高温喷水冷却后混凝土柱性能对比分析

为对比分析高温喷水冷却后3种约束再生混凝土柱（即螺旋筋再生混凝土柱、方钢管再生混凝土柱和圆钢管再生混凝土柱）的力学性能退化规律，以截面类型、历经温度和再生粗骨料取代率为变化参数，共设计了36个试件，进行高温喷水冷却后的轴心受压加载试验，观察了试件破坏全过程，并对比分析高温喷水冷却后这3种约束再生混凝土柱的极限承载力、初始轴压刚度和延性的差异。结果表明：随历经最高温度的增大，各种约束再生混凝土柱的极限承载力、初始轴压刚度和延性均出现了不同程度的退化，其中圆钢管再生混凝土柱退化幅度最小且较为稳定，方钢管再生混凝土柱的延性随温度升高出现了正增长；随再生粗骨料取代率的增加，方钢管和圆钢管试件的极限承载力、初始轴压刚度和延性呈现先减小后增大的变化趋势，其波动范围为-15.3%~2.3%，而螺旋筋约束混凝土柱试件受取代率影响则相对较小，其变化范围为0~12.9%。

Comparative analysis on performance ofconcrete columns after high temperature water cooling

In order to compare and analyze the degradation law of mechanical properties of three kinds of confined recycled concrete columns (spiral reinforced recycled concrete column, square steel tube recycled concrete column and circular steel tube recycled concrete column) after high-temperature water spraying cooling, 36 specimens were designed to carry out axial compression loading test after high-temperature water spraying cooling with section type, temperature and recycled coarse aggregate replacement rate as variable parameters. The whole failure process of the specimens was observed, and the differences of ultimate bearing capacity, initial axial compression stiffness and ductility of the three kinds of confined recycled concrete columns after high temperature water cooling were compared and analyzed. The results show that: with the increase of the maximum temperature, the ultimate bearing capacity, initial axial compression stiffness and ductility of recycled concrete columns with various constraints are degraded to varying degrees, and the degradation range of circular steel tube recycled concrete columns is the smallest and more stable. The ductility of recycled concrete-filled square steel tubular columns increases with the increase of temperature. With the increase of replacement rate of recycled coarse aggregate, the ultimate bearing capacity, initial axial compression stiffness and ductility of square steel tube and round steel tube specimens first decrease and then increase, and the fluctuation range is -15.3%~2.3%, while the influence of replacement rate on spiral reinforced concrete column specimens is relatively small, and the variation range is 0~12.9%.