Experimental and Parametric Study of Circular Short Columns Confined with CFRP Composites

This paper presents an experimental and nonlinear finite-element analysis (NLFEA) results of circular short reinforced concrete (RC) columns confined externally with carbon fiber-reinforced polymers (CFRP) subjected to pure axial loading. The experimental program involves the fabrication and testing of 55 specimens wrapped with different number and configuration of CFRP sheet layers in the transverse and longitudinal directions. In addition, the columns were modeled using NLFEA. After reasonable validation of NLFEA with the experimental test results of companion columns and available technical literature results, NLFEA was expanded to provide a parametric study of 96 columns that correlates the ultimate axial stress of CFRP-confined RC columns to unconfined strength of concrete (f(co)), the volumetric ratio of CFRP (rho(f)), and the size effect. Results indicated that the ultimate capacity and ductility increase with the increase in volumetric ratio of CFRP (rho(f)) and unconfined strength of concrete (f(co)). In addition, the results indicated that size effect exists and the confinement effectiveness was more pronounced for columns with low f(co) and rho(f).