1、TS-1b T 224-1 AASHTO Standard Method of Test for Correction for Coarse Particles in the Soil Compaction Test AASHTO Designation: T 224-10 1. SCOPE 1.1. This method describes a procedure for adjusting the densities of soil and soil aggregate mixtures to compensate for differing percentages of coarse
2、particles retained on either the 4.75-mm (No. 4) or 19.0-mm (3/4-in.) sieve. This is necessary to adjust either the field wet density to a dry density of the material passing these sieves or the reverse, by adjusting the lab density to the field density when doing compaction control testing. Compari
3、sons are made by comparing the field densities with the maximum dry density as determined by T 99 or T 180. 1.2. Two methods are available for correction: either lab-to-field or field-to-lab density. The method specified in Section 4.1 adjusts the compacted lab density to the field density. The meth
4、od specified in Section 4.2 adjusts the field wet density to dry density of the fine fraction and compares its results with the compacted lab density. 1.3. This test method applies to soil mixtures that have 40 percent or less retained on the 4.75-mm (No. 4) sieve, when Method A or B of T 99 or T 18
5、0 is used, or mixtures that have 30 percent or less retained on the 19.0-mm (3/4-in.) sieve, when Method C or D of T 99 or T 180 is used. The material retained on these sieves shall be defined as oversize particles (coarse particles). 1.4. This method applies to soils with any percentage of oversize
6、 particles as specified in Section 1.3. However, the correction may not be of practical significance for soils with only a small percentage of oversize particles. The person or agency specifying this method shall specify a minimum percentage of oversize particles below which the method need not be a
7、pplied. If a minimum percentage is not specified, this method shall be applied to samples with more than 5 percent by weight of oversize particles. 1.5. The following applies to all specified limits in this standard: For the purposes of determining conformance with these specifications, an observed
8、value or a calculated value shall be rounded off to the nearest 10 kg/m3(1 pcf), according to ASTM E 29. 1.6. The values stated in SI units are to be regarded as the standard. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: T 85, Specific Gravity and Absorption of Coarse Aggregate T 99, Moisture-Dens
9、ity Relations of Soils Using a 2.5-kg (5.5-lb) Rammer and a 305-mm (12-in.) Drop T 180, Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) Drop 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a v
10、iolation of applicable law.TS-1b T 224-2 AASHTO T 217, Determination of Moisture in Soils by Means of a Calcium Carbide Gas Pressure Moisture Tester T 255, Total Evaporable Moisture Content of Aggregate by Drying T 265, Laboratory Determination of Moisture Content of Soils T 272, Family of CurvesOne
11、-Point Method 2.2. ASTM Standard: E 29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications 3. OUTLINE OF METHOD 3.1. When Method A or Method B of T 99 or T 180 is employed, the total field wet density is compared with the dry density of the soil
12、particles passing the 4.75-mm (No. 4) sieve. 3.2. When Method C or Method D of T 99 or T 180 is employed, the total field wet density is compared with the dry density of the soil particles passing the 19.0-mm (3/4-in.) sieve. 3.3. Significant figures are as follows: 3.3.1. Adjusted wet density of th
13、e fine material passing the 4.75-mm (No. 4) sieve, Methods A and B; or 19.0-mm (3/4-in.) sieve, Methods C and D; (Df) 1 kg/m3(0.1 pcf). 3.3.2. Bulk specific gravity of the coarse material retained on the 4.75-mm (No. 4) sieve, Methods A and B; or 19.0-mm (3/4-in.) sieve, Methods C and D; (Gm) 0.01.
14、3.3.3. Percent by mass, of coarse and fine particles, of material retained and passing the 4.75-mm (No. 4) sieve, Methods A and B; or 19.0-mm (3/4-in.) sieve, Methods C and D; (Pc) and (Pf) 0.1 percent. 3.3.4. In-place (field) wet density of the total sample (D) 1 kg/m3(0.1 pcf). 4. ADJUSTMENT EQUAT
15、ION 4.1. Compacted Laboratory Dry Density Corrected to Field Dry Density: 4.1.1. This section corrects the laboratory density obtained by either T 99 or T 180 for the moisture content and density of the material retained on the 4.75-mm (No. 4) sieve, Methods A and B; or the material retained on the
16、19.0-mm (3/4-in.) sieve, Methods C and D. The maximum lab dry density, adjusted for oversized particles and total moisture content, is compared with the field dry density and field moisture content. This method is limited to field samples containing 40 percent or less for material retained on the 4.
17、75-mm (No. 4) sieve, Methods A and B; or 30 percent or less of material retained on the 19.0-mm (3/4-in.) sieve, Methods C and D. 4.1.2. Determine the moisture content of the fine particles and oversize particles of the material used during compaction. The moisture contents can be determined by T 26
18、5, T 217, or T 255. The moisture content of the oversize material retained on the sieve can be assumed to be 2 percent for most construction applications. If the moisture content of the oversized material is generally known, substitute that moisture content in the calculations. It is recommended tha
19、t if drying equipment is available, determine the actual moisture contents. Calculate the moisture contents according to the calculations specified in T 265. 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable l
20、aw.TS-1b T 224-3 AASHTO 4.1.3. Calculate the dry mass of the coarse and fine particles as follows: ( )/1= +DMM M MC (1) where: MD= mass of dry material (fine or oversize particles); MM= mass of moist material (fine or oversize particles); and MC = moisture content of respective fine or oversize part
21、icles, expressed as a decimal. 4.1.4. Calculate the percentage of the fine particles and oversized particles by dry weight of the total sample as follows: 100 /( )= +f DF DF DCP MM M (2) and 100 /( )= +C DC DF DCP MM M (3) where: Pf= percent of fine particles of sieve used, by weight; MDF= mass of d
22、ry particles; MDC= mass of oversize particles; and PC= percent of oversize particles of sieve used, by weight. 4.1.5. Calculate the corrected moisture content and corrected dry density of the total sample (combined fine and oversized particles) as follows: ( ) 100= +T f f CCMC MC P MC P / (4) where:
23、 MCT= corrected moisture content of the combined fine and oversize particles, expressed as a decimal; MCf= moisture content of the fine particles, expressed as a decimal; Pf= percent of fine particles of sieve used, by weight; MCC= moisture content of the oversize particles, expressed as decimal; an
24、d PC= percent of oversize particles of sieve used, by weight. and 100 /( )= +d f fC fD D k D P kP (5) where: Dd= corrected total dry density (combined fine and oversize particles), kg/m3(pcf); Df= dry density of the fine particles, kg/m3(pcf); k = 1000 Bulk Specific Gravity (Gm) (oven-dry basis) of
25、coarse particles, kg/m3; or 62.4 Bulk Specific Gravity (Gm) (oven-dry basis) of coarse particles, pcf; PC= percent of oversize particles of sieve used by weight; and Pf= percent of fine particles of sieve used, by weight. Note 1If the specific gravity has been determined, this value may be used in t
26、he calculations. Determine the Bulk Specific Gravity according to T 85. For most construction activities, the specific gravity can be assumed to be 2.60. 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.T
27、S-1b T 224-4 AASHTO 4.2. Field-Wet Density Corrected to Compacted-Laboratory Density: 4.2.1. The in-place total (field) wet density is corrected to a dry density of the sample passing the 4.75-mm (No. 4) sieve or the sample passing the 19.0-mm (3/4-in.) sieve. This adjusted dry density is compared w
28、ith the maximum dry density obtained by methods T 99 or T 180. 4.2.2. Determine the moisture content of the total sample and for the material retained on the sieve used during compaction. Moisture content can be determined by T 265, T 217, or T 255. If using the nuclear moisture/density gauge, read
29、the moisture content directly from the gauge for the total moisture content. The moisture content of the oversize material retained on the sieve can be assumed to be 2 percent for most construction applications. If the moisture content of the oversize material is generally known, substitute that moi
30、sture content in the calculations. It is recommended that if drying equipment is available, determine the actual moisture contents. Calculate the moisture contents according to the calculations specified in T 265. 4.2.3. Calculate the moisture content of the fine particles of the field sample as fol
31、lows: ( )100= f T CC fMC MC MC P / P (6) where: MCf= moisture content of the fine particles, expressed as a decimal; MCT= moisture content of total field sample, expressed as a decimal; MCC= moisture content of the oversize particles, expressed as a decimal; Pc= percent of oversize particles of siev
32、e used, by weight; and Pf= percent of fine particles of sieve used, by weight. 4.2.4. Calculate the dry field density of the sample as follows: ( )1= +dTD D / MC (7) where: Dd= dry field density of total sample, kg/m3(pcf); D = total field wet density, kg/m3(pcf); and MCT= moisture content of total
33、field sample, expressed as a decimal. 4.2.5. Calculate the dry field density of the fine particles of the field sample as follows: ( ) ( )( )( )100f d f dCD DP / DP / k= (8) where: Df= adjusted dry density of the fine particles, kg/m3(pcf); Dd= total field dry density, kg/m3(pcf); Pf= percent of fin
34、e particles of sieve used, by weight; PC= percent of oversize particles of sieve used, by weight; k = 1000 Bulk Specific Gravity (Gm) (oven-dry basis) of coarse particles, kg/m3; or 62.4 Bulk Specific Gravity (Gm) (oven-dry basis) of coarse particles, pcf (Note 1). 5. PRECISION 5.1. Because this cor
35、rection for coarse particles involves no testing but instead utilizes the results of other tests and mathematically combines the results, determination of the precision and accuracy is not applicable. 2013 by the American Association of State Highway and Transportation Officials.All rights reserved.
36、 Duplication is a violation of applicable law.TS-1b T 224-5 AASHTO APPENDIX (Nonmandatory Information) X1. NOTES X1.1. These methods, described for coarse particle correction, are applicable to one type of soil and soil aggregate material only. If the characteristic of the material changes, then a m
37、oisture density relationship (T 99 or T 180) test is performed to determine a new maximum density. X1.2. T 272 describes the methods for determining different maximum densities of soil and soil-aggregate materials, which reveal certain similarities and trends characteristic of the material type and
38、source. X1.2.1. Utilization of a Family of CurvesWhen using the One Point Method (T 272), the percentage of oversized particles, when performing the density of soil and soil aggregate in-place, must be determined to adjust the T 99 or T 180 maximum density to compensate for this percentage. 2013 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
