Design models for circular and square RC columns confined with GFRP sheets under axial compression

The confinement of reinforced concrete structural elements can significantly increase their strength and ductility. This motivated numerous research works using different materials, among which are composites. A significant number of constitutive models developed to predict the behaviour of columns confined with fiber polymer sheets have been proposed. Nonetheless, the existing design-oriented models were mainly calibrated for carbon fiber based materials. In the research presented in this paper, sixty experimental results of concrete columns confined with glass fiber reinforced polymers under quasi-static monotonic loading were analysed. This made it possible to calibrate the parameters of a design-oriented model for the prediction of the response of confined concrete columns, with both circular and square cross-sections. The comparison of the proposed model and of an analysis-oriented model with experimental results is presented. The results of the former model show good correlation with experimental data and are generally more accurate than those of the analysis-oriented model considered.