Appendix A of “Building Code Requirements for Structural Concrete (ACI 318-2011) and Commentary” provides requirements for design using strut-and-tie models, including provisions for the effective capacities of prismatic and nonprismatic (bottle-shaped) struts. The authors examine whether an increase in the width of a strut results in a reduction of its unit bearing strength. Based on their test results, the authors conclude that attributing a reduction in allowable compressive strength to the shape of a strut is an unnecessary rationalization