ASTM_D_7981_-_20.pdf

Designation:D798120Standard Practice forCompaction of Prismatic Asphalt Specimens by Means ofthe Shear Box Compactor1This standard is issued under the fixed designation D7981;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.1.Scope1.1 This practice covers the fabrication of prismatic speci-mens of asphalt mixture using the shear box compactor(SBC).Compacted specimens are suitable for volumetric and physicalproperty testing.This standard practice should not be used foracceptance or rejection of a material or for purchasing pur-poses.1.2 UnitsThe values stated in SI units are to be regardedas standard.No other units of measurement are included in thisstandard with exception of degrees()where angle is specified.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 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D2041/D2041M Test Method for Theoretical MaximumSpecific Gravity and Density of Asphalt MixturesD2726/D2726M Test Method for Bulk Specific Gravity andDensity of Non-Absorptive Compacted Asphalt MixturesD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD6752/D6752M Test Method for Bulk Specific Gravity andDensity of Compacted Asphalt Mixtures Using AutomaticVacuum Sealing MethodD6857/D6857M Test Method for Maximum Specific Grav-ity and Density of Asphalt Mixtures Using AutomaticVacuum Sealing MethodE644 Test Methods for Testing Industrial Resistance Ther-mometers2.2 AASHTO Standards:3AASHTO T 378 Standard Method of Test for Determiningthe Dynamic Modulus and Flow Number for AsphaltMixtures Using the Asphalt Mixture Performance Tester(AMPT)AASHTO T 321 Standard Method of Test for Determiningthe Fatigue Life of Compacted Asphalt Mixtures Sub-jected to Repeated Flexural BendingAASHTO T 342 Standard Method of Test for DeterminingDynamic Modulus of Hot-MixAsphalt Concrete Mixtures3.Terminology3.1 Definitions:3.1.1 load cyclethe angular movement of the shearingplatens in the compactor going from the vertical position to theposition of maximum shear angle at one side,then going to themaximum shear angle at the other side and back to the verticalposition(90 6 0.25 with reference to the horizontal plane).3.1.2 shear anglethe external angle measured between avertical plane(angle of 90 with respect to a horizontal plane)and the plane formed by a shearing plate in the compactorwhen it has reached its maximum travel.Set at 4.4.Summary of Practice4.1 A sample of loose asphalt mixture is compacted in afully automatic apparatus by the combination of a staticvertical force and a horizontal cyclic shear force applied totwin vertical parallel platens up to a fixed maximum shear1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.20 onMechanical Tests of Asphalt Mixtures.Current edition approved March 15,2020.Published March 2020.Originallyapproved in 2015.Last previous edition approved in 2015 as D7981 15.DOI:10.1520/D7981-20.2For 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.3Available from American Association of State Highway and TransportationOfficials(AASHTO),444 N.Capitol St.,NW,Suite 249,Washington,DC 20001,http:/www.transportation.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.angle,to produce a prismatic specimen of compacted asphalt toa target uncorrected density(that is,based on the geometricvolume of the specimen).5.Sign