路基寬度26米行車道寬43.75公路一級四車道高速公路說明書、土方計(jì)算表cad圖-翻譯原文

Low-temperaturefailurebehaviorofbituminousbindersandmixesAresearchincludingalargeexperimentalnonthermo-mechanicalbehaviorofdifferentbituminousmaterialsinthelargestrainamplitudeisproposed.Theprimarygoalofthispristoidentifyanddeterminethelinksbetweenthefailurepropertiesofbituminousbindersandthoseofmixesatlowtemperatures.Thethermo-mechanicalbehaviorofbituminousbinderswasevaluatedwiththetensilestrength onstantstrainrateandconstanttemperatures.Thethermo-mechanicalbehaviorofbituminousmixeshasbeenstudiedbyperformingmeasurementsofthecoefficientofthermaldilatationandcontraction,tensiletestsatconstanttemperaturesandstrainrates,andThermalStressRestrainedSpecimenTests.Somepertinentlinksbetweenfundamentalpropertiesofbindersandmixesareestablished.Someregardtothelow-temperaturefailurepropertiesofbituminousmixesareKeywords:bitumens,bituminousmixes,rheologicalbehavior,thermo-mechanicalproperties,failureproperties,tensilestrength,TSRST,lowtemperature,brittle,ductile,brittle/ductileThedifferentsofbitumenbehaviorcanbeillustratedaccordingtothestrainamplitude(_ε_)andthetemperature(T),atagivenstrainrate.FIGURE1(drawnfrom(1)and(2))pointsoutthebrittleandductiles,wherethetensilestrengthσpcanbethebrittlefailure,whichcouldbecharacterizedbythefracturetoughnessKc(LinearElasticFracturethelinearelasticbehavior,characterizedbythemoduliEandthelinearviscoelastic,characterizedbythecomplexmoduliE*andthepurelyviscous(Newtonian)behavior,characterizedbytheviscosityforstrainsofafewpercent,thewherethebehaviorishighlynon-Abituminousmixhasalsoacomplextemperature-sensitivebehavior.Itsresponsetoagivenloadingisstronglydependentontemperatureandloadingpath.Inaddition,atagiventemperatureandagivenstrainrate,fourmaintypicalbehaviorscanbeidentifiedaccordingtothestrainamplitude(ε)andthenumberofappliedcyclicloadings(N)(seeFIGURE2,from(3)).Thisp risaimedatprovidinganassessmentoftheworkconductedtodatewithintheframeworkofapartnershipbetweenthe“DépartementGénieCiviletBatiment”oftheEcoleNationaledesTPE,AppiaandEurovia.Thisstudyfocusedonthethermo-mechanicalbehaviorofdifferentbituminousmaterialsinboththesmallstrainandthelargestrain,atlowandmidtemperatures,whenconsideringonlyasmallnumberofloadingsThisp ronlydealswiththecharacterizationofthefailureproperties(helargestrainamplitude)ofbituminousmaterials,atlowandmidtemperatures.Itmaybeunderlinedthatthis rcompletestwopreviousp rswhichfocusedonthelinearviscoelasticbehaviorofbituminousmaterials(hesmallstrain)atlowandintermediatetemperatures(2)and(4).Fourverydifferentbitumenshavebeentested:twopurebitumens(10/20and50/70penetrationgrade),andtwopolymermodifiedbitumenswithahighcontentofpolymer,onewithplastomerandonewithelastomer.Thepolymermodifiedarenamed PMB1andPMB2.TABLE1presentstheresults conventionaltests(theFraassbrittlepoint,thePenetrationat25°CandtheSofteningPointRingandBall)initiallyperformedonthedifferentbinders.Fourdifferentbituminousmixes,madefromthe10/20,50/70,PMB1andPMB2bitumenswithonetypeof aggregateandgrading,havebeentested.Themixturesampleshadacontinuous0/10mmdioritegrading,a3±1%voidcontentandabindercontentof6%bydryweightofaggregate.TESTSONSHRPDirectTensileTestsAsdescribedinAASHTOTP3and(5),theSHRPDirectTensileTestconsistsinelongating27mmhigh samplesat1mm/minandatconstanttemperatures.Thecorrespondingstrainrate(?)equals2.22m/m/h.Atleastsix repeatsateachtemperaturewererealizedonunagedsamples.Apartfromthedeterminationoftheconventionaltemperatureleadingtofailureat1%strain,Tε=1%,ourysisalsoconsistsincharacterizingathresholdtemperatureseparatingthebrittlebehaviorandtheductileone.Moreover,thetensilestrength (umtensilestress) andthecorrespondingstrainforeachtemperatureareconsideredandrepresentedinFIGUREInouropinion,therankingofbindersinfunctionoftheirstraintoleranceusingtheparameterTε=1%doesnotseemtobereallypertinentinthesensethatthisapproachisratherempirical.Thisparameterwill comparedwithanewconceptofbrittle/ductiletransitiontemperatureofbinders,whichisintroducedatthestudiedstrainrate.Thedeterminationofthisbrittle/ductiletransitiontemperatureofbindersisexplainedinthenextparagraphs.Anyisothermaldirecttensiletestyieldsmuoredatathanjustfailurestrainorstressvalues.In particular,the ortheductile-likesh ofthestress-straincurvecanbeexaminedateachtemperature.Athightemperatures,bindershaveapurelyductilebehavior,whereasatverylowtemperaturestheirbehaviorispurelyfragile.Followingtheconsideredtemperature,thebitumenbehaviorsweepsfromductile(hightemperature)tobrittle(lowtemperature).Nevertheless,atintermediatetemperatures,thereisaslowevolutionofthebehaviorfromaductileonetoabrittleonewhendecreasingthetemperature.Thus,practically,thereisnodetermininganaccuratetransitiontemperaturedirectlyfromtheexaminationofthe ofthestress-straincurve.Inthebestcase,itisjustpossibletodetermineamoreorlesswidetemperaturerangewhichcorrespondstothisslowtransitionofthephysicalpropertiesofbinders.Fromourresults,weintroduceabrittle/ductiletransitiontemperatureofbindersatthestudiedstrainrate,Tbdb,whichisthetemperatureatwhichthetensilestrengthpeaksintheaxestensilestrength-temperature(FIGURE3).ThismakesthedeterminationofTbdbeasierandmoreaccuratesincetheumofthetensilestrengthmaybeclearlyidentified.Kingetal.(5)havealreadynoticedthatwhenthetemperaturedropsbelowabout-15°C,thetensilestrengthofbituminousmixturesdecreasesandthetensilespecimenfracturesatlowstrainasabrittlefailure.Thebrittle/ductiletransitiontemperature,hereafternamedTbdb(forastrainrateof2.22m/m/h),canbe consideredas handyand low-temperatureparameter.Itsphysicalmeaningisdirectlylinkedtothetypeoffractureprocessofspecimens,whichinfluencesthesh ofthestress-straincurves.ThevaluesofTbdbarepresentedinTABLE1alongwiththetemperaturecorrespondingtoastrainof1%atfailure,Tε=1%.TbdbandTε=1%arehighlycorrelatedwitheachother(r2=0.977).Nevertheless,furtherinvestigationsonotherbituminousbindersarestillneededbeforeanydefinitiveconclusioncanbeAsshowninFIGURE3,thefailurestressresultsarenoticeablyscatteredatlowtemperatures,wherethebehaviorisbrittle.However,theperformanceofsuchatestatintermediateandhightemperaturesleadstoaminorscatterofresults.Therefore,fromourresultsonfourverydifferentbinders,theumtensilestress(tensilestrength)seemstobeallthemorerepeatablethanthetemperatureishigh(FIGURE3).AsassumedbyLargeaudetal.(7),thescatteringatlowtemperaturecouldbeexplainedbythedetrimentalinfluenceofocclusionsofairbubblesinthesmallsectionofbinderTESTSONDirectTensileTestsDTTresultsonThesetestswereperformedatconstanttemperaturesbetween5°Cto-46°Catconstantstrainrate.Twoverydifferentstrainrates(300and45000μm/m/h)werechosensoastostudytheinfluenceofstrainrateuponthefailurepropertiesofbituminousmixtures.220mmhighcylindrical(diameter=80mm)samplesweretestedintensionusingaservo-hydraulicpressattheEurovialaboratory.Thestraininthesamplewasconsideredasthemeanvalueofthemeasuresgivenbythreetransducersplacedat120°aroundthesample.TwoorthreetestreplicateswereperformedateachOnonehand,aspreviouslyshownbyDiBenedettoetal.(8)(9),theexperimentalresultsonthefourstudiedbituminousmixturesevidencethatthestressatfailure(viscoplasticflaw)ishighlydependentonthestrainrateintheductile(hightemperature).Ontheotherhand,theobtainedstressatfailureonlyslightlydependsuponthestrainrateinthebrittle(lowtemperature).So,asaapproximation,thetensilestrengthinthebrittlecanbeconsideredasindependentofthechosenstrainrate.Thispointisofprimaryimportancesinceahighstrainratecanbeusedinthebrittleinordertosavetime.Nevertheless,itisnoteworthythatStockandArand(10)previouslystatedthatinthebrittle,atverylowtemperatures,thetensilestrengthslightlydecreaseswhileincreasingthestrainrate. needstobedeepened furtherinvestigation.Furthermore,inreferencetothetransitiontemperatureconceptpresentedforbinders,weintroducedthebrittle/ductiletransitiontemperatureofbituminousmixes,Tfdm,whichdependsontheappliedstrainrate().The differenceforthetwoconsideredstrainrates(300and45000μm/m/h)canreach9°C.Thislow-temperatureparameterisreportedinTABLE1forthetwoconsideredstrainrates.AsillustratedinFIGURE4whereallreplicateresultsareplotted,thescatterofresultsisrathersmallwhateverthestrainrateandthetemperature.Therepeatabilityofsuchatestonmixesappearsasespeciallygood,aswellinthefragileasintheductile.FIGURE5sumsuptheinfluenceofboththetemperatureandthestrainrateonthebrittle/ductilebehaviorfortensiletestsatconstantstrainrateonbindersandDTTonbindersVsDTTonAscanbeseeninFIGURE6,thetensilestrengthofbindersfoundwiththeSHRPDirectTensileTestsat1mm/min(2.22m/m/h)isquiteclosetothetensilestrengthofmixesat300μm/m/h.Thispointisnoticeableandneedsfurtherinvestigation.Indeed,astestingbituminousmixturesisveryexpensiveandtime-consuming,oneofthecurrentgreatissuesistodeterminemethodsinwhichthepropertiesofmixescouldbeevaluatedwithenoughaccuracyfromthepropertiesofthebinderandfromthemixcomposition.Toconfirmtheseresults,nextstepscouldconsistintestinganotherstrainrateforbinders(150mm/min,i.e.333m/m/h,ifpossible)andalsodifferentmixcompositions.Inaddition,inthebrittleatverylowtemperatures,andonlyasaapproximation(lackofrepeatability),thepreviousobservations(cf.FIGURE6)allowtoconsiderthatthetensilestrengthofbindersequalsthetensilestrengthofmixeswhichdoesnotdependonthestrainrate(FIGURE4).Toourknowledge,thisstatementwhichissometimessupposedtobevalidhasbeenbutlittleexperimentallychecked.Moreover,thisstatementisoftheutmostimportancesincethefailureinmixescouldbepredicted,asaapproximation,fromthefailureinbinders.Forinstance,asregardsthecurrent revisionofthe AASHTOlow specificationMP1(MP1A),thefailurestressfromDTTonbindersisincorporatedinacomprehensivemodeltocalculateandpredictthesocalledcriticalcrackingtemperatureofpavement(11)(12).Coefficientofthermaldilatation/contractionofThelinearcoefficientofthermaldilatation/contraction“α”dependsonthethermalcharacteristicsofthecomponentsofthebituminousmixture(binder,aggregateandair).Itespeciallyhighlydependsonthebindercontentsincethecoefficientoflinearthermaldilatation/contractionofbitumenissome30timesgreaterthanthatofthemineralaggregate(13)(14)(15).Inourstudy,asonlyonemixdesignisconsidered,theinfluenceoftheamountofbinderandaggregatecannotbeParallelepipedicasphaltsamples(L*W*H=16*4*4cm3)ofthefourtypesofinvestigatedmixeswerelaidontheirlengthonalayerofsmallglassmarblescoatedwithasiliconespray.Thisbaseprovidesnearlyfrictionlessmovement.Eachsamplewassubmittedtodifferentplateausoftemperatureintherangeof+24to–26°C.Thetemperaturewasheldconstantforaboutthree-hourperiodsaftereachincrementofaroundthreedegreesCelsius.Twoidenticalstraingagesareusedforeachtest:theoneisgluedontheupperpartoftheasphaltbeam,thesecondoneonthelowerpart,fornottakingintoaccounttheflexionofthebeamduringthetest.Theaveragevalueisconsidered.Athirdstraingagewasgluedonareferencetitaniumsilicatebeam,ofknownα-value(0.03μm/m/°C),inordertoaccountforandcorrecttheeffectoftemperature.Inaddition,atemperatureprobewasusedtomeasurethetemperatureatthesurfaceofasphaltsamples.Thethermalstrainεcanbewrittenasfollowsε=α?Twhereα:linearcoefficientofthermaldilatation/contraction?T:changeintemperatureThermalAftereachtemperaturechange,thetemperatureisheldconstantduring3hourssoastoallowthespecimen,thetitaniumsilicatebeamandthethreestraingagestoequilibrateattheconsideredtemperature.Attheonsetofthisplateauoftemperature,atransitionalperiodisobserved,inwhicheachelementiscontracting(ordilating)untilthermalequilibrium.Thetransitionalperiodofeachelementdependsi)onitsdimensions(thestraingagereachesmorequicklythethermalequilibriumthanthemixsample),ii)onitsthermo-physicalcoefficients,iii)onthetemperaturechangeamplitude,iv)etc.Fromourresults,thistransitionalperiodlastsabout1hour.ExperimentalFIGURE7showsthatthethermaldilatationcoefficientofmixesandtheirthermalcontractioncoefficientarereallyclose(seealso(16)).Thetwocoefficientsarehereafterconsideredasequal.Moreover,FIGURE7highlightsthatthefourdifferentmixeshaveveryclosethermalcontractioncoefficientsovertheconsideredrangeoftemperature(from-26to+24°C).AsDiBenedettoandNeifar(16),usingaspeciallydesignedtestmethod,andSerfassetal.(17)havealreadyshown,alinearrelationshipbetweenthethermalcontractioncoefficientandthetemperaturecanbeconsidered,asaapproximation,below5°C.Thesecoefficientsvaryslowlyfromaround30to15μm/m/°Cwhiledecreasingtemperaturefrom5°to–26°C.ThethermalcontractioncoefficientappearsasnearlyconstantattemperaturesabovebuttheexcessivecreepofthesamplemakesthemeasurementsTheenvironmentalchamberdidnotallowtoinvestigatetemperatureslowerthan–26°Csothatnoglasstransitionpoint(changeintheslopeofα-Tcurve)couldhavebeenidentifiedfromourresults.ItisnoteworthythatDiBenedetto&Neifar(16)previouslypointedouttheanisotropicbehaviorofmixes.Theymeasuredoncylindricalsamplesthecoefficientsofbothradialandaxialthermalcontraction.Theselatterwerefoundtobedifferent(30to50%).ThermalStressRestrainedSpecimenTestsTypically,restrainedcoolingtests(orTSRST)areconsideredasanacceleratedperformancetesttopredictlowtemperaturecrackingofbituminousmixtures.Thesetestswerecarriedout oolingrateof10°C/hfromaninitialtemperatureof5°Cusingaservo-hydraulicpressattheEurovialaboratoryandwereruninduplicateortriplicateon250mmhighsamples(diameter=60mm).Atemperatureprobewasusedtomeasurethetemperatureatthesurfaceofasphaltsamples.Thethermalregulationisdirectlyrealizedfromthemeasuredsurfacetemperature.Theairintheenvironmentalchamberiscirculatedwithafansothatthetemperaturedistributionisuniform.Thestraininthesamplewasconsideredasthemeanvalueofthevaluesgivenbythreetransducersplacedat120°aroundthesample.Thisstrainεiskeptequaltozeroduringthewholetest.Asthematerialisrestrained,itstendencytoshortenresultsinthedevelopmentofatensilestressthatproducesfailure.Thestrainεcanbemodeledasthesumofa“thermal”strainanda“mechanical”strain: :mechanicalstrain,describedbytheDBNviscoplasticmodel(24-25)(notdevelopedinthisp :thermalstrainwhichisequaltoα.?Τ(cf.equationMoreover,asthecoefficientsofthermalcontractionofthefourmixesvaryfrom30to15μm/m/°Cwhenthetemperaturedropsfrom5°to-30°C(FIGURE8),theequivalentmechanicalstrainrate( )rangesfrom300to150μm/m/hduringtherestrainedcoolingtests(sinceε=0).ItisnoteworthythataluminumcapswereusedtofixsamplestotheMTShydraulicpressinordertoavoidexcessiveshearstressesatthetopandatthebottomofsamples.Thestandardvalueofthecoefficientofthermalcontractionofaluminumisaround23μm/m/°C,whichisclosetothatofmixesovertheconsideredrangeoftemperatures.Fromourresults,failureoccursinthebrittlewhentheinducedthermalstressequalsthetensilestrengthobtainedat300μm/m/h(FIGURE8).Thismeansthatthestrengthofthebituminousmixesseemstobeafunctionofthetemperature(18)andthestrainrateonly,anddoesnotdependuponthepreviousfollowedstressandtemperaturepaths.Moreover,totheextentthatthetensilestrengthonlyslightlydependsonthestrainrateinthefragile(FIGURE4),itseemspossibletoforecastthethermalcrackinginthebrittlebymeansofthetensilestrengthcurveobtainedatanystrainrate.Thetemperaturewhichcorrespondstofailure,theso-calledfracturetemperatureTTSRST,isgiveninTABLE1.Forequivalentchangesintemperature,thelowerthethermallyinducedtensilestress,thebetterthemixbehavior.Likewise,thecoldertheTSRSTfracturetemperature,thegreaterthemix tolow-temperaturecracking.Therefore,amongthefourconsideredbituminousmixes,thetwopolymermodifiedmixturesarethebestregardingtheirtolow-temperaturecracking.Moreover,theperformancerankingofthefourconsideredmixtureswhichweremadefromthesamemixdesignandfourdifferentbindersisverydiscriminating.Thus,fortheconsideredmixdesign,thisconfirmsthatthebitumenpropertyappearsasakeyfactorregardingthe tolow-temperaturecrackingofbituminousmixes.TheinfluenceofthecoolingratehasnotbeenstudiedduringthislaboratoryMixturesthermalcrackinghasbeenmeasuredunderverysevereconditions(-10°C/h).Itisofparticularinteresttonotethatmorerealisticpavementsurfacecoolingratesaregenerallyintherangefrom0.5to2°C/h(19)(20).Amidresultsdrawnfromtheliterature,Fabb(21)previouslyshowedthatthecoolingratehaslittleeffectonthefracturetemperatureandthefracturestrengthwhentheratewasgreaterthan5°C/h.FromtheresultsofJungandVinson(22)(23),whenconsideringcoolingratesof1°C/hand10°C/h,therelativedifferencebetweentheamplitudesofinducedthermalstressescanreach100%nearthefracturetemperature.Typically,TTSRSTiscoldestat1°C/h,whichcanbeeasilysimulatedbythe“DBN”law(27).Notwithstandingthisfact,therankingofbituminousmaterialsdoesnotseemtobeinfluencedbythechosencoolingrate.Therefore,theTSRSTwithcoolingrateof10°C/hcanprovideratherquicklypertinentinformationregardingtothelow-temperaturecrackingpropertiesofbituminousEventually,thethermallyinducedstressofthegivenmixesmayalsohavebeenpredictedusingthelawdescribedbyDiBenedettoetal.(24-26)andNeifaretal.(27-28).Thepredictionisgivenbyteralviscoplastic“DBNlaw”(DiBenedettoandNeifar)usingtheresultsofi)complexmodulusii)thetensilestrengthofandiii)theknowledgeofthethermalcontractioncoefficient.Thisprocedureconsists yeffectivealternativetothewidesprerocedureswhicharebasedonlyonthelinearviscoelasticpropertiesofthesematerials.TheinfluenceofnonlinearitiesforthepredictionoftheTSRSThasbeenpreviouslyevidencedwiththeDBNlaw(25)(28).Then,thecrackingtemperaturecanbedeterminedfromtheintersectionofthecoolingandtensilestrengthcurves(27-28).Formoredetails,thereaderisreferredtothefollowingreferencesThemixturestothermalcyclesremainstobetestedsooninacomplementarystudyor,alternatively,canbetheoreticallypredictedbymeansofthe“DBNlaw”forFindingthattherankingsmixturesregardingtoeitherlow-temperaturecrackingorcyclicthermalaresimilarcouldbeinparticularofgreatYSIS–TheparametersTε=1%,Tbdb,Tbdm(300μm/m/h),Tbdm(45000μm/m/h)andthefailuretemperatureattheTSRST,namedTTSRST,arepresentedinTABLE1forthefourstudiedbituminousTABLE2gathersthecoefficientsbetweenallthepreviouslyintroduced,TbdbandTε=1%arehighlycorrelatedwitheachother(r2=0.977).OnemustbearinmindthatthephysicalmeaningoftheintroducedTbdbisdirectlylinkedtothetypeoffractureprocessofspecimens,whichinfluencesthesh ofthestress-straincurves.Thatiswhythispertinentparametercouldbeassociatedtothecurrentlow-temperaturespecificationforasphaltbindersbaseduptonowonTε=1%.Second,fortheconsideredmixdesign,Tbdm(300μm/m/h)andTbdm(45000μm/m/h)exhibitprettygoodcorrelationwithTbdb(resp.r2=0.936and0.908)andTε=1%(resp.r2=0.929and0.925).Moreover,thecorrelationbetweenTbdbandTTSRSTisr2=0.992.Thisevidencesthat,atlowtemperatures,thefailurepropertiesofbituminousmixturescanbepredictedfromthoseofThesecorrelationcoefficientsbetweenmixesandbinderspropertiesstillneedtobeconfirmedbyadditionaltestswithotherbindersandespeciallyothermixFortheconsideredsetofbinders,theSofteningPointRingandBallandtheFraassBrittlePointarenotgoodindicatorsofthelow-temperaturecrackingpropertiesofbituminousIndeed,thecoefficientsofthesetwotraditionalparameterswithTε=1%,Tbdb,Tbdm(300μm/m/h),Tbdm(45000μm/m/h)andTTSRSTarenotgood.Eventually,thecorrelationcoefficientsofthePenetrationat25°CwithTε=1%,Tbdb,Tbdm(300μm/m/h),Tbdm(45000μm/m/h)andTTSRSTappearasnotsogood.Indeed,asfarastheauthorsknow,intheliterature,excepttheresultsofJungandVinson(23)(29)thatevidencedprettygoodcorrelationbetweenTTSRSTandthePenetrationat15°C,poorcorrelationisusuallyemphasizedFinally,asthePenetrationat25°C,theSofteningPointRingandBallandtheFraassBrittlePointareconcerned,theseconventionaltestsdonotbringrelevantinformationnordotheyprovideaveryaccuraterankingregardingtothefailurebehaviorofthebituminousmaterialsatlowtemperatures.Let’saddthatthePenetrationat25°CandtheSofteningPointRingandBallarenotwellcorrelatedwiththelow-temperaturecriterionssince,obviously,theyarenotassociatedwiththesameoftemperature.Arationalapproachwhichconsistsincomparingthepropertiesofbindersandmixesonlyinthesameofbehavior(thelargestrainuptofailure)hasbeenconsideredinthisp r.Fromourresults,thefollowingconclusionscanbedrawn:Anewwayofdeterminingthebrittle/ductiletransitiontemperaturerelatedtothepeakofthetensilestrength/temperatureresponsecurve(atagivenstrainrate)isproposed.Thismakesthedeterminationofsuchatransitionaltemperatureeasierandmoreaccurate.Fortheconsideredsetofbinders,thetensiletestsonbindersandmixesrankthematerialsinthesamemannerregardingtherate-dependentbrittle/ductiletransitiontemperaturesofbindersandmixes.Asaapproximation,thetensilestrengthofmixescanbeconsideredasindependentofthestrainrateinthebrittle(atverylowtemperatures).Thispointisofprimaryimportancesinceahighstrainratecanbeusedinthebrittlesoastosavetime.Onlyasaroughapproximation,inthebrittle(atverylowtemperatures),thetensilestrengthofbindersandmixescanbeconsideredasclose.Thispointneedsfurtherinvestigation.Anexpandedlaboratorytestingprogramis mendedtofurtherexploretheeffectsofstrainrateandmixdesignonthetensilestrengthofbituminousbindersandParameterssuchasi)thetemperatureleadingtofailureat1%strainattheSHRPtensiletestsonbinders,ii)andiii)thefragile/ductiletransitiontemperaturesofbindersandmixes(fivenstrainrates)andiv)thefailuretemperatureobtainedattheTSRSTtestshavebeendeterminedforea aterial.Ithasbeenshownthattheselow-temperatureparameterswellcorrelatewitheachother.Thisseriesofparametersranksinthesamemannerthebituminousmaterialsregardingtotheirlow-temperatureproperties.ThatmeansthatthesefourparameterscanbegoodsurrogatestoeachConcerningtherelevancyofthetraditionalparameters(thePenetrationat25°C,theSofteningPointRingandBallandtheFraassBrittlePoint),asmanyotherauthorshavepreviouslystated,badcorrelationbetweenthelatterparametersandmorerationalcharacteristicshavebeenfoundherein.瀝青和瀝青混合料的低溫破壞性本文是對含有不同添加劑材料的瀝青熱力行為在大應(yīng)變情況下的對比實(shí)驗(yàn)建立起基本成分性狀和混合物的特性間的關(guān)系以得出瀝青混合料低溫破壞的一些明顯的特征。關(guān)鍵字:瀝青，含摻合劑的瀝青混合料，流動行為，熱力學(xué)特性，破壞，拉應(yīng)力，TSRST，低溫,脆性，延性，脆、延性隨溫度的改變。緒述。從圖1(從（1）和（2）得出)可以看出：知道了拉伸應(yīng)力σpKc來表示；線彈性的破壞性質(zhì),用模量E和G線性兼具黏彈性的破壞性質(zhì),用復(fù)雜模量E*G*,來表示；純黏性(體)的破壞性質(zhì),用黏著系數(shù)η來表示；瀝青混合料也對溫度復(fù)雜的敏感性。給定的荷載的反應(yīng)與溫度和加載過程有關(guān)。除此之外,對給定的溫度和給定的應(yīng)變率,四種主要的典型破壞ε)和重復(fù)加載次數(shù)來表示。(見到圖2,表(3))本文旨在為“DépartementGénieCiviletBatiment”oftheEcoleNationaledesAppiaandEurovia瀝青材料的熱力學(xué)行為本文只廣義大應(yīng)變下的在較低溫度和正常溫度間化的瀝青混合料的破壞性能。在早先的兩篇中了（2）號和（4）號試件在小應(yīng)變條件下從較低溫度向中間溫度變化時(shí)的線黏彈性破壞。實(shí)驗(yàn)材現(xiàn)在四種有顯著差別的瀝青已經(jīng)被測試:二種純?yōu)r青(針入度分別為10/2050/70),PMB1PMB2的改性瀝青混合料（一種添加的合劑的瀝青混合料試件（10/20,50/70,PMB1，PMB2，它們包含有0/10米間的連續(xù)級配的閃綠巖，31%的空隙率，6%的添加劑。結(jié)合料SHRP接拉伸測試按照AASHTOTP3和TP(5)的試驗(yàn)規(guī)程,做了SHRP直接拉伸測試(DTT),在恒定溫度下以1毫米/分鐘的速度將瀝青混合料試件拉長272.22m/m/h。每個(gè)未老化的試件在一個(gè)溫度點(diǎn)上至少重復(fù)測試六次，除了傳統(tǒng)試驗(yàn)中在%的應(yīng)變時(shí)由溫度導(dǎo)致的破壞,的分析還表明存在一個(gè)區(qū)分脆性破壞和延性破壞的臨界溫度,而且,在每一個(gè)溫度點(diǎn)上拉伸應(yīng)力(最大的)和它對應(yīng)的應(yīng)變也表現(xiàn)在了圖3中?？磥?，因?yàn)閭鹘y(tǒng)方法有相當(dāng)大的經(jīng)驗(yàn)成分在其中,Tε=1%的容許應(yīng)變和混合料的功能間似乎并不相關(guān),與含摻合料的中說明任何的等溫直接拉伸試驗(yàn)跟僅用失效應(yīng)變或應(yīng)力比起來產(chǎn)生數(shù)據(jù)和在高況下含摻合料的瀝青混合料純粹的延性行為但在非常低的溫度下又是純粹的脆性行為。在他們之間的過渡溫度,瀝青的行為從延性從試驗(yàn)結(jié)果中得出 得到了在確定應(yīng)變率下的脆延性轉(zhuǎn)變的臨界溫---Tbdb，在應(yīng)力——溫度曲線上（圖3）對應(yīng)著拉伸應(yīng)力的峰值。因此可以更容易更準(zhǔn)確的確定Tbdb。Kingetal.先前已經(jīng)發(fā)現(xiàn)當(dāng)溫度降到-15°C以下性轉(zhuǎn)變的臨界溫度,由此被命名為Tbdb(相應(yīng)于2.22m/m/h的應(yīng)變率),它是1可以看出1Tbdb