Evaluation of ultimate conditions of concrete confined by GFRP wire jackets

Abstract

This study investigated the ultimate conditions of concrete confined by glass-fiber-reinforced polymer (GFRP) wire. For this purpose, the experimental data obtained from a previous study was examined. The ultimate strain in wires was investigated through a strain reduction factor, which was the percentage of the rupture strain of the GFRP jackets to the ultimate material strain of GFRP. It is believed that the factor declined with an increase in the unconfined concrete strength. The concrete confined by using a single layer showed a higher maximum strain of the wire than concrete confined by multiple layers. An increase in the number of layers in the multilayer cases did not significantly affect the maximum strain of the wire. Equations to predict an ultimate stress and ultimate strain of the concrete with respect to the ultimate strain of the wire were introduced. The proposed equations achieved acceptable results in comparison to experimental results and results obtained from literature equations.