高轴压比下圆钢管再生混凝土柱的抗震性能试验分析

Experimental analysis on seismic behavior of recycled concrete filled circular steel tubular columns under high axial compression ratio

为了研究高轴压比下圆钢管再生混凝土柱的抗震性能,选取再生骨料取代率、轴压比、长细比和壁厚作为变化参数,设计7根圆钢管再生混凝土柱拟静力试验。通过试验分析高轴压比下圆钢管再生混凝土柱的破坏形态、滞回性能以及耗能能力。研究结果表明:在低周反复加载作用下,试件的破坏特征均属于压弯破坏,在钢管鼓曲处混凝土被完全压溃;在低轴压比下,试件的滞回曲线均较为饱满,并且骨架曲线上升段及下降段均较为平缓,说明具有良好的延性及耗能能力;在高轴压比下试件的滞回曲线以及骨架曲线会发生突降现象,说明圆钢管再生混凝土柱在高轴压比下延性较差,且高轴压比会降低试件的耗能能力;试件的等效粘滞阻尼系数ξ_(eq)在0.278~0.364范围之内,说明钢管再生混凝土柱在低周反复荷载作用下具有较为优秀的耗能能力。

In order to study the seismic performance of recycled concrete-filled circular steel tubular columns under high axial compression ratio,the replacement rate of recycled aggregate,axial compression ratio,slenderness ratio and wall thickness were selected as variation parameters,and the pseudo-static tests of 7 recycled concrete-filled circular steel tubular columns were designed.The failure mode,hysteretic behavior and energy dissipation capacity of recycled concrete-filled circular steel tubular columns under high axial compression ratio were analyzed.The results shown that the failure characteristics of the specimens under low cycle repeated loading belong to compression bending failure,and the concrete was completely crushed at the bulge of the steel tube.At low axial compression ratio,the hysteretic curves of the specimens were relatively full,and the rising and falling sections of the skeleton curve were relatively flat,indicating good ductility and energy dissipation capacity.The hysteretic curve and skeleton curve of the specimens will drop suddenly under high axial compression ratio,which shown that the ductility of recycled concrete-filled circular steel tubular columns was poor under high axial compression ratio,and high axial compression ratio will reduce the energy dissipation capacity of the specimens.Equivalent viscous damping coefficient of specimen was in the range of 0.278~0.364,indicating that the recycled concrete-filled steel tubular column had excellent energy dissipation capacity under low cyclic loading.