中英用碳纖維板cfr修復(fù)剪切不足的矩形簡支梁

英文原文：RehabilitationofrectangularsimplysupportedRCbeamswithsheardeficienciesusingCFRPcompositesAhmedKhalifaa,*,AntonioNannibaDepartmentofStructuralEngineering,UniversityofAlexandria,Alexandria21544,EgyptbDepartmentofCivilEngineering,UniversityofMissouriatRolla,Rolla,MO65409,USAReceived28April1999;receivedinrevisedform30October2001;accepted10January2002AbstractThepresentstudyexaminestheshearperformanceandmodesoffailureofrectangularsimplysupportedreinforcedconcrete(RC)beamsdesignedwithsheardeficiencies.Thesememberswerestrengthenedwithexternallybondedcarbonfiberreinforcedpolymer(CFRP)sheetsandevaluatedinthelaboratory.Theexperimentalprogramconsistedoftwelvefull-scaleRCbeamstestedtofailinshear.Thevariablesinvestigatedwithinthisprogramincludedsteelstirrups,andtheshearspan-to-effectivedepthratio,aswellasamountanddistributionofCFRP.TheexperimentalresultsindicatedthatthecontributionofexternallybondedCFRPtotheshearcapacitywassignificant.Theshearcapacitywasalsoshowntobedependentuponthevariablesinvestigated.Testresultswereusedtovalidateasheardesignapproach,whichshowedconservativeandacceptablepredictions.eq\o\ac(○,C)2002ElsevierScienceLtd.Allrightsreserved.Keywords:Rehabilitation;Shear;Carbonfiberreinforcedpolymer1.IntroductionFiberreinforcedpolymer(FRP)compositesystems,composedoffibersembeddedinapolymericmatrix,canbeusedforshearstrengtheningofreinforcedcon-crete(RC)members[1–7].ManyexistingRCbeamsaredeficientandinneedofstrengthening.TheshearfailureofanRCbeamisclearlydifferentfromitsflexuralfailure.Inshear,thebeamfailssuddenlywithoutsufficientwarninganddiagonalshearcracksareconsid-erablywiderthantheflexuralcracks[8].Theobjectivesofthisprogramwereto:1.InvestigateperformanceandmodeoffailureofsimplysupportedrectangularRCbeamswithsheardeficien-ciesafterstrengtheningwithexternallybondedCFRPsheets.2.Addressthefactorsthatinfluenceshearcapacityofstrengthenedbeamssuchas:steelstirrups,shearspan-to-effectivedepthratio(a/dratio),andamountanddistributionofCFRP.3.Increasetheexperimentaldatabaseonshearstrength-eningwithexternallybondedFRPreinforcement.4.Validatethedesignapproachpreviouslyproposedbytheauthors[9].Fortheseobjectives,12full-scale,RCbeamsdesignedtofailinshearwerestrengthenedwithdifferentCFRPschemes.Thesemembersweretestedassimplebeamsusingafour-pointloadingconfigurationwithtwodifferenta/dratios.2.Experimentalprogram獨(dú)2.1.踩Tes族tsp挑ecim屋ens究and冰mate辛rial帆s丘Twel終vef徐ull-蹤scal怖ebe碌ams蛾peci怒mens跌wit永ha楊tota茄lsp扮ano槽f30如50m林m.a訪nda軋rec菊tang故ular搭cro乖ss-s君ecti駛ono赴f15惜0-mm涼-wid規(guī)ean歌d30鉆5-mm第-dee慣pwe遺ret檢este滑d.T掙hes聲peci懼mens科wer貫egr姓oupe邁din梢tot祖wom痛ain格seri纖esd勢esig沾nate心dSW攏and鑼SO介depe臂ndin椒gon蜘the蜂pre緞senc躍eof嫁ste際els忍tirr梅ups種int浪hes雙hear釀spa錄nof迎int賄eres狗t.薪Seri常esS餃Wco挽nsis葬t(yī)ed低off母our柴spec耕imen等s.T印hed某etai韻lsa翅ndd欠imen長sion坡sof賤the椒spe許cime貼nsd陜esig品nate嗚dse爛ries旅SW忠are相illu襯stra檔ted賢inF艦ig.渾1a.去Int平his繼seri石es,史four棗32-益mms活teel產(chǎn)bar板swe漸reu球sed言asl移ongi筆tudi達(dá)nal梢rein石forc勝emen雨twi圈tht梅woa兇tto命pan哥dtw害oat刑bot靜tom酒face惹of滔the怠cros斯s-se欲ctio氧nto約ind江uce廊ash鬧ear攀fail耳ure.譽(yù)The充spe盼cime楚nsw愧ere宅rein綿forc妥edw記ith盡10-m咳mst撇eel刻stir你rups驗(yàn)thr應(yīng)ough感out銹thei哪ren柜tire擱spa掛n.T巖hes智tirr錢ups度spac殘ing界int矮hes噸hear遙spa盈nof話int獸eres蹄t,r偵ight拌hal男f,w夜ass光elec南ted排toa代llow劃fai唱lure血in窮that許spa生n.鈔Seri布esS罵Oco懲nsis裳ted凈ofe斯ight濱bea浩msp墾ecim祥ens,雀whi臘chh莖adt季hes維ame慌cros若s-se巧ctio子ndi墓mens胡ion葬and盜long震itud礙inal冊ste或elr艇einf叉orce舉ment煉as失for負(fù)seri炭esS脂W.N止ost逮irru搖psw榆ere賣prov夢ided撇in身the姓test淡h(huán)al可fsp禿ana球sil凍lust拜rate竹din做Fig爭.1b拿.坡Each輛mai半nse析ries答(i.撫e.s滾erie廟sSW晃and某SO)撲was陣sub書divi贈ded靜into倒two多sub牙grou忍psa知ccor笛ding跟to貌shea泄rsp毅an-t晨o-ef我fect有ive縮dept戚hra泰tio.釀Thi釣swa翼sse蒸lect肺edt非obe豈a/d體=3腸and酷4,姜resu喊l(fā)tin拌gin灣the柄fol骨lowi萄ngf敞our約subg伏roup喪s:S標(biāo)W3;S省W4;秘SO3;宇and生SO4蕩.把The侍mech呼anic索alp足rope叔rtie根sof描the烏mat病eria距l(xiāng)su應(yīng)sed津for員manu昂fact移urin秀gth喜ete住sts他peci屋mens花are際lis腦ted躲inT反able杠1.F誦abri外cati對ono攝fth眾esp膜ecim簡ens胃incl館udin默gsu芬rfac僻epr眉epar智atio愿nan郊dCF始RPi卸nsta森llat毒ion害isd伯escr欄ibed揉els洲ewhe頭re[息10].械Tabl撓e1飽2.2.姓Str圈engt岸heni悄ngs授chem竭es嫁One版spec必imen黎fro揀mea傭chs殺erie那s(S根W3-1套,SW頓4-1,說SO3懼-1a縮ndS殊O4-1省)wa哄sle父ftw斥itho嚼uts籍tren務(wù)gthe筍ning六as雙aco輸ntro駁lsp錫ecim狠en,編wher肺eas吐eigh御tbe拳ams賢peci監(jiān)mens叫wer披est廢reng議then工edw饅ith腸exte局rnal景l(fā)yb錯onde稼dCF誠RPs未heet扯sfo歪llow燒ing斬thre芹edi侄ffer伯ent燕sche訪mes沈asi符llus季trat傘edi場nFi勤g.2痰.歪Ins品erie估sSW腰3,s蝶peci扭men汪SW3-撈2wa斬sst盤reng霉then我edw裳ith擇two皇CFRP桐pli題esh唇avin轎gpe管rpen斯dicu益lar奴fibe店rdi刑rect慚ions曬(90幫°/0°耍).T丹hef及irst式ply敬was演att貪ache怨din驢the豆for枯mof持con菠tinu暖ous草U-wr顫apw核ith帽the退fibe計(jì)rdi隙rect簡ion爽orie客nted醫(yī)per捎pend殊icul粥art翻oth起elo耳ngit憐udin容ala磨xis赴oft蛙hes做peci恨men丑(90°省).貪The斬seco臨ndp涂lyw而asb焰onde促don刮the種two討sid膛eso圍fth伙esp傭ecim寶enw嫁ith緣the猜fibe悔rdi憤rect泳ion提para獻(xiàn)llel植to愈the唇beam腸axi論s助（縮0主°眉）氏.Thi鏟spl攏y[i位.e.賞0°pl既y]w角ass糧elec泡ted大toi透nves擺tiga腎tet己hei丈mpac遮tof肌add掏itio漸nal儲hori白zont讓alr羊estr虛aint敵on位shea買rst沾reng臉th.燈Ins逢erie達(dá)sSW嚴(yán)4,s輩peci佩men回SW4-塑2wa虛sst溝reng向then養(yǎng)edw飛ith計(jì)two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