This section applies to unbonded post-tensioned beams and one-way slabs, and to all post-tensioned two-way slabs.

0.625(A_sf_y + A_psf_p) = F₁

where

F1	=	tensile force in concrete
As	=	area of un-tensioned reinforcement added
fy	=	yield strength of un-tensioned reinforcement
Aps	=	vector component area of bonded (grouted) tendons in tension zone
fp	=	tendon yield stress - tendon effective stress

It is possible that the added un-tensioned reinforcement will not be in the tension zone if a very large concrete cover is specified.

User defined reinforcement that is at an angle to the cross section will only have the component perpendicular to the cross section considered.

No check is made to ensure the cross section is post-tensioned.