Models for Predicting Strength of Biaxially Loaded RC Columns Strengthened using NSM-CFRP Strips and Fabric

An experimental study on large scale short reinforced concrete (RC) columns strengthened using near surface mounted (NSM) carbon fiber reinforced polymer (CFRP) strips and confined with CFRP fabric was carried out to determine the effects of the strengthening mechanism on the load carrying capacity of RC columns.The specimens were subjected to concentric and eccentric loading conditions resulting in axial and biaxial bending.The specimens were categorized according to the applied eccentricity ratio.Based on part of the experimental results, multiple empirical Linear and Nonlinear models were developed to predict the load carrying capacity for concentrically and biaxially loaded columns strengthened with NSM CFRP strips and confined with CFRP fabric wraps using the resultant eccentricity ratio as a parameter.The results obtained from the empirical models are validated against the experimental results.The empirical models were able to predict the load carrying capacity for axially and biaxially loaded columns with an average Mean Absolute Percent Error (MAPE) of 7.1% for the Nonlinear models and 24.0% for the Linear models.It has been concluded that the developed Nonlinear models can be used as practical tools for accurately predicting the capacity of RC columns strengthened with NSM-CFRP strips and CFRP wraps subjected to axial loading and biaxial bending conditions.