CFRP布约束方钢管混凝土短柱轴压性能试验研究

基于16根CFRP布约束外包圆弧化砂浆面层方钢管混凝土(CFRP-circular arc cement mortar layer-square concrete-filled steel tube,C-C-SCFST)短柱轴压承载试验,研究了CFRP层数和外包圆弧化水泥砂浆面层(circular arc cement mortar layer,CAM)对C-C-SCFST柱承载力和变形的影响规律。试验结果表明:随方钢管外包圆弧化砂浆面层中部厚度的增加,构件竖向承载力有较大幅度的提高。CAM的存在使得CFRP布在方钢管角部应力集中得到一定程度缓解,试件总体受力特征类似于CFRP约束圆CFST柱,轴压极限荷载作用下内部SCFST柱发生剪切破坏导致外部CFRP布断裂。基于试验结果和现有规范提出C-C-SCFST短柱承载力计算式,计算结果与试验结果吻合良好。

Experimental study on axial compression performance of CFRP-confined square concrete-filled steel tube short columns

Based on 16 CFRP-circular arc cement mortar layer-square concrete-filled steel tube(C-C-SCFST)short columns,the effect of CFRP layers and circular arc cement mortar layer(CAM)on the bearing capacity and deformation of C-C-SCFST column had been studied.With the increase of the thickness of the middle part of the circular arc mortar layer of the square steel pipe,there will be a great improvement in the vertical bearing capacity of the component.The existence of CAM made the stress concentration of the CFRP cloth at the corner of the square steel tube significantly relieved.The force characteristics of the specimens were similar to the CFRP confined circular CFST column.Under the axial compression limit load,the shear failure of the internal SCFST column caused the external CFRP to break.Based on the test results and existing specifications,the calculation formula for the bearing capacity of C-C-SCFST short columns is proposed,the calculated results agree well with the experimental results.