The prediction of compressive strength of ungrouted hollow concrete block masonry

• A large database of compressive test results on ungrouted masonry was assembled from literature.
• Collected data was used to develop a formula to predict compressive strength of ungrouted masonry.
• Predictive ability of the proposed formula was compared to those of international masonry codes.
• This research effort can enhance the economic competitiveness of masonry as a choice for engineers.

The objective of this paper is to develop a simple and accurate empirical formula to predict the compressive strength of ungrouted hollow concrete block masonry fm′. A large database of compressive test results on masonry prisms reported in the literature was assembled and analyzed for this purpose. The collected database was also utilized to evaluate the predictive capability of the proposed model compared to those of major international masonry design codes. The study showed that the masonry codes underestimate the compressive strength of ungrouted masonry with high coefficients of variation, whereas the proposed formula gives the most accurate prediction of compressive strength with the least variation. The research also highlights the necessity for improving the prediction of compressive strength of concrete masonry by masonry design codes.