1、Standard Method of Test for Particle Size Analysis of Soils AASHTO Designation: T 88-13 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1a T 88-1 AASHTO Standard Method of Test for Particle Size Analysis of Soils A
2、ASHTO Designation: T 88-13 1. SCOPE 1.1. This method describes a procedure for the quantitative determination of the distribution of particle sizes in soils. 1.2. The following applies to all specified limits in this standard: For the purposes of determining conformance with these specifications, an
3、 observed value or a calculated value shall be rounded off “to the nearest unit” in the last right-hand place of figures used in expressing the limiting value, in accordance with ASTM E29. 1.3. The values stated in SI units are to be regarded as the standard. 1.4. Refer to R 16 for regulatory inform
4、ation for chemicals. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 92, Wire-Cloth Sieves for Testing Purposes M 145, Classification of Soils and Soil-Aggregate Mixtures for Highway Construction Purposes M 147, Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses M 231, We
5、ighing Devices Used in the Testing of Materials R 16, Regulatory Information for Chemicals Used in AASHTO Tests R 58, Dry Preparation of Disturbed Soil and Soil-Aggregate Samples for Test T 100, Specific Gravity of Soils T 146, Wet Preparation of Disturbed Soil Samples for Test T 265, Laboratory Det
6、ermination of Moisture Content of Soils 2.2. ASTM Standards: C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications E100, Standard Sp
7、ecification for ASTM Hydrometers 3. APPARATUS 3.1. The apparatus shall consist of the following: 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 88-2 AASHTO 3.1.1. OvenA thermostatically controll
8、ed drying oven capable of maintaining temperatures of 110 5C (230 9F) for drying the sieve analysis samples. 3.1.2. BalanceThe balance shall have sufficient capacity, be readable to 0.1 percent of the sample mass, or better, and conform to the requirements of M 231. 3.1.3. Stirring ApparatusA mechan
9、ically operated stirring apparatus consisting of an electric motor suitably mounted to turn a vertical shaft at a speed not less than 10 000 rpm without load, a replaceable stirring paddle made of metal, plastic, or hard rubber similar to one of the designs shown in Figure 1. The shaft shall be of s
10、uch length that the stirring paddle will operate not less than 19.0 mm (3/4in.) nor more than 38 mm (1.5 in.) above the bottom of the dispersion cup. A dispersion cup conforming to either of the designs is shown in Figure 2. Dimensional Equivalents mm in. 19.1 3/412.7 1/25.16 0.025 0.203 0.001 1.24
11、0.049 (No. 18 BW Ga.) Note: All dimensions are shown in millimeters unless otherwise noted. Figure 1Details of Stirring Paddles 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 88-3 AASHTO Dimensi
12、onal Equivalents mm in. 33.0 1.3 66.0 2.6 95.2 3.75 178 7.0 Note: All dimensions are shown in millimeters unless otherwise noted. Figure 2Dispersion Cups 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.T
13、S-1a T 88-4 AASHTO 3.1.3.1. (Alternate B)An air-jet type dispersing device similar to either of the designs shown in Figure 3. Figure 3The Wintermyer Soil Dispersion Cups Note 1The amount of air required by an air-jet dispersion cup is of the order of 0.06 m3/min (2 cfm); some small air compressors
14、are not capable of supplying sufficient air to operate a cup. Note 2Another air-type dispersion device, known as a dispersion tube, developed by Chu and Davidson at Iowa State College, has been shown to give results equivalent to those secured by the air-jet dispersion cups. When it is used, soaking
15、 of the sample can be done in the sedimentation cylinder, thus eliminating the need for transferring the slurry. When the air-dispersion tube is used, it shall be so indicated in the report. Note 3Water may condense in air lines when not in use. This water must be removed, either by using a water tr
16、ap on the air line, or by blowing the water out of the line before using any of the air for dispersion purposes. 3.1.4. HydrometerAn ASTM hydrometer, graduated to read in either specific gravity of the suspension or grams per liter of suspension, and conforming to the requirements for hydrometers 15
17、1 H or 152 H in ASTM E100. Dimensions of both hydrometers are the same, the scale being the only item of difference. 3.1.5. Sedimentation CylindersA glass cylinder approximately 460 mm (18 in.) in height and 60 mm (21/2in.) in diameter and marked for a volume of 1000 mL. The inside diameter shall be
18、 such that the 1000 mL mark is 360 20 mm (14 1.0 in.) from the bottom on the inside. 3.1.6. ThermometerA calibrated thermometer readable to 0.5C (1F). 3.1.7. SievesA series of sieves of square mesh woven cloth, conforming to the requirements of M 92. The sieves normally required are as follows: 2015
19、 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 88-5 AASHTO Standard Designation, mm Alternate Designation 75 3 in. 50 2 in. 25 1 in. 9.25 3/8in. 4.75 No. 4 2.00 No. 10 0.425 No. 40 0.075 No. 200 Not
20、e 4The above sieves fulfill the requirements of M 145 and M 147. If desired, intermediate sieve sizes may be used in such sizes as: Standard Designation, mm Alternate Designation 75 3 in. 37.5 11/2in. 19 3/4in. 9.5 3/8in. 4.75 No. 4 2.36 No. 8 1.18 No. 16 0.60 No. 30 0.30 No. 50 0.15 No. 100 0.075 N
21、o. 200 3.1.8. Water Bath or Constant Temperature RoomA water bath or constant temperature room for maintaining the soil suspension at a constant temperature during the hydrometer analysis. A satisfactory water bath is an insulated tank that maintains the suspension at a convenient constant temperatu
22、re as near 20C (68F) as the room and faucet-water temperature will permit. Such a device is illustrated in Figure 4. In cases where the work is performed in a room at an automatically controlled constant temperature, the water bath is not necessary and subsequent reference to a constant temperature
23、bath shall be interpreted as meaning either a water bath or a constant temperature room. 3.1.9. BeakerA glass beaker having a capacity of at least 250 mL and not greater than 500 mL. 3.1.10. Timing DeviceA watch or clock readable to the nearest second. 3.1.11. ContainersSuitable containers made of m
24、aterial resistant to corrosion and not subject to change in mass or disintegration on repeated heating and cooling. Containers shall have close-fitting lids to prevent loss of moisture from samples before initial mass determination and to prevent absorption of moisture from the atmosphere following
25、drying and before final mass determination. One container is needed for each moisture content determination. 3.1.12. Stirring DeviceAny nonporous device suitable for stirring the sample mixture without loss of material. 2015 by the American Association of State Highway and Transportation Officials.A
26、ll rights reserved. Duplication is a violation of applicable law.TS-1a T 88-6 AASHTO Dimensional Equivalents mm in. mm in. 939.8 37 31.8 11/4355.6 14 22.2 7/8158.8 61/419.0 3/4136.5 53/815.8 5/8117.5 45/812.7 1/298.4 37/89.5 3/876.2 3 6.4 1/469.8 23/44.8 3/1652.4 21/161.6 1/1650.8 2 Note: All dimens
27、ions are shown in millimeters unless otherwise noted. Figure 4Tank for Maintaining Soil Suspension at Constant Temperature during Hydrometer Analysis Spring Clip Spacer Bar Clip BlockDrill for ScrewsCountersink 1019.098.4136.519.04.84.81.612.769.852.422.212.76.415.831.876.2OverflowGraduatedGlasses93
28、9.8355.6Wood BaseIntakeGalv SheetMetal50.8 Cork22.2 Wood CasingSlip Back under Springs117.5117.576.276.276.2158.815.89.5 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 88-7 AASHTO 4. DISPERSING
29、AGENT 4.1. A solution of sodium hexametaphosphate shall be used in distilled or demineralized water, at the rate of 40 g of sodium hexametaphosphate per liter of solution. 4.1.1. Solutions of this salt, if acidic, slowly revert or hydrolyze back to the orthophosphate form with a resultant decrease i
30、n dispersing action. Solutions shall be prepared frequently (at least once a month) or adjusted to pH of 8 or 9 by means of sodium carbonate. Bottles containing solutions shall have the date of preparation marked on them. 5. GENERAL REQUIREMENTS FOR WEIGHING 5.1. The masses of subsamples and size fr
31、actions in the hydrometer analysis and hygroscopic moisture determination shall be determined to the nearest 0.01 g. The mass of the subsample for mechanical analysis of the fraction retained on the 4.75-mm sieve, the 2.00-mm sieve, or the 0.425-mm sieve for coarse sieve analysis, and each size frac
32、tion in the coarse sieve analysis, shall be determined to within 0.1 percent of the mass of the subsample. For example, a subsample with a mass of 1000 g, its size fractions in the coarse sieve analysis, must be weighed to the nearest gram. 6. SAMPLES 6.1. The test sample for particle size analysis
33、shall be prepared in accordance with either R 58 for Dry Preparation of Disturbed Soil and Soil-Aggregate Samples for Test, or T 146 for Wet Preparation of Disturbed Soil Samples for Test. The representative portion of the original air-dry sample selected for test shall be weighed. The mass of this
34、sample shall be sufficient to yield quantities for particle size analysis as follows: 6.1.1. The minimum amount required of material retained on the 4.75-mm sieve, the 2.00-mm sieve, or the 0.425-mm sieve depends on the maximum particle size, but shall not be less than the amount shown in the follow
35、ing table: Normal Size of Largest Particles Standard (Alternate) Approximate Minimum Weight of Portion mm in. kg 9.5 3/80.5 25 1 2 50 2 4 75 3 5 6.1.2. The size of the portion passing the 2.00-mm (No. 10) or 0.425-mm (No. 40) sieve shall be: (a) for the hydrometer test, approximately 100 g for sandy
36、 soil and approximately 50 g for silty or clayey soils, and (b) for hygroscopic moisture determination, at least 10 g. 6.2. The test sample selected in Section 5.1 shall be processed by one of the following methods: 6.2.1. Alternate Method Using 4.75-mm and 2.00-mm (No. 4 and No. 10) SievesAfter sep
37、arating the test sample on the 4.75-mm sieve as described in Section 5.2.2 of R 58, the two fractions shall be weighed. A representative portion of the passing 4.75-mm sieve fraction adequate for mechanical analysis shall be selected and separated into two fractions using a 2.00-mm sieve. Each of th
38、ese fractions shall be weighed and the subsamples for hydrometer analysis and hygroscopic moisture 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 88-8 AASHTO determination shall be obtained from
39、 the passing 2.00-mm sieve fraction by use of a riffle sampler or sample splitter, and either weighed immediately or placed in airtight containers until tested. 6.2.2. Alternate Method Using 2.00-mm (No. 10) SieveThe sample shall be separated on the 2.00-mm sieve as described in Section 5.2.1 of R 5
40、8. The portion retained on the 2.00-mm sieve after the second sieving shall be processed in accordance with Section 7, Sieve Analysis of Fraction Retained on 2.00-mm (No. 10) Sieve. The portion passing the 2.00-mm sieve in both sieving operations shall be weighed and prepared as described in Section
41、 6.2 of R 58. Subsamples for hygroscopic moisture, hydrometer analysis, and sieve analysis shall be weighed immediately or placed in airtight containers until tested. 6.2.3. Alternate Method Using 0.425-mm (No. 40) SieveThe sample shall be processed as described in T 146, the portions retained on an
42、d passing the 0.425-mm sieve shall be weighed, and the subsamples for hydrometer analysis and hygroscopic moisture determination shall be obtained by use of a riffle sampler or sample splitter, and either weighed immediately or placed in airtight containers until tested. Note 5Most laboratories prep
43、are the sample in accordance with Section 5.2.1 of R 58, which provides for splitting the original sample on the 2.00-mm sieve. Hereafter in this method the triple designation, 4.75-mm, or 2.00-mm, or 0.425-mm sieve, is not used. When reference to the fraction retained or passing the 2.00-mm sieve i
44、s used, the 4.75-mm sieve is implied if the sample was processed in accordance with Section 6.2.1, and the 0.425-mm sieve is implied if the sample was processed in accordance with Section 6.2.3. 7. SIEVE ANALYSIS OF FRACTION RETAINED ON 2.00-MM (NO. 10) SIEVE 7.1. The portion of the sample retained
45、on the 2.00-mm (No. 10) sieve shall be separated into a series of sizes by the use of the 75, 50, 25.0, 9.5, and 4.75-mm (3 in., 2 in., 1 in., 3/8in., and the No. 4) sieves, and using other sieves as may be needed depending on the sample or upon the specification for the material being tested. The 2
46、.00-mm sieve shall be used if the sample was prepared in accordance with T 146. 7.2. The sieving operation shall be conducted by means of a lateral and vertical motion of the sieve, accomplished by jarring action so as to keep the sample moving continuously over the surface of the sieve. In no case
47、shall fragments in the sample be turned or manipulated through the sieve by hand. Sieving shall be continued until not more than 1 percent by mass of the residue passes any sieve during 60 s. When sieving machines are used, their thoroughness of sieving shall be tested by comparison with hand method
48、s of sieving as described in this paragraph. 7.3. The portion of the sample retained on each sieve shall be weighed and the mass recorded, although it shall be permissible to record the accumulated masses as the contents of each successive sieve are added to the fractions previously deposited on the
49、 scales pan. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1a T 88-9 AASHTO HYDROMETER AND SIEVE ANALYSIS OF FRACTION PASSING THE 2.00-MM SIEVE 8. DETERMINATION OF COMPOSITE CORRECTION FOR HYDROMETER READING 8.1. Equations for percentages of soil remaining in suspension, as given in Section 16.3, are based on the use of distilled or demineralized water. A dispersing agent is used in the water, how
