All Cracked Up Over Icr

TMS 402-22 provides an equation for determining the cracked moment of inertia of a reinforced masonry wall under out-of-plane loading. TMS 402-22 states that the equation is valid for a fully grouted wall or a partially grouted wall with the neutral axis in the face shell. Other implicit assumptions that are not stated in TMS 402- 22 are that the tension reinforcement has yielded, there is only one layer of tension reinforcement, and the axial load can be replaced by equivalent reinforcement at the mid-depth of the section, with the area of the reinforcement being the factored axial load divided by the yield stress. This paper provides equations for the cracked moment of inertia when these assumptions are not met. Tips for design are also provided.