道路橋梁路基路面論文

RoaddrainagedesignfeaturesAbstract:WithChina'srapideconomicandsocialdevelopment,roadconstructionhasenteredarapiddevelopmentperiod.However,increasingtrafficandloadcases,theuseoftraditionalmaterialsandconstructiontechniquesintotheroadpavementinuserevealedmanyproblems,especiallyinthesouthernrain-fedareas,roads,waterandsurfacewaterdamagetothephenomenonofperformancewasveryprominent.Thishasbecomesoforeignroadconstructionofamajordifficulty.Therefore,theconventionalasphaltconcretepavementinboththedesignandconstructionprocessneedstobeimprovedon.Theporousasphaltconcretepavementisadaptedtotheneedsanddevelopedanewtypeofpavementstructure,isparticularlysuitableforwetareas.Thispaperbrieflystudied.

Keywords:porousasphaltconcrete,pavement,mixdesign,constructiontechniques,qualitycontrol

1Background

WithChina'srapideconomicandsocialprogress,andinfrastructurearealsoatanunprecedentedpace,highwayconstructionistheconstructionofinfrastructurefacilitiesoneofthekey.Asoftheendof2005,highwaymileagehasmorethan41,000km.Althoughwiththenewmaterialsandconstructionprocessoptimization,continuousimprovementofthequalityofasphaltpavement,butthereisstillaconsiderablepartoftheasphaltconcretepavementintheprocessofusingacertaindegreeofdamageoccurringphenomenon,especiallybecauseofacombinationoffactorscausedtheearly(with3yearsorso)damage,resultingintheuseofasphaltpavementperformanceandlifeoftenachievetheirdesignlevel,hasaseriousimpactonroadtransportnormalfunctioning,causinghugeeconomiclosses,butalsotosomeextenthamperedthedevelopmentofhighway.Pastroaddamageintheformmainlyasrutting,lowtemperaturecrackingandfatiguecracking,whiletheuseofasemi-rigidpavementstructureandthequalityoftheasphaltmixturehasbeeneffectivelymitigated.Butthedamageintheformofwaterdamageisreplaced,atroubledcompanydevelopedanewissueofhighway.EspeciallyintherainyareasinsouthernChina,thehighwayinthespringmeltseason,therainyseasonandtherainyseason,theroadwillappearMasurface,loose,andevenoutthegrainpits,thisdramaticearlydestruction,isthatpeopleanticipated.

2ofwaterdamage

Waterdamagetoasphaltpavementproblems,thefirstthingcomestohighwaydrainagesystem.Inordertoensurethestabilityofroadbed,goodroadsafetyperformanceanddriving,highwaydrainagefacilitiesaresetupwelltoruleoutroadsectorwithinthescopeofsurfacewaterandgroundwater.Highwaydrainagefromtheroadsector,thegeneralsurfacedrainage,surfacedrainageandundergrounddrainagewithinthreeparts.Roadsurfacedrainagesector,includingroadsurfacedrainage,drainageandslopethemediandrainage.Withintheporouspavementsurfacedrainage,includingdrainage,roaddrainageandpermeableedgeprimarydrainage.Undergrounddrainageincludingsewer,ditches,undergrounddrainorundergroundpipe.Researchshowsthatsettingagooddrainagesystem,canimprovethelifeofasphaltupto30%ormore.Incontrast,poordrainageasphaltpavement,whichisusuallycausedbyprematuredestructionofthesurfacelayerofpavementstructureinwater-saturatedstate,andtrafficcausedbyheavyvehicles.Anylayerofpavementlayer,orsoakedinasaturatedstate,willleadtolowerstructurallayerstrength,speeduptheroadtheemergenceanddevelopmentofvariousdiseases.Waterdamagetoasphaltpavementfromwater,surfacewaterinfiltrationispossibleonlyleadtostrippingofasphaltfilmandaggregate,resultinginroaddamage.Therefore,theseepageofasphaltpavementwillproducekeyindicatorsofwaterdamage.Itshouldbesaidtoincreasetheseepagecoefficientindexforimprovingthequalityofconstructionofasphaltpavement,preventingwaterdamageisimportant.Theporousasphaltroadsurfacedrainagesystemisbasedontheabovecharacteristicsanddevelopedanewtypeofroadpavementstructure.Drainageasphaltpavement,alsoknownaspermeableasphaltpavement,thesurfacelayerisalsoknownforporousasphaltwearingcourse;referstothecompactedporosityof20%,themixturecanformadrainagechannelwithinthenewasphaltconcretesurfacelayer,itsrealmechanismfortheformationoftheskeletoninaccordancewithembeddedcrowded-gapstructureofopen-gradedasphaltmixture.Itscharacteristicsare:first,theraincanpreventtheformationofroadsurfacewaterfilm,slidingperformance,improveroadroughness,vehicleslipresistance;toeliminateorreducetherearwaterflowers,andraisethedriver'slineofsightofthedefinitiontoimprovetrafficsafety;second,hightemperaturestability,resistancetoruttingability;third,withlightandglaretoreducetrafficnoiseandotherfunctions.Seenwithbothenvironmentallyfriendlyroaddrainage,andmanycharacteristicsconducivetotrafficsafety,inlinewithcurrenttechnologicaldevelopmentsandsocialtrends.

3researchstatus

Sincethe1960s,someEuropeancountriessuchasGermany,France,BritainandItalyhaveproposedaporousasphaltpavementconcept,andstartedresearchontheasphaltmaterial,madealotofusefulresults,thuscontributingtothetechnologytheapplication.Europeanresearchanddevelopmentisafirstporosityashighas20%to25%,athicknessof4~5cmofthewearlayer.Asporosity,watercanpenetrateintotheroad,connectedbyaroadinthedischargegaptotheedgeoftheroad.Thereisnorainsothickwaterfilm,toavoidthe"hydroplaning"generation,butalsonolongerappearssplashing,andeffectivelytoensuretrafficsafety.Becauseofthismulti-gapcanquicklydraintheroad,socalledporousasphaltpavement.SofarEuropeancountriesporousasphaltpavementresearchandtheuseofmorethan30years,partofthestateasphaltpavementdrainageareaof??aboutroadaccountedfor10%ormore.Europeancountriesthechoiceoftheasphaltmaterialtoreachabasicconsensusistousethemodifiedasphalt,andmainlyconsiderthefollowingrequirements:haveagoodhightemperaturestability,lowtemperaturecrackingresistanceandoxidationresistance.NotifytheUnitedStatesin1973recommendtheuseofopen-gradedthecountryslidingwearlayersurface,significantlyreducetherainyday"hydroplaning"phenomenon,haveachievedgoodresults.Intothelatetwentiethcentury,countriesontheapplicationofporousasphaltpavementtechnologyresearchenteredanewphaseofhighwayprojectsintheU.S.long-termperformanceofroadprojectsthereisaspecialporousasphaltmaterialforthelargeexperimentalstudyofsub-surface;intheUnitedStatesin1990TRBAnnualMeetingheldinWashington,themainissueisthedrainageoftheasphaltmaterialinroadengineeringexperience.Inthesameyear,theU.S.FederalHighwayAdministrationhasdeveloped.Slidingsurfaceofopen-gradedasphaltmixturedesignmethodwassurfaceporosity,thicknessandmajorfunctionsaredescribed.TheUnitedKingdomsince1984invarioustrialsaroundthecountrypavedtheway,thepurposeistoverifytheporousasphaltpavementnoisereductionanddurability.Austriaforenvironmentalprotectionneeds,inmanytownsontheroadafterthedrainageofpavedroad,10yearsago,hasaccumulated6.5millionm2,andplanstopermeablepavementforurbanroads.Thecountryhasbeenontheroadtodevelopatypeofporousdrainagedesignspecifications.Netherlands,2.5millionayearlayingpermeablepavementm2,theNetherlandshas15.4%ofthecarlanepavedthisroad.Franceusesthedrainageoftheroadveryquickly,hasbeenpavedafewyearsago20millionm2,butalsoanannual4millionm2annually.

4layerofporousasphaltconcretesurfacedesignfeatures

4.1Determinationofdisplacement

Newelementsoftheinternalstructureofasphaltconcretepavementanddrainagedesignstillneedtocalculatetheareaundernormalcircumstances,requirethedischargeofdisplacement,theformulahasbeenbuiltwithcementconcretepavementstructureswithinthedisplacementformula.

4.2Determinationofthedrainagestructure

Drainagestructureswithinthepavementstructuredividedintothree:thefirstoneisthecentralreservedrainageforwetareasseparated

Withnopavedhighway;secondistheedgeoftheroaddrainage;thirdistosetprimarydrainage.Thechoiceofthesetypesofstructure,accordingtoroadclass,pavementtypeandlocalrainfallandotherspecificcircumstancescalculatedtodetermine.Forrain-fedareasofthehighway,undertheconditionspermit,theabovethreestructurescanalsousethebest.

CentralreservedrainagesewermapNewroadedgesandprimarydrainageplans

4.3newasphaltconcretepavementstructuredrainagesystemmaterialsandconstructionrequirements

4.1Mainmaterialsandrequirements

Duetodrainageoftheasphaltmixtureporosity,bysunlight,air,waterdemandsagreaterinfluencebitumenviscosity,anti-agingperformance,designedtousehighviscositymodifiedasphalt,asphaltandaggregatetoincreasethebondforce,topreventtheaggregateintheflyingwheelloads,improvemixturedurability.Themainfeaturesofhighviscosityasphaltsofteningpointishigh,60℃highviscosity,hightoughnessandadhesivetoughness.HighviscositymodifiedasphaltpropertiesrequiredinTable4.1.

Segregation,softeningpointofdifferenceisless

4.2Constructionofdrainagesystemrequirementsofthemedian

Dumpingwithinthemedianofthehorizontalgradientoftheinfiltrationofrainwaterwithacentrallow-flowsplitcavity,andflowthroughthedischargeportorlongitudinalrowofcirclesacrosstheroadbridgeandculvertwaterways.Mediantransverseslopenotsteepat1:6;medianlongitudinaldrainageslope,nopavementinthecrosssectionshallnotbeslowto0.25%,withpavementshallnotslowto0.12%.Whentheflowrateexceedsthemaximumallowableflowrateofthegroundsoil,shouldbeinthecrosssectionwidthoftherangemaponthegroundforanti-erosionprocess,madeoftriangularor"U"shapedcross-sectionoftheditch.Anti-erosionlayeroflimeorcementstabilizedsoilcanbeused,ortheuseofmortarrubblepaving,thickness10cm~15cm.Aroundthesewer

Parcelfiltrationfabric(geotextile)topreventinfiltrationofwatertocarrythefinewillbesewerblockage.Sewerbackfillandpavementonthestructureoftheinterfaceatthelayingofasphaltcoateddoublelayerofgeotextilefabricacrosstheseepage.70mm~150mmdiameterpipescanbeusedinPVCplasticpipe.

4.3theedgeoftheroaddrainagesystemmaterialsandconstructionrequirements

FillingbythecementpavementedgedrainTreatmentofopen-gradedcoarseaggregatecomponents,materialsandconstructionmethodsanddrainagehavebeencompletedandtheroadedgefillthesame,butsettheminimumwidthoftheditchbottomshouldnotbelessthan30cm.

4.4Primarydrainagematerialandconstructionrequirements

Primarydrainagesetdirectlyundertheconcretepavement.DrainagefromthecementorasphaltTreatmentofprimarynon-smallparticlesize,orwithfine4.75mmthefollowingopen-gradedmaterialcomposedofcrushedstoneaggregate,orbyacombinationofmaterialswithouttheTreatmentofopen-gradedcrushedstoneaggregateform.Aggregateshouldbeusedclean,hard,durablegravel,crusheditsvalueshouldnotexceed30%.Maximumsizefor20cmor25cm,andthicknessofnomorethan2/3.Thefollowingparticlesize4.75mmfinematerialcontentshouldnotexceed10%.Aggregategradationshallmeetthepermeabilityrequirements(permeabilitycoefficientofnotlessthan300m/d),canoftenheadorvariableheadpermeabilitytestaftertesttodeterminethedistribution.CementTreatmentofgravelaggregateamountofcementshouldnotbelessthan160kg/m3,thecompressivestrengthofnotlessthan7dimmersion3MPa~4MPa.Treatmentofgravelaggregateasphaltasphaltaggregateamountofthedryweightofabout2.5%to4.5%.Thethicknessoftheprimarydrainageshallberequiredtodischargewaterandbasematerialbyhydrauliccalculationstodeterminethepermeabilitycoefficient,usually8cm~15cmrangetochoosefrom,buttheminimumthicknessofnotlessthan6cm(Treatmentofgravelasphalt)or8cm(Treatmentofbrokencementstone).Thewidthofthesurfacelayerofconstructionshouldbeconsideredbeyondthesurfacelayerofthewidthoftheneedsof30cm~90cm.Drainagematlyingunderthegrass-rootslevelshouldbeusedimpermeableorlowpermeabilityofdense-gradedmixture,inordertoblocktheinfiltrationoffreewaterandfinematerialinthesoiloftheroadbedonthemove.

Sectionsinthehighwatertable,tointerceptgroundwater,waterorspringwaterintotheroadstrandedstructure,orexcludedbecauseofthenegativetemperatureeffectandtheaccumulationoffreewaterinthetopoftheembankmentcanbesetdirectlyonthetopsurfaceoftheroadbedpermeabledrainageblanket,and,whereappropriateConfigurationverticalgullies.

5Summary

Andinfiltrationofwaterintotheroadsurfacewater,iscausedbyprematureoracceleratedpavementdamagetooneofthemainstructure,newmaterials,waterproof,bothfromaneconomicpointofview,orfortheconstructionprocess,caneffectivelyimprovepavementperformance,extendingitsuselife.Constructionforroadconstructiontoprovideeffectiveprotection.

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[7]ZhuYongning.Drainageperformanceofporousasphaltpavementresearchanddesignofdrainagefacilities.SoutheastUniversity,Wen,2003.03路面排水設(shè)計要點摘要：隨著我國經(jīng)濟和社會的高速發(fā)展，公路建設(shè)也進入了快速發(fā)展時期。然而在車流量及載荷越來越大的情況下，采用傳統(tǒng)的路面材料和施工工藝建成的路面在使用中暴露出很多的問題，尤其是在南方多雨地區(qū)，道路積水以及路面水損壞現(xiàn)象表現(xiàn)得非常的突出。這已成為國內(nèi)以致國外道路建設(shè)的一大難點。因此，傳統(tǒng)的瀝青混凝土路面在設(shè)計和施工工藝上均需要作出改進。而排水性瀝青混凝土路面正是適應(yīng)了上述需要而發(fā)展起來的一種新型的路面結(jié)構(gòu)形式，對于多雨地區(qū)尤為適用。本文對此作了簡單的研究。關(guān)鍵詞:排水性瀝青混凝土，路面，配合比設(shè)計，施工工藝，質(zhì)量控制1研究背景隨著我國經(jīng)濟及社會快速進步，基礎(chǔ)設(shè)施建設(shè)也正以前所未有的速度發(fā)展，高速公路建設(shè)就是基礎(chǔ)建設(shè)施建設(shè)的重點之一。截至2005年底，高速公路通車里程已超過4.1萬公里。盡管隨著新材料的應(yīng)用和施工工藝的優(yōu)化，瀝青路面的質(zhì)量不斷提高，但仍有相當部分瀝青混凝土路面在使用過程中發(fā)生一定程度的損壞現(xiàn)象，特別是由于各種綜合因素引起的早期（使用3年左右）破壞，致使公路瀝青路面的使用性能與壽命常達不到應(yīng)有的設(shè)計水平，已嚴重影響了公路交通運輸功能的正常發(fā)揮，造成巨大的經(jīng)濟損失，同時也在一定程度上制約了我國高速公路事業(yè)的發(fā)展。以往路面破壞形式主要表現(xiàn)為車轍、低溫開裂和疲勞開裂，而采用了半剛性基層路面結(jié)構(gòu)和對瀝青混合料品質(zhì)得到了有效緩解。但水損壞的破壞形式則取而代之，成為困擾公我國高速公路發(fā)展得新課題。尤其是在我國南方多雨地區(qū)，高速公路在春融季節(jié)、梅雨季節(jié)及雨季，路面會出現(xiàn)麻面、松散、掉粒乃至坑槽，這種引人注目的早期破壞，是人們始料不及的。2水損害研究瀝青路面的水損壞問題，首先就要涉及到公路的排水系統(tǒng)。為保證公路路基的穩(wěn)定、路面的良好使用性能以及行車的安全，公路都會設(shè)置完善的排水設(shè)施，以排除路界范圍內(nèi)的地表水和地下水。公路排水一般由路界地表排水、路面內(nèi)部排水和地下排水三部分組成。路界地表排水包括路表排水、中央分隔帶排水和坡面排水。路面內(nèi)部排水包括多孔隙面層排水、路邊緣排水及透水基層排水。地下排水包括滲溝、邊溝、暗溝或暗管。研究表明，設(shè)置良好的排水系統(tǒng)，能提高瀝青的使用壽命達30%以上。相反，排水不暢的瀝青路面，其過早破壞通常是由于路面面層結(jié)構(gòu)處于飽水狀態(tài)下，又通行重載車輛引起的。路面結(jié)構(gòu)層中任何一層處于飽水或泡水狀態(tài)，都會導(dǎo)致結(jié)構(gòu)層強度降低，加速路面各種病害的產(chǎn)生和發(fā)展。瀝青路面的水損壞來源于水，只有水滲入路面才有可能引發(fā)瀝青膜和集料剝離，從而造成路面的破壞。因此，滲水性是瀝青路面會不會產(chǎn)生水損壞的關(guān)鍵性指標。應(yīng)該說增加滲水系數(shù)指標對于提高瀝青路面的施工質(zhì)量，預(yù)防水損壞有重要意義。而排水性瀝青路面正是基于公路排水系統(tǒng)的以上特點而發(fā)展起來的一種新型公路路面結(jié)構(gòu)形式。排水瀝青路面，又稱透水瀝青路面，針對表面層來說又稱多孔隙瀝青磨耗層;指壓實后空隙率在20%左右，能夠在混合料內(nèi)部形成排水通道的新型瀝青混凝土面層，其實質(zhì)為按照嵌擠機理形成骨架-空隙結(jié)構(gòu)的開級配瀝青混合料。其特點為:第一，雨天能防止路表水膜的形成，抗滑性能好，提高路面粗糙度，抵抗車輛的滑移;消除或減輕車尾噴水花的現(xiàn)象，提高駕駛員視線的清晰度，從而提高行車安全性;第二，高溫穩(wěn)定性好，抗車轍能力強;第三，具有防眩光和降低交通噪聲等功能?？梢娕潘访婢哂屑壤诃h(huán)保，又利于交通安全的諸多特點，符合當前的技術(shù)發(fā)展及社會發(fā)展的趨勢。3國內(nèi)外研究現(xiàn)狀二十世紀六十年代以來，一些歐洲國家如德國、法國、英國和意大利相繼提出了排水性瀝青路面這種概念，并著手對瀝青材料進行研究，取得了很多有益的成果，從而促進了該技術(shù)的推廣應(yīng)用。歐洲國家首先研究開發(fā)的是一種空隙率高達20%~25%，厚度為4~5cm的磨耗層。因為空隙率大，雨水可以滲入路面之中，由路面中的連通空隙向路面邊緣排出。這樣雨天不存在很厚的水膜，避免了“水漂”的產(chǎn)生，同時也不再出現(xiàn)濺水現(xiàn)象，有效地保證了行車的安全。因為這種多空隙的路面能很快地排水，所以稱之為排水性瀝青路面。迄今為止歐洲國家對排水性瀝青路面的研究和使用已超過30年，部分國家排水性瀝青混合料路面占道路面積約達10%以上。歐洲各國對瀝青材料的選擇達成的基本共識是使用改性瀝青，并主要考慮以下要求:具有較好的高溫穩(wěn)定性、低溫抗裂性以及抗氧化性能。美國在1973年通知全國建議使用開級配抗滑磨耗層路面，明顯降低下雨天的“水漂”現(xiàn)象，取得了良好得效果。進入二十世紀末期以來，各國對排水性瀝青路面的應(yīng)用技術(shù)研究進入了一個新的階段，美國公路計劃中的路面長期性能項目中就有專門針對大孔隙瀝青混合材料的試驗路面研究的子項目;1990年在美國華盛頓召開了TRB年會，主要議題就是排水性瀝青材料在道路工程中的應(yīng)用經(jīng)驗。同年，美國聯(lián)邦公路管理局制定了。開級配瀝青抗滑表層混合料設(shè)計方法對表層得孔隙率、厚度及主要功能均進行了說明。英國從1984年起在全國各地鋪筑了各種試驗路，目的是為了驗證排水性瀝青路面的降噪效果和耐久性。奧地利出于環(huán)境保護的需要，在許多經(jīng)過城鎮(zhèn)的道路上鋪筑了排水性路面，10多年前已累計有650萬m2，并且計劃將透水路面用于城市道路。該國己就多孔排水式路面制定了設(shè)計規(guī)范。荷蘭每年鋪設(shè)透水性路面250萬m2，即荷蘭已有15.4%的汽車專用道鋪設(shè)了這種路面。法國采用排水性路面速度非常之快，幾年前就己經(jīng)鋪筑了2000萬m2，而且還以每年400萬m24排水性瀝青混凝土面層設(shè)計要點4.1排水量的確定新建要點瀝青混凝土路面結(jié)構(gòu)內(nèi)部排水的設(shè)計仍需計算所在地區(qū)正常情況下需要排出的排水量，計算公式同已建成的水泥混凝土路面結(jié)構(gòu)內(nèi)部排水量的計算公式。4.2排水結(jié)構(gòu)的確定公路路面結(jié)構(gòu)內(nèi)部排水結(jié)構(gòu)分三種:第一種是中央分隔帶排水，用于多雨地區(qū)分隔帶無鋪面的高速公路;第二種是路面邊緣排水;第三種是設(shè)置排水基層。這幾種結(jié)構(gòu)形式的選擇，可根據(jù)公路等級、路面結(jié)構(gòu)類型及當?shù)氐慕涤炅康染唧w情況經(jīng)過計算來確定。對于多雨地