高温后方钢管再生混凝土轴压短柱的受力性能研究

为研究高温后方钢管再生混凝土短柱的轴心受压承载性能,以再生粗骨料取代率和温度为变化参数,设计了24个试件进行轴心受压加载试验,观察高温后方钢管再生混凝土轴压短柱的受力过程及破坏形态,获取其应力-应变曲线、极限承载力等重要数据,并分析再生骨料取代率、温度对该类新型组合构件轴压性能的影响规律;最后对高温后方钢管再生混凝土轴压短柱的极限承载力计算方法予以探讨。试验结果表明:随温度的升高,高温后试件的极限承载力和弹性刚度整体上均呈降低之势,延性系数和耗能均先减后增;随再生骨料取代率的增大,高温后试件的极限承载力降低,弹性刚度先增后减,延性系数和耗能均呈增长之势。

MECHANICAL BEHAVIOR OF SQUARE STEEL TUBE SHORT COLUMNS FILLED WITH RECYCLED AGGREGATE CONCRETE UNDER AXIAL COMPRESSION AFTER HIGH TEMPERATURE

Twenty-four specimens were designed to study the mechanical behavior of square steel tube short columns filled with recycled aggregate concrete under axial compression after high temperature. Two parameters, i. e replacement ratio and temperature were taken into consideration. The damage process and failure mode of specimens were observed,and stress-strain curve and ultimate bearing capacity as well as other important data were obtained by test. The effects of replacement ratio and temperature of that new kind of composite structures were investigated. The method to calculate ultimate bearing capacity of square steel tube short columns filled with recycled aggregate concrete under axial compression after high temperature was analyzed. The results indicated that the ultimate bearing capacity and elastic stiffness of the specimens after high ten perature presented a decrease trend with an increase temperature.With the increasing of temperature,ductility and energy dissipation first decreased and then increased. An increase recycled aggregate replacement ratio decreased the bearing capacity but increased ductility and energy dissipation.While increasing recycled aggregate replacement ratio,the elastic stiffness first increased and then decreased.