Shear performance of basalt fiber-reinforced concrete beams reinforced with BFRP bars

Abstract

This paper reports on the experimental and analytical investigation of the shear performance of concrete beams
\ncast with basalt fiber-reinforced concrete (BFRC) and longitudinally reinforced with basalt fiber-reinforced
\npolymer (BFRP) bars. Fourteen hybrid (BFRC-BFRP) beams with no stirrups were tested to failure under a
\nfour-point loading setup. The investigated parameters included the volume fraction, Vf, of the added fibers (0.75
\nand 1.5%), the reinforcement ratio of the BFRP bars,ρ, (0.31, 0.48, 0.69, 1.05, and 1.52%), and the shear span-todepth ratios, a/d, of the beams (3.3 and 2.5 for slender and short beams, respectively). The tests results showed
\nthat adding 0.75% of basalt macrofibres (BMF) improved the shear capacity of the slender and short beams by 46
\nand 43 %, respectively, compared to 81 and 82% when 1.5% of BMF were added. The impact of adding the BMF
\non the shear strength of the beams diminished as the longitudinal reinforcement ratios increased. The existing
\nmodels overestimated the shear strength of the tested beams with an average predicted-to-experimental ratio
\nranging between 1.15 ± 0.03 and 2.48 ± 0.29. A shear model that accounts for the type of the longitudinal
\nreinforcement and the added fibers was proposed to predict the shear strength of the BFRC-BFRP beams. A good
\nagreement between the predicted and experimental shear strength was evident with a predicted-to-experimental
\nratio that ranged between 0.98 ± 0.11 and 0.88 ± 0.02 for the slender and short beams, respectively.