 in at 60min.
4 Calculate the difference between initial slump value and slump value at 60min to obtain the test result of concrete slump loses through time of 60min.
4.2.4 If the engineering requires to adjust the time for keeping still, the concrete slump loses through time shall be determined and calculated according to the actual time for keeping still.
Contents of GB/T 50080-2016
Foreword i
1 General Provisions
2 Terms and Symbols
2.1 Terms
2.2 Symbols
3 Basic Requirements
3.1 General Requirements
3.2 Sampling and Preparation of Specimen
4 Test of Slump and Slump Loses through Time
4.1 Test of Slump
4.2 Test of Slump Loses through Time
5 Test of Slump-flow and Slump-flow Loses through Time
5.1 Test of Slump-flow
5.2 Test of Slump-flow Loses through Time
6 Test of Vebe Consistometer
7 Test of Flow Time of Mixture from the Inverted Slump Cone
8 Test of Passing Ability
9 Test of Funnel
10 Test of Slump-flow Time
11 Test of Setting Time
12 Test of Bleeding
13 Test of Pressure Bleeding
14 Test of Apparent Density
15 Test of Air Content
16 Test of Uniformity
16.1 Mortar Density Method
16.2 Concrete Consistency Method
17 Test of Anti-segregating
18 Test of Temperature
19 Test of Adiabatic Temperature Rise
Annex A Test of Compacting Factor
Explanation of Wording in This Standard
List of Quoted Standards
