Section 11.2.9.1 Shear Consideration Due to Torsion

The cracking torsion is calculated using equation 11-2:

Torsion reinforcement is provided only if factored torsion T_f > 0.25 T_cr.

T_{c r} = (\frac{A_{c}^{2}}{p_{c}}) 0.38 λ ϕ_{c} \sqrt{{f^{'}}_{c}}

where

λ	=	taken as per section 8.6.5. For sections with multiple values of density the smallest density is used.
A_c	=	calculated as outside perimeter of concrete cross section, including area of holes.
p_c	=	calculated as perimeter of the cross section.

For sections with multiple values of f'_c, the minimum f'_c used for the cracking torsion calculation.