Axial compressive behaviors of partial deteriorated strength concrete columns confined with CFRP

This paper aims to present an effective method to partial deteriorated strength columns, and to investigate the mechanical behavior of the defect part. Five groups of 150×150 mm×mm plain square columns are cast; each specimen has two different strengths, the lower strength in the middle segment and higher strength in both ends. The lower strength is to simulate the status of partial deteriorated region. Different layers of CFRP sheets have been wrapped just on the lower strength part to gain the reinforcement with CFRP sheets, and to verify the practicability of partial confinement. Specimens are subjected to monotonic axial compression until failure. Axial load, axial and transverse strains are measured to compare the different behaviors between the two parts. Experimental results show that partial confinement can significantly enhance the strength and the ductility of the deteriorated strength part, then, the load capacity of the whole column can be increased subsequently. Test data indicate that the ultimate load of the confined column is higher than that of the original column without deterioration; partial confinement on weakness is a feasible approach.