Residual behaviour of glass FRP bars subjected to high temperatures

The adoption of glass fiber reinforced polymer (GFRP) bars is becoming an interesting solution for different structural application, as a replacement of ordinary steel reinforcement, mainly for durability performance. The behavior of GFRP reinforcement, after high temperature exposure, is of critical importance for applications in concrete structures potentially subjected to fire. Accordingly, the aim of this study is the experimental evaluation of the residual behavior of GFRP bars subjected to different temperatures treatments, ranging between 100 and 700 °C. In particular, tensile tests on E-CR Glass FRP bars with nominal diameter of 14 mm were carried out after thermal treatment in an electric muffle, in order to characterize the degradation of the material residual properties after high temperature exposure. Young's modulus and tensile strength decay were recorded. The experimental results are discussed with reference to practical structural applications as tunnel segmental lining.