Confinement of concrete columns with large rupture strain FRP composites

Abstract

Fibre-reinforced polymer (FRP) composites can be used as a confinement mechanism to improve the strength and ductility of concrete columns. In recent years, a number of large rupture strain (LRS) FRP composites have emerged, namely polyethylene naphthalate (PEN) and polyethylene terephthalate (PET), and they are a promising solution for the seismic retrofitting of reinforced concrete (RC) columns. These composites are desirable as they are made from recycled plastic bottles, making them a cheaper and more environmentally friendly alternative to traditional FRPs (i.e. carbon FRP and glass FRP). This paper presents an experimental study on the axial compressive behavior of LRS FRPconfined normal-strength concrete columns. The effect of FRP layers on the stress-strain behavior of these columns is investigated. Furthermore, several tests on traditional FRP-confined columns were tested in parallel and these results are used to make comparisons to those LRS FRP-confined columns. Results show that LRS FRP-confined columns achieve a similar ultimate strength and significantly higher ultimate strains to their traditional FRP counterpart when the confining ratio is similar.