Behavior of Concrete Bridge-Deck Slabs Reinforced with Basalt Fiber-Reinforced Polymer and Steel Bars

Recently, hybrid reinforcement by combining steel with fiberreinforced polymer (FRP) bars has emerged as a new system in reinforced concrete (RC) constructions. This reinforcement system can effectively overcome the ductility and serviceability challenges of FRP-RC structures. A total of 11 full-scale bridge-deck slabs were constructed and tested. The test parameters were reinforcement type, ratio, arrangement, and slab thickness. Moreover, a comparison between the experimental and predicted deflections from design provisions was carried out to verify the efficiency of the models for hybrid RC sections. Based on test results, hybrid RC slabs exhibited ductility leading to an ample warning before failure rather than brittle shear failure observed for FRP-RC slabs. In addition, hybrid RC slabs displayed good stiffness, serviceability, and load-carrying capacity. Furthermore, test results give an average bond-dependent coefficient, [k.sub.b], of 1.27, close to the 1.2 recommended by ACI CODE-440.11-22. In addition, some modifications were proposed to shear equations available in different design codes to be valid for hybrid RC members without shear reinforcement. Keywords: basalt fiber-reinforced polymer (BFRP) bar; concrete bridge; hybrid reinforcement; shear behavior.