Three-dimensional stress distribution in concrete masonry prisms and walls

Abstract

Synopsis Three-dimensional finite element analysis is used to study the stress distribution at working stress levels in masonry constructed of hollow concrete blocks. The stress analysis is performed on models of ungrouted and grouted concrete block prisms and walls. The effects of the following factors are examined: grouting, mortaring style, capping, platen restraint, shell taper of concrete blocks, core alignment of walls constructed in running bond, and mortar stiffness. The stress patterns are used to evaluate the validity of certain masonry failure theories. The stress distribution in a running-bond wall, where the cores of the blocks do not align vertically, is found to be significantly different from the distribution in a stack-bonded prism. Substantial improvement in the performance of walls in running bond is attainable if the cores are aligned and the taper of the core is made as small as practicable.