Behaviour of FRP confined concrete cylinders under different temperature exposure

Bridge structures are exposed to the elements with a high variation in temperature. The purpose of this study is to investigate the effect of different high temperatures on the behaviour of concrete cylinders wrapped with Fibre Reinforced Polymer (FRP). Twelve concrete cylinders made of 60 MPa having 100 mm diameter and 200 mm height were cast and tested. The cylinders were divided into four groups: cylinders wrapped with a single CFRP layer, cylinders wrapped with two CFRP layers, cylinders wrapped with a single GFRP layer, and cylinders wrapped with two GFRP layers. Each group was exposed to temperatures of 20°C, 20°C to 70°C, and 70 °C for 30 days. All cylinders were then tested to failure by the application of an axial concentric compression loading. The study indicated that the ultimate strength of concrete cylinders wrapped with one and two layers of CFRP and GFRP did not significantly change after being exposed to 20°C to 70°C, and 70°C. The exception was observed on the cylinder wrapped with one layer of GFRP where its ultimate strength decreased. However, the results had shown a good performance (increased) of their ductility. The exception was observed on cylinders wrapped with one and two layers of GFRP where their ductility did not significantly change.