重复荷载作用下箍筋约束混凝土T形柱性能

Performance of T-shaped Concrete Columns Confined by Stirrups Under Axial Repeated Loading

结构构件在实际使用期间可能会承受荷载随机或有规律地多次重复加卸作用,为研究轴压重复荷载作用下箍筋约束混凝土T形柱的性能,对5根不同配箍特征值的试件进行轴压重复荷载试验,并与1根单调轴心受压荷载作用下的试件对比,结果表明:轴压重复荷载作用下试件的破坏特征与单调轴心受压荷载作用下相似,随着配箍特征值增大,试件的破坏类型由斜向破坏变为纵向压碎破坏,峰值荷载及相应位移增大,骨架曲线下降段趋于平缓,试件的刚度退化得到有效延缓,延性变好,延性系数的计算结果与试验结果吻合良好,建立的公式可用于轴压重复荷载作用下箍筋约束混凝土T形柱延性系数的计算。

Structures may bear randomly or regularly repeated loading during usage. To study the performance of T-shaped concrete columns confined by stirrups under axial repeated loading,5 specimens with different reinforcement characteristic value were tested under axial repeated loading while one was tested under axial loading for comparison. Results show that the failure characteristics of specimens are similar when tested under axial repeatedloading or under axial loading,and with the increasing of reinforcement characteristic value,the failure mode of specimens is changed from oblique failure to longitudinal failure,the peak load and peak displacement of specimens increase,the descending segment of skeleton curves turn to be more flat,the stiffness degeneration of specimens is delayed effectively,and the ductility of specimens becomes better. The calculated results of ductility coefficient are in good agreement with the test results,and the formula established can be used to calculate the ductility of T-shaped concrete columns confined by stirrups under axial repeated loading.