Behavior of normal and high-strength concrete cylinders confined with E-glass/epoxy composite laminates

Abstract

This paper is aimed at studying the behavior of concrete cylinders with varying compressive strength wrapped with E-glass/epoxy fiber reinforced polymer (GFRP) jackets and subjected to uniaxial compressive loads. A comprehensive experimental program which involves 54 plain concrete cylinders was conducted in this study. The cylinders evaluated in this study, were divided into six groups, and each group contain a control cylinder without confinement to quantify the amount of gain obtained using the GFRP laminates. Experimental results indicated that the use of GFRP jackets substantially increases both the compressive strength and ductility of unreinforced concrete cylinders. In this paper, the influences of two parameters influencing the behavior of the GFRP confined cylinder is investigated. These parameters are: the number of composite plies (i.e. composite thickness) and concrete compressive strength. The results of this study showed that: (i) compressive strength and ductility of the concrete cylinders increases with number of composite layers; and (ii) effect of confinement is substantial for normal strength concrete and marginal for high-strength concrete. A semi-empirical theoretical model is also presented in order to predict stress–strain relationship of GFRP confined concrete cylinders. The model results showed an excellent agreement with experimental values.