1、Designation: D3282 15Standard Practice forClassification of Soils and Soil-Aggregate Mixtures forHighway Construction Purposes1This standard is issued under the fixed designation D3282; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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 U.S. Department of Defense.1. Scope*1.1 This practice co
3、vers a procedure for classifying mineraland organomineral soils into seven groups based on laboratorydetermination of particle-size distribution, liquid limit, andplasticity index. It may be used when a precise engineeringclassification is required, especially for highway constructionpurposes. Evalu
4、ation of soils within each group is made bymeans of a group index, which is a value calculated from anempirical formula.NOTE 1The group classification, including the group index, should beuseful in determining the relative quality of the soil material for use inearthwork structures, particularly emb
5、ankments, subgrades, subbases, andbases. However, for the detailed design of important structures, additionaldata concerning strength or performance characteristics of the soil underfield conditions will usually be required.1.2 UnitsThe sieve designations are identified using the“standard” system in
6、 accordance with Specification E11, suchas 75-mm and 75-m, followed by the “alternative” system of3-in. and No. 200, respectively.1.3 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 to establis
7、h appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This practice offers a set of instructions for performingone or more specific operations. This practice cannot replaceeducation or experience and should be used in conjunctionwith p
8、rofessional judgment. Not all aspects of this practice maybe applicable in all circumstances. This practice is notintended to represent or replace the standard of care by whichthe adequacy of a given professional service must be judged,nor should this practice be applied without consideration of apr
9、ojects many unique aspects. The word “Standard” in thetitle of this document means only that the document has beenapproved through the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D421 Practice for Dry Preparation of Soil Samples forParticle-Size Analysis and Determination of So
10、il Con-stantsD422 Test Method for Particle-Size Analysis of SoilsD653 Terminology Relating to Soil, Rock, and ContainedFluidsD1140 Test Methods for Determining the Amount of Mate-rial Finer than 75-m (No. 200) Sieve in Soils by WashingD1452 Practice for Soil Exploration and Sampling by AugerBoringsD
11、1586 Test Method for Penetration Test (SPT) and Split-Barrel Sampling of SoilsD1587 Practice for Thin-Walled Tube Sampling of Soils forGeotechnical PurposesD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and Const
12、ructionD4318 Test Methods for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsD4700 Guide for Soil Sampling from the Vadose ZoneD6913 Test Methods for Particle-Size Distribution (Grada-tion) of Soils Using Sieve AnalysisE11 Specification for Woven Wire Test Sieve Cloth and TestSieves2.2 AAS
13、HTO Document:3M 145 The Classification of Soils and Soil Aggregate Mix-tures for Highway Construction Purposes3. Terminology3.1 Definitions of Terms Specific to This Standard:1Thispractice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommitte
14、e D18.07 on Identification andClassification of Soils.Current edition approved Nov. 1, 2015. Published December 2015. Originallyapproved in 1973. Last previous edition approved in 2009 as D3282 09. DOI:10.1520/D3282-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact A
15、STM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC
16、20001,http:/www.transportation.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.1 The following terms are frequently used in this prac-tice. These terms differ sl
17、ightly from those given in Terminol-ogy D653, but are used here to maintain consistency withcommon highway usage.3.1.2 bouldersparticles of rock with a minimum dimen-sion of 305-mm (12-in.) or more.3.1.3 cobblesparticles of rock with a minimum dimensionof less than 305-mm (12-in.) and be retained on
18、 a 75-mm(3-in.) sieve.3.1.4 gravelparticles of rock that will pass a 75-mm(3-in.) sieve and be retained on a 2-mm (No. 10) sieve.3.1.5 coarse sandparticles of rock or soil that will pass a2-mm (No. 10) sieve and be retained on a 425-m (No. 40)sieve.3.1.6 fine sandparticles of rock or soil that will
19、pass a425-m (No. 40) sieve and be retained on a 75-m (No. 200)sieve.3.1.7 silt-clay (combined silt and clay)fine soil and rockparticles that will pass a 75-m (No. 200) sieve.3.1.8 siltyfine-grained material that has a plasticity indexof 10 or less.3.1.9 clayeyfine-grained material that has a plastic
20、ityindex of 11 or more.3.1.10 irreversible mineral colloid, nin soils, certain min-erals such as feldspars, when weathered bind with water toform clay minerals containing interlayer moisture, that whendried above 50C, permanently lose this structural moisture.3.1.10.1 DiscussionThe dewatering proces
21、s changes thenature of the mineralogy. This permanent dehydration has beenshown to reduce plasticity, increase particle size and maypotentially skew the soil classification3.1.11 stone fragmenta small piece of rock that has beenmechanically broken from a larger stone.NOTE 2The terminology used above
22、 differs from terminology used inTerminology D653. The above terminology conforms in part to AASHTOstandard M 145.4. Significance and Use4.1 The practice described classifies soils from any geo-graphic location into groups (including group indexes) basedon the results of prescribed laboratory tests
23、to determine theparticle-size characteristics, liquid limit, and plasticity index.4.2 The assigning of a group symbol and group index can beused to aid in the evaluation of the significant properties of thesoil for highway and airfield purposes.4.3 The various groupings of this classification system
24、correlate in a general way with the engineering behavior ofsoils. Also, in a general way, the engineering behavior of a soilvaries inversely with its group index. Therefore, this practiceprovides a useful first step in any field or laboratory investi-gation for geotechnical engineering purposes.NOTE
25、 3The quality of the result produced by this standard isdependent upon the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/
26、inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluation some of those factors.5. Apparatus5.1 Apparatus for Preparation of SamplesSee Pract
27、iceD421.5.2 Apparatus for Particle-Size AnalysisSee Test MethodsD1140, D422, and D6913.5.3 Apparatus for Liquid Limit and Plastic Limit TestsSeeTest Methods D4318.6. Sampling6.1 Conduct field investigations and sampling in accordancewith one or more of the following procedures:6.1.1 Guide D4700,6.1.
28、2 Practice D1452,6.1.3 Test Method D1586, and6.1.4 Practice D1587.7. Test Samples and Testing Procedures7.1 Prepare test specimens and perform testing in accor-dance with the following procedures:7.1.1 Test Samples and Testing for Particle-Size AnalysisUse either Test Methods D1140, D422 or D6913.7.
29、1.2 Test Samples and Testing for Liquid Limit and PlasticLimit TestsUse Test Method D43188. Classification Procedure8.1 Using the test data determined by the methods inSection 7, classify the soil into the appropriate group orsubgroup, or both, in accordance with Table 1 or Table 2. UseFig. 1 to cla
30、ssify silt-clay materials on the basis of liquid limitand plasticity index values. Classification of materials in thevarious groups applies only to the fraction passing the 75-mm(3-in.) sieve. Boulders and cobbles shall be excluded from theportion of the sample to be classified. However, the percent
31、ageof such material, if any, shall be recorded.8.1.1 All limiting values are shown as whole numbers. Iffractional numbers appear on test reports, convert to the nearestwhole numbers for the purpose of classification.8.1.2 With the required test data available, proceed from leftto right in Table 1 or
32、 Table 2 and the correct classification willbe found by the process of elimination. The first group from theleft into which the test data will fit is the correct classification.NOTE 4Classification of materials in the various groups applies onlyto the fraction passing the 75-mm (3-in.) sieve. Theref
33、ore, any specifica-tion regarding the use of soil and soil-aggregate mixtures in constructionshould state whether boulders, or cobbles, or both, are permitted.9. Description of Classification Groups9.1 Granular Materials, containing 35 % or less passing the75-m (No. 200) sieve:9.1.1 Group A-1The typ
34、ical material of this group is awell-graded mixture of stone fragments or gravel, coarse sand,fine sand, and a nonplastic or feebly-plastic soil binder.However, this group also includes stone fragments, gravel,coarse sand, volcanic cinders, etc., without a soil binder.D3282 1529.1.1.1 Subgroup A-1-a
35、 includes those materials consistingpredominantly of stone fragments or gravel, either with orwithout a well-graded binder of fine material.9.1.1.2 Subgroup A-1-b includes those materials consistingpredominantly of coarse sand, either with or without a well-graded soil binder.9.1.2 Group A-3The typi
36、cal material of this group is finebeach sand or fine desert-blown sand without silty or clayeyfines, or with a very small amount of nonplastic silt. This groupalso includes stream-deposited mixtures of poorly-graded finesand and limited amounts of coarse sand and gravel.9.1.3 Group A-2This group inc
37、ludes a wide variety of“granular” materials which are borderline between the materi-als falling in GroupsA-1 andA-3, and the silt-clay materials ofGroups A-4, A-5, A-6, and A-7. It includes all materialscontaining 35 % or less passing a 75-m (No. 200) sieve whichcannot be classified in Groups A-1 or
38、 A-3, due to the finescontent or the plasticity indexes, or both, in excess of thelimitations for those groups.9.1.3.1 SubgroupsA-2-4 andA-2-5 include various granularmaterials containing 35 % or less passing a 75-m (No. 200)sieve and with a minus 425-m (No. 40) portion having thecharacteristics of
39、Groups A-4 and A-5, respectively. Thesegroups include such materials as gravel and coarse sand withsilt contents or plasticity indexes in excess of the limitations ofGroup A-1 and fine sand with nonplastic-silt content in excessof the limitations of Group A-3.9.1.3.2 Subgroups A-2-6 and A-2-7 includ
40、e materials simi-lar to those described under Subgroups A-2-4 and A-2-5,except that the fine portion contains plastic clay having thecharacteristics of the A-6 or A-7 group, respectively.9.2 Silt-Clay Materials, containing more than 35 % passinga 75-m (No. 200) sieve:9.2.1 Group A-4The typical mater
41、ial of this group is anonplastic or moderately plastic silty soil usually having 75 %or more passing a 75-m (No. 200) sieve. This group alsoincludes mixtures of fine silty soil and up to 64 % of sand andgravel retained on a 75-m (No. 200) sieve.9.2.2 Group A-5The typical material of this group issim
42、ilar to that described under Group A-4, except that it isusually of diatomaceous or micaceous character and may behighly elastic as indicated by the high liquid limit.9.2.3 Group A-6The typical material of this group is aplastic clay soil usually having 75 % or more passing a 75-m(No. 200) sieve. Th
43、is group also includes mixtures of fineclayey soil and up to 64 % of sand and gravel retained on aTABLE 1 Classification of Soils and Soil-Aggregate MixturesGeneral ClassificationGranular Materials35 % or Less Passing 75 m (No. 200)Silt-Clay MaterialsMore Than 35 % Passing 75 m (No. 200)Group Classi
44、fication A-1 A-3AA-2 A-4 A-5 A-6 A-7Sieve analysis, % passing:2.00 mm (No. 10) . . . . . . .425 m (No. 40) 50 max 51 min . . . . .75 m (No. 200) 25 max 10 max 35 max 36 min 36 min 36 min 36 minCharacteristics of fraction passing 425 m(No. 40):Liquid LimitPlasticity Index.6 max.N.P.BB40 max10 max41 m
45、in10 max40 max11 min41 min11 minGeneral rating as subgrade Excellent to Good Fair to PoorAThe placing of A-3 before A-2 is necessary in the “left to right elimination process” and does not indicate superiority of A-3 over A-2.BSee Table 2 for values.Reprinted with permission of American Association
46、of State Highway and Transportation OfficialsTABLE 2 Classification of Soils and Soil-Aggregate MixturesGeneral ClassificationGranular Materials35 % or Less Passing 75 m (No. 200)Silt-Clay MaterialsMore Than 35 % Passing 75 m (No. 200)Group ClassificationA-1A-3A-2A-4 A-5 A-6A-7A-1-a A-1-b A-2-4 A-2-
47、5 A-2-6 A-2-7A-7-5,A-7-6Sieve analysis, % passing:2.00 mm (No. 10) 50 max . . . . . . . . . .425 m (No. 40) 30 max 50 max 51 min . . . . . . . .75 m (No. 200) 15 max 25 max 10 max 35 max 35 max 35 max 35 max 36 min 36 min 36 min 36 minCharacteristics of fraction passing425 m (No. 40):Liquid LimitPla
48、sticity Index.6 max.N.P.40 max10 max41 min10 max40 max11 min41 min11 min40 max10 max41 min10 max40 max11 min41 min11 minAUsual types of significantconstituent materialsStone Fragments,Gravel and SandFineSandSilty or Clayey Gravel and Sand Silty Soils Clayey SoilsGeneral rating as subgrade Excellent
49、to Good Fair to PoorAPlasticity index of A-7-5 subgroup is equal to or less than LL minus 30. Plasticity index of A-7-6 subgroup is greater than LL minus 30 (see Fig. 1).Reprinted with permission of American Association of State Highway and Transportation Officials.D3282 15375-m (No. 200) sieve. Materials of this group usually have ahigh volume change between wet and dry states.9.2.4 Group A-7The typical material of this group issimilar to that described under GroupA-6, except that it has thehigh liquid limits characteristic
