1、Designation:D42185(Reapproved 2007)Standard Practice forDry Preparation of Soil Samples for Particle-Size Analysisand Determination of Soil Constants1This standard is issued under the fixed designation D421;the number immediately following the designation indicates the year oforiginal adoption or,in
2、 the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This pra
3、ctice covers the dry preparation of soil samplesas received from the field for particle-size analysis and thedetermination of the soil constants.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard
4、 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2217 Practice for Wet Preparation of Soil Samples forParticle-Size Analysis and Determination of Soil Con-stantsE11 Specification
5、for Woven Wire Test Sieve Cloth and TestSieves3.Significance and Use3.1 This practice can be used to prepare samples forparticle-size and plasticity tests where it is desired to determinetest values on air-dried samples,or where it is known that airdrying does not have an effect on test results rela
6、tive to samplesprepared in accordance with Practice D2217.4.Apparatus4.1 Balance,sensitive to 0.1 g.4.2 Mortar and Rubber-Covered Pestle,suitable for break-ing up the aggregations of soil particles.4.3 SievesA series of sieves,of square mesh woven wirecloth,conforming to Specification E11.The sieves
7、 required areas follows:No.4(4.75-mm)No.10(2.00-mm)No.40(425-m)4.4 SamplerA riffle sampler or sample splitter,for quar-tering the samples.5.Sampling5.1 Expose the soil sample as received from the field to theair at room temperature until dried thoroughly.Break up theaggregations thoroughly in the mo
8、rtar with a rubber-coveredpestle.Select a representative sample of the amount required toperform the desired tests by the method of quartering or by theuse of a sampler.The amounts of material required to performthe individual tests are as follows:5.1.1 Particle-Size AnalysisFor the particle-size an
9、alysis,material passing a No.10(2.00-mm)sieve is required inamounts equal to 115 g of sandy soils and 65 g of either silt orclay soils.5.1.2 Tests for Soil ConstantsFor the tests for soil con-stants,material passing the No.40(425-m)sieve is requiredin total amount of 220 g,allocated as follows:TestG
10、ramsLiquid limit100Plastic limit15Centrifuge moisture equivalent10Volumetric shrinkage30Check tests656.Preparation of Test Sample6.1 Select that portion of the air-dried sample selected forpurpose of tests and record the mass as the mass of the total testsample uncorrected for hygroscopic moisture.S
11、eparate the testsample by sieving with a No.10(2.00-mm)sieve.Grind thatfraction retained on the No.10 sieve in a mortar with arubber-covered pestle until the aggregations of soil particlesare broken up into the separate grains.Then separate theground soil into two fractions by sieving with a No.10 s
12、ieve.6.2 Wash that fraction retained after the second sieving freeof all fine material,dry,and weigh.Record this mass as the1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.03 on Texture,Plasticityand Density Characte
13、ristics of Soils.Current edition approved Sept.1,2007.Published September 2007.Originallyapproved in 1935.Last previous edition approved in 2002 as D421 85(2002).DOI:10.1520/D0421-85R07.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.
14、org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 mass of coarse material.Sieve the coarse material,after beingwashed an
15、d dried,on the No.4(4.75-mm)sieve and record themass retained on the No.4 sieve.7.Test Sample for Particle-Size Analysis7.1 Thoroughly mix together the fractions passing the No.10(2.00-mm)sieve in both sieving operations,and by themethod of quartering or the use of a sampler,select a portionweighing
16、 approximately 115 g for sandy soils and approxi-mately 65 g for silt and clay soil for particle-size analysis.8.Test Sample for Soil Constants8.1 Separate the remaining portion of the material passingthe No.10(2.00-mm)sieve into two parts by means of a No.40(425-m)sieve.Discard the fraction retained on the No.40sieve.Use the fraction passing the No.40 sieve for thedetermination of the soil constants.9.Keywords9.1 dry preparation;particle-size analysis;soilASTM International takes no position re
