According to the program manual, for one-way slabs, two-way slabs or beams, the program checks AS 3600-2009 section 8.1.6 and 9.4.3.2. If you turn on "Controlling Criteria" through visible objects in Ram Concept you should be able to see which is controlling in your case.
A few details for how each is implemented is posted below, but the formatting is not as clean as the RamConcept.pdf.
62.6.5 8.1.6 Minimum Flexural Strength
• Cross sections within 1/6 span from supports or 1/6 span from midspan are considered “at critical sections”.
• If the design section is not declared as post-tensioned in the design section or design strip segment, then the Pe/Ag and Pee terms of 8.1.6.1 are assumed to be zero (even if the cross section includes tendons), where Pe is the total effective prestress force considered.
• 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.
• See ““Cracking Moment” Used in Design Calculations” for a theoretical discussion of the “cracking load”.
62.6.15 Section 9.4.3.2 Shrinkage and Temperature
• 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 σ cp )(Ag)/1000
• For “normal” environments, the amount of reinforcement provided is: As = (0.75)(3.5 – 2.5 σ cp )(Ag)/1000
• For “corrosive” or “very corrosive” environments, the amount of reinforcement provided is: As = (0.75)(6.0 – 2.5 σ cp )(Ag)/1000
• For non-PT design strips and design sections, σ cp is taken as zero.