Influence of Elevated Temperature on the Mechanical and Thermal Performance of BFRP Rebar

Compared to glass fiber reinforced polymer (GFRP) rebars, basalt fiber reinforced polymer (BFRP) rebars possess many advantages as internal reinforcement of concrete structures, in terms of the enhanced corrosion resistance. In the present study, mechanical and thermal properties of BFRP rebar at elevated temperatures and after elevated temperature treatment were conducted. The study is believe to offer the basic mechanical and thermal property data of BFRP rebars during and post- fire, which is helpful for the the safe design of BFRP in rehabilitation when considering the fire hazarder. The tensile properties of BFRP rebars were performed in the temperature ranging from room temperature to 350°C. Three stages of deterioration of the tensile strength and modulus are observed based on the degradation rate. It was found that the strength and stiffness of BFRPs still remain high values (e.g., more than half of the room temperature values) even at the temperature much higher than Tg (glass transition temperature) of the system. The deterioration is attributed to the decreased force transferring capacity of the resin. In addition, BFRP rebars were treated at elevated temperatures for various periods in an oven. The oxidation of the resin and the deterioration of the interface between fiber and resin bring in remarkable degradation of the mechanical and thermal properties.