ASTM_D_7981_-_15.pdf

Designation:D798115Standard 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 andphysical property testing.This standard practice should not beused for acceptance or rejection of a material or for purchasingpurposes.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 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.1.4 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.2.Referenced Documents2.1 ASTM Standards:2D1188 Test Method for Bulk Specific Gravity and Density ofCompacted Bituminous Mixtures Using Coated SamplesD2041 Test Method for Theoretical Maximum SpecificGravity and Density of Bituminous Paving MixturesD2726 Test Method for Bulk Specific Gravity and Densityof Non-Absorptive Compacted Bituminous MixturesD3666 Specification for Minimum Requirements for Agen-cies Testing and Inspecting Road and Paving MaterialsD6752 Test Method for Bulk Specific Gravity and Densityof Compacted Bituminous Mixtures Using AutomaticVacuum Sealing MethodD6857 Test Method for Maximum Specific Gravity andDensity of Bituminous Paving Mixtures Using AutomaticVacuum Sealing MethodD6925 Test Method for Preparation and Determination ofthe Relative Density of Asphalt Mix Specimens by Meansof the Superpave Gyratory CompactorE644 Test Methods for Testing Industrial Resistance Ther-mometers2.2 AASHTO Standards:3AASHTO TP79 Standard Method of Test for Determiningthe Dynamic Modulus and Flow Number for Hot MixAsphalt(HMA)Using the Asphalt Mixture PerformanceTesterAASHTO T321 Standard Method of Test for Determiningthe Fatigue Life of Compacted Hot Mix Asphalt(HMA)Subjected to Repeated Flexural BendingAASHTO T342 Standard Method of Test for DeterminingDynamic Modulus of Hot Mix Asphalt 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 shearangle,to produce a prismatic specimen of compacted asphalt to1This 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 Aug.1,2015.Published September 2015.DOI:10.1520/D7981-15.2For 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 States1 a target uncorrected density(that is,based on the geometricvolume of the specimen).5.Significance and Use5.1 Asphalt prisms compacted with the Shear Box Compac-tor can be used to obtain specimens for further testing,including bulk specific gravity following Test Methods D6752and D2726,Dynamic modulus following AASHTO T342,dynamic modulus,flow number,and flow time followingAASHTO TP79,and fatigue performance characteristics fol-lowing AASHTO T321.5.2 Specimens to perform other standard tests could also beobtained,as long as their volume is contained within thevolume