Using Fibers Instead of Stirrups for Enhancing Torsional Strength in Reactive Powder Concrete Beams

This study investigates the torsional behavior of Fiber-Reinforced Concrete (FRC) beams subjected to pure torsion. Six concrete mixtures incorporating different fiber types and dosages were tested, including Basalt Fibers (BF), Steel Fibers (SF), and Glass Fibers (GF), to evaluate their potential as substitutes of traditional transverse reinforcement. The findings show that the fiber type and dosage significantly influence the torsional strength and ductility. Incorporating 1% BF reduced the torsional capacity by 53%, while 1% GF caused a 14% reduction. In contrast, adding 1% SF improved the torsional strength by 106%. The hybrid mixtures further enhanced the performance, with a combination of 0.5% BF and 0.5% GF, increasing the torsional capacity by 29.6% compared to the control beam. Overall, the results indicate that FRC can effectively replace stirrups in torsion-resistant beams, with hybrid fiber systems offering additional structural benefits.