高温后圆钢管再生混凝土偏压柱力学性能研究

为研究高温后圆钢管再生混凝土柱偏压力学性能的退化规律,考虑温度作用场、再生粗骨料取代率2个变化参数,对9个设计的圆钢管再生混凝土柱试件进行高温后的偏心受压加载试验。观察其受力破坏过程及形态,获取受力全过程的荷载-位移曲线、荷载-应变曲线、极限承载力等数据,并分析温度和取代率对高温后圆钢管再生混凝土偏压柱承载力、刚度退化、位移延性、耗能等力学性能指标的影响。结果表明:高温后钢管再生混凝土偏压柱的破坏过程和形态与常温试件相似,具有承载力高、变形性能好的特征;随着温度的升高,钢管再生混凝土偏压柱的极限承载力和初始刚度显著降低,随着取代率的变化,钢管再生混凝土偏压柱的承载力、刚度、位移延性、能量耗散等力学性能指标变化不大。

STUDY OF MECHANICAL BEHAVIOR OF RECYCLED AGGREGATE CONCRETE FILLED CIRCULAR STEEL TUBE COLUMNS UNDER ECCENTRIC LOADING AFTER HIGH TEMPERATURE

To study the mechanical behavior of recycled aggregate concrete-filled circular steel tube( RACFCST) columns under eccentric loading after high temperatures,by changing parameters including replacement ratio and high temperature,9 RACFCST columns with different recycled coarse aggregate after different high temperatures were designed and tested under monotonic static loading. The failure modes of specimens were observed,and then the loading-deformation and loading-strain curves of the entire loading process were obtained. The influence of the two varying parameters on the mechanical behavior of RACFSCT eccentric compression columns,for instance,bearing capacity,stiffness degradation,displacement ductility,and energy dissipation was analyzed. The results showed that the failure process and failure modes of RACFCST columns after high temperature were similar to normal specimens. It was found that RACFCST columns had high bearing capacity and better deformation performance. With the increase of temperature,ultimate bearing capacity and initial stiffness of RACFCST columns significantly reduced,while the influence of aggregate replacement ratio on the mechanical behaviors,such as bearing capacity,stiffness etc was not obvious.