This criterion is applied as part of the minimum reinforcement designer as it is independent of the magnitude of forces upon a cross section.
This criterion is applied to both beams and slabs, although its application to beams is not required by AS 3600.
The cracking is assumed to be top (negative moment) or bottom (positive moment) based on the "Min. Reinforcement Pattern" selected in the design strip segment or design section.
Reinforcement may be applied to both faces if the cross section is subject to both positive and negative moments and the "tension face" reinforcement location is chosen.
User defined reinforcement that is at an angle to the cross section will only have the component perpendicular to the cross section considered.
The amount of reinforcement provided is equal to 0.75 (per 9.4.3.2(b)) times the amount specified by either 9.4.3.4(a)(i), 9.4.3.4(b)(i), or 9.4.3.4(c).
For "protected" environments, the amount of reinforcement provided is: As = (0.75)(1.75 – 2.5 σcp)(Ag)/1000
For "normal" environments, the amount of reinforcement provided is: As = (0.75)(3.5 – 2.5 σcp)(Ag)/1000
For "corrosive" or "very corrosive" environments, the amount of reinforcement provided is: As = (0.75)(6.0 – 2.5 σcp)(Ag)/1000
For non-PT design strips and design sections, σcp is taken as zero.
