路桥外文翻译 毕业设计.docx
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路桥外文翻译 毕业设计.docx
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路桥外文翻译毕业设计
附录外文资料原文及翻译
PorousElasticRoadSurfaceasAnUltimateHighwayNoiseMeasure
S.MEIARASHI
AdvancedMaterialTeam,Material&GeotechnicalResearchGroup,PublicWorksResearchInstitute,Japan
***********.jp
Abstract:
HighwaytrafficnoiseinurbanareasofJapanisaseriousproblem,notonlyforresidentsalonghighways,butalsoforhighwayadministrators.Only13percentofurbanhighwayshavemettheenvironmentstandardfornoise.Noisebarrierscannotbeusedasanoisecountermeasureonthemajorityofhighwaysonwhichaccessisnotcontrolled.Noiselevelsofareasalongsomeurbanhighwaysexceedthestandardby15dB(A)ormore.Thisproblemisimpedingnewhighwayconstructioninurbanareas.PorousasphaltpavementhasrecentlybeenintroducedonurbanhighwaysinJapan.Itsnoisereductioneffectof3dB(A)isinsufficient,becauseitonlyimprovesthenoiseenvironmentsatisfactionratebyafewpercent.Furthermore,thedurabilityofitsnoisereductioneffectusuallyseemstobeonlythreeyears,whichisshorterthanitslife-cycleaspavement.
ThePublicWorksResearchInstitute(PWRI)has,since1993,beendevelopinganewlow-noisepavementnamed“PorousElasticRoadSurface”(PERS).Thisnewpavementhasaporousstructurecomposedofgranulaterubbermadefromoldusedtiresasitsaggregateandurethaneresinasitsbinder.Itsporosityisapproximately40percent.ThepavementwasfirstproposedinSwedeninthe1970s,however,Swedishresearchershavefailedtoimproveitasapracticalpavement.Noisereductionlevelsare15dB(A)forcarsand8dB(A)fortrucks.TheauthorestimatesthatthepotentialnoisereductionlevelsinLeqexceed10dB(A).Morethan90percentofhighwaysinurbanareaswouldmeetthestandardifthisnoisereductionlevelwereachieved.ThePWRIhasalreadysolvedseveraloftheproblemswithPERS,forexample,insufficientadhesionbetweenthepavementandthebasecourse,lowskidresistance,anditspoorfireproofperformance.Itstechnicallevelhasalreadyreachedthestageoftestconstructiononurbanhighways.
ThispaperexaminesthegeneralperformanceofPERSobtainedthroughpastdevelopmentatthePWRI.ItalsosummarizestheresultsofrecentresearchdonetofurtherimprovethenoisereductionlevelsofPERSandthefirsttestconstructionusingPERSinJapan.Thefinalnoisereductiontargetforanytypeofvehicleisbetween15-20dB(A).TheauthorexpectsthatPERSwillreducehighwaytrafficnoiseproblemsinurbanareasofJapantoaminor,negligiblelevelinthenearfuture.
Keywords:
pavement,noisereduction,highwaytrafficnoise,skidresistance,durability,adhesion
1.Introdution
ThePublicWorksResearchInstitute(PWRI)has,since1993,beendevelopinganewlow-noisepavementnamed“PorousElasticRoadSurface”(PERS).Thisnewpavementhasaporousstructurecomposedofgranulaterubbermadefromoldusedtiresasitsaggregateandurethaneresinasitsbinder.Itsporosityisapproximately40percent.ThepavementwasfirstproposedinSwedeninthe1970s,however,Swedishresearchershavefailedtoimproveitasapracticalpavement.Noisereductionlevelsare15dB(A)forcarsand8dB(A)fortrucks.TheauthorestimatesthatthepotentialnoisereductionlevelsinLeqexceed10dB(A).Morethan90percentofhighwaysinurbanareaswouldmeetthestandardifthisnoisereductionlevelwereachieved.ThePWRIhasalreadysolvedseveraloftheproblemswithPERS,forexample,insufficientadhesionbetweenthepavementandthebasecourse,lowskidresistance,anditspoorfireproofperformance.Itstechnicallevelhasalreadyreachedthestageoftestconstructiononurbanhighways
ThispaperexaminesthegeneralperformanceofPERSobtainedthroughpastdevelopmentatthePWRI.ItalsosummarizestheresultsofnoisereductionlevelsofPERSatthefirsttestconstructionsiteinJapan.Thefirstpartdealsmainlywithimprovementofnoisereductioneffectwithchangingitsporosityandthickness,adhesiontothebasecourse,durability,wearresistance,wetfriction,andfireresistance,whereasthesecondpartfocusesonthelaboratoryperformancetestinginadvancetoidentifyanewconstructionmethodofPERSbeforetrialconstructiononhighwaysandthenoisereductioneffectobservedattheconstructionsite
2.Latesttechnology
2.1Noisereduction
TheauthorhasconductedfournoisemeasurementsintotalatthePWRItestingcoursetoimprovethenoisereductioneffectofPERS,includingthefirstonedescribedabove.Thesecondnoisemeasurementin1995wasfocusedontheinfluenceofporosityonnoisereduction.Figure2showsthatnoisereductionofPERSisalmostsaturatedattheporosityof35%andover.Inthethirdnoisemeasurementof1996,amajorissuewastheeffectofPERSthicknessonnoisereduction.TheoptimalPERSnoisereductionlevelsforpassengercars,lighttrucks,andheavytrucksare14-16dB(A),4-5dB(A),and3-5dB(A),respectively.Figure3revealsthatthenoisereductionofPERSbecomesamaximumatthethicknessof3cm.Consideringtherelativelysmalldifferenceofnoisereductionbetween3cmthicknessofPERSand2cmthicknessofPERS,andmaterialcostreduction,theoptimalthicknessofPERSseemstoexistbetween2cmand3cm.TheoptimalPERSnoisereductionlevelsforpassengercars,lighttrucks,andheavytrucksare13-19dB(A),8-9dB(A),and6-10dB(A),respectively.
trucksare8-10dB(A).Asaresult,theauthorhadtoimprovewetfrictionwhilesacrificingnoisereductionforpassengercars
performancethanDAP,withfarbetterdeformationperformancethanconventionalpavementsuchasDENAP
Figure4-Acceleratedpavementtest
2.5Fireresistance
Fireresistancewasthoughttobeapotentialproblem,sincerubbermayburnfiercely.ThefirehazardproblemhasbeenstudiedbyPWRI.SquaresofPERS5×5mwereplacedoutsidealaboratory,36litersofdieseloilorgasolineweresprinkledonthesurfaceaswellasonanadjacent(conventional)asphaltpavement.Thefluidwasthenignitedwithatorch,andfactorssuchaspavementmaterials,heightofflamesandgenerationofsmokewereobservedandthetestswerealsofilmed.
Intheexperiments,threesurfaceswerecompared:
denseasphaltconcrete,porousasphaltconcreteandthe5×5mpanelsofPERS.Theresults,asgiveninTable1,showthatregardingspreadingspeedandflameheight,thePERSwassaferthanthedenseasphaltconcrete.Figure8illustratesthesetests.
Table1-Fireresistancetestcondition
Surfacetype
Burningoffuelandpavementmaterials
Flameheight
Smokegeneration
Denap
Fueloilspreadingoverthepavementsurfacestronglyburnedwithreddishflamesbutthepavementdidnotburn.
2.5-3.0m
Fueloilburnedincompletely,producingacolumnofblacksmoke.
Dap
Fueloilevaporatingthroughthevoidsofthepavementignited,causingblueflames.However,pavementmaterialsdidnotburn.
Approximately0.3m
Onlyalittlesmokewasobserved.
Pers
Fueloilevaporatingthroughpavementvoidsignited;rubberpanelsburnedup,causingreddishflames.Firespreadoverthepavementveryslowly.
1.0-1.5m
Acolumnofblacksmokewasobservedfromtheburningrubberpanels.
3.Firsttestconstruction
PERSconstructioninhighwaysrequiresthestructuretobedevelopedasatotalpavementsystemandaconstructionmethodthatisverydifferentfromthepreviousonesinPWRItestcourses.Therearetworeasonsforimprovingthestructureandconstructionmethod.
Thefirstoneisatimeconstraint.OnepotentialapplicationofPERSisforheavy-trafficarterialhighwaysinurbanareas,wheretheworkingtimeislimitedto10hoursatnight(suchasfrom8PMto6AM)toavoidcausingtrafficcongestion.Thestandardareaofpavementresurfacingofanurbanhighwayis2,000-3,000squaremetersperday.Theconstructionworkinvolvesremovingtheexistingwearingcourse&basecourse,constructingnewsemi-flexiblepavementasthebasecourse,puttingadhesiveonthebasecourse,andpavingPERSasshowninFigure9(a).ConsideringtheworkingtimebeforepavingPERS,itisimpossibletocompletealltheworkswithinthelimit.
Thesecondreasonisforqualitycontrolofadhesiveperformance.IntheearlystageofdevelopmentofPERS,therewerevarioustroublesconcerningtheadhesiveasmentionedintheprevioussection.Thepolymertypeofadhesiveisverysensitivetotheambientconditionsofcuringsuchastemperatureandhumidity.Itseemsverydifficulttomaintainstableperformanceoftheadhesiveduringoutdoorwork.
Inresponsetotheseproblems,pre-fabricatedtypesofPERSwouldappeartobetheonlysolution.Themainpre-fabricatedtypesofpavementproductsareInter-LockingBlock(ILB),Pre-stressedConcretePanel(PCP),andReinforcedConcretePanel(RCP).TheILBhasbeenwidelyusedforpedestrianwaysespeciallyinprestigeareasandshoppingmalls,wherearchitectsandplannersareinterestedinthevisualimpactofpaving.SomeILBsarealsotobefoundinindustrialareas,suchasstorageyardsanddock-sidepaving,wherethemainconcernsarestructuralperformance,costandmaintenance.ThePCPispre-tensionedinthetransversedirectionduringfabrication,andpost-tensionedtogetherinthelongitudinaldirectionafterplacement.ThePCPandRCParemainlyusedforsectionswhereextremelyhighdurabilityisrequired,suchasthepavementintunnels.
.
Inviewofthetimeconstraints,itisimpossibletousePCPandRCPasthebasecourseofPERSbecauseoftheslowspeedofconstructionoflessthan100squaremeterspertenhours.ThepresentmechanicalmethodoflayingILBimprovestheconstructionefficiencyandovercomestheconstraint.Withthisbackground,theaut
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