低周反复荷载下型钢再生混凝土短柱抗震性能试验研究

通过8个不同再生粗骨料取代率、轴压比、体积配箍率下的型钢再生混凝土短柱的低周反复加载试验，观察其受力过程及破坏形态，分析了不同设计参数对短柱的荷载-位移滞回曲线、骨架曲线、承载能力、刚度退化、延性及耗能等力学性能的影响。试验结果表明:型钢再生混凝土短柱的主要破坏形态为剪切斜压破坏；试件荷载-位移滞回曲线基本呈梭形；试件达到峰值荷载后，承载力下降较快、变形小、延性较差；再生粗骨料取代率对试件承载力影响不大，延性耗能随着取代率增大而有所减低；随着轴压比的增大，试件承载力提高但延性耗能降低幅度大；随体积配箍率的增大，试件承载力及延性耗能均相应增大。除轴压比较小的短柱外，其余型钢再生混凝土短柱的延性系数均小于3，表明短柱抗震性能较差。因此，在实际工程中应采取相应的措施以改善短柱抗震性能。

EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF STEEL REINFORCED RECYCLED CONCRETE SHORT COLUMN UNDER LOW-CYCLIC REVERSED LOADING

Through eight column specimens with various replacement rates of recycled coarse aggregate, axial compression ratios, stirrup ratios were tested under low cyclic reversed loading. The failure process and pattern were observed. The mechanical behaviors such as load-displacement hysteretic loops and skeleton curves, load carrying capacity, ductility, energy dissipation capacity and stiffness degradation of steel reinforced recycled concrete short columns were analyzed. Test results show that the failure pattern of steel reinforced recycled concrete short columns is the shear diagonal compression failure. The load-displacement hysteretic loops of specimens can be approximated as a spindle shape. After the peak load, the load carrying capacity decreases rapidly, while the deformation is small and the ductility or energy dissipation capacity is poor. With the replacement rate of recycled coarse aggregate increase, there is no obvious influence for the load carrying capacity of specimens, while the ductility or energy dissipation capacity reduces somewhat. With increase of axial compression ratio of the specimens, the load carrying capacity increase, while the ductility or energy dissipation capacity reduces a lot. The load carrying capacity and ductility or energy dissipation capacity of specimens increase with the stirrup ratio increase. Except for the short column with a small axial compression ratio, the ductility factors of the other short columns are less than 3, showing that the seismic performance of steel reinforced recycled concrete short columns is poor. Therefore, certain measures are necessary for improving the seismic performance of steel reinforced recycled concrete short columns in the practical engineering.