Damage assessment of GFRP bar reinforced ultra-high-strength concrete beams under overloading impact conditions
© 2020 Elsevier Ltd This paper investigates the damage assessment of Glass Fiber Reinforced Polymer (GFRP) bar reinforced Ultra-High Strength Concrete (UHSC) beams under overloading impact conditions. The overloading impact condition is defined as the input impact energy larger than the quasi-static energy absorption capacity of the beam. Impact (drop load) tests were carried out on nine GFRP bar reinforced UHSC (GFRP-UHSC) beams. Three increasing input impact energies were used in this study. To investigate the influence of the shear capacity on the damage of the GFRP-UHSC beams, the beams were designed with three different shear capacities. The midspan deflection histories, dynamic forces, and accelerations along the beams were measured. The crack patterns were recorded using a high-speed video camera to analyze the failure modes of the beams. It was found that the shear reinforcement ratio, longitudinal reinforcement ratio, and input impact energy influenced the failure modes of the GFRP-UHSC beams under overloading impact conditions. Flexural and flexural-shear failure modes were observed in beams with higher shear capacities, whereas dominant shear and flexural-shear failure modes were observed in beams with lower shear capacities. Design recommendations for GFRP-UHSC beams to resist overloading impact conditions are provided.