Flexural behavior of hybrid fiber‐reinforced concrete beams reinforced with <scp>GFRP</scp> bars

Abstract This paper aims to experimentally evaluate the flexural behavior of hybrid fiber‐reinforced concrete beams reinforced with glass fiber‐reinforced polymer (GFRP) bars. The effects of different fiber dosages and GFRP bars on the flexural behavior of concrete beams were investigated. This study included three reinforced concrete beams with different fiber dosages, three hybrid fiber concrete beams with different GFRP reinforcement ratios, and one steel‐reinforced concrete beam. The results indicated that the inclusion of hybrid fiber improved the flexural behavior of concrete beams reinforced with GFRP bars, enhanced their flexural capacity, and significantly reduced their deflection and crack width under service loads. The experimental flexural capacity values of hybrid fiber‐reinforced concrete beams reinforced with GFRP bars were higher than those calculated from ACI 440.1R‐15 and GB 50608‐2020. The experimental deflection values and crack widths of under service loads of hybrid fiber‐reinforced concrete beams reinforced with GFRP bars were lower than those calculated from ACI 440.1R‐15 and GB 50608‐2020. Based on the GB 50608‐2020, the deflection calculation formula for hybrid fiber‐reinforced concrete beams reinforced with GFRP bars under service loads has been modified to account for the synergistic effects of multiscale fiber reinforcement.