In this study,finite element(FE)analysis is utilized to investigate the shear capacity of reinforced concrete(RC)beams strengthened with embedded through-section(ETS)bars.Effects of critical variables on the beam shea...In this study,finite element(FE)analysis is utilized to investigate the shear capacity of reinforced concrete(RC)beams strengthened with embedded through-section(ETS)bars.Effects of critical variables on the beam shear strength,including the compressive strength of concrete,stiffness ratio between ETS bars and steel stirrups,and use of ETS strengthening system alone,are parametrically investigated.A promising method based on the bond mechanism between ETS strengthening and concrete is then proposed for predicting the shear resistance forces of the strengthened beams.An expression for the maximum bond stress of the ETS bars to concrete is developed.This new expression eliminates the difficulty in the search and selection of appropriate bond parameters from adhesion tests.The results obtained from the FE models and analytical models are validated by comparison with those measured from the experiments.Consequently,the model proposed in this study demonstrates better performance and more accuracy for prediction of the beam shear-carrying capacity than those of existing models.The results obtained from this study can also serve researchers and engineers in selection of the proper shear strength models for design of ETS-strengthened RC beams.展开更多
现有桥梁交通量增加、重型卡车靠边跨行驶使得传统混凝土桥面板易发生支座附近区域抗剪破坏,而现有加固方式多针对构件抗弯加固而忽视抗剪问题。本文根据实际桥面板受力状况,采用截面贯入式加固(Embedded Through Section,简称"ETS...现有桥梁交通量增加、重型卡车靠边跨行驶使得传统混凝土桥面板易发生支座附近区域抗剪破坏,而现有加固方式多针对构件抗弯加固而忽视抗剪问题。本文根据实际桥面板受力状况,采用截面贯入式加固(Embedded Through Section,简称"ETS")方法并结合纤维增强复合材料(Fiber Reinforced Polymer,简称"FRP")筋对桥面板进行抗剪加固,对比加固筋的筋材类型、筋材直径以及钻孔损伤的影响。通过分析试件承载力、裂缝分布、破坏模式发现:该加固方法能有效提高桥面板板带抗剪承载力,构件破坏模式从脆性的剪切破坏转变为延性的弯曲破坏或弯剪复合破坏;钻孔损伤和筋材类型变化对桥面板受力与变形影响较小,并且采用FRP材料更能提高加固后结构的耐久性。最后,针对此加固方法提出了相应的承载力计算公式,计算结果与试件承载力吻合良好。展开更多
文摘In this study,finite element(FE)analysis is utilized to investigate the shear capacity of reinforced concrete(RC)beams strengthened with embedded through-section(ETS)bars.Effects of critical variables on the beam shear strength,including the compressive strength of concrete,stiffness ratio between ETS bars and steel stirrups,and use of ETS strengthening system alone,are parametrically investigated.A promising method based on the bond mechanism between ETS strengthening and concrete is then proposed for predicting the shear resistance forces of the strengthened beams.An expression for the maximum bond stress of the ETS bars to concrete is developed.This new expression eliminates the difficulty in the search and selection of appropriate bond parameters from adhesion tests.The results obtained from the FE models and analytical models are validated by comparison with those measured from the experiments.Consequently,the model proposed in this study demonstrates better performance and more accuracy for prediction of the beam shear-carrying capacity than those of existing models.The results obtained from this study can also serve researchers and engineers in selection of the proper shear strength models for design of ETS-strengthened RC beams.
文摘现有桥梁交通量增加、重型卡车靠边跨行驶使得传统混凝土桥面板易发生支座附近区域抗剪破坏,而现有加固方式多针对构件抗弯加固而忽视抗剪问题。本文根据实际桥面板受力状况,采用截面贯入式加固(Embedded Through Section,简称"ETS")方法并结合纤维增强复合材料(Fiber Reinforced Polymer,简称"FRP")筋对桥面板进行抗剪加固,对比加固筋的筋材类型、筋材直径以及钻孔损伤的影响。通过分析试件承载力、裂缝分布、破坏模式发现:该加固方法能有效提高桥面板板带抗剪承载力,构件破坏模式从脆性的剪切破坏转变为延性的弯曲破坏或弯剪复合破坏;钻孔损伤和筋材类型变化对桥面板受力与变形影响较小,并且采用FRP材料更能提高加固后结构的耐久性。最后,针对此加固方法提出了相应的承载力计算公式,计算结果与试件承载力吻合良好。
