方钢管再生混凝土轴压短柱力学性能试验研究

Experimental research on mechanical behavior of recycled concrete-filled square steel tubular stub columns subjected to axial compression

设计了4个方钢管再生混凝土短柱,截面形式分别为方实心、方套圆中空夹层、方套方中空夹层(内管位置不同)。另外设计了2个方套方中空夹层钢管普通混凝土短柱(内管位置不同)作为对比。对短柱施加轴向荷载,分析了试件的破坏形态、荷载-位移关系曲线、荷载-应变关系曲线与横向变形等。结果表明:方钢管再生混凝土短柱与方钢管普通混凝土短柱有着类似的破坏形态;内管斜45°放置的方套方短柱的极限荷载比内管正向放置的方套方短柱的极限荷载提高约3.2%;钢管普通混凝土短柱的极限荷载比钢管再生混凝土短柱的极限荷载提高约6.2%;实心短柱的横向应变发展速率较中空短柱的快。在此基础上,采用有限元软件ABAQUS建立了方钢管混凝土轴压短柱的分析模型,分析结果表明,有限元分析的柱破坏形态和荷载-应变关系曲线上都与试验结果吻合较好。

In this research,four recycled concrete-filled square steel tubular stub columns with various section forms were tested under axial compression. Section forms included the square solid specimen,concrete-filled double-skin specimen( SHS outer and CHS inner),concrete-filled double-skin specimens( SHS outer and SHS inner at different places). In addition,two normal concrete-filled double-skin steel tubular stub columns where inner tubes had different positions were designed for comparison. The research results show that the recycled concrete-filled double-skin steel tubes have similar failure modes to the normal concrete-filled steel tubular stub columns. The ultimate axial capacity of specimen SS-DS-R-b is higher than specimen SS-DS-R-a by 3. 2%. The ultimate axial capacity of normal concretefilled double-skin steel tubular stub columns is higher than recycled concrete-filled double-skin steel tubular stub columns by 6. 2%. The horizontal strain development of the solid specimen is faster than the recycled concrete-filled double-skin steel specimens. All the specimens were numerically calculated by finite element software ABAQUS. The numerical results are found to be in good agreement with test data in both failure modes and load-strain curves.