Strength and ductility of circular concrete columns confined width GFRP wraps

Abstract

Fiber reinforced polymer (FRP) has been used inconcrete structures for over two decades for its significant enhancement in concrete strength and ductility as a confinement material, in both the seismic retrofit of existing reinforced concrete columns and the construction of earthquake resistant columns in new construction. Among different FRP materials, glass-FRP (GFRP) was the most widely applied because of its best cost-performance combination. To that end a great number of studies have been conducted to give an accurate model of GFRP confined concrete under various load conditions.The problem with the previous models is that they are based on a limited test database that was available in the time, which with the new tests leads to lower performance.The aim of this work is to develop a new confinement model of GFRP confined concrete under compressive and flexural loading, with and without considering steel confinement, that shows better accuracy, and evaluate the performance of the previous proposed models based on a larger test database. And finally establish a new stress-strain relationship.