AASHTO-R-29-2008

TS-2bR29-1AASHTOStandardPracticeforGradingorVerifyingthePerformanceGrade(PG)ofanAsphaltBinderAASHTODesignation:R29-081.SCOPE1.1.Thispracticedescribesthetestingrequiredtodeterminetheperformancegrade(PG)ofanasphaltbinderaccordingtoM320,Table1.Itpresentstwoapproaches.Inthefirst,thePGofanunknownasphaltbinderisdetermined.Inthesecond,thenominalPGofanasphaltbinderisverified.Italsoprovidesanestimateofthetimerequiredtocompleteasingletestsequence.1.2.Thisstandardmayinvolvehazardousmaterials,operations,andequipment.Thisstandarddoesnotpurporttoaddressallofthesafetyconcernsassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.2.REFERENCEDDOCUMENTS2.1.AASHTOStandards:M320,Performance-GradedAsphaltBinderR28,AcceleratedAgingofAsphaltBinderUsingaPressurizedAgingVessel(PAV)T48,FlashandFirePointsbyClevelandOpenCupT240,EffectofHeatandAironaMovingFilmofAsphalt(RollingThin-FilmOvenTest)T313,DeterminingtheFlexuralCreepStiffnessofAsphaltBinderUsingtheBendingBeamRheometer(BBR)T314,DeterminingtheFracturePropertiesofAsphaltBinderinDirectTensionT315,DeterminingtheRheologicalPropertiesofAsphaltBinderUsingaDynamicShearRheometer(DSR)T316,ViscosityDeterminationofAsphaltBinderUsingRotationalViscometer3.SUMMARYOFTHEPRACTICE3.1.Thetank(as-received)sampleofasphaltbinderistestedtodeterminetheflashpoint(T48),viscosityat135°C(T316),andshearmodulus(G*)andphaseangle(δ)(T315).3.2.Theasphaltbinderisagedintherollingthin-filmoven(T240),andtheresidueistestedtodeterminethemasschange(T240)andtheshearmodulus(G*)andphaseangle(δ)(T315).3.3.Theresiduefromtherollingthin-filmoven(RTFO)isagedinthepressurizedagingvessel(R28),andthisresidueistestedtodeterminetheshearmodulus(G*)andphaseangle(δ)(T315),creepstiffness(S)andslope,m,ofthelogcreepstiffnessversuslogtimerelationshipat60seconds(T313),andthefailurestrainindirecttension(T314),asnecessary.TS-2bR29-2AASHTO3.4.BasedonthesetestresultstheasphaltbinderisgradedaccordingtoM320,Table1.4.SIGNIFICANCEANDUSE4.1.ThispracticedescribesthetestingrequiredforgradingorverifyingthePGofanasphaltbinderaccordingtoM320,Table1.5.ESTIMATEDTIMENECESSARYFORTESTING5.1.Forbothgradingandverification,iftheanalysisisstartedatthebeginningofamorningworkshift,alltestingandanalysisshouldbecompletedduringtheafternoonofthenextday.Thisscheduleprovidesthe20hoursneededforPAVconditioning.Ofcourse,samplescanbeagedandanalyzedinparallel,andtheproductivityofthelaboratorythusincreased.However,forthepurposeofthisdocument,analysisofasingleasphaltbinderwillbediscussed.6.TESTPROCEDUREFORGRADINGANUNKNOWNASPHALTBINDER6.1.Preparesamplesandtestspecimensusingtheproceduresspecifiedintheapplicabletestmethods.Inthecasewherethegradeoftheasphaltbinderisunknown,approximately400gofunagedasphaltbinderisrequiredtocompletethetestswiththenecessaryreplicates.6.2.BeginconditioningasphaltbinderintheRTFO.Conditionasufficientamountofasphaltbinderdependingonthetypeandnumberofteststobeperformed.Note1—TwoBBRbeamsrequiringPAVagedmaterialareneededateachtesttemperature.Inaddition,atleastsixdirecttension(DT)specimensrequiringPAVagedmaterialmayalsobeneededateachtesttemperature.Aminimumoftwotesttemperatureswillberequired.Thistestingwillutilizeapproximately200gofRTFOresidue.6.3.PerformtheDSRtest(T315)ontheoriginalasphaltbinderbeginningat58°C,andincreaseordecreasethetesttemperatureat6.0°CincrementsuntilavalueforG*/sinδ≤1.00kPaisobtained.ThehighesttesttemperaturewherethevalueforG*/sinδ≥1.00kPadeterminesthestartingPGgrade.Note2—Forexample,ifG*/sinδis0.60kPaat64°Cand1.20kPaat58°C,thestartingasphaltbindergradeisPG58-xx.6.4.DeterminetheflashpointonasampleoforiginalbinderusingT48.Theflashpointmustbegreaterthan230°CtomeettherequirementsofM320.6.5.Determinetheviscosityoftheoriginalasphaltbinderat135°CusingT316.Theviscositymustnotexceed3Pa⋅stomeettherequirementsofM320.6.6.AftertheRTFOconditioning(T240)iscomplete,determinethemasschangeoftheoriginalasphaltbinder.Themasschangemustbe≤1.00percenttomeettherequirementsofM320.6.7.IftheoriginalasphaltbinderdoesnotmeetM320requirementsforthetestsinSections6.4,6.5,or6.6;theasphaltbinderwillnotsatisfythespecificationforanyPG,andnofurthertestingisrequired.--````,,,,`,``,,`,``,`,,,```,-`-`,,`,,`,`,,`---TS-2bR29-3AASHTO6.8.PerformtheDSRtest(T315)ontheRTFOresidueatthetesttemperatureusedtodeterminethestartingPGgrade(Section6.3)toconfirmthehightemperaturegradeoftheasphaltbinder(e.g.PG46-xx,52-xx,58-xx,etc.).ThevalueforG*/sinδoftheRTFOresiduemustbe≥2.20kPa.ChoosethelowerperformancegradeincaseswherethetestvaluesinSections6.3and6.8giveconflictinggrades.6.9.AgeasufficientquantityofRTFOresidueinthePAV(R28)(Note1).Useanagingtemperatureof90°CforstartinggradesPG46-xxor52-xxand100°CforstartinggradesPG58-xxandhigher.APAVtemperatureof110°Cisusedinsimulatingdesertenvironments.Note3—CompleteSections6.1through6.9duringthefirstdayoftesting.ThisschedulewillallowfurthertestingtobeginontheseconddayafterPAVagingiscomplete.6.10.AttheconclusionofthePAVagingprocedu