关键词: CFRP-PVC方管, 约束混凝土柱, 轴向压缩, 力学性能指标

Abstract: To study the mechanical properties of CFRP-PVC square tube confined concrete columns, six specimens are designed with the number and width of CFRP layers as variables, and axial compression tests are conducted. The entire process of specimen failure are observed, and mechanical performance indicators such as axial load displacement curve, peak bearing capacity, and ductility coefficient are obtained. The results show that the strongly restrained specimens exhibit tearing failure at the corners of CFRP-PVC pipes, while the weakly restrained specimens exhibit buckling failure of PVC pipes; The presence of CFRP significantly improves the bearing capacity of PVC pipe concrete columns. Increasing the number of layers of CFRP strips can increase the peak bearing capacity by 46.7%, but ductility is reduced by 34.5%. Increasing the width of CFRP strips will result in a maximum increase of 41.8% in peak bearing capacity and a 9.6% increase in ductility. Based on experimental results and existing literature calculation methods, a method for calculating the axial compressive bearing capacity of CFRP-PVC square tube confined concrete columns is proposed. The error between the calculated value and the actual value is 3.0%, and the coefficient of variation is less than 0.03. The proposed calculation method has high reliability.

Key words: CFRP-PVC square tube, constrained concrete columns, axial compression, mechanical performance indicators