Canada/US (CANUS) Comparison of Out-of-Plane Reinforced Masonry Wall Design Provisions

As part of a larger project jointly sponsored by the National Concrete Masonry Association (NCMA) Foundation, Canadian Concrete Masonry Producers Association (CCMPA), Canada Masonry Design Centre (CMDC) and Canadian Standards Association (CSA), a team of engineers and researchers from U.S. and Canada worked together to examine the key differences and similarities between the design provisions for reinforced masonry walls subject to out-of-plane (OOP) and axial loads. The scope was limited to the strength design provisions of TMS 402-16 and the limit state design provisions of CSA S304-14 masonry design standards. Several parametric studies were conducted to quantify the comparisons, as well as to identify possible limitations within each code. These studies explored factors that directly impact the calculation of combined flexural and axial capacity, wall stiffness, second-order moments, and shear capacity of the masonry walls subjected to OOP loading. Parameters considered include the compressive strength of the masonry assembly, wall geometry, as well as the size, strength and spacing of the steel reinforcement. In general, it was found that the Canadian provisions are more conservative than those in the U.S. The paper also provides a list of areas of further research or code revisions that should be considered in the future. It is the team’s goal to propose improvements to both codes as a result of this work.