Experimental Investigation of the Shear Performance of Concrete Beams Reinforced with BFRP Bars

Basalt fiber-reinforced polymer (BFRP) bars offer a sustainable alternative to steel reinforcement due to their high strength, lightweight properties, and corrosion resistance. This study investigates the shear performance of 20 concrete beams reinforced solely with BFRP bars, excluding stirrups, and compares these beams with two steel-reinforced control beams. Key variables included shear span-to-depth ratios (a/d = 1.5, 2.1, 2.5), concrete strengths (f'_c = 35, 50, 70 MPa), and reinforcement ratios (ρ = 0.0176, 0.0321, 0.0446). Experimental results revealed that all beams failed due to diagonal shear cracking, with cracks propagating from the supports to the load points. The maximum experimental shear capacity recorded was 218 kN at a midspan displacement of 11.40 mm, achieved with a/d = 1.5, f'_c = 70 MPa, and ρ = 0.0446. From an analysis of the main effect trends, the optimal parameter levels were identified as those obtained experimentally: a/d = 1.5, f'_c = 70 MPa, and ρ = 0.0446, which yielded the highest shear capacity. Comparisons with existing design codes revealed that predictions from CAN/CSA-S806-12 closely matched the experimental outcomes, while ACI 440, JSCE-97, and ISIS-2007 were conservative.