预览加载中，请您耐心等待几秒...

土木工程桥梁毕业设计外文文献翻译中英文.pdf

预览
1/5
2/5
3/5
4/5
5/5

在线预览结束，喜欢就下载吧，查找使用更方便

下载提示 文本预览

如果您无法下载资料，请参考说明：

1、部分资料下载需要金币，请确保您的账户上有足够的金币

2、已购买过的文档，再次下载不重复扣费

3、资料包下载后请先用软件解压，在使用对应软件打开

文献翻译BridgeMaintenanceTechniquesEssentialmaintenancegenerallyinvolvesstrengtheningorreplacementofbridgeelements.Strengtheningtechniquesincludewelding,platebondingandexternalpost-tensioningwhichincreasethestiffnessofbridgedecks.Replacementofelementshasbeenusedfordeckslabsandbeams,piersandcolumns.Theprimarypurposeofessentialmaintenanceistoincreasetheloadcarryingcapacityandthereasonfortheinadequatecapacityissecondary.Ifthereasonissimplyincreasedloadingthemaintenancecanbelimitedtoincreasingthecapacity,butifthereasonisdeteriorationthenmaintenancemustalsoincluderepairsandpreventativemaintenance.Theselectionofthemaintenancemethodforrepairspreventiondependsprimarilyonthecauseofdeterioration.ForsteelconstructionthemaincauseofdeteriorationiscorrosionandregularmaintenancepaintingshouldbecarriedouttopreventthesteelfromcorrodingIf.corrosiondoesoccurthentheonlyrepairoptionistogritblastbacktoshinymetalbeforerepainting.Anassessmentofloadcarryingcapacityshouldbecarriedoutifcorrosionhasresultedinasignificantreductionofsteelsection.Theselectionofrepairandpreventionmethodsforconcreteconstructionismorecomplexbecausetherearenumerouscausesofconcretedeterioration.Thedeteriorationofreinforcedconcretecanbeconvenientlysub-dividedintodeteriorationoftheconcreteanddeteriorationofthesteelreinforcement.Themaincausesofconcretedeteriorationaresulphates,free-thawcyclesandalkali-silicareaction(ASR).Deteriorationcanalsoberelatedtopoormixdesignandconstructionprocesssuchascompactionandcuring.Thesetypesofdeteriorationcanonlybepreventedbyactionstakenatthetimeofconstruction;therearenoeffectivepreventativeactionsthatcanbetakenafterconstruction.ForexamplewheretheenvironmentisknowntocontainsignificantquantitiesofsulphideitissensibletoconsidertheuseofsulphateresistingPortlandcement.Inregionsexperiencinglargenumbersoffreeze-thawcyclesfrostdamagetoconcretecanbepreventedbyaddingairentrainingagenttotheconcretemix.Frostdamageisworseinconcretethatissaturatedwithsaltywatersotechniquessucha