Models for Predicting Strength of RC Columns Strengthened with NSM-CFRP Strips and CFRP-Fabric Wraps

Abstract

A comprehensive experimental investigation was carried out on reinforced concrete (RC) columns strengthened with near surface mounted (NSM) Carbon fiber reinforced polymer (CFRP) strips with CFRP fabric wraps as confinement. The number of NSM-CFRP strips and the number of CFRP-Fabric wraps were varied. The RC columns were subjected to concentric and eccentric loads with different eccentricities that resulted in uniaxial bending. Significant improvements in strength and ductility were observed in the strengthened columns compared to that of the control specimen. In this investigation four empirical models, based on the experimental results, were developed to predict the un-strengthened and the NSM-CFRP strengthened RC columns using different parameters. The capacities of the columns predicted by the developed empirical models were validated using the obtained experimental results. It is observed that the developed empirical models have exponential decay and a near-perfect fit to the experimental results, with R2 averaging more than 99% and an average mean absolute percent error (MAPE) of 6.6%. It is concluded that the developed models can be used as useful tools for predicting capacity of columns with NSM-CFRP strips and CFRP wraps under axial loading and uniaxial bending.