Hagel, Mark1; Cruz-Noguez, Carlos2; Woods, Josh3 and Pettit, Clayton4

1 Executive Director, Alberta Masonry Council, Calgary, AB, Canada, markhagel@albertamasonrycouncil.ca
2 Assistant Professor, University of Alberta, Department of Civil engineering, 7-306 Donadeo Innovation Centre for Engineering (ICE)9211-116 Street NW Edmonton, AB Canada, cruznogu@ualberta.ca
3 PhD. Candidate, Carleton University, 1125 Colonel By Dr., Ottawa, ON, Canada, josh.woods@carleton.ca
4 BSc. Student, University of Alberta, 116th Street & 85th Ave., Edmonton, AB, Canada, cpettit@ualberta.ca

In the design of steel, wood, and reinforced concrete walls the slenderness limit is based on the radius of gyration (r) of the cross-section rather than thickness (t). For concrete, the sister material to concrete masonry, the slenderness limit is (kh/r) < 100 with r for a rectangular crosssection rounded to 0.3t yields the same slenderness ratio limit in the current CSA S304.1-14 design standard for masonry structures. This paper proposes the use of the two-dimensional radius of gyration to better capture the geometry of partially grouted walls when compared to using the wall thickness. This results in an increase in the height that walls can be designed and constructed before the conditions for slender wall design are imposed. Elastic and inelastic analysis presented on two tall walls supports the recommendation to establish a new limit based on the radius of gyration.