锈蚀钢筋混凝土梁斜截面抗剪失效分析
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摘要
为了研究锈蚀对钢筋混凝土构件抗剪性能的影响,设计并制作了7根配有箍筋和斜筋的钢筋混凝土矩形梁,其中1根为未锈蚀的对比梁,采用电化学快速锈蚀方法对其余6根钢筋混凝土梁进行加速锈蚀试验。开展相同剪跨比下钢筋混凝土梁的斜截面抗剪性能试验,讨论钢筋混凝土梁表面初始锈胀裂缝的分布特征,分析箍筋锈蚀、斜筋锈蚀和主筋锈蚀对钢筋混凝土梁斜裂缝的形成与发展、荷载-挠度曲线、剪压区混凝土压力传递过程以及钢筋的内力变化情况,研究不同锈蚀程度钢筋混凝土梁斜截面极限承载能力与失效特征。研究结果表明:弯剪斜裂缝的数量随着钢筋锈蚀水平的增长逐渐减少,斜裂缝的延伸长度变短,主拱传递压应力路径逐步由直线变为抛物线形;锈胀引起的剪压区混凝土截面损伤对钢筋混凝土构件的抗剪强度有很大影响;箍筋锈蚀和斜筋锈蚀对斜裂缝的发展影响较大,而对钢筋混凝土梁的破坏形态影响相对较小,但其截面面积的减小会导致箍筋和斜筋过早的发生断裂,进而降低钢筋混凝土梁的斜截面抗剪强度;随着主筋锈蚀程度的增长,临界斜裂缝的倾角变大,并且与仅箍筋锈蚀梁相比,其倾角增幅更为显著。该研究可为钢筋混凝土梁的抗剪强度预测模型的建立以及有限元分析提供试验基础。
To investigate the influence of corrosion on the shear behavior of reinforced concrete bridge members,seven rectangular reinforced concrete beams with diagonal bars and stirrups were designed and manufactured,one of which was a non-corroded contrast beam.An accelerated corrosion test was performed for the other six beams by electrochemical rapid corrosion method.The shear behavior tests of reinforced concrete beams in the diagonal section were carried out under an equivalent shear-span ratio. The distribution characteristics of initial corrosion expansion cracks on the surface of reinforced concrete beams were discussed.The formation and propagation of diagonal cracks in reinforced concrete beams by stirrups corrosion,diagonal bars corrosion and main reinforcement corrosion,the load-deflection curve,concrete compressivetransfer in shear compression region,the variation of internal force of reinforcement,the ultimate bearing capacity and failure characteristics of reinforced concrete beams with different corrosion degrees were analyzed.The results show that the number of bending shear diagonal cracks gradually decreases with the increase of corrosion level,the extended length of diagonal cracks becomes shorter,and the compressive transfer path of main arch changes from straight line into parabolic,the shear strength of reinforced concrete members is greatly affected by the damage of concrete section in shear compression region caused by corrosion expansion,the corrosion of stirrups and diagonal bars has significant effect on diagonal crack propagation,but has insignificant effect on the failure mode of beams.Corrosion leads to the ruptures in stirrups and diagonal bars due to the area of the section loss,reducing the shear strength of beams.However,the reduction of the section will lead to the premature rupture of stirrups and diagonal bars,and then reduce the shear strength of reinforced concrete beams in the diagonal section.With the increase of the corrosion degree of the main reinforcement,the angle of the critical inclined crack becomes larger,and it is more significant than that of the corroded beams with only stirrups.The present study provides an experimental basis for the establishment of shear strength prediction model and finite element analysis of reinforced concrete beams.5 tabs,11 figs,24 refs.
To investigate the influence of corrosion on the shear behavior of reinforced concrete bridge members,seven rectangular reinforced concrete beams with diagonal bars and stirrups were designed and manufactured,one of which was a non-corroded contrast beam.An accelerated corrosion test was performed for the other six beams by electrochemical rapid corrosion method.The shear behavior tests of reinforced concrete beams in the diagonal section were carried out under an equivalent shear-span ratio. The distribution characteristics of initial corrosion expansion cracks on the surface of reinforced concrete beams were discussed.The formation and propagation of diagonal cracks in reinforced concrete beams by stirrups corrosion,diagonal bars corrosion and main reinforcement corrosion,the load-deflection curve,concrete compressivetransfer in shear compression region,the variation of internal force of reinforcement,the ultimate bearing capacity and failure characteristics of reinforced concrete beams with different corrosion degrees were analyzed.The results show that the number of bending shear diagonal cracks gradually decreases with the increase of corrosion level,the extended length of diagonal cracks becomes shorter,and the compressive transfer path of main arch changes from straight line into parabolic,the shear strength of reinforced concrete members is greatly affected by the damage of concrete section in shear compression region caused by corrosion expansion,the corrosion of stirrups and diagonal bars has significant effect on diagonal crack propagation,but has insignificant effect on the failure mode of beams.Corrosion leads to the ruptures in stirrups and diagonal bars due to the area of the section loss,reducing the shear strength of beams.However,the reduction of the section will lead to the premature rupture of stirrups and diagonal bars,and then reduce the shear strength of reinforced concrete beams in the diagonal section.With the increase of the corrosion degree of the main reinforcement,the angle of the critical inclined crack becomes larger,and it is more significant than that of the corroded beams with only stirrups.The present study provides an experimental basis for the establishment of shear strength prediction model and finite element analysis of reinforced concrete beams.5 tabs,11 figs,24 refs.
引文
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[2]MA Ya-fei,XU Fu-you,WANG Lei,et al.Influence of corrosion-induced cracking on structural behavior of reinforced concrete arch ribs[J].Engineering Structures,2016,117:184-194.
[3]ZHONG J,GARDONI P,ROSOWSKY D.Stiffness degradation and time to cracking of cover concrete in reinforced concrete structures subject to corrosion[J].Journal of Engineering Mechanics,2009,136(2):209-219.
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[6]MA Ya-fei,XIANG Yi-bing,WANG Lei,et al.Fatigue life prediction for aging RC beams considering corrosive environments[J].Engineering Structures,2014,79:211-221.
[7]ZHU W,FRANCOIS R,CLELAND D,et al.Failure mode transitions of corroded deep beams exposed to marine environment for long period[J].Engineering Structures,2015,96:66-77.
[8]WANG Xiao-hui,GAO Xiang-hua,LI Bing,et al.Effect of bond and corrosion within partial length on shear behavior and load capacity of RC beam[J].Construction and Building Materials,2011,25(4):1812-1823.
[9]JUAREZA C A,GUEVARA B,FAJARDO G,et al.Ultimate and nominal shear strength in reinforced concrete beams deteriorated by corrosion[J].Engineering Structures,2011,33(12):3189-3196.
[10]姜庆远,谭人杰.钢筋混凝土梁抗剪承载力的有限元分析[J].哈尔滨工业大学学报,2000,32(3):104-107.JIANG Qing-yuan,TAN Ren-jie.FEA of RC beams shear strength[J].Journal of Harbin Institute of Technology,2000,32(3):104-107.
[11]狄谨.无腹钢筋混凝土梁的抗剪承载力[J].长安大学学报:自然科学版,2004,24(5):43-47.DI Jin.Shear capacity of reinforced concrete beams without web[J].Journal of Chang'an University:Natural Science Edition,2004,24(5):43-47.
[12]HIGGINS C,FARROW W C.Tests of reinforced concrete beams with corrosion-damaged stirrups[J].ACIStructural Journal,2006,103(1):133-141.
[13]徐善华,牛荻涛.锈蚀钢筋混凝土简支梁斜截面抗剪性能研究[J].建筑结构学报,2004,25(5):98-104.XU Shan-hua,NIU Di-tao.The shear behavior of corroded simply supported reinforced concrete beam[J].Journal of Building Structures,2004,25(5):98-104.
[14]赵羽习,金伟良.锈蚀箍筋混凝土梁的抗剪承载力分析[J].浙江大学学报:工学版,2008,42(1):19-24.ZHAO Yu-xi,JIN Wei-liang.Analysis on shearing capacity of concrete beams with corroded stirrups[J].Journal of Zhejiang University:Engineering Science,2008,42(1):19-24.
[15]XIA Jin,JIN Wei-liang,LI Long-yuan.Shear performance of reinforced concrete beams with corroded stirrups in chloride environment[J].Corrosion Science,2011,53(5):1794-1805.
[16]王小惠,刘西拉.锈蚀钢筋混凝土梁的斜截面抗剪承载能力[J].上海交通大学学报,2007,41(6):944-949.WANG Xiao-hui,LIU Xi-la.Shear carrying capacity of corroded reinforced concrete beams[J].Journal of Shanghai Jiaotong University,2007,41(6):944-949.
[17]VENIR R,RUSSO G,PAULETTA M.Reinforced concrete deep beams-shear strength model and design formula[J].ACI Structural Journal,2005,102(3):429-437.
[18]BHATT K,ABDEL KADER M.Prediction of shear strength of reinforced concrete beams by nonlinear finite element analysis[J].Computers&Structures,1998,68(1/2/3):139-155.
[19]卢朝辉,李海,赵衍刚,等.锈蚀钢筋混凝土梁抗剪承载力预测经验模型[J].工程力学,2015,32(增):261-270.LU Zhao-hui,LI Hai,ZHAO Yan-gang,et al.An empirical model for shear strength prediction of corroded RC beams[J].Engineering Mechanics,2015,32(S):261-270.
[20]EL-SAYED A K.Shear capacity assessment of reinforced concrete beams with corroded stirrups[J].Construction and Building Materials,2017,134:176-184.
[21]王景全,戚家南.有腹筋与无腹筋钢筋混凝土梁抗剪承载力统一计算方法[J].土木工程学报,2013,46(7):47-57.WANG Jing-quan,QI Jia-nan.Unified shear strength computation model for reinforced concrete beams with and without stirrups[J].China Civil Engineering Journal,2013,46(7):47-57.
[22]魏巍巍,贡金鑫.钢筋混凝土构件基于修正压力场理论的受剪承载力计算[J].工程力学,2011,28(2):111-117.WEI Wei-wei,GONG Jin-xin.Shear strength of reinforced concrete members based on modified compression field theory[J].Engineering Mechanics,2011,28(2):111-117.
[23]张建仁,刘彬,王磊,等.箍筋锈蚀的配斜筋混凝土梁抗剪试验[J].中国公路学报,2013,26(6):73-79.ZHANG Jian-ren,LIU Bin,WANG Lei,et al.Test on shear behavior of diagonal reinforcement RC beams with corroded stirrups[J].China Journal of Highway and Transport,2013,26(6):73-79.
[24]张建仁,孙乐坤,马亚飞,等.基于MCFT理论的配斜筋RC梁抗剪承载力计算[J].公路交通科技,2012,29(9):58-63.ZHANG Jian-ren,SUN Le-kun,MA Ya-fei,et al.Calculation of shear capacity of RC beam with diagonal reinforcement based on modified compression field theory[J].Journal of Highway and Transportation Research and Development,2012,29(9):58-63.
[2]MA Ya-fei,XU Fu-you,WANG Lei,et al.Influence of corrosion-induced cracking on structural behavior of reinforced concrete arch ribs[J].Engineering Structures,2016,117:184-194.
[3]ZHONG J,GARDONI P,ROSOWSKY D.Stiffness degradation and time to cracking of cover concrete in reinforced concrete structures subject to corrosion[J].Journal of Engineering Mechanics,2009,136(2):209-219.
[4]MA Ya-fei,ZHANG Jian-ren,WANG Lei,et al.Probabilistic prediction with Bayesian updating for strength degradation of RC bridge beams[J].Structural Safety,2013,44:102-109.
[5]STEWART M G.Spatial variability of pitting corrosion and its influence on structural fragility and reliability of RC beams in flexure[J].Structural Safety,2004,26(4):453-70.
[6]MA Ya-fei,XIANG Yi-bing,WANG Lei,et al.Fatigue life prediction for aging RC beams considering corrosive environments[J].Engineering Structures,2014,79:211-221.
[7]ZHU W,FRANCOIS R,CLELAND D,et al.Failure mode transitions of corroded deep beams exposed to marine environment for long period[J].Engineering Structures,2015,96:66-77.
[8]WANG Xiao-hui,GAO Xiang-hua,LI Bing,et al.Effect of bond and corrosion within partial length on shear behavior and load capacity of RC beam[J].Construction and Building Materials,2011,25(4):1812-1823.
[9]JUAREZA C A,GUEVARA B,FAJARDO G,et al.Ultimate and nominal shear strength in reinforced concrete beams deteriorated by corrosion[J].Engineering Structures,2011,33(12):3189-3196.
[10]姜庆远,谭人杰.钢筋混凝土梁抗剪承载力的有限元分析[J].哈尔滨工业大学学报,2000,32(3):104-107.JIANG Qing-yuan,TAN Ren-jie.FEA of RC beams shear strength[J].Journal of Harbin Institute of Technology,2000,32(3):104-107.
[11]狄谨.无腹钢筋混凝土梁的抗剪承载力[J].长安大学学报:自然科学版,2004,24(5):43-47.DI Jin.Shear capacity of reinforced concrete beams without web[J].Journal of Chang'an University:Natural Science Edition,2004,24(5):43-47.
[12]HIGGINS C,FARROW W C.Tests of reinforced concrete beams with corrosion-damaged stirrups[J].ACIStructural Journal,2006,103(1):133-141.
[13]徐善华,牛荻涛.锈蚀钢筋混凝土简支梁斜截面抗剪性能研究[J].建筑结构学报,2004,25(5):98-104.XU Shan-hua,NIU Di-tao.The shear behavior of corroded simply supported reinforced concrete beam[J].Journal of Building Structures,2004,25(5):98-104.
[14]赵羽习,金伟良.锈蚀箍筋混凝土梁的抗剪承载力分析[J].浙江大学学报:工学版,2008,42(1):19-24.ZHAO Yu-xi,JIN Wei-liang.Analysis on shearing capacity of concrete beams with corroded stirrups[J].Journal of Zhejiang University:Engineering Science,2008,42(1):19-24.
[15]XIA Jin,JIN Wei-liang,LI Long-yuan.Shear performance of reinforced concrete beams with corroded stirrups in chloride environment[J].Corrosion Science,2011,53(5):1794-1805.
[16]王小惠,刘西拉.锈蚀钢筋混凝土梁的斜截面抗剪承载能力[J].上海交通大学学报,2007,41(6):944-949.WANG Xiao-hui,LIU Xi-la.Shear carrying capacity of corroded reinforced concrete beams[J].Journal of Shanghai Jiaotong University,2007,41(6):944-949.
[17]VENIR R,RUSSO G,PAULETTA M.Reinforced concrete deep beams-shear strength model and design formula[J].ACI Structural Journal,2005,102(3):429-437.
[18]BHATT K,ABDEL KADER M.Prediction of shear strength of reinforced concrete beams by nonlinear finite element analysis[J].Computers&Structures,1998,68(1/2/3):139-155.
[19]卢朝辉,李海,赵衍刚,等.锈蚀钢筋混凝土梁抗剪承载力预测经验模型[J].工程力学,2015,32(增):261-270.LU Zhao-hui,LI Hai,ZHAO Yan-gang,et al.An empirical model for shear strength prediction of corroded RC beams[J].Engineering Mechanics,2015,32(S):261-270.
[20]EL-SAYED A K.Shear capacity assessment of reinforced concrete beams with corroded stirrups[J].Construction and Building Materials,2017,134:176-184.
[21]王景全,戚家南.有腹筋与无腹筋钢筋混凝土梁抗剪承载力统一计算方法[J].土木工程学报,2013,46(7):47-57.WANG Jing-quan,QI Jia-nan.Unified shear strength computation model for reinforced concrete beams with and without stirrups[J].China Civil Engineering Journal,2013,46(7):47-57.
[22]魏巍巍,贡金鑫.钢筋混凝土构件基于修正压力场理论的受剪承载力计算[J].工程力学,2011,28(2):111-117.WEI Wei-wei,GONG Jin-xin.Shear strength of reinforced concrete members based on modified compression field theory[J].Engineering Mechanics,2011,28(2):111-117.
[23]张建仁,刘彬,王磊,等.箍筋锈蚀的配斜筋混凝土梁抗剪试验[J].中国公路学报,2013,26(6):73-79.ZHANG Jian-ren,LIU Bin,WANG Lei,et al.Test on shear behavior of diagonal reinforcement RC beams with corroded stirrups[J].China Journal of Highway and Transport,2013,26(6):73-79.
[24]张建仁,孙乐坤,马亚飞,等.基于MCFT理论的配斜筋RC梁抗剪承载力计算[J].公路交通科技,2012,29(9):58-63.ZHANG Jian-ren,SUN Le-kun,MA Ya-fei,et al.Calculation of shear capacity of RC beam with diagonal reinforcement based on modified compression field theory[J].Journal of Highway and Transportation Research and Development,2012,29(9):58-63.