Aashto

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classification of soils and soil-Aggregate Mixtures for v Highway Construction purposesr-This standard is issued under the fixed desigmtion D3282; rhe number irnmerliately following thedesignarion indi'cates the year of ttriginal adoption or' in the case of revision, the yar of last revision. A number in parentheses irulicates the year of last reapproval. A supencript epsilon (e) indicatesan editorial change since the last revision or reapproval.
7'his standanl

Standard Practíce for

ht* been appntedJor use by agencies ofthe l)eparrment ofDefense.

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Scope

Thispractice covers a procedure for classifing mineral and orsanomineral soils into seven groups based on liboratory determjnation of particle-size disrribuiion, liquid limit, aná plasticity index. It may beused when a precise engineering classification is required, especially fbr highway construction purposes. Evaluation of soils within each group is rnade by means of a grozrp index. which is a valuecalcujated from an enrpirical fomrula,
N-ort
useful in determining the relative quality ofihe so¡t mate¡a1 for use in eartbrvork struch;res, particularly embankments, subgrades, subbases, and basss.Horvever fbr the detailed design of important"structures, additional data. concerning strengtl or perfonnánce chücteristics of the soil under field conditions will usually be required.

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2.Referenced Documents
2.1 ASTM Standards: 2 D 420 Gr¡ide to Site Characterization for Engineering, De-

D42l

sign. and Construction purposes Practice for Dry preparation of Soil Samples lorParticle-Size Analysis and Determination of Soil Con_
stants

I -'Ihe group classification.

including the group index, should be

1.2 This standard does not purport to address all of the ,salbn,concerns, i/' any, assoc¡atál with its use. It is the re:sponsibilíty oJ'the user oJ'this standatcl to establish appra_ priate safety and health pracfices ant] cletermine the appiica_ bili4, r¡ rufu¡otorv-...