瀝青路面的鋪設中英文參照翻譯

附錄一外文原文AsphaltPavingOperationIntroductionThesubjectofthistermprojectwasanasphaltpavingprocessutilizingapavingmachineand20tonscapacitytri-axletrucks.ThelocationoftheprocesswasatthecornerofMainandMadisoninGreenwood(SouthofIndianapolis).TheprojectisbeingrunbytheReith-RileyConstructionCompany.-Indianapolis.Theoverallprocessinvolved:Hot-mixbatchplantcycleTri-axletruckcycleRollercycleSpreadercycleCrewcycleBecauseofthecomplexityoftheoverallconstructionprocess,wechosetoobserve,reporton,analyzeandmodelthepavingprocessonthebaselayerofthe15'laneroad.Atthattime,theotherlaneoftheroadwasnotpavedyet.Theroadhasslightlyincreasinggradeandcurvealongtheprocess.Thepreliminaryprocessofgatheringthedatausedinthisproject,theefficiencyoftheoperation,amodelandMicroCYCLONEsimulationoftheprocess,and川ustrationswillbediscussedandpresented.Asphalthasbeenusedbymanforitsadhesiveandwaterproofingproperties.Asphaltwasusedin3800B.C.intheEuphratesand2500B.C.inEgypt.TheSumeriansusedasphaltin6000B.C.foritsshipbuildingindustry.Today,asphaltisappliedtoroofing,sealants,caulking,brakelinings,paints,enamels,andmostwidelyusedinthepavingindustry(Asphalt-ScienceandTechnology,1968).ProcessDescriptionBatchPlantProductionFirst,aggregatetravelsthroughthecoldfeedbins,whereinitialproportioningoftheaggregatetakesplace.Thequantityofmaterialleavingeachbinisregulatedbythesizeofthegateopening,orthespeedofabelt,oracombinationofthetwo.Theaggregateissenttoadrier.Herethemoistureisremovedandisheatedto共15頁providethepropermixingtemperatureinthepugmill.Theaggregatecontinuestothehotelevatorbyscreenstothehotbins.Thescreensprovidethefinalseparationoftheaggregate.Thedifferentsizesofaggregatearereleasedintotheweighthopperonebinatatime.Theaggregateisdroppedintothepugmillformixingwiththeasphalt.Themixtureisthendroppedintoawaitingtruckormovedtoastoragesilo.Samplesaretakenfromeachhotbinfortesting.Asieveanalysisisconductedaswellasgradationtest.Fromthegradationinformation,theweightoftheaggregatemustbeequaltothedesigngradation.Atrialrunshouldbeperformedandtheweightsadjusteduntilthedesiredmixisproduced.(U.S.DepartmentofTransportation,December1984)Thedifferentsizesofaggregatearereleasedintotheweighthopperonebinatatime.Theaggregateisdroppedintothepugmillformixingwiththeasphalt.Themixtureisthendroppedintoawaitingtruckormovedtoastoragesilo.Samplesaretakenfromeachhotbinfortesting.Asieveanalysisisconductedaswellasgradationtest.Fromthegradationinformation,theweightoftheaggregatemustbeequaltothedesigngradation.Atrialrunshouldbeperformedandtheweightsadjusteduntilthedesiredmixisproduced.(U.S.DepartmentofTransportation,December1984)PlacingAsphaltPavementPlacingtheCoatBeforethepavingoperationstarts,anasphaltdistributorisusedtosprayasphaltontheunpavedsurface.Thisfilmofasphaltservesastheprimeandtactcoats.Thecoatsarethenallowedtocurebeforetheactualpavingresume.Thepurposeofhavingthesecoatsistopreventanyslippagebetweenthesurfaceandoverlayduringorafterthecompaction.(TheAsphaltInstitute)PlacingtheAsphaltMix共15頁Tostartthepavingoperation,thepaverispositionedproperlyontotheroad.Thescreedofthepaverisloweredontoblockofthesamedepthofthelooseasphaltmatthatisgoingtobelaidontheroad.(Thescreedisresponsibleforthesettingthedepthoftheasphaltmix.)Afterthat,theblockcanberemovedandpavingcanstart.Assoonasthehaultruckarrivesatthejobsite,thepavinginspectormustcheckthattheasphaltdeliveredmustbeinasatisfactorycondition.Thepavinginspectorusuallycheckforthesecriterialistedbelow:1.bluesmoke-bluesmokeindicatethatthemixistoohot.2.stiffappearance3.mixslumpedintruck.4.lean,dullappearance-thisindicatesthatthemixhasinsufficientasphalt.5.risingsteam-toomuchmoisture.6.segregation.7.contamination.Ifthereisanyofthesignsaboveisobserved,themixwillbesentbacktothebatchplanttobereprocessed.Afterallconditionsaresatisfied,thehaultruckcanloadthemixintothereceivinghopperofthepaver.Whenloadingthemixintothereceivinghopper,thehaultruckisplacedcarefullyinfrontofthepaver.Therearwheelsofthetruckshouldbeincontactwiththetruckrollerofthepavertoavoidanymisalignmentwiththepaver.Thepaverwillpushthetruckforwardsasitpavestheroad.Ifskewnesshappens,thewholeprocesswillbedelayedbecausetheyhavetorepositionthetruckinfrontofthepaver.Mostpaverusedareself-propelledpaver.Eachofthemconsistsoftwomainunits:tractorunit.-itincludesthereceivinghopper,slotconveyor,flowcontrolgates,spreadingcrew,powerplant,transmission,operatorcontrolforuseoneitherside,andoperator'sseat.Thisunitwillmovethewholesystemforward.screedunit.-itisattachedtothetractorunitbylongscreedarmsonbothsidesofthemachine.Itconsistsofscreedplate,vibratorsortamperbars,thicknesscontrol,crowncontrol,andscreedheater.Assoonasthethefirstloadofasphaltmixhasbeenspread,theuniformityoftheasphalttextureshouldbechecked.Operatorswilladjustthetheappropriateadjustmentpointstocorrectanynonuniformity.Anysegregationofmaterialsalsoshouldnotbeallowed.Operationshouldbestoppedimmediatelyifanysegregationisdetected.Theoperatorsshouldalsobeawareofisthecrowncontrol.Pavementwithcrownhastoberedonealloveragain.Inadditiontothat,operatorsshouldcontinuouslyloosenthemixthatclingstothe共15頁sidesofthehopperandpushitbackintotheactivemix.Iftheasphaltmixgrowcold,itcannotbeproperlycompactedandthus,loosesitsstrength.Thelastprocessofpavingiscompaction.Thisprocessishighlyinfluencedbymajormixproportion;(1)asphaltcontent:aggregatesize,shapetextureanddistributiongradation;(2)fillercontent,and;(3)mixtemperature.Appropriaterollersandrollingmethodsshouldbeusedinaccordancewiththeseproportion.Thereareseveralrollercombinationsusedformaximumresults:1.steel-tiredstaticandpneumatic-tiredrollers,.vibratoryandsteel-tiredstaticrollers,or.vibratoryrollersusedinvibratingandstaticmodes.Thesecombinationsarehighlyrecommendedbytheasphaltinstitute.Rollersshouldbemovedinaslowbutuniformspeedtoachievethebestresult.(Seetable)Theserollersshouldalsobeingoodconditions.Anyirregularitiesintherollers'performanceswillresultinpoorcompactionoftheasphalt;thus,thepavementwillnotlastlong.Therollersshouldnotreversesuddenlywhilecompactingbecausethisactioncandisplacethemix.Ifdisplacementhappens,thewholematshouldbeloosenedwithlutesorrakesandrestoredtotheoriginalgradebeforerollingcanrestart.Apatternthatiseconomicalandprovidesthemaximumcompactionresultshouldbeestablished.(TheAsphaltInstitute)TestingMethodWhyEvaluateDensityofHotAsphaltConcreteAsweknow,lackingofdensityduringconstructionofasphaltconcretecausesmanyproblems.Itisnecessarytoobtainhighdensitytoinsurethattheasphaltconcretewillprovidethenecessarystabilityanddurabilityforperformance.Forinstance,lowdensitygenerallycauseslong-termdeteriorationwhentheasphaltbeginscracking.Thereforevariousmethodshavebeenusedtomeasurethedensityintheasphaltconcrete.ProceduresUsedtoObtainDensityProperaggregategradationandasphaltcontentareimportantparameterstoensurethatthedensityofasphaltconcretemeetstherequirement.Generally,poorgradationresultsinareductionofvoidsinthemixture;thus,reducestheasphaltcontentwhichservesasthelubricantforaggregatesinthemix.Thestiffmixismoredifficulttocompact.Boththeaggregategradationandtheasphaltcontentareinterrelatedandequallyimportant.共15頁Pavingasphaltisreallydifficultincoldclimate.Thehotmixcoolsdownfasterandhardertocompact.Toovercomethis,contractorsusuallyincreasethetemperatureofthemix.Unfortunatelyexcessivelyincreasingthetemperatureofasphaltmixturemaycauseproblemsduringcompactionandincreaseoxidationoftheasphaltcement.Thismayresultinahardandbrittlepavement.Themixtemperatureshouldbeselectedsothatthemixturewouldbeabletosupporttherollerimmediatelybehindthepaver.Sincethereislesstimetorollthemixturebeforeitcools,morerollersorlargerrollersarerequiredforthecompactionprocess.Afterthemixtureistransportedtothesite,thenextstepistoensureproperdensitywhilelayingdowntheasphaltwithaspreader.Acontinuosavailabilityoftheasphaltmixforthepaveriscrucial.Thespreadercannotaffordtostartandstopwhilewaitingforthematerials.Itimportanttohavematerialthathasthesametextureandappearance.EvaluationofIn-PlaceDensityAnevaluationofthein-placematerialisnecessarytoensurethatasatisfactorydensityisobtained.Mostofthetime,anucleargageisusedtoestimatethedensity.However,theresultsobtainedusingthisequipmentarenotaccurate.Ithastobecalibratedbytakinganumberofmeasurementsfromdifferentlocationassoonastheprojectstarts.Aftercalibrations,aseriesofreadingsaretakenandthen,thereadingsarecomparedtothedensityobtainedfromthelaboratory.Thelaboratoryresultsarethedensityofcoresamplestakenfromthesamelocation.(PlacementandCompactionofAsphaltMixtures,1982)LaboratoryandFieldPavementStabilityTestsTheAmericanAssociationofStateHighwayOfficials(AASHO)andtheAmericanSocietyforTestingandMaterials(ASTM)aretwoagencieswhichsetforthmethodsandtestproceduresthepavingindustrymustfollow.Fivetestmethodsreadilyusedinthefieldandlaboratoryare:.TheHubbardFieldStabilityTest(ASTM-D-1138-52orAASHOTest169)-teststheresistancetoplasticflowoffineaggregatemixtures..TheUnconfinedCompressionTest(ASTM-D-1074-52-T)-measuresthecohesionofpavingbinderandperformanceoftheinternalfrictionoftheaggregate..TheMarshallTest(ASTM-Method-D-1559)-measurestheflowvalueorflowindexbydistortingthespecimenuntilfracture..TheHveemTest(ASTM-Method-1560)-usesstabilometerandcohesiometerapparatus.Thestabilometerdeterminesthemaximumamountofasphaltwhichwillobtainthegreateststabilitybymeasuringtheinternalfictionofthemineralaggregate.Thecohesiometerdeterminesthecohesionpropertiesandthestrength共15頁ofasphaltfilmsbybendingandbreakingaspecimen..TheTriaxialCompressionTest-isusefulindeterminingthecohesionofthemixandasphaltcontentsandtheangleofinternalfrictionoftheentiremixturebyapplyinglateralpressures.Thesesarethemostwidelyusedalthoughavarietyofothermethodsexist.Itmustbestatedthatdifferentlocal,state,andfederalorganizationswillrequirecertainteststobeperformedandmayacceptadifferentrangeofvalues.ResourcesDescriptionMat