震损钢筋混凝土框架节点修复后抗震性能试验研究

Experimental study on seismic behavior of strengthened RC column-beam joints damaged by simulated earthquake

针对已震损的钢筋混凝土框架节点加固后的抗震性能,进行了8个带楼板的三维框架节点的预震损、加固和低周反复荷载破坏试验。试验研究了玄武岩纤维和外包钢套两种加固方法,不同的预震损程度,灌缝等因素对加固效果的影响。对加固节点的滞回曲线、骨架曲线、延性系数、承载力及刚度退化等参数的分析可知:玄武岩纤维加固提高节点的承载力作用有限,但提高抗震性能效果明显;外包钢套法在提高节点承载力、刚度及抗震性能各方面均有显著的效果。加固后节点由"弱柱强梁"转变成了"强柱弱梁"的破坏形式。试验表明,通过加固,节点恢复并超过了受损前的抗震性能,说明此类加固方法是合理、有效的。

This paper presents the experimental study on the seismic behavior of 8 repaired column-beam joints（C-BJs）,which had been pre-damaged under cyclic loads.The test procedures included pre-damage,rehabilitation and re-test under cyclic loads.The study concentrated on the effect of different strengthening schemes（enveloped steel or basalt fiber sheet）,different levels of pre-damage and epoxy injection.Through the test data,namely the hysteretic loops,ductility,strength and stiffness degradation,etc,the following conclusion was drawn： the rehabilitation with basalt fiber sheets has notable influence on the seismic performance of joints,but leads limited increment to the ultimate strength,while the method of enveloped steel has significant improvements in both the strength,the stiffness and all aspects of seismic performance.Furthermore,the failure of‘strong beam and weak column’was changed into ‘strong column and weak beam’after rehabilitations.The study indicates the rehabilitated C-BJs can reach or even exceed the level of their original seismic performances before pre-damage,and proves the rehabilitation effective and reasonable.