NUMERICAL ANALYSIS OF SELF-COMPACTED CONCRETE BEAMS REINFORCED WITH STEEL FIBERS UNDER TORSION

This study aims to numerically investigate the behavior of steel fiber-reinforced self-compacted concrete (SCC) beams subjected to pure torsional loading. A three-dimensional (3D) non-linear finite element analysis is carried out using the ANSYS software to predict the effect of steel fibers on the torsional behavior of SCC beams. A comprehensive validation study was conducted by adopting a multi-example validation approach to enhance the credibility and robustness of the conclusions drawn from the numerical investigation. Many variables were studied, including the compressive strength of SCC, the spacing between stirrups, the diameter of stirrups, the volume ratio of steel fibers and the beam width. The numerical model well captured the failure patterns, torque-angle of twist responses, stress distributions, and the ultimate load-carrying capacity of the SCC beams. The numerical results demonstrate that including steel fibers leads to enhanced mechanical properties and improved torsional resistance of the SCC beams. The effect of steel fibers is most significant at a volume ratio of 2%, which resulted in a 77.29% increase in the ultimate torsional capacity. Furthermore, the study proposes a rational approach in the form of an equation to predict the ultimate torsional capacity of SCC beams. The developed equation was compared against a range of experimental data and design codes to assess the accuracy and reliability of the predicted equation. The results of these comparisons demonstrate that the proposed analytical model provides acceptable predictions of the ultimate torsional capacity of SCC beams.