Investigate the flexural strength behavior of concrete beams reinforced with glass fiber reinforced polymer bar under elevated in-service temperature

This article aims to investigate the flexural strength behavior of concrete beams reinforced with glass fiber reinforced polymer bar (GFRP) under elevated in-service temperatures. It also evaluates the effectiveness of GFRP as a replacement for steel reinforcement. The research used two types of reinforcement i.e., GFRP and steel, with a diameter of 12 millimeters. Concrete beam sample, with dimensions of 150 x 200 x 1600 mm were prepared. Three GFRP bars, each 1550 mm in length, were installed longitudinally in the concrete beams, which had a compressive strength of 33.5 MPa at 90 days. A heating apparatus was used to heat the beams until the GFRP bars reached a temperature of 150°C for 1 hour, after they were tested under flexural strength. The study found that the concrete beams reinforced with GFRP exhibited increased deflection and a decrease in load capacity as the temperature increased. When comparing concrete beams reinforced with GFRP to those reinforced with steel, the study found that the deflection increased by 52.6%, and the load capacity decreased by 46.1%. In tests involving GFRP-reinforced concrete beams at room temperature and at 150°C, it was found that the deflection increased by 34.3% when the temperature was elevated, and the load capacity decreased by only 2.6%.