Experimental and Analytical Studies on Concrete Cylinders Wrapped with Fiber Reinforced Polymer

Fibre-reinforced polymers (FRPs) are being introduced into a wide variety of civil engineering applications. These materials have been found to be particularly attractive for applications involving the strengthening and rehabilitation of existing reinforced concrete structures. In this paper, experimental investigations and analytical studies on four series of the concrete cylinders wrapped with FRP are presented. First series consist of concrete cylinders wrapped with one layer carbon fiber reinforced polymer (CFRP), second series concrete cylinders wrapped with two layers CFRP, in third series, concrete cylinders were wrapped with one layer glass fiber reinforced polymer (GFRP) and the fourth series consist of concrete cylinders wrapped with two layers of GFRP.The results show that external confinement significantly improves the ultimate strength and ductility of the specimens.Coupon tests have also been carried out to determine the mechanical properties of the FRP. Further, review of three analytical models for confined concrete from the literature is presented in detail. The stress-strain curve of confined concrete in these models consists of a parabolic first portion and a straightline second portion. Predicted stress-strain curve of these models are compared with authors's experimental curves. In predicting the second portion of the stress-strain curve considerable deviation was observed. An analytical model is also proposed for determining the stress-strain relationship of confined concrete.The model is validated by comparing with experimental values. It is observed that the proposed model well predicts the ultimate axial strains and stresses and reproduce finely the stress-strain response of confined concrete with carbon or glass FRP.