Torsion reinforcement is not provided if the requirements of 8.3.4(a)(i) are met [T* < 0.25 φ Tuc]. The requirements of 8.3.4(a)(ii) and (iii) are conservatively ignored.
All torsion is assumed to be taken by the "core". See "Concrete "Core" Determination" for calculation of the core.
Where the core consists of multiple ribs, the calculations are based on an average rib (and then factored up by the number of ribs).
Section 8.3.3 is used to reduce the maximum shear capacity.
In calculating At and ut, the side cover to the centroid of the longitudinal bar is assumed to be the maximum of the top cover and bottom cover to the centroid of their respective longitudinal bars.
Longitudinal torsion reinforcement in the compression zone is not reduced by the flexural compression force [8.3.6(a) is used for both tension and compression faces]
Torsion capacity is reported.
Section 8.3.4(b) is considered when designing the transverse closed ties.
Transverse closed ties (Asw) are provided for the lesser of T* and Tu,max. If T* is greater than Tu,max, then the section will be reported as failing sections 8.2 and 8.3. The minimum requirements of 8.3.7(b) are also met.
Longitudinal reinforcement is provided based on the Asw value calculated for the lesser of T* and Tu,max.
