Flexural Behavior of Reinforced Concrete Beams with FRP Bars Exposed to Elevated Temperature

Abstract

The present study aims to evaluate the performance of concrete beams with different Fiber Reinforced Polymer (FRP) and steel bars exposed to elevated temperatures through a detailed experimental investigation. Flexural behavior of beams is analyzed with Carbon Fiber Reinforced Polymer bars (CFRP), Basalt Fiber Reinforced Polymer bars (BFRP), Glass Fiber Reinforced Polymer bars (GFRP), and steel bars tests. Beams were exposed to elevated temperature 925 °C (1 hr) following standard fire curve, and subsequently cooled by either natural or forced water spraying. After the cooling, beam specimens were tested under four-point loading up to the failure load. Ultimate load and deflection profile of heated and unheated beams are evaluated. At higher temperatures (925 °C), the steel and GFRP specimens show a higher strength loss of about 60–80% with higher deformation values. The load carrying capacity of CFRP beams is found to be higher as compared to other types of beams. Specimens cooled by water shows higher strength loss of about 7–12% than air cooled specimens. The failure pattern of beams with FRP and steel beams are different, and it is based on heating cooling regime.