Abstract:
South Africa has a housing shortage estimated in excess of 2 million units. This backlog is being
addressed predominantly with the construction of 40 m2 low-income, single-storey, detached,
state-subsidised houses built with conventional concrete masonry units, regulated by the
Application of the National Building Regulations, SANS 10400. However, several developments
warrant a reconsideration of SANS 10400 deemed-to-satisfy masonry wall provisions. Two
critical configurations of single-storey, unreinforced, bonded masonry walls are generated,
based on these deemed-to-satisfy provisions. Subsequently, a simplified micro-scale finite
element model is used to analyse these configurations under serviceability and ultimate limit
state loading conditions. Characterisation tests of the concrete masonry material, together with
numerical fitting to test data and data taken from literature, generate the necessary parametric
input. The numerical analyses reveal that in half of the load cases, the walls’ resistances
failed to achieve the design load as required by the South African loading code. A significant
shortfall was found for the out-of-plane resistance against the wind load, as well as structural
vulnerability under seismic loading due to the geometric layout permitted by the deemed-tosatisfy
rules. This indicates that the SANS 10400 provisions for masonry wall panel geometries
require reconsideration, especially given the recent revision of the South African loading code.
