ASTM_D_4791_-_10.pdf

Designation:D479110Standard Test Method forFlat Particles,Elongated Particles,or Flat and ElongatedParticles in Coarse Aggregate1This standard is issued under the fixed designation D4791;the number immediately following the designation indicates the year oforiginal adoption or,in 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 U.S.Department of Defense.1.Scope1.1 This test method covers the determination of the per-centages of flat particles,elongated particles,or flat andelongated particles in coarse aggregates.Two procedures,Method A and Method B,are presented in this standard.MethodAis a reflection of the original procedure as developedprior to Superpave and is intended for all non-Superpaveapplications.Method B is a comparison of the maximumparticle dimension to the minimum particle dimension and isintended for use with Superpave specifications.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.2.1 Exception(Regarding sieves,per SpecificationE11)The values stated in SI units shall be considered standard forthe dimensions of the wire cloth openings and the diameter ofthe wires used in the wire cloth.When sieve mesh sizes arereferenced,the alternate inch-pound designations are providedfor information purposes and enclosed in parenthesis.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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsC702 Practice for Reducing Samples ofAggregate to TestingSizeD75 Practice for Sampling AggregatesE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Terminology3.1 Definitions:3.1.1 elongated particles of aggregatethose particles ofaggregate having a ratio of length to width greater than aspecified value.3.1.2 flat and elongated particles of aggregatethose par-ticles having a ratio of length to thickness greater than aspecified value.3.1.3 flat particles of aggregatethose particles of aggre-gate having a ratio of width to thickness greater than a specifiedvalue.3.1.4 lengthmaximum dimension of the particle,as illus-trated in Fig.1.3.1.5 thicknessminimum dimension of particle.It is themaximum dimension perpendicular to the length and width asillustrated in Fig.1.3.1.6 widthintermediate dimension of the particle.It is themaximum dimension in the plane perpendicular to the lengthand thickness.The width dimensions is greater than or equal tothe thickness as illustrated in Fig.1.4.Summary of Test Method4.1 Individual particles of aggregate of specific sieve sizesare measured to determine the ratios of width to thickness,length to width,or length to thickness.5.Significance and Use5.1 The particles shape of course aggregates influences theproperties of some construction materials and may affect theirplacement and consolidation.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.51 onAggregate Tests.Current edition approved June 1,2010.Published October 2010.Originallyapproved in 1989.Last previous edition approved in 2005 as D4791 05e1.DOI:10.1520/D4791-10.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.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 5.2 This test method provides a means for checking com-pliance with specifications that limit such particles or todetermine the relative shape characteristics of coarse aggre-gates.6.Apparatus6.1 The apparatus used shall be equipment suitable fortesting aggregate particles for compliance with the definitionsin 3.1,at the dimensional ratios desired.6.1.1 Proportional Caliper DeviceThe proportional cali-per devices illustrated in Fig.2 and Fig.3 are examples ofdevices suitable for this test method.The device illustrated inFig.2 and consists of a base plate with two fixed posts and aswinging arm mounted between them so that the openingsbetween the arms and the posts maintain a constant ratio.Theaxis position can be adjusted to provide the desired ratio ofopening dimensions.Fig.2 illustrates a device on which ratiosof 1:2,1:3,and 1:5 may be