U.l.S. 3D domain of rectangular cross-sections in r.c. subject to shear and torsion

This paper aims to illustrate a unified approach for the process of the Ultimate Limit State (ULS) design and check of rectangular sections in reinforced concrete (r.c.) subject to composed forces of shear and torsion. This approach was developed by the authors starting from established theoretical hypotheses and categorizations and from the resulting equations; it can solve the shear-torsion problem in a unified and organic way considering a single 3D resistance domain obtained from assembling three distinct 2D graphics actually utilized in the current procedure. The 3D domain has the high advantage to propose a more comprehensive approach to the problem and more careful and precise results.