Performance of RC Beams reinforced with Steel Fibers under Pure Torsion

Reinforced Concrete (RC) beams are designed to resist torsion and shear and flexural failure due to applied loading. The failure mode of concrete elements owing to shear and torsion is unwanted and occurs without warning. So, in the design process it must be taken into account that if failure takes place, it is preferable for it to be flexural as this gives an indication before it occurs. The aim of the present study is to investigate the impact of using steel fibers with and without ordinary torsional reinforcements, on the torsional strength, crack distribution, and ductility of RC beams. The intended plan is to investigate the torsional capacity enhancement of RC beams with added steel fibers under monotonic torsional load. The finite element approach was adopted in the ABAQUS software in which the RC beams were simulated and the torsional load was applied. The results indicate that the presence of steel fibers within the concrete matrix raises torque resistance, reduces twist angle, and increases ductility, stiffness, and energy dissipation. An increase in the steel fiber percentage improves the performance of RC beam torque strength capacity and minimizes twist angle. The percentage of steel fiber has an important impact on the ultimate torque value. The ultimate torque increased by about 15, 21.6, 29, 39.3, 46.6, and 5.9% for 0.5, 1, 1.5, 2, 2.5 and 3%, respectively, added steel fibers, in comparison with the reference beam.