Some standard content:
ICs13.300,11.100
National Standard of the People's Republic of China
GB/T27845—2011
Chemicals
Test method for particle-size analysis of soils2011-12-30Issued
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of ChinaStandardization Administration of the People's Republic of China
Implementation on August 1, 2012
This standard was drafted in accordance with the rules given in GB/T 1.1—2009. GB/T 27845--2011
This standard has the same technical content as the American Society for Testing and Materials Standard ASTM D 422-63:2007 Standard test method for particle-size analysis of soils3 (Standard test method ior particie-size analysis of svils) (English version). This standard has been revised as follows: "this standard" is used instead of "this test method"; the original ASTM standard foreword, keywords and other informative parts are deleted; all units are converted to the international system of units; the figures and tables with missing titles are supplemented with titles, and the figures, tables and formula numbers of the whole text are uniformly adjusted. This standard is proposed and submitted by the National Technical Committee for Standardization of Hazardous Chemicals Management (SAC/TC251). The drafting units of this standard are: China Inspection and Quarantine Scientific Research Institute, China Chemical Economic and Technological Development Center. Jiangsu Coal Chemical Engineering Design and Research Institute Co., Ltd., Sinochem Chemical Standardization Research Institute. The main drafters of this standard are: Li Xi, Chen Huiming, Wang Xiaobing, Yang Ting, Guo Xinyu. I
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1 Scope
Test method for particle size analysis of chemical soil fill
This standard specifies the quantitative test method for soil particle size distribution. GB/T 27845—2011
This standard applies to the quantitative determination of soil particle size analysis. The particle size distribution of particles larger than 75μm (retained on a 200-mesh sieve) is determined by sieving, and the particle size distribution of particles smaller than 75um is determined by the necessary data measured by a reduced density meter during the barrier process. Note 1: 4.75mm (4 mesh), 42%m (40 mesh) or 75±m (200 mesh) sieves can be used instead of 2.00mm (10 mesh) sieves for separation. Regardless of the sieve used, the report Both indicate the size of the pores. Note 2: There are two types of separation devices: one is a high-speed mechanical agitator, and the other is an air dispersion device. A large survey shows that for plastic soils with a soil fill particle size of less than 20um, the separation effect of the air dispersion device is better. For sandy soils, the use of the air dispersion device can slightly reduce the problem. The use of the air dispersion device has obvious advantages and is recommended. The results obtained using the two devices are very different. This is because the different types of soils lead to significant differences in particle size distribution, especially when the soil fill particle size is less than 20um. 2 Normative references
The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest version (including all amendments) applies to this document. ASTMD421 Practice for dry preparation of soil samples for particle size analysis and determination of soil eonstants? Specification for wire cloth and sieves for testing purposes: ASTMEIl
ASTME10o American Society for Testing and Materials Specification for bulk density meter (Specification or ASTMhydrorneters) 3 Receiver equipment
3.1 The material that can pass through a 2,00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm; the material retained on a 2.00 mm (10 mesh) sieve shall be weighed using a balance with a sensitivity of 0.01 μm The material on the sieve shall be weighed using a balance with a sensitivity of 0.1% of the mass of the sample to be weighed. 3.2 Stirring device
3.2.1 Either device A or device B may be used.
3.2.2 Device A shall contain a mechanically operated stirring device, equipped with a suitable motor to drive the vertical shaft, which can rotate at a speed of not less than 10 000 1/rain when unloaded. The vertical shaft shall be equipped with a replaceable stirring case made of metal, plastic or hard rubber. The stirring paddle of device A is shown in Figure 1.
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GB/T 27845—2011
Figure 1 Stirring paddle of device A
Unit: mm
The length of the shaft is such that the stirring paddle can operate at a distance of 19.0 mm to 38.1 mm from the bottom of the dispersion cup. A special dispersion cup of the type shown in Figure 2 is used to store the sample during the dispersion test. The unit is meter
Permanent
Diverter
Diameter 66
Diverter
Storage plane
Figure 2 Dispersion cup of device A
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Diameter 95.2
Removable
Divider
Radius 33
Huanggangting Seat
3.2.3 Device B should include a jet dispersion cup that meets the requirements of Figure 3. Handcart and
vent
3-foot rod
dirty seat,
annular air bag
trachea (5
barometer
one-air
cross-plane
the jet dispersion cup of device B in Figure 3
Note 1: The air volume required for the jet micro-dispersion cup reaches 57dm*/min (2ft*/min). GB/T 27845-2011
Non-handled vent
Air duct, air inlet
Air connection
Note 2: Another air type dispersion device is the dispersion tube, which is basically the same as the use of the jet dispersion cup. When using a dispersion tube, the sample is placed on the test plate to avoid the need for transfer filter. If an air dispersion tube is used, it should be stated in the report. Note 3: Moisture in the air tube may condense when not in use. Before using air for dispersion, check whether there is a water trap in the air tube or a way to reflect moisture out of the air tube. Remove moisture
3.3 Liquid density meter
The liquid density meter should ensure that the specific density of the suspension or the number of grams of suspended matter per liter of liquid can be read, and meet the requirements of ASTME100 for liquid density meter 151H or 152H. The two liquid density meters have the same dimension, only the scale is different. 3.4 Sedimentation tube
The glass flow sedimentation tube is 457mm high and 63.5mm in diameter, with a capacity of 1000mL. Its inner diameter is: 36cm ± 2cm from the bottom to the 1000mL mark.
3. 5 Thermometer
A thermometer with an accuracy of 0.5.
The sieves used in this standard are a series of sieves with square wire mesh that meet the requirements of ASIME11. A complete set of sieves should include the following types: 75m;
50mm;
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GB/T 27845—2011
4. 75 mm (4 days);
-2.00mm (10 days);
850μm (20 months)
425μm (40 months);
-250 μm (60 mesh)
106μm (140 days)
~75 μm (200 Note: If necessary, a set of sieves that can produce the uniform intervals between points on the graph required in 8.6 may be used. The following types are available: 75 mm:
-4. 75 mm (4 days)
2. 36 rm (8 months)
1.18 mm (16 days);
600 m (30 days);
: 300 μm (50 days),
150 μm (100 months)
75 μm (200 days).
3.7 Water bath or constant temperature chamber
During the liquid density analysis, a water bath or constant temperature chamber is used to keep the soil suspension at a constant temperature. The water bath that meets the requirements should be an insulated water bath that can keep the total suspension at a suitable temperature of 20°C or around 20°C. See Figure 4 for a schematic diagram of the device. When operating in an automatic temperature control cabinet, it is not necessary to use a water bath.
Unit is meter
Water inlet day
Huang Tongliang
By peak alcohol steel plate
22.2 Insulated water
50. Hot water
4 Insulated water bath
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Overflow
3.8 Beaker
Beaker with a capacity of 250 mL.
3. 9 Timing device
Watch or clock with a second hand.
4 Dispersant
4.1 Add 40% sodium hexametaphosphate (also known as sodium hexametaphosphate) per liter of distilled/softened water. GB/T 27845—2011
Note: If the salt solution becomes acidic, it will slowly recover or hydrolyze to orthophosphate, and the sensitization effect will be reduced accordingly. Prepare the solution frequently (at least once a month) or adjust the pH value to 8 or 9 with carbonic acid. The preparation date should be marked on the container containing the solution. 4.2 The test water should be distilled water or softened water. The temperature of the water used for liquid density test should reach the predetermined temperature. For example, if the settling tube is placed in a water bath, the temperature of the distilled/softened water used should be the same as the temperature of the temperature-controlled water bath; or, if the settling tube is used in a temperature-controlled room, the test water temperature should be the same as the room temperature. The basic agitation for liquid density test is 20 ℃. Small temperature changes will not produce substantial differences and will not prevent the use of correction values in accordance with regulations. 5 Test specimens
5.1 Prepare the specimens for mechanical (particle size) analysis in accordance with ASTM D421. During the preparation stage, the specimens are divided into two parts, one part is the particles retained on the 2.00 mm (10 mesh) sieve, and the other part is the particles passing the 2.00 mm sieve. According to the requirements of ASTM D421, the mass of the particle size test sample is selected to meet the requirements of mechanical particle size analysis: the mass of the portion retained on the 2.00 mm sieve depends on the particle size of the largest particle, see Table 1. Table 1 Comparison table of the mass of the portion retained on the 2.00 mm sieve and the maximum particle size Nominal diameter of the particle
Approximate minimum mass of the portion retained on the 2.00 rtm sieve/surface
The portion passing the 2.00 mm sieve is about 115 g for sandy soil and about 65 g for silty soil and clay soil. 5.2 Section 5 of ASTM DM21 specifies the weighing method for air-dried soil for testing: Dry sieving and rinsing on a 2.00 mm sieve to separate the soil, and weigh the rinsed and dried portion retained on the 2.00 mm sieve. From the above two quantities, the percentage of the portion retained on the 2.00 mm sieve and the percentage of the portion passing can be calculated according to 8.1.1. Note: To check the completeness of crushing of soil and soil clods, the fraction passing through the 2.00 mm sieve may be weighed and compared with the value of the rinsed and dried fraction retained on the 2.00 mm sieve.
CB/T 27845--2011
6 Sieve analysis of the fraction retained on the 2.00 mm sieve 6.1 Use a 75 mm sieve, a 50 mm sieve, a 37.5 mm sieve, a 25.0 mm sieve, a 19.0 mm sieve, a 9.5 mm sieve, a 4.75 mm sieve and a 2.00 mm sieve, or separate the fraction retained on the 2.00 mm sieve into a series of smaller fractions, depending on the possible needs of the sample and the specification requirements of the test material.
6.2 While beating, shake the sieve horizontally and vertically to sieve so that the sample can move continuously on the sieve surface. In any case, do not touch or move the crushed sample through the sieve. Continue sieving until the mass of the fraction passing through the sieve is less than or equal to 1% of the mass remaining on the sieve during the 1-min sieving process. If mechanical sieving is used, check the thoroughness of sieving using the hand sieving method described above. 6.3 Determine the mass of each fraction using a balance (see 3.1). After weighing, the sum of the mass of the sample retained on all sieves should be approximately equal to the original mass of the sample sieved.
7 Liquid densimeter and sieving analysis of the fraction passing the 2.00 mm sieve 7.1 Comprehensive correction of liquid densimeter readings
7.1.18.3.3 The formula for the mass fraction of residual soil in the suspension given in 3.3 is based on the use of distilled/demineralized water. However, due to the use of dispersants in the water, the specific density of the resulting liquid will be slightly greater than the density of distilled/demineralized water. The soil liquid densimeter is calibrated at 20°C. In the actual reservoir densimeter reading, the deviation of the actual temperature from this standard temperature will cause an error in the reading. The greater the deviation from the standard temperature, the greater the error. Since the axillary densitometer is designed to take readings from the bottom of the meniscus formed by the liquid on the column center, it is impossible to ensure that the soil suspension reading at the bottom of the meniscus can be obtained. The reading should be taken from the top of the meniscus and corrected. The net total value of the three corrections listed is called the comprehensive correction value, which can be determined by experiment. 7.1.2 A comprehensive correction chart or table for a series of temperatures with a difference of 1"C within the expected test humidity range may be prepared or used as needed. The comprehensive correction value may be measured at two temperatures within the expected test temperature range, and the correction value for the intermediate temperature may be calculated assuming a linear relationship between the two measured values.
7.1.3 Prepare 1000 mL of a mixture of distilled/softened water and dispersant in the same proportions as in the sedimentation (liquid densimeter) test. Place the mixture in a sedimentation tube, which is placed in a constant temperature water bath, and set the temperature at one of the two temperatures to be used. After the liquid temperature reaches a constant level, place the liquid densimeter in the chamber, wait a moment for the liquid densimeter to reach the same temperature as the liquid, and read the scale value corresponding to the top of the meniscus formed by the center of the liquid densimeter column. For a 151H liquid densimeter, the comprehensive correction value is the difference between this reading and 1; for a 1 52H liquid density meter, its integrated calibration value is the difference between this reading and 0. Make sure that the integrated calibration value is the same as before, and let the liquid and liquid density meter reach another temperature value.
7.2 Hygroscopic moisture
After weighing the sample used for the liquid density test, weigh another 10g~15g sample in a small metal or glass container, dry the sample in an oven at 110±5°C to a constant mass, and weigh it again. Record the mass value. 7.3 Separation of soil samples
7.3.1 If the soil is mainly composed of clay and silt, weigh about 50g of air-dried soil sample. If the soil is mainly composed of sandy soil, weigh about 100g of soil sample. 7.3.2 Place the sample in a 250mL beaker and add 125mL (40g/L) of sodium hexametaphosphate solution. Stir until the soil is completely wet. Soak for at least 16 h.
7.3.3 At the end of the non-foaming stage, use device A or B to further disperse the sample. If using stirring device A, transfer the soil-cement slurry from the beaker to the special dispersion cup shown in Figure 2, rinse the beaker with distilled water/softened water, and transfer all the residue in the beaker into the dispersion cup. If necessary, add distilled water/softened water to make the solution in the dispersion cup larger than half a cup. Stir for 1 minute. GB/T 27845—2011
Note: A large-diameter syringe may be used as a simple device during the washing operation. Other devices include a water washing bottle and a hose connecting the nozzle to the pressurized steam water tank. 7.3.4 If agitator device B (see Figure 3) is used, remove the cover and connect the dispersion cup to the compressed air supply device with a rubber hose. A barometer should be installed between the dispersion cup and the regulating valve. Open the control valve and adjust the pressure to 7 kPa. The initial air pressure should reach 7 kPa to prevent the soil-water mixture from entering the air jet chamber when transferring to the dispersion cup. Rinse the beaker with distilled/softened water and transfer the soil-cement slurry in the beaker to the air jet dispersion cup. Add distilled/softened water as necessary to make the total volume in the dispersion cup reach but not exceed 250 mL. 7.3.5 Place the cover on the dispersion cup, open the air control room and adjust the pressure to 140 kPa. Disperse the soil according to Table 2. Table 2 Correspondence between soil plasticity coefficient and dispersion time Plasticity index
Dispersion time!
Mica-rich soils only need to be dispersed for 1 min. After dispersion, reduce the pressure to 7 kPa before transferring the soil-cement slurry to the sedimentation tube.
7.4 Liquid density test
7.4.1 Transfer the soil-cement slurry to a glass sedimentation tube immediately after dispersion and add distilled/softened water to make the total amount reach 1000 mL. 7.4.2 Seal the mouth of the sedimentation tube with the palm of your hand (or place a leather stopper on the open end) and turn the sedimentation tube upside down for 1 minute to stir the slurry. The number of inversions within 1 min should be about 60 times,One inversion counts as two flips. During the first few flips, any soil remaining at the bottom of the settling tube should be loosened by shaking vigorously as the settling tube compacts. After 1 minute of inversion, place the settling tube in a suitable position and take readings of the volume densimeter at the following time intervals (calculated from the start of settling): 2 minutes, 5 minutes, 15 minutes, 30 minutes, 60 minutes, 250 minutes, and 1440 minutes, or as many readings as necessary based on the sample or specification of the test material. If a temperature-controlled water bath is used, the settling tube should be placed in the water bath between the 2nd and 5th minute readings. 7.4.3 If it is necessary to obtain a volume densimeter reading, place the densimeter 20 seconds to 25 seconds before the reading, depending on the depth at which the reading is taken. After the reading, remove the densimeter and place it in a graduated container filled with distilled water/softened water. It is important to remove the liquid densimeter immediately after each reading. Since it is not possible to ensure that the soil suspension reading is obtained at the bottom of the meniscus, the reading should be taken from the top of the meniscus formed by the suspension around the column core.
7.4.4 After each reading, insert a thermometer into the suspension to determine its temperature. 7.5 Sieve analysis
After the last reading of the liquid density meter, transfer the suspension to a 75 J (200 mesh) sieve and rinse it with tap water until the rinse water becomes semi-clear. Transfer the material retained on the 75 μm sieve to a suitable container and dry it in an oven at 110 ± 5 ° C. Use multiple sieves as needed according to the material requirements or the specification requirements of the material under test, and sieve the remaining part of the sieve for analysis.
8 Calculation and reporting
8.1 Sieve analysis of the fraction retained on the 2.00 mm sieve 8.1.1 Divide the mass of soil passing the 2.00 mm sieve by the mass of the upper soil originally separated on the 2.00 mm sieve and multiply by 100 to obtain the mass fraction of soil passing the 2.00 mm sieve. Subtract the mass of the upper soil retained on the 2.00 mm sieve from the initial mass to obtain the mass fraction of soil passing the 2.00 mm sieve.
8.1.2 Add the mass of soil passing the 2.00 mm sieve and the mass of soil passing the 4.75 mm (4 mesh) sieve to obtain the mass fraction of soil passing the 4.75 mm (4 mesh) sieve. Divide the total mass of the pile that passes the 4-mesh sieve by the mass of soil that passes the 9.5-mm sieve but is retained on the 4.75-mm sieve to obtain the total mass of soil that passes the 9.5-mm sieve. Calculate in the same manner for the other sieves.
8.1.3 Divide the mass of soil that passes the sieve (see 8.1.2) by the total mass of the sample and multiply the result by 100 to obtain the mass fraction of soil that passes each sieve.
8.2 Wetting moisture correction factor
The moisture correction factor is the ratio of the mass of the oven-dried sample to the mass under wind before drying. Unless there is no moisture absorption, this factor should be less than 1.
8.3 Mass fraction of soil in the bulk
8.3.1 Multiply the wind-dried mass by the moisture correction factor to obtain the mass of the oven-dried bulk for the liquid densimeter analysis. 8.3.2 Divide the mass of the oven-dried bulk by the mass that passes 2.00 mm(10 mesh sieve mass fraction, and then multiply by 100 to obtain the total sample mass expressed as the mass of soil used in the liquid density test. This value is the mass W in the formula for the mass fraction of the remaining soil in the suspension. 8.3.3 On the surface of the liquid densitometer measuring the density of the suspension, the ten-mesh fraction remaining in the suspension can be calculated according to formula (1) or formula (2):
For liquid densitometer 151H:
P = [(100 000/W)XG/(GG) (RG)++++(1
Note, the part in square brackets of the formula of liquid density meter 151H is a constant for a series of readings, which can be calculated first and then multiplied by the part in parentheses. For liquid density meter 152H:
P=(Ra/W)×100
Correction coefficient used for liquid density meter 152H readings (the value displayed on the scale is calculated based on a specific density of 2.65. The correction coefficient is shown in Table 3)
Measurement of suspension density using liquid density meter =Mass fraction of soil remaining in suspension at the liquid level of 1000 m/s; Reading of the liquid densimeter after comprehensive correction (see Chapter 7); Mass of oven-dried soil in the total sample, expressed as dispersed soil mass (see 8.3.2), in grams (g); Specific density of soil particles;
Specific density of suspension of soil particles. In both cases, the value 1 is used in the formula. In the first case, any possible changes will not have a significant effect. In the second case, a comprehensive correction is made to R based on the value of G, (see Table 3). Table 3 Correction factors (α) for soil particles of different densities Specific density
Correction factor
Specific density
Table 3 (continued)
When using a liquid densimeter 152H, the remaining soil mass fraction in the suspension is used in the calculation formula. 8. 4 Diameter of soil particles
Correction factor
GB/T 27845—2011
8.4.1 When a particle of a certain diameter settles initially on the surface of the suspension, it will eventually settle at the surface of the liquid where the density of the suspension is measured by the liquid densimeter. On this basis, the particle diameter corresponding to the mass fraction shown in the liquid densimeter reading can be calculated according to Stokeslaw:
D-V30n/980(GG:)JXL/T
Where:
Particle diameter, in mm
Viscosity coefficient of the suspension medium (in this case water) (which varies with the temperature of the suspension medium): ·(3)
-The distance from the surface of the suspension to the surface of the suspension density measurement, in cm (for a given liquid densimeter and sedimentation device, this value varies with the liquid densimeter reading). This distance is called effective depth, see Table 4) T: time from the start of settlement to the reading, in minutes (min) G-Specific density of soil particles
: Specific density (relative density) of the suspension medium (1.000 can be used in actual use). Note: Stokes' law states that in an infinite volume, the dimension calculated from the final velocity of a sphere falling is the diameter of the sphere falling at the same velocity as the soil particles.
Table 4 Effective depth values based on specific liquid densitometers and sedimentation tubes
Actual reading of liquid densitometer
Effective depth L/
Actual reading of liquid densitometer
Actual reading of liquid densitometer
Body densitometer 151H
Effective depth L/
Actual reading of liquid densitometer
Effective depth L/
CB/T27845—2011
Actual reading of liquid densitometer 151H
1, 010
Effective depth L/
Table 4 (continued)
|Actual reading of liquid density meter
Liquid density meter 152H
Effective depth L/
|Actual reading of liquid density meter
Effective depth L./Rinse with tap water until the rinse water becomes half clean. Transfer the material retained on the 75μtm sieve to a suitable container and dry it in an oven at 110±5℃. According to the material requirements or the specification requirements of the material under test, use multiple sieves as needed to sieve the retained portion.
8 Calculation and reporting
8.1 Sieve analysis value of the portion retained on the 2.00mm sieve 8.1.1 Divide the mass of soil passing the 2.00mm sieve by the mass of the upper soil originally separated on the 2.00mm sieve, and multiply by 100 to obtain the mass fraction of the main soil passing the 2.00mm sieve. Subtract the mass of soil retained on the 2,00 mm sieve from the initial mass to obtain the mass of soil passing the 2.00 mm sieve.
8.1.2 Add the mass of soil passing the 2.00 mm sieve and the mass of soil passing the 4.00 mm sieve but retained on the 2.00 mm sieve to obtain the mass of soil passing the 4.75 mm (4 mesh) sieve. Divide the total mass of the soil passing the 4 mesh sieve with the mass of soil passing the 9.5 mm sieve but retained on the 4.75 mm sieve to obtain the total mass of soil passing the 9.5 mm sieve. Calculate in the same way for other sieves.
8.1.3 Divide the mass of soil passing the sieve (see 8.1.2) by the total mass of the sample and multiply the result by 100 to obtain the mass fraction of soil passing each sieve.
8.2 Wetting moisture correction factor
The moisture correction factor is the ratio of the mass of the oven-dried sample to the mass under wind before drying. Unless there is no moisture absorption, this factor should be less than 1.
8.3 Mass fraction of soil in the bulk density
8.3.1 Multiply the wind-dried mass by the moisture correction factor to obtain the mass of the oven-dried soil fill for liquid densimeter analysis. 8.3.2 Divide the mass of the oven-dried soil fill by the mass passing 2.00 mm(10 mesh sieve mass fraction, and then multiply by 100 to obtain the total sample mass expressed as the mass of soil used in the liquid density test. This value is the mass W in the formula for the mass fraction of the remaining soil in the suspension. 8.3.3 On the surface of the liquid densitometer measuring the density of the suspension, the ten-mesh fraction remaining in the suspension can be calculated according to formula (1) or formula (2):
For liquid densitometer 151H:
P = [(100 000/W)XG/(GG) (RG)++++(1
Note, the part in square brackets of the formula of liquid density meter 151H is a constant for a series of readings, which can be calculated first and then multiplied by the part in parentheses. For liquid density meter 152H:
P=(Ra/W)×100
Correction coefficient used for liquid density meter 152H readings (the value displayed on the scale is calculated based on a specific density of 2.65. The correction coefficient is shown in Table 3)
Measurement of suspension density using liquid density meter =Mass fraction of soil remaining in suspension at the liquid level of 1000 m/s; Reading of the liquid densimeter after comprehensive correction (see Chapter 7); Mass of oven-dried soil in the total sample, expressed as dispersed soil mass (see 8.3.2), in grams (g); Specific density of soil particles;
Specific density of suspension of soil particles. In both cases, the value 1 is used in the formula. In the first case, any possible changes will not have a significant effect. In the second case, a comprehensive correction is made to R based on the value of G, (see Table 3). Table 3 Correction factors (α) for soil particles of different densities Specific density
Correction factor
Specific density
Table 3 (continued)
When using a liquid densimeter 152H, the remaining soil mass fraction in the suspension is used in the calculation formula. 8. 4 Diameter of soil particles
Correction factor
GB/T 27845—2011
8.4.1 When a particle of a certain diameter settles initially on the surface of the suspension, it will eventually settle at the surface of the liquid where the density of the suspension is measured by the liquid densimeter. On this basis, the particle diameter corresponding to the mass fraction shown in the liquid densimeter reading can be calculated according to Stokeslaw:
D-V30n/980(GG:)JXL/T
Where:
Particle diameter, in mm
Viscosity coefficient of the suspension medium (in this case water) (which varies with the temperature of the suspension medium): ·(3)
-The distance from the surface of the suspension to the surface of the suspension density measurement, in cm (for a given liquid densimeter and sedimentation device, this value varies with the liquid densimeter reading). This distance is called effective depth, see Table 4) T: time from the start of settlement to the reading, in minutes (min) G-Specific density of soil particles
: Specific density (relative density) of the suspension medium (1.000 can be used in actual use). Note: Stokes' law states that in an infinite volume, the dimension calculated from the final velocity of a sphere falling is the diameter of the sphere falling at the same velocity as the soil particles.
Table 4 Effective depth values based on specific liquid densitometers and sedimentation tubes
Actual reading of liquid densitometer
Effective depth L/
Actual reading of liquid densitometer
Actual reading of liquid densitometer
Body densitometer 151H
Effective depth L/
Actual reading of liquid densitometer
Effective depth L/
CB/T27845—2011
Actual reading of liquid densitometer 151H
1, 010
Effective depth L/
Table 4 (continued)
|Actual reading of liquid density meter
Liquid density meter 152H
Effective depth L/
|Actual reading of liquid density meter
Effective depth L./Rinse with tap water until the rinse water becomes half clean. Transfer the material retained on the 75μtm sieve to a suitable container and dry it in an oven at 110±5℃. According to the material requirements or the specification requirements of the material under test, use multiple sieves as needed to sieve the retained portion.
8 Calculation and reporting
8.1 Sieve analysis value of the portion retained on the 2.00mm sieve 8.1.1 Divide the mass of soil passing the 2.00mm sieve by the mass of the upper soil originally separated on the 2.00mm sieve, and multiply by 100 to obtain the mass fraction of the main soil passing the 2.00mm sieve. Subtract the mass of soil retained on the 2,00 mm sieve from the initial mass to obtain the mass of soil passing the 2.00 mm sieve.
8.1.2 Add the mass of soil passing the 2.00 mm sieve and the mass of soil passing the 4.00 mm sieve but retained on the 2.00 mm sieve to obtain the mass of soil passing the 4.75 mm (4 mesh) sieve. Divide the total mass of the soil passing the 4 mesh sieve with the mass of soil passing the 9.5 mm sieve but retained on the 4.75 mm sieve to obtain the total mass of soil passing the 9.5 mm sieve. Calculate in the same way for other sieves. bZxz.net
8.1.3 Divide the mass of soil passing the sieve (see 8.1.2) by the total mass of the sample and multiply the result by 100 to obtain the mass fraction of soil passing each sieve.
8.2 Wetting moisture correction factor
The moisture correction factor is the ratio of the mass of the oven-dried sample to the mass under wind before drying. Unless there is no moisture absorption, this factor should be less than 1.
8.3 Mass fraction of soil in the bulk density
8.3.1 Multiply the wind-dried mass by the moisture correction factor to obtain the mass of the oven-dried soil fill for liquid densimeter analysis. 8.3.2 Divide the mass of the oven-dried soil fill by the mass passing 2.00 mm(10 mesh sieve mass fraction, and then multiply by 100 to obtain the total sample mass expressed as the mass of soil used in the liquid density test. This value is the mass W in the formula for the mass fraction of the remaining soil in the suspension. 8.3.3 On the surface of the liquid densitometer measuring the density of the suspension, the ten-mesh fraction remaining in the suspension can be calculated according to formula (1) or formula (2):
For liquid densitometer 151H:
P = [(100 000/W)XG/(GG) (RG)++++(1
Note, the part in square brackets of the formula of liquid density meter 151H is a constant for a series of readings, which can be calculated first and then multiplied by the part in parentheses. For liquid density meter 152H:
P=(Ra/W)×100
Correction coefficient used for liquid density meter 152H readings (the value displayed on the scale is calculated based on a specific density of 2.65. The correction coefficient is shown in Table 3)
Measurement of suspension density using liquid density meter =Mass fraction of soil remaining in suspension at the liquid level of 1000 m/s; Reading of the liquid densimeter after comprehensive correction (see Chapter 7); Mass of oven-dried soil in the total sample, expressed as dispersed soil mass (see 8.3.2), in grams (g); Specific density of soil particles;
Specific density of suspension of soil particles. In both cases, the value 1 is used in the formula. In the first case, any possible changes will not have a significant effect. In the second case, a comprehensive correction is made to R based on the value of G, (see Table 3). Table 3 Correction factors (α) for soil particles of different densities Specific density
Correction factor
Specific density
Table 3 (continued)
When using a liquid densimeter 152H, the remaining soil mass fraction in the suspension is used in the calculation formula. 8. 4 Diameter of soil particles
Correction factor
GB/T 27845—2011
8.4.1 When a particle of a certain diameter settles initially on the surface of the suspension, it will eventually settle at the surface of the liquid where the density of the suspension is measured by the liquid densimeter. On this basis, the particle diameter corresponding to the mass fraction shown in the liquid densimeter reading can be calculated according to Stokeslaw:
D-V30n/980(GG:)JXL/T
Where:
Particle diameter, in mm
Viscosity coefficient of the suspension medium (in this case water) (which varies with the temperature of the suspension medium): ·(3)
-The distance from the surface of the suspension to the surface of the suspension density measurement, in cm (for a given liquid densimeter and sedimentation device, this value varies with the liquid densimeter reading). This distance is called effective depth, see Table 4) T: time from the start of settlement to the reading, in minutes (min) G-Specific density of soil particles
: Specific density (relative density) of the suspension medium (1.000 can be used in actual use). Note: Stokes' law states that in an infinite volume, the dimension calculated from the final velocity of a sphere falling is the diameter of the sphere falling at the same velocity as the soil particles.
Table 4 Effective depth values based on specific liquid densitometers and sedimentation tubes
Actual reading of liquid densitometer
Effective depth L/
Actual reading of liquid densitometer
Actual reading of liquid densitometer
Body densitometer 151H
Effective depth L/
Actual reading of liquid densitometer
Effective depth L/
CB/T27845—2011
Actual reading of liquid densitometer 151H
1, 010
Effective depth L/
Table 4 (continued)
|Actual reading of liquid density meter
Liquid density meter 152H
Effective depth L/
|Actual reading of liquid density meter
Effective depth L./Then multiply by the part in parentheses. For liquid densitometer 152H:
P=(Ra/W)×100
Correction factor for the reading of liquid densitometer 152H (the value shown on the scale is calculated based on a specific density of 2.65. See Table 3 for correction factors)
Mass fraction of soil remaining in the suspension above the liquid level at which the density of the suspension is measured by the liquid densitometer; Liquid densitometer reading after comprehensive correction (see Chapter 7); The main mass of oven-dried soil particles in the total sample, expressed as dispersed soil mass (see 8.3.2), in grams (g);
Specific density of the suspension of soil particles. In both cases, the value 1 is used in the formula. In the first case, any possible changes will not have a significant impact. In the second case, a comprehensive correction is made to R based on the value of G, (see Table 3). Table 3 Correction coefficients (α) of soil-fill particles with different densities Specific density
Correction coefficient
Specific density
Table 3 (continued)
When using a liquid densitometer 152H, use it in the calculation formula to record the residual soil mass fraction in the suspension, 8.4 Diameter of soil-carrying particles
Correction coefficient
GB/T 27845—2011
8.4.1 Particles of a certain diameter are on the surface of the suspension at the beginning of sedimentation and will eventually stay at the liquid surface where the liquid densitometer measures the density of the suspension. On this basis, the particle diameter corresponding to the mass fraction shown in the liquid density meter reading can be calculated according to Stokeslaw:
D-V30n/980(GG:)JXL/T
Where:
Particle diameter, unit is meter (mm)
-Viscosity coefficient of the suspension medium (water in this case) (changes with the temperature of the suspension medium): ·(3)
-The distance from the surface of the suspension to the surface of the suspension density measurement liquid, unit is centimeter (cm) (For a given liquid density meter and sedimentation chart, this value changes with the liquid density meter reading. This distance is called the effective depth, see Table 4) T: The time from the start of sedimentation to the reading, unit is minute (min) G-Specific density of soil particles
: Specific density (relative density) of the suspension medium (1.000 can be used in actual use). Note: Stokes' law states that the final velocity of a sphere falling in an infinite volume is calculated as the diameter of the sphere of soil particles falling at an intermediate velocity.
Table 4 Effective depth values based on specific liquid densitometers and sedimentation tubes Liquid densitometer 151H
Liquid densitometer
Actual reading
Effective depth L/
Liquid densitometer
Actual reading
Liquid densitometer 152H
Effective depth L/
Liquid densitometer
Actual reading
Effective depth L/
CB/T27845—2011
Reduced liquid densitometer 151H
Liquid densitometer
Actual reading
1, 010
Effective depth L/
Table 4 (continued)
|Actual reading of liquid density meter
Liquid density meter 152H
Effective depth L/
|Actual reading of liquid density meter
Effective depth L./Then multiply by the part in parentheses. For liquid densitometer 152H:
P=(Ra/W)×100
Correction factor for the reading of liquid densitometer 152H (the value shown on the scale is calculated based on a specific density of 2.65. See Table 3 for correction factors)
Mass fraction of soil remaining in the suspension above the liquid level at which the density of the suspension is measured by the liquid densitometer; Liquid densitometer reading after comprehensive correction (see Chapter 7); The main mass of oven-dried soil particles in the total sample, expressed as dispersed soil mass (see 8.3.2), in grams (g);
Specific density of the suspension of soil particles. In both cases, the value 1 is used in the formula. In the first case, any possible changes will not have a significant impact. In the second case, a comprehensive correction is made to R based on the value of G, (see Table 3). Table 3 Correction coefficients (α) of soil-fill particles with different densities Specific density
Correction coefficient
Specific density
Table 3 (continued)
When using a liquid densitometer 152H, use it in the calculation formula to record the residual soil mass fraction in the suspension, 8.4 Diameter of soil-carrying particles
Correction coefficient
GB/T 27845—2011
8.4.1 Particles of a certain diameter are on the surface of the suspension at the beginning of sedimentation and will eventually stay at the liquid surface where the liquid densitometer measures the density of the suspension. On this basis, the particle diameter corresponding to the mass fraction shown in the liquid density meter reading can be calculated according to Stokeslaw:
D-V30n/980(GG:)JXL/T
Where:
Particle diameter, unit is meter (mm)
-Viscosity coefficient of the suspension medium (water in this case) (changes with the temperature of the suspension medium): ·(3)
-The distance from the surface of the suspension to the surface of the suspension density measurement liquid, unit is centimeter (cm) (For a given liquid density meter and sedimentation chart, this value changes with the liquid density meter reading. This distance is called the effective depth, see Table 4) T: The time from the start of sedimentation to the reading, unit is minute (min) G-Specific density of soil particles
: Specific density (relative density) of the suspension medium (1.000 can be used in actual use). Note: Stokes' law states that the final velocity of a sphere falling in an infinite volume is calculated as the diameter of the sphere of soil particles falling at an intermediate velocity.
Table 4 Effective depth values based on specific liquid densitometers and sedimentation tubes Liquid densitometer 151H
Liquid densitometer
Actual reading
Effective depth L/
Liquid densitometer
Actual reading
Liquid densitometer 152H
Effective depth L/
Liquid densitometer
Actual reading
Effective depth L/
CB/T27845—2011
Reduced liquid densitometer 151H
Liquid densitometer
Actual reading
1, 010
Effective depth L/
Table 4 (continued)
|Actual reading of liquid density meter
Liquid density meter 152H
Effective depth L/
|Actual reading of liquid density meter
Effective depth L./
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