CFRP布加固局部腐蚀圆钢管混凝土轴压短柱受力性能

Concrete-filled steel tube (CFST) has been widely used in various kinds of buildings and structures, but steel has the disadvantage of easy corrosion, especially the local corrosion. When local corrosion occurs on CFSTs, the mechanical performance of CFSTs will degrade, so it is necessary to study the axial compressive behavior of CFSTs with local corrosion and the reinforcement method. Seven circular concrete-filled steel tubular stub columns were tested under axial compressive loads to study the influence of simulated local corrosion on axial compressive behavior. And the influence of different carbon fiber reinforced polymer (CFRP) layers on the strengthening effect of CFRP-reinforced mechanical open-hole circular CFST was studied. The results show that the local notch has an obvious effect on the behavior of the specimens, and the reduction amplitude of the bearing capacity, stiffness and ductility increases with the increase of notch length. CFRP improves the bearing capacity of the circular concrete-filled steel tubular stub columns with notch. When there is only one layer of CFRP, the CFRP breaks suddenly when reaches the ultimate load, and the ductility of specimens is poor. However, when the CFRP is increased to 2 layers, the ductility of specimens is improved, and the reinforcement effect is better. The behavior of the specimen is similar to that of the circular CFST without notch. Furthermore, the finite element models were established by ABAQUS software and the accuracy was validated by comparing with the experimental results. Based on the analysis of CFRP-reinforced circular CFST, it is recommended that the calculation method of hoop stress equal to the steel yield strength can be used conservatively to calculate the equivalent CFRP thickness for the reinforcement of local corroded circular CFST.