低周反复荷载下方钢管再生混凝土框架柱损伤试验研究

Experimental Study on the Damage of Recycled Aggregate Concrete Filled Square Steel Tube Frame Columns under Cyclic Reversed Loading

为了更加深入的了解地震作用下方钢管再生混凝土框架柱的损伤演化过程,设计制作了4根方钢管再生混凝土框架柱模型,通过改变加载制度、轴压比和含钢率进行了低周反复荷载试验。通过观察试件的破坏失效过程得到了试件的滞回曲线、骨架曲线、承载力退化及耗能能力,并从损伤的角度出发分析了不同设计参数及加载制度对方钢管再生混凝土框架柱抗震性能的影响。研究结果表明,试件在地震作用下的损伤进程分为无损伤、损伤稳定发展及损伤急剧发展3个阶段;随着加载的持续进行,试件的损伤逐步加大,使得其承载力和刚度不断下降,从而导致试件的变形能力降低。该研究结果可供建立方钢管再生混凝土地震损伤模型作为参考,并为揭示损伤对方钢管再生混凝土柱力学性能的影响提供试验支撑。

In order to study the evolution of the damage of recycled aggregate concrete filled square steel tube(RACFST)frame column under earthquake function,four RACFST frame column specimens are designed and manufactured,and all columns are tested by varying loading system,various axial compression ratios and steel ratios under the low recycled loads.The damage process of every specimen is observed,and the hysteretic loops,skeleton curves,dissipative ability and strength degradation,etc are obtained.The influence of design parameters and loading system on the seismic performance of RACFST frame column are analyzed from the viewpoint of damage.The results show that the damage process of the specimens can be divided into three stages,such as undamaged,gradual stable damage and rapid damage.With the loading going on,the damage of the specimen is accumulated gradually,which causes the strength and stiffness degradation and decrease of ultimate deformability.The research result provides a support for establishing seismic damage model and revealing the effect of damage on the mechanical property of RACFST frame columns.