预应力混凝土路面的发展与

TheDevelopmentandResearchofThePrepareShouldDintConcreteRoadSummary：Thistexttotheinternationalcommunityintheaspectsofpreparingshoulddintroadaworkfordoingproceededthereviewandoutlook.Mainbelowafewaspectsproceedstoexpatiate:Prepareattherequestofthedevelopmentofthedintconcreteroad,itsmeritandshortcoming,prepareshoulddintconcreteroadtype,material,thedesignmethod,roadbedcontrols,expensesanditsfutureandfurtherresearchwork.Keywords：Prepareshoulddintconcreteroad；designmethod；development；research1.BriefIntroductionThoughprepareshouldtheprincipleofthedintdrivebroadlyappliedinhouse,bridge...etc.constructionrealm,butintheapplicationontheroadverylimited.Knowtoall,themaincharacteristicoftheconcreteisananti-topressthestrengthfarlargerthananti-pullsthestrength.Prepareshouldthedintconcreteroadistomakesuseofthischaracteristicwell,inadvancetheinflictionpressinworkingtocutshoulddint,theanti-thattoincreaseitbendtopullthestrength,increasingtheacceptancecarrytheability.Prepareshouldthedintconcreteroadincreasestocutthecurvedstrengthinactualanti-of.Generalthicknessis10～15cm.Ifagainthinwillmakethefront-panelproducethebiganenduringfor,toroadfront-panelisalldisadvantageouswiththestabilityofthefoundation,moreover,alsoenlargedtheconstructiondifficulty.Prepareshouldthedintmakeconcreteroadfront-panellongandcanenlargeconsumedly,takinggenerally90～120m,theabroadalsoreaches150～300mlong.2.DevelopmentprocessPrepareshouldthedintconcreteroadisakindofspecialcementconcreteroadthat20centuries40'sempressperioddevelop.UsedinFranceattheearlieststage,usedfortheroadroadorairportatopwithotherEuropeannationsuccessivelyinEnglandafterwards.TheUnitedStates,JapanwaitthenationtoalsoallfixedtosetupwiththeformerSovietUnioncertainthequantitypreparesshoulddintconcreteroadwithairport.AccordingtocarryintheworldanabridgeforpreparingshoulddintconcreteroadappearingintheFrenchLuzancyleadsthewaythetop.ButtherunwayofOrlythatriseintheworldsetsupdidnotmakeprepareuntil1947shoulddintconcreteroadcompleteestablishment.Atthattime,thatrunwayforthesakeofsatisfymodernflyingofdemandbutestablishof.Thealllongatrianglefor,fromtakinghorizontalsteelwirewithsetfront-panelconstitutes.In1953,insamelocation,adoptedtheopeningstypejackonthecontinuousrectangleplankwiththehorizontalsteelwire,otherengineeringsuchas:UsedtheinclineddirectionsteelwireatLuzancyandEsbly,butadoptedtheopeningstypejackonlongtheBourg-Servasroadsegmentofthe295.2mswiththeof"consecutiontype"plank.(namelyhavenotheinflationsew,continuousconcreteplank)Amongthem,anexperimentstheroadisaplanksidethininplankinside,otherisallaverageroughlyathicketc.cuts.FranceisinadditiontousingintheontheroadofBourg-Servasthebeginningofthe5.18MPastarttoprepareshoulddint,preparinglengthwaystotheplankaninflictionshouldthedintisallwithothernationonthequantityclasssamealike.TheFranceengineerdonotapprovethehorizontalinflictionpreparesshoulddint.EnglandjuststartspreparingfromtheroadofCrawleyofthe1950shouldthedintconcreteroadisinvestigative.Thatroadpreparesforthesakeoftheinquisitionprimarilyshoulddintconcreteisintheroadusageindevelopmentscircumstance,designingthefactortothesomewithstartconstructioninthatontheroadthemethod(adoptedtheFreysinnettypesteelwiretohavewithanchorman,asteelwireforgrowingbecamearhombuspatterninacenter)proceededtheresearch.Fixapronofairfield,theroadofEssex,theroadofPortTaLbot,Catwickapronofairfieldetc.thatsetuptheairportofLondonafterwardandagainandsuccessively.PrepareBritishlyshoulddintconcreteroadfront-panelgreatmajorityareallinflationthat"alonetype"of,thenhavethesteelwirewithboxofftosew.Becausetheythink,the"alonetype"plankisgoodfriendswithin"consecutiontype".InEngland,useanetc.slabbroadly,thetriangleplankthatdividedbytouseontheairportofLondonisanoutside.Biggestathatitonceuseisplankthatanetc.slab,butapieceofadoptionopeningstypejackisthickfor10cms.ItisBritishtopreparinglengthwaysshouldthedintisgeneralfor:1.575MPas(highway),3.15MPas(airport),1.925MPas;(inclinedtietosteelwire)Itishorizontaltopreparingshouldthedintisgenerallessthan0.35MPas,inadditiontotriangleplank.AtalittlebitGermanrelevantprepareshouldearlierperiodinknotholeindintanalysistheworkwantstocomparetheothernationearly,butitstheoriesapplicationislimitedbybridgefront-panel,floorplanketc.,notroadfront-panel.JuststarttoconstructtoprepareintheMergelstettenin1953shoulddintroad,constructedafewroadsafterwardandagain.ThePatuxentRiverNavaeAirStationofthepreparedattheearlieststageshoulddintisbuildfromBureauofYardsandDocksin1953ssetupin1954inTheUnitedStates,thisisbeginningthatalongaroadfor,thick17.5cms,lengthwaysthesteelstartedtoprepareshoulddintabout4.9MPas.Fixedthemanyexperimentingtheroadafterwardandagain,theamongthemnearerisfamousNewYorkinternationalairporttoascendin1980setsupofprepareshoulddintconcretecover,thisistheUnitedStatestowillpreparefortheveryfirsttimeshouldthedintconcreteusedforthecompanyusestheairport.AlsoallfixinginHolland,Switzerlandmanypreparingshoulddinta,amongthemnearersetupintheSchipolsuchasHolland.(1980～1987)3.PrepareshouldthemeritandshortcomingofthedintconcreteroadManyresearchesworkexpressestoprepareshouldthedintconcreteroadhavebelowtheadvantageofseveralaspects:(1)theroadfront-panelthicknessneedsthick40%～60%inroadfront-panelintraditionalconcrete.Theveryhighloadinginofferingdinttransformstheabilitywiththehigheranti-,isverybeneficialtothethicknessthatletuptheairport.(2)prepareshouldthedintconcreteroadislongerbecauseoftheplank.Thejointquantitycanreduceconsumedly,improvingthesteadyofacar.(3)prepareshouldtheesseofthedintmakeroadfront-panelstronger,canimprovementinweakpartinCapeinside.Reducedthehorizontalopenningthepossibilityofthe,increasestheenduringoftheroad.(4)prepareshouldthedintconcreteroadusetheamountoflittle.Theresearchpointsout,usedingfornormalpreparingshouldthereinforcingbarthatdintneedwhendesigningmeasuresroughly2.7125kms/m2,thisfarlessthancontinuegotogetherwiththeroad.Itsmainweaknessconsistsin:(1)seefromeconomicstandpoint,lettingupthethicknessoftheroadfront-panel.Butneedtobepreparedafloodoflyshouldmainreinforcingbarindint,constructioncraftthancomplicacy,theworkthathandicraftoperationhasgreatcapacity,andingishardtorealizemechanization,automationconstruction.Theearlyinvestmentisbigger.(2)althoughprepareshouldthedintconcreteroadfront-panelcanmakeoutlonger,withtheincrementofthelength,bepulledbythepiecethatroadbedcausewhencontrolingshouldthedintalsoenlargeimmediately.Moreover,theknotholeadesignformovingdealtoowouldenlarging,thisrightnessofhorizontaljointsesrequestisverystrict.(3)requesttobehightoconstructiontroopspersonnel'scharacter.Needtheproceedingquantitycontrol.4.PrepareshoulddintconcreteroadtypeAccordingtothecurrentdata,startconstructionthemethodcanisdividedintothetwomajortypemostly:Theroadofthe"alonetype"with"consecutiontype"ofroad.The"alonetype"roadistoinstallsthecertainquantityprepareshoulddintreinforcingbar.Beingsewnbylongerstretchandshrinkinpartitiontheroadfront-panelthatbeseparatedconstitutes.Pressinflictiontoprepareshouldthedintcanisdividedintoorderofsequenceandagainfirstpiece'smethodissimilartoempresspiece'smethodistwokindsof,thiswithhouse,thewayofdoingonthebridge,generallymuchafteradoptingpiece'smethod."consecutiontype"theroadistohavenoreinforcingbarroad.(getsingamethodforbecausehavingnotheinflationsews),thiskindofroadcanmakingoutverylongly,accordingtoinflictionpreparingshoulddintcanisdividedintothejackaddsthedintwithfromaddingshoulddint.Thejackaddsthedintisgeneraltosprinkletobuildtheconcreteintwofixedanchormans,combiningtostaythecreviceplacetoaddthedintjack,needingtheconcretehardentoattainafterrulingthestrength,usethejacktoaddthedintfromthebothends,attaintorulethepressure,closethebothendscrevice.Itwillofcoursetheneednotjackininroadindintaddsthedint,butchoosetousetoinflatethecement,theconcretehardens,thephysicalvolumeenlarges,becausethebothendssuffersthestipulationbutmakeautomaticcreationinconcreteinsidepressedshoulddint.Thinkgenerally,the"alonetype"knotholeroadisgoodfriendswithin"consecutiontype"knotholeroad.Mainreasonanistodeducttheroadbedafterrubbingofprepareshouldthedintkeepsalmosttooftenmeasuresinhadinflationsewedroad,butin"consecutiontype"plank,plankcan'tfreeinflation,besidesverylong,frombutmakeitsshouldthedintchangewiththeoutsidertemperature,degreeofhumidityverybig,verydifficultneedtoofprepareshouldthedintproceedtheestimateof.Therefore,adopt"alonetype"roadmoreontheengineering,"consecutiontype"theroadstillisplacedintheresearchandexperimentthestage,theactualapplicationisnotmuch.5.DesignmethodCurrent,internationalcommunitytodesignthatprepareshouldthedintconcreteroadstillhavenoanunitedofmethodsystem,andisallexperienceonacertaindegree,therefore,aninflictionpreparesshoulddintmainfrom:(1)thetransportationcontrols;(2)fromtemperaturewithdegreeofhumidityaflectionforcausingstipulation;(3)theplankcontractstheplankbottomoftheperiodrubsthestipulation.Threefactorsdecides:Squaredistanceinbasicdesignis:Ft+fpf△T+fF+fLTypeinside:Fp——Frompreparingshouldtheconcretethatdintcauseinsideofpressshoulddint;Theft——Concreteallowsflectionshoulddint;(Concretecurvedfoldmoldmeasure/safecoefficient)Thef△T——Isbadtocausefromthetemperatureofshoulddint;ThefF——Isrubbedbyroadbedtocauseofshoulddint;ThefL——Iscausablefromtheflectionthatcontrolshoulddint.TemperatureIfsupposethetemperaturestepsdegreechangealongtheline,so:F△T=(Ecac△T2)/(1-V)TheroadbedrubstocauseofshoulddintFF=μ×ρ×χAmongthem,μisdensitythatroadbedcoefficientoffriction,theρisaconcrete,χfordistancethatbeapartfromthejack.Whenχ=L/2(theLislongforplank),thefFattainsbiggest.Atmakesuretoprepareshoulddintsize,takethefF=μ×ρ×L/2.ThecarriesThecarriesshoulddintcalculationnowallaccordingtotheformulaofWestevgaard,thatmethodassumptionasuggestionforcarryingevenlydistributinginroundprintingtheradiusa,accordingtoTellerwithSutherland,givebelowanusedfortheplanksidewiththecorrectionoutoftheplankCapetype:6.RoadbedstipulationThegrass-rootsavarietyforallexsittingfrictioncontroling,shouldcontrolingarrestmentplankwithtemperature,degreeofhumiditythatisunderanyconcreteplankwithitsbutmove.Inprepareshoulddintconcreteroad,letuptothebestthatfrictioniscountformuch,becauseitisamainfactortocausetoprepareshoulddintlose,italsodecidetheknotholelengthatthesametime.Thoughtheabroadisinthisrespecttohavedonenotafewworks,thesizeofthecoefficientoffrictionisstillhardcertain.Somesectionssuggestioncoefficientoffrictionis0.25～0.5butalsodiscoversitsvalueasinsandoraglideforconstitutinglayersthattryletupthefriction1.25～2.0.Manythecoefficientoffrictionthatindoorsmakesurewhenexperimentingsisallsmallerthanthespot's,thisisbecausetheindoorscouldsnottheconditiontermthatrealityreflectthespotwiththeresultthat.7。ExpensesBuildthepriceexpensesmostcannowthedevelopmentprospectofthenew-bornthing,peopleusuallyevenmakeapointofhowitseconomicperformanceis,butneglectedtheotheraspect.Althoughtheabroaddoesmanyandmoreanalyzingofthetraditionalconcreteroad,can'tstillexplaintheproblem,becausebigparttheworkisallanexperiment,soratiothecostexpensesnaturewantshigherthanexpectsof.Veryobviously,bethetechniqueperfectwithuniversal,itsexpenseswilldescend.Current,fromthesomeinabroadthereportcansee,preparingshouldthedintconcreteroaddifferwithtraditionalroadonthedevelopmentsexpensesnotvery.Althoughthevaluationpreparesshouldthedintconcreteroadprotecttheexpensesoveralongperiodoftimeapparentlyoverearly,itisveryconsiderableineconomicthatprotect.TheBritishCrawleypreparesshouldthedintashowitisbasicwiththedevelopmentsexpensesofthecommonreinforcedconcreteroadsamealike.Atcompleteapieceofknotholebuildbehind,onceproceedtheinvitationtobidfixtosetuptherestplank,theearlierperiodofresultbidsthepricewantstobelowerthananofferforanticipatingusedingforcommonroadbuildingprice,4lowestofferonlycomparingcommonroadhigh6%.Moreover,1980acoveraftertheairportofO'HareoftheUnitedStatesfixsetuptheworldthefirstusedforcompanyusetheairportanof.Table1giveaprojectforfixingbeforesettingupcomparison40yearsin—in—usethetotalcostofthetimelimitanalyzes,thoughtable1havetheestimateofcomposition,thetoocertaindegreeexplainstoprepareshouldtheeconomicperformanceofthedintconcreteroad.Moreover,1980acoveraftertheairportofO'HareoftheUnitedStatesfixsetuptheworldthefirstusedforcompanyusetheairportanof.Table1giveaprojectforfixingbeforesettingupcomparison40yearsin—in—usethetotalcostofthetimelimitanalyzes,thoughtable1havetheestimateofcomposition,thetoocertaindegreeexplainstoprepareshouldtheeconomicperformanceofthedintconcreteroad.Form1ProjecttA

(Commmoncconcrreteroadd)ProjecttBEarlyiitemexpeensess187400001986000039yearrs'jjointtprootectts22850045700Thejoiintssweeppsevvery5yeearswithhtheefilller

((Totaally7tiimes))100140000Needtoocovveraafterr20yearrs5307000Needtoocovveraafterr30yeears864400864400Total44990000287810008．FutureoutlookwithfurtherofresearchInregardtocurrent,stillisinneedoftothecognitionthatprepareshoulddintconcreteroadeveryone's.Theauthorthinksthatdesigntheoriesthatprepareshoulddintconcreteroadwithdevelopmentthatstartconstructionthemethodwillsurroundprimarilybelowafewaspects:(1)needtothelongineverykindofplankofpreparefittinglyshoulddint.(2)knotholeinflation,contractwiththebentcharacteristic.(3)knotholeloadingcharacteristic,amongthemincludetheresearchpreparesshouldthedintloadtheinfluenceoftheabilitytotheknothole,andtotheinfluenceofthetiredcharacteristicetc.inplank.(4)plankandthefrictioncharacteristicofthefoundationandhandlemethod.(5)jointwithdesignthatdrainthesystem.(6)thedevelopmentoftheconstructionprocedure,whethercanusetopaveroadsurfacethewayofdoingtraditionally,oreconomicmethod.Alreadythegreatmajoritythatsetuppreparesshouldthedintconcreteroadallbelongtothe"alonetype"of,butthetype'sroadcan'tmakeoutverylong.(canamounttogenerally120ms)Ifthefrictionproblemoftheroadbedresolved,andto"consecutiontype"oftheroadhadthecertaincognition,fixingtosetupsolong300msorlongerroadsarepossible.Wecanseefromthe"alonetype"with"theconsecutionthetype"thesomecharacteristicoftheroad:Unitesthesetworoadstheusagewouldbemorebeneficial,"consecutiontype"theroadcanusedfortheroadbedconditionthankeeptheontheroadgoodly,the"alonetype"roadusedsfortheroadbedcircumstanceslightlybadwithcurveontheroad.Alongwiththeoriessystemthatprepareshouldthematurityofthedintconcreteroadwithstartconstructiontechnicaldevelopment,prepareshouldthedintconcreteroadwillhavethegooddevelopmentforeground.论文译文：预应力混凝土路面的发展与研究摘要：本文对各国在预应力路面方面所做的工作进行了回顾与展望。主要就以下几个方面进行论述：预应力混凝土路面的发展，其优缺点、预应力混凝土路面类型、材料要求、设计方法、路基约束、费用及其未来的进一步研究。关键词：预应力混凝土路面设计方法发展研究简介尽管预应力的原理被广泛地应用于房屋、桥梁等结构领域，但在道路上的应用却很有限。众所周知，混凝土的主要特性就是抗压强度远大于抗拉强度。预应力混凝土路面就是充分利用这一特性，事先在工作截面上施加压应力。以提高它的抗弯拉强度，提高承受荷载能力。预应力混凝土路面提高了截面的实际抗弯强度。一般厚度为10～15cm。如果再薄会使面板产生过大的挠度，对路面板的耐久性和地基的稳定性都不利，另外，也增大了施工难度。预应力使混凝土路面板长可增大很多，一般取90～120m，国外也有长达150～300m。发展过程预应力混凝土路面是二十世纪四十年代后期发展起来的一种特殊的水泥混凝土路面。最早是在法国使用，后来在英国和其它欧洲国家先后用于道路路面或机场道面上。美国、日本和前苏联等国家也都修建了一定数量的预应力混凝土路面和机场道面。据载世界上第一条预应力混凝土路面出现在法国的Luzancy的一座桥梁的引路上。但直到1947年，闻名于世的Orly跑道的建成才使预应力混凝土路面完全确立。当时，该跑道为了满足现代飞行的需要而设置的。全长409.5m，由带横向钢丝和台座的三角形面板组成。1953年，在同一地点，在连续的矩形板上采用了开口式千斤顶和横向钢丝。其它工程如：在Luzancy和Esbly使用了斜向钢丝，而在长295.2m的Bourg-Servas路段上采用了开口式千斤顶和墩座的“连续型”板(无膨胀缝、连续的混凝土板)。其中，一条试验路是板边薄于板中，其他都是平均约15cm厚的等截面。法国除在Bourg-Servas路上使用了5.18MPa的初始预应力外，对板所施加的纵向预应力在数量级上与其他国家都相同。法国工程师不赞成横向施加预应力。英国是自1950年的Crawley道路才开始预应力混凝土路面研究的。该路主要是为了调查预应力混凝土在道路建设中的使用情况，在该路上对一些设计因素和施工方法(采用了Freysinnet型钢丝和锚具，24.6m长的钢丝在2.25m中心处形成了一个菱形图案)进行了研究。其后又先后修建了伦敦机场的停机坪、Essex道路、PortTaLbot道路、Catwick停机坪等。英国的预应力混凝土路面板绝大多数都是“单独型”的，即有钢丝和分隔的膨胀缝。因为它们认为，“单独型”板要好于“连续型”。在英国，广泛地使用15cm等厚板，除在伦敦机场上用的三角形板为16.25cm外。它曾使用的最大截面是25cm等厚板，而一块采用开口式千斤顶的板却为10cm厚。英国的纵向预应力一般为：1.575MPa(公路)，3.15MPa(机场)，1.925MPa(斜向钢丝束)；横向预应力一般少于0.35MPa，除三角形板外。在德国一些有关预应力板的早期分析工作要比其他国家早，但其理论应用只限于桥面板、楼板等，而不是路面板。在1953年才开始在Mergelstetten修筑预应力路面，其后又修筑了几条道路。美国最早著名的PatuxentRiverNavaeAirStation预应力道面是由BureauofYardsandDocks于1953～1954年建的，这是一条长150m、宽3.6m、厚17.5cm的路面，纵向钢索的初始预应力大约为4.9MPa。其后又修了许多试验路，其中较近的就是1980年闻名的纽约国际机场上所建的预应力混凝土罩面(240m长，45m宽，20～22.5cm厚的跑道)，这是美国首次将预应力混凝土用于商用机场道面。在荷兰、瑞士也都修了许多预应力道面，其中较近的如荷兰在Schipol建的(1980～1987年)。预应力混凝土路面的优缺点许多研究工作表明预应力混凝土路面有以下几方面的优点：(1)路面板厚度只需传统混凝土路面板厚的40%～60%。提供很高的承载力和较高的抗变形能力，对减小机场道面的厚度非常有利。(2)预应力混凝土路面由于板较长。接缝数量可大大减少，改善了行车的平稳性。(3)预应力的存在使路面板体性较强，边角软弱部分得以改善。减少了横向开裂的可能性，提高了路面的耐久性。(4)预应力混凝土路面的用筋量少。研究指出，用于正常预应力设计所需的钢筋量约为2.7125km/m2，这远少于连续配筋路面。其主要缺点在于：(1)从经济观点来看，减小了路面板的厚度。但需大量的预应力主筋，施工工艺较复杂，手工操作的工作量大，难以实现机械化、自动化施工。初期投资较大。(2)虽然预应力混凝土路面板可以做得较长，但随长度的增加，由路基约束所引起的张拉应力也随之增大。另外，板的位移量也会增大，这对横向接缝的设计要求很严。(3)对施工队伍人员素质要求高。需进行质量控制。预应力混凝土路面类型据现有资料，施工方法大致可分为两大类：“单独型”的路面和“连续型”的路面。“单独型”路面就是配置一定数量的预应力钢筋。由间隔较长的伸缩缝相隔的路面板组成。按施加预应力的先后次序又可分为先张法和后张法两种，这与房屋、桥梁上的做法相同，一般多采用后张法。“连续型”路面就是无筋路面。（因无膨胀缝而得名），这种路面可以做得很长，按照施加预应力的方法可分为千斤顶加力和自加应力。千斤顶加力是一般在两个固定的锚固端间浇筑混凝土，并留有空隙放置加力千斤顶，待混凝土硬化达到规定强度后，用千斤顶从两端加力，达到规定压力时，将两端空隙封闭。自应力路面不用千斤顶加力，而是选