外贴碳纤维布加固大比例钢筋混凝土梁抗弯性能

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1、维普资讯http://www.cqvip.com第4卷第4期铁道科学与工程学报Vo1．4NO．42007年8月JOURNALOFRAILI，＼／AYSCIENCEANDENGINEERINGAug2007外贴碳纤维布加固大比例钢筋混凝土梁抗弯性能周朝阳，李毅卉，贺学军(中南大学土木建筑学院，湖南长沙410075)摘要：以某类铁路桥梁为原型，通过5根粘贴碳纤维布加固钢筋混凝土梁的1／3比例模型试验，研究了梁表面处理方式和加固前预栽历史对加固梁抗弯能力和破坏形态的影响。试验结果表明，粘贴表面打磨的梁发生纤维布带面层

2、剥离破坏，而凿毛处理时最终破坏均为混凝土压碎；若不出现剥离破坏，则碳纤维布具有良好的加固效果；加固时，梁上既有荷栽越小，则加固效果越好基于《规程》(CECS146：2003)的基本假定，考虑既有荷栽的影响，对本文试件的屈服弯矩和极限弯矩进行理论分析，其结果与实测值较吻合，说明《规程》中计算屈服后压碎时的的正截面承栽力公式对碳纤维布加固较大尺度、较高配筋混凝土粱也是适用的。关键词：外贴：碳纤维布；抗弯加固；钢筋混凝土梁中图分类号：U448．34文献标识码：A文章编号：1672—7029(2007)04—0041—

3、06Flexuralbehavioroflarge——scaleRCbeamsreinforcedwithexternallybondedcarbonfibersheetsZHOUChao—yang，LIYi—hui，HEXue—jun(SchoolofAmhitectureandCivilEngineefing，CentralSoulhUnive~ity，Changsha410075，China)Abstract：Withatypeofrailwaybridgeasaprototype，fiveone—thi

4、rd—scalespecimensofreinforcedconcretebeamsweremade，andfourofthemwerestrengthenedwithexternallybondedcarbonfibersheets．Theparametersinvestigatedinthisstudyincludedthewayoftreatingconcretesurfaceandthelevelofpre—loadingatstrengthening．Theireffectsontheflexural

5、capacityandfailuremodewereparticularlyconsidered．Theexperimentalresultsshowthattheultimatefailureischaracterizedbyconcretecrushingwhenthebeamsurfaceisroughenedbypicking．Incontrast，peeling—ofhappensincaseofsurfaceplaning．ExternallybondedCFRPsheetscanincreaset

6、heflexuralcapacityofthebeamsig—nificantlyifdebondingisavoided．Inaddition，theresultsindicatethatthelighterthepre—loadonthebeam，themoretheincrementofitsultimateloadcomparedtothatofunstrengthenedspecimen．Inconsiderationoftheinfluenceofpre—load，theoreticalanalys

7、esarecarriedouttopx~dictthebendingmomentsatrebaryieldingandconcretecrush—ingonthehasisoftheassumptionsfromthespecification(CECS146：2003)．Thecalculatedresuhsareingoodagree—mentwiththemeasuredvaluesforrefeiTedmenl}lers．Meanwhiledesignalgorithmofthecorrespondin

8、gcapacityinthespecificationisvalidatedforCFRPsheet——strengthenedconcretebeamswithratherlanesizesofsectionandheavyra-tiopercentageofsteelreinforcement．Keywords：externallybonded；carbonfibersheet；f