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(jì)要點(diǎn)摘要：隨著我國經(jīng)濟(jì)和社會的高速發(fā)展，公路建設(shè)也進(jìn)入了快速發(fā)展時(shí)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(diǎn)。因此，傳統(tǒng)的瀝青混凝土路面在設(shè)計(jì)和施工工藝上均需要作出改進(jìn)。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(jì)，施工工藝，質(zhì)量控制1研究背景隨著我國經(jīng)濟(jì)及社會快速進(jìn)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(diǎn)之一。截至2005年底，高速公路通車?yán)锍桃殉^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(dāng)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(dá)不到應(yīng)有的設(shè)計(jì)水平，已嚴(yán)重影響了公路交通運(yùn)輸功能的正常發(fā)揮，造成巨大的經(jīng)濟(jì)損失，同時(shí)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(dá)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(qiáng)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(biāo)。應(yīng)該說增加滲水系數(shù)指標(biāo)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(diǎn)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(shí)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(shí)質(zhì)為按照嵌擠機(jī)理形成骨架-空隙結(jié)構(gòu)的開級配瀝青混合料。其特點(diǎn)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(qiáng);第三，具有防眩光和降低交通噪聲等功能。可見排水路面具有既利于環(huán)保，又利于交通安全的諸多特點(diǎn)，符合當(dāng)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(jì)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(jìn)行研究，取得了很多有益的成果，從而促進(jìn)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(dá)20%~25%，厚度為4~5cm的磨耗層。因?yàn)榭障堵蚀螅晁梢詽B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(shí)也不再出現(xiàn)濺水現(xiàn)象，有效地保證了行車的安全。因?yàn)檫@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(dá)10%以上。歐洲各國對瀝青材料的選擇達(dá)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(jìn)入二十世紀(jì)末期以來，各國對排水性瀝青路面的應(yīng)用技術(shù)研究進(jìn)入了一個(gè)新的階段，美國公路計(jì)劃中的路面長期性能項(xiàng)目中就有專門針對大孔隙瀝青混合材料的試驗(yàn)路面研究的子項(xiàng)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(yàn)。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(jì)方法對表層得孔隙率、厚度及主要功能均進(jìn)行了說明。英國從1984年起在全國各地鋪筑了各種試驗(yàn)路，目的是為了驗(yàn)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(hù)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(jì)有650萬m2，并且計(jì)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(jì)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(jì)要點(diǎn)4.1排水量的確定新建要點(diǎn)瀝青混凝土路面結(jié)構(gòu)內(nèi)部排水的設(shè)計(jì)仍需計(jì)算所在地區(qū)正常情況下需要排出的排水量，計(jì)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(jì)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(dāng)?shù)氐慕涤炅康染唧w情況經(jīng)過計(jì)算來確定。對于多雨地