The reinforcement selection required to resist flexure in a footing is performed according to the user-defined criteria on the Reinforcement Selection tab of the Criteria > Design dialog box. The final optimized reinforcement selection will always adhere to all ACI code limits regarding reinforcement spacing, reinforcement area ratios, and development length.

From the list of the acceptable flexure reinforcement sets (quantity and size of bars), the best-fit set is selected given the users preference. In the selection of the best fit reinforcement set, the optimization method does make provisions for sets that may have very similar optimization limits. For example, when optimizing for minimum reinforcement area if the following two bar sets were found to be acceptable: (10) #6 (4.4 ) and (40) #3 (4.4 ) the (10) #6 would be selected as the optimum reinforcement over the (40) #3.

If the option “Keep all bars in Layer the same” is selected on the Reinforcement Selection tab of the Criteria > Design dialog box, the reinforcement parallel to both the major and minor axis will be considered in finding the optimum reinforcement. Note that a Layer contains both the Length and Width direction reinforcement for flexure in a given direction. This is performed independently for the reinforcement at the bottom of the footing and at the top of the footing.