冻融循环后预应力混凝土梁受弯性能研究_李琮琦

4524201512BuildingStructureVol．45No．24Dec．2015*1222121201322251270.350.520.624。。、。。TU375.1A1002-848X201524-0101-05Studyonthemechanicalbehaviorsofprestressedconcretebeamsafterfreeze-thawcyclesLiCongqi12GeWenjie2CaoDafu21CollegeofCivilEngineeringandMechanicsJiangsuUniversityZhenjiang212013China2CollegeofCivilScienceandEngineeringYangzhouUniversityYangzhou225127ChinaAbstractInordertostudytheflexuralbehaviorofprestressingconcretebeamsafterfreeze-thawcyclesfournormalconcretebeamsandfourprestressedconcretebeamswiththreedifferentpartialprestressingratiosPPＲ0.350.52and0.62weremadeandtheirsstaticflexuralexperimentswerecarriedoutaftercertainfreeze-thawcycles．TheresultsshowthatPPＲandfreeze-thawcyclesarethetwomaininfluencefactortotheflexuralbehaviorofprestressingconcretebeams．Ultimatemomentdecreasessignificantlywiththeincreasingoffreeze-thawcycles．UltimatemomentsofprestressingconcretebeamswithmoderateandlowPPＲdecreaseslowerthanprestressingconcretebeamswithhighPPＲ．Crackingmomentofprestressedconcretebeamsafterthefreeze-thawcyclecouldcalculatebycurrentdesigncodeofconcretestructure．Ultimatemomentcouldalsocalculatebycurrentdesigncodebutcomprehensiveinfluencecoefficientshouldbetakenintoconsideration．KeywordsprestressedconcretebeampartialprestressingratioPPＲfreeze-thawcycleflexuralbehavior*512784455127823050978224CXZZ12-0655。[e-mail]。0。。1、。2-5、、、。、、、。。。11.1、b×h=100mm×150mml=600mmC40。210286@1006@50p5。1612306。。123。2015123。1231PPＲσconωpωnPTB100000.124PPB1-11P50.350.75fptk0.1040.228PPB2-12P50.520.75fptk0.2080.332PPB3-13P50.620.75fptk0.3130.4370PTB200000.124PPB1-21P50.350.75fptk0.1040.228PPB2-22P50.520.75fptk0.2080.332PPB3-23P50.620.75fptk0.3130.43725PTB300000.124PPB1-31P50.350.75fptk0.1040.228PPB2-32P50.520.75fptk0.2080.332PPB3-33P50.620.75fptk0.3130.43750PTB400000.124PPB1-41P50.350.75fptk0.1040.228PPB2-42P50.520.75fptk0.2080.332PPB3-43P50.620.75fptk0.3130.43775PPＲPPＲ=Apfpy/Apfpy+Asfyωp=Apfpy/fcbh0ω=Apfpy+Asfy－As'fy/fcbh0ApAsAs'、、fyfpy、fcbh0fptkn。2D/mmfy/MPafu/MPaEs/GPaδ/%ψ/%HＲB3006256380210——HＲB3358370575200——HPB40010430668200——P5515631708205646DfuEsδψ。3ε1/×10－6ε2/×10－6fpe/N/mm2PPB1-11P5512550621037.7PPB1-21P5641359441218.5PPB1-31P5555851551056.8PPB1-41P5507050441034.0PPB2-12P5593958771204.8PPB2-22P5585957301174.7PPB2-32P5524051171049.0PPB2-42P5549953841103.7PPB3-13P5579254731122.0PPB3-23P548004794982.7PPB3-33P5521051531056.4PPB3-43P5503849121007.0ε1ε2fpe。1.24ASTM730、25、5075。、4。425502014524．75。255。55。。46fd。6。6/N/mm24nfcufckftk046.921.92.562533.315.62.145029.614.11.997520.9101.58fcufckftk。。8fd/fc=a+bn1ab。a=0.9577b=－0.006791fd/fc=0.9577－0.00679n21.31.01.6PPＲ0.351.0PPＲ0.520.621.6。7。7589。5Mcr/kN·mMy/kN·mMu/kN·mPTB12.815.946.56PTBPTB22.505.316.25PTB32.504.695.94PTB42.194.385.31PPB1-13.7511.8812.50PPB1PPB1-23.4410.9411.56PPB1-33.139.7510.94PPB1-42.819.3110.31PPB2-14.5012.0014.94PPB2PPB2-24.0011.0015.12PPB2-34.5010.5014.03PPB2-44.009.5013.11PPB3-15.5016.5016.96PPB3PPB3-24.5013.5014.03PPB3-34.5011.5012.94PPB3-44.5010.5012.00McrMyMu。30120158-9-8。9。26Mcr=σpc+γftkW03σpcW0γftk4。36。6。。36PPＲMcrt/kN·mMcre/kN·mMcre/Mcrt0.35PPB1-13.453.751.09PPB1-23.283.441.05PPB1-33.023.131.04PPB1-42.902.810.970.52PPB2-14.364.501.03PPB2-23.974.001.01PPB2-33.774.501.19PPB2-43.604.001.110.62PPB3-15.355.501.03PPB3-25.104.500.88PPB3-34.794.500.94PPB3-44.544.500.99McrtMcre。9。Mu=α1fcbxh0－x2+fy'As'h0－as'4x=fpyAp+fyAs－fy'As'α1fcb54PPＲ0.350.527。7PPＲMut/kN·mMue/kN·mMue/Mut0.35PPB1-111.7412.501.06PPB1-29.3411.561.24PPB1-38.6210.941.27PPB1-47.5210.311.370.52PPB2-112.7414.941.17PPB2-210.9615.121.38PPB2-310.6214.031.32PPB2-49.3413.111.40MueMut。775。。8。、。4014524．ζdMud=ζdMu0'6MudMu0'。ζdnζd=1.146+0.00344n77PPＲ0.62MutMue8。8PPＲ0.627。PPＲ0.628Mut/kN·mMue/kN·mMut/MuePPB3-116.9616.071.06PPB3-214.0314.460.97PPB3-312.9413.200.98PPB3-412.0011.841.0141。。2。、。3。。4。1．J．200940S2281-286．2．J．2014356137-144．3．J．201346838-44．4CAODAFUZHOUKAIFUZHOUMIN．StudyontheshearbehaviorsofＲCbeamsafterfreeze-thawcyclesC//2013InternationalConferenceonMaterialsScienceandEngineeringApplication．Beijing2013750-754．5．J．2014441188-193．6GB50010—2010S．2011．7GB/T50082—2009S．2009．8．J．200529-11．9．M．2002291．501