ASTM_D_6816_-_11.pdf

Designation:D681611Standard Practice forDetermining Low-Temperature Performance Grade(PG)ofAsphalt Binders1This standard is issued under the fixed designation D6816;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 calculation of low-temperatureproperties of asphalt binders using data from the bending beamrheometer(see Test Method D6648)(BBR)and the directtension tester(see Test Method D6723)(DTT).It can be usedon data from unaged material or from material aged using TestMethod D2872(RTFOT),Practice D6521(PAV),or TestMethod D2872(RTFOT)and Practice D6521(PAV).It can beused on data generated within the temperature range from+6C to-36C.This practice generates data suitable for use inbinder specifications such as Specification D6373.1.2 This practice is only valid for data on materials that fallwithin the scope of suitability for both Test Method D6648 andTest Method D6723.1.3 This practice can be used to determine the following:1.3.1 Critical cracking temperature of an asphalt binder,and1.3.2 Whether or not the failure stress exceeds the thermalstress in a binder at a given temperature.1.4 This practice determines the critical cracking tempera-ture for a typical asphalt binder based on the determination ofthe temperature where the asphalt binders strength equals itsthermal stress as calculated by this practice.The temperature sodetermined is intended to yield a low temperature PG Grade ofthe sample being tested.The low temperature PG grade isintended for use in purchase specifications and is not intendedto be a performance prediction of the HMA(Hot Mix Asphalt)in which the asphalt binder is used.1.5 The development of this standard was based on SI units.In cases where units have been omitted,SI units are implied.1.6 This standard may involve hazardous materials,operations,and equipment.This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1The algorithms contained in this standard require implemen-tation by a person trained in the subject of numerical methods andviscoelasticity.However,due to the complexity of the calculations theymust,of necessity,be performed on a computer.Software to perform thecalculation may be written,purchased as a spreadsheet,or as a stand-aloneprogram.22.Referenced Documents2.1 ASTM Standards:3C670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD8 Terminology Relating to Materials for Roads and Pave-mentsD2872 Test Method for Effect of Heat and Air on a MovingFilm of Asphalt(Rolling Thin-Film Oven Test)D6373 Specification for Performance Graded AsphaltBinderD6521 Practice for Accelerated Aging of Asphalt BinderUsing a Pressurized Aging Vessel(PAV)D6648 Test Method for Determining the Flexural CreepStiffness of Asphalt Binder Using the Bending BeamRheometer(BBR)D6723 Test Method for Determining the Fracture Propertiesof Asphalt Binder in Direct Tension(DT)3.Terminology3.1 DefinitionsFor definitions of general terms used in thisstandard,refer to Terminology D8.3.2 Definitions of Terms Specific to This Standard:3.2.1 Arrhenius parameter,a1,nthis is the constant coef-ficient in the Arrhenius model for shift factors:ln(aT)=a1(1/T)(1/Tref).3.2.2 coeffcient of linear thermal expansion,nthefractional change in size in one dimension associated with atemperature increase of 1C.1This practice is under the jurisdiction of ASTM Committee D04 on Road andPaving Materials and is the direct responsibility of Subcommittee D04.44 onRheological Tests.Current edition approved July 1,2011.Published August 2011.Originallyapproved in 2002.Last previous edition approved in 2002 as D6816 02 which waswithdrawn 2007 and reinstated in July 2011.DOI:10.1520/D6816-11.2The sole source of supply of the software package TSAR known to thecommittee at this time is Abatech,Incorporated.If you are aware of alternativesuppliers,please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee1,which you may attend.3For 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 3.2.3 creep compliance,D(T,t),nthe reciprocal of thestiffness of a material,1/S(T,t),at temperature T and time t,which may also be