桥梁毕业设计外文翻译.docx

《桥梁毕业设计外文翻译.docx》由会员分享，可在线阅读，更多相关《桥梁毕业设计外文翻译.docx（7页珍藏版）》请在优知文库上搜索。

1、外文资料TheTenthEastAsia-PacificConferenceonStructuralEnghieerhigandConstructionAugust3-5f2006,Bangkok,ThailandStructuralRehabilitationofConcreteBridgeswithCFRpcomposites-PracticalDetailsandApplicationsRiyadS.ABOUTAHA1,andNuttawatCHUTARAT2ABSTRACT:Manyoldexistingbridgesarestillactiveinthevarioushighwayt

2、ransportationnetworks,carryingheavierandfastertrucks,inallkindsofenvironments.Water,salt,andwindhavecauseddamagetotheseoldbridges,andscarcityofmaintenancefundsHasaggravatedtheirconditions.Oneattempttorestoretheoriginalcondition;andtoextendtheservicelifeofconcretebridgesisbytheuseofcarbonfiberreinfor

3、cedpolymer(CFRP)Composites.ThereappeartobeverylimitedguidesonrepairofdeterioratedconcretebridgeswithCFRPcomposites.Inthispaper,guidelinesfornondestructiveevaluation(NDE),nondestructivetesting(NDT),andrehabilitationofdeterioratedconcretebridgeswithCFRPcompositesarepresented.Theeffectofdetailingonduct

4、ilityandbehaviorofCFRPstrengthenedconcretebridgesarealsodiscussedandpresented.KEYWORDS:Concretedeterioration,corrosionofsteel,bridgerehabilitation,CFRPcomposites.!IntroductionThereareseveraldestructiveexternalenvironmentalfactorsthatlimittheservicelifeofbridges.Thesefactorsincludebutnotlimitedtochem

5、icalattacks,corrosionofreinforcingsteelbars,carbonationofconcrete,andchemicalreactionofaggregate.Ifbridgeswerenotwellmaintained,Ihesefactorsmayleadtoastructuraldeficiency,whichreducesthemarginofsafety,andmayresultinstructuralfailure.Inordertorehabilitateand/orstrengthendeterioratedexistingbridges,th

6、oroughevaluationshouldbeconducted.Thepurposeoftheevaluationistoassesstheactualconditionofanyexistingbridge,andgenerallytoexaminetheremainingstrengthandloadcarrycapacityofthebridge.7AssociateProfessor,SyracuseUniversity,U.S,A.2Lecturer,SripatumUniversity,Thailand.Oneattempttorestoretheoriginalconditi

7、on,andtoextendtheservicelifeofconcretebridgesisbytheuseofcarbonfiberreinforcedpolymer(CFRP)composites.InNorthAmerica,EuropeandJapan,CFRPhasbeenextensivelyinvestigatedandapplied.SeveraldesignguideshavebeendevelopedforstrengtheningofconcretebridgeswithCFRPcomposites.However,thereappeartobeverylimitedg

8、uidesonrepairofdeterioratedconcretebridgeswithCFRPcomposites.Thispaperpresentsguidelinesforrepairofdeterioratedconcretebridges,alongwithproperdetailing.Evaluation,nondestructivetesting,andrehabilitationofdeterioratedconcretebridgeswithCFRPcompositesarepresented.SuccessfulapplicationofCFRPcompositesr

9、equiresgooddetailingastheforcesdevelopedintheCFRPsheetsaretransferredbybondattheconcrete-CFRPinterface.TheeffectofdetailingOnductilityandbehaviorofCFRPstrengthenedconcretebridgeswillalsobediscussedandpresented.2DeterioratedConcreteBridgesDurabilityofbridgesisofmajorconcern.Increasingnumberofbridgesa

10、reexperiencingsignificantamountsofdeteriorationpriortoreachingtheirdesignservicelife.Thisprematuredeteriorationconsideredaproblemintermsofthestructuralintegrityandsafetyofthebridge.Inaddition,deteriorationofabridgehasaconsiderablemagnitudeofcostsassociatedwithit.Inmanycases,therootofadeteriorationpr

11、oblemiscausedbycorrosionofsteelreinforcementinconcreteStructures.Concretenormallyactstoprovideahighdegreeofprotectionagainstcorrosionoftheembeddedreinfbrcement.However,corrosionwillresultinthosecasesthattypicallyexperiencepoorconcretequality,inadequatedesignorconstruction,andharshenvironmentalcondit

12、ions.Ifnottreatedadurabilityproblem,e.g.corrosion,mayturnintoastrengthproblemleadingtoastructuraldeficiency,asshowninFigurel.FigurelCorrosionofthesteelbarsisleadingtoastructuraldeficiency3Non-destructiveTestingofDeterioratedConcreteBridgePiersInordertodesignasuccessfulretrofitsystem,theconditionofth

13、eexistingbridgeshouldbethoroughlyevaluated.Evaluationofexistingbridgeelementsorsystemsinvolvesreviewoftheasbuiltdrawings,aswellasaccurateestimateoftheconditionoftheexistingbridge,asshowninFigure2.Dependingonthepurposeofevaluation,non-destructivetestsmayinvolveestimationofstrength,saltcontents,corros

14、ionrates,alkalinityinconcrete,etc.Figure2VisibleconcretedistressmarkedonanelevationofaconcretebridgepierAlthoughmostofthenon-destructivetestsdonotcauseanydamagetoexistingbridges,someNDTmaycauseminorlocaldamage(e.g.drilledholes&coring)thatshouldberepairedrightaftertheNDT.Thesetestsarealsoreferredtoas

15、partialdestructivetestsbutfallundernon-destructivetesting.Inordertoselectthemostappropriatenon-destructivetestforaparticularcase,thepurposeofthetestshouldbeidentified.Ingeneral,therearethreetypesofNDTtoinvestigate:(1)strength,(2)Otherstructuralproperties,and(3)qualityanddurability.Thestrengthmethods

16、mayinclude;Compressivetest(e.g.coretest/reboundhammer/ultrasonicpulsevelocity),surfacehardnesstest(e.g.reboundhammer),penetrationtest(e.g.Windsorprobe),andpullouttest(anchortest).Otherstructuraltestmethodsmayinclude;concretecoverthickness(cover-meter),locatingrebars(rebarlocator),rebarsize(somerebarlocators/rebardatascan),concretemoisture(acquametermoisturemeter),cracking(visualtest/impactecho/ultrasonicpulsevelocity),delamination(hammertest/ultrasoni