Shear behavior of basalt FRC beams reinforced with basalt FRP bars and glass FRP stirrups: Experimental and analytical investigations

This study investigated the shear behavior of basalt fiber reinforced concrete (BFRC) beams reinforced with basalt (B) and glass (G) fiber-reinforced polymers (FRP) bars and stirrups, respectively. Fourteen beams were tested under four-point loading up to failure. The investigated parameters were the volume fractions (Vf) of basalt macro-fibers (BMF), the reinforcement ratio, the shear-span-to-depth ratio, and the stirrup spacing. An enhancement in shear capacities of the tested beams was observed with the increase of the Vf of the added BMF from 0 to 1.5%. The shear capacities of the tested beams were also improved as their reinforcement ratios increased. On the other hand, there was a significant reduction in the ultimate strengths and stiffnesses of beams with GFRP stirrups compared to their counterpart beams with steel stirrups. The experimental capacities of the tested beams and experimental results of 178 FRP-RC beams available in the literature were compared to those predicted by existing models and code equations. A good correlation between the predicted and experimental results was obtained using the equations of CAN/CSA-S806-12. A proposed modified shear equation incorporating CAN/CSA-S806-12 provisions and a model suggested by Al-Ta'an and Al-Feel predicted the shear design capacities of BFRP-BFRC reinforced concrete beams with reasonable accuracy.

Automated summary

The study found that the shear capacity of the beams increased with the addition of basalt macro-fibers and higher reinforcement ratios. Beams reinforced with GFRP stirrups showed significant reductions in ultimate strengths and stiffnesses compared to those with steel stirrups. The predicted shear design capacities of BFRP-BFRC reinforced concrete beams using existing models and code equations showed good correlation with experimental results.