Evaluation of the Compressive Strength of Dry-Stack Concrete Masonry

The earliest forms of masonry construction were mortarless, utilizing tight-fitting stones bearing directly on one another to enclose space, provide security, or define boundaries. Yet, despite the historical precedent and broad applications of dry-stack masonry, contemporary construction and its supporting research have focused on masonry's mortared counterpart. To bring dry-stack masonry back into mainstream discussion, efforts are under way within the Masonry Society to compile relevant information and publish a new guide focused on the design and construction of dry-stack concrete masonry. As part of those efforts, knowledge gaps have been identified highlighting the need for additional research on or analysis of the performance of dry-stack masonry. One such topic lacking comprehensive data was the establishment of a correlation between the compressive strength of individual masonry units and the corresponding compressive strength of the dry-stack masonry assembly constructed of those units for design application. This research investigation was subsequently undertaken to build on available test data to refine this correlation, particularly at the low end of compressive strengths where data are lacking. Conclusions of this project support a dry-stack assembly compressive strength of 1,500 psi (10.3 MPa) when constructed of units having a minimum compressive strength of 2,000 psi (13.8 MPa).