Shear behaviour of one-way high strength plain and FRC slabs reinforced with basalt FRP bars

The purpose of this study is to investigate the shear behavior of high-strength one-way plain and basalt fiber reinforced concrete (BFRC) slabs reinforced with basalt fiber reinforced polymers (BFRP) bars. A total of 8 slabs having 2550 mm length, 600 mm width and 150 mm height were tested under four-point loading until failure. The main test variable was the BFRP longitudinal reinforcement ratio with two ratios of 0.792 % and 1.27 %. Also, two slabs were cast with basalt macro fibers (BMF) at a volume fraction (Vf) of 0.75 % to explore the effect of the added fibers on the shear capacity of the tested one-way slabs. Following the experimental testing, the shear capacities of the BFRC-BFRP one-way slabs were evaluated analytically using two approaches. The first approach considers the individual contribution of concrete and BMF to shear strength, while the second takes into account a direct alteration to the concrete contribution owing to the addition of BMF. The experimental results showed that the shear capacity was enhanced by 25 % to 29 % when the reinforcement ratio was increased from 0.792 % to 1.27 %. In addition, the shear capacity of the slab containing 0.75 % of BMF was notably enhanced over the plain concrete slab, however, this enhancement was less notable when a higher reinforcement ratio was used. Based on the analytical investigation, a new model that accounts for the individual contribution of concrete and the BMF is proposed. The model has accurately and conservatively predicted the experimental data with a mean experimental to predicted shear capacity of 1.10 and a coefficient of variation of 7.95 %.