INFLUENCE OF CONCRETE MASONRY UNIT WEB GEOMETRY ON THE RESISTANCE OF CONCENTRICALLY AND ECCENTRICALLY LOADED HOLLOW MASONRY PRISMS

An experimental investigation of 198 hollow concrete block masonry prisms was conducted to assess the influence of web geometry on their response to either concentric loading using a test setup conforming to CSA S304 requirements or axially eccentric loading. Prisms were five courses tall and one block wide, constructed in running bond, and were either constructed using concrete masonry units with full height webs conforming to the requirements of CSA A165 or ASTM C90, or knock-out units meeting the normalized web area requirements in ASTM C90. The stress versus strain response for prisms constructed with any of the three concrete masonry unit geometries were consistent for each type of loading applied. Prisms constructed with concrete blocks with thicker webs experienced lower strain immediately prior to failure. Results also showed that web geometry influenced resistance to concentric loading but does not affect resistance to eccentric loading.