不锈钢管约束混凝土短柱轴压性能试验

Experimental Study on Circular Stainless Steel Tube Confined Concrete Stub Columns Under Axial Compression

为研究混凝土在不锈钢侧向约束下的受压力学性能,开展不锈钢圆管约束混凝土短柱的轴压试验研究.在试验中,设置素混凝土短柱和碳素钢管约束混凝土短柱作为对比,主要研究参数为加载边界条件和不锈钢管壁厚.试验结果表明:素混凝土短柱出现沿竖向劈裂破坏,破坏前变形较小;其余约束混凝土短柱均呈现较好的变形能力,破坏表现为钢管外屈及相应位置混凝土压溃破坏;在圆不锈钢管约束下,混凝土短柱的轴压承载力和变形能力均得到显著提升;不锈钢管混凝土短柱的初始刚度大于不锈钢约束混凝土短柱;随着不锈钢管壁厚的增大,约束混凝土短柱的轴压承载力近似呈线性增长;采用不锈钢管约束混凝土的承载力高于采用相近屈服强度的碳素钢管约束混凝土.

Axial compression tests were carried out on stainless steel tube confined concrete stub columns,to investigate the effect of lateral confinement of stainless steel tube on the axial compressive performance of concrete stub columns.The main test parameters included the loading boundary and wall thickness of stainless steel tube.The plain concrete stub column and concrete stub column confined with carbon steel tube were conducted for comparison.The test results show:the plain concrete stub column splits longitudinally with minor deformation;while all the confined concrete stub columns present ductile failure modes with outward local buckling of steel tube and crush of concrete inside;the load-carrying capacity and deformation capacity of concrete stub columns are significantly enhanced by the lateral confinement of stainless steel tubes;the initial stiffness of concrete-filled stainless steel tube is greater than the stiffness of stainless steel tube confined concrete;as wall thickness increases,the load-carrying capacity of the stainless steel tube confined concrete increases approximately linearly;the stainless steel tube confined concrete owns a higher strength than the carbon steel tube confined concrete.