1、Designation:D2940/D2940M15Standard Specification forGraded Aggregate Material For Bases or Subbases forHighways or Airports1This standard is issued under the fixed designation D2940/D2940M;the number immediately following the designation indicates theyear of original adoption or,in the case of revis
2、ion,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript 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.Scope1.1 This specification cov
3、ers quality-controlled graded ag-gregates that,when hauled to and properly spread and com-pacted on a prepared grade to appropriate density standards,may be expected to provide adequate stability and load supportfor use as highway or airport bases or subbases.NOTE1The engineer is cautioned to provid
4、e appropriate constructionspecifications to ensure compaction to an extent that further densificationfrom traffic loadings on the completed pavement will be insignificant.Themethod suggested is to require compaction on a firm foundation of a shortcontrol strip of the material at a suitable moisture
5、content,by means ofvibratory or other proven effective rollers or tampers,until no furtherincrease in density results.Compaction requirements should ensure that anaverage density of certain appropriate percentages of the control stripmaximum density be achieved on the balance of the job;for base cou
6、rses,98%is suggested as the minimum average requirement.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues fro
7、m the two systems may result in non-conformancewith the standard.1.3 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)shall not be consideredas requirements of the standard.1.4 This standard doe
8、s not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standard
9、s:2C136 Test Method for Sieve Analysis of Fine and CoarseAggregatesD75 Practice for Sampling AggregatesD422 Test Method for Particle-Size Analysis of SoilsD2419 Test Method for Sand Equivalent Value of Soils andFine AggregateD4318 Test Methods for Liquid Limit,Plastic Limit,andPlasticity Index of So
10、ilsD4792 Test Method for Potential Expansion of Aggregatesfrom Hydration ReactionsD5821 Test Method for Determining the Percentage ofFractured Particles in Coarse AggregateE105 Practice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision
11、,the Average for a Characteristic of aLot or Process3.General Requirements3.1 Coarse aggregate retained on the 4.75-mm(No.4)sieveshall consist of durable particles of crushed stone,gravel,orslag capable of withstanding the effects of handling,spreading,and compacting without degradation productive o
12、f deleteriousfines.Of the particles which are retained on a 9.5-mm 38-in.sieve,at least 75%shall have two or more fractured faces.NOTE2No standard ASTM method is recognized to be capable ofmeasuring the quality,or tendency of coarse aggregate to degrade to theextent that deleterious fines may be pro
13、duced.Some local jurisdictionshave developed tests believed to be of value in this respect.The purchaserof material under this specification is advised to investigate the availabilityand reliability of such tests in order to specify quality requirementsappropriate to the local area.3.1.1 The fractur
14、ed particle requirement of 3.1 is modifiedwhen specified in the contract documents,providing for the use1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.50 onAggregate Specifications.Current edition a
15、pproved June 1,2015.Published July 2015.Originally approvedin 1971.Last previous edition approved in 2009 as D2940/D2940M 09.DOI:10.1520/D2940_D2940M-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStanda
16、rds 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 of another method for measuring interparticle friction whichhas been correlated with good field performance.3.2 Fine aggregate passing the 4.75-mm(No.4)sieve shallnormally consist of fines from the operation of crushing thecoarse aggregate.Where available and suitable,addition ofnatural sand or finer m
