A. SISE, N. G, SHRIVE and E. L. JESSOP University of Calgary

Bivariate tests have often been used to assess the effect of various parameters on bond strength. On site many parameters vary simultaneously and there is no substantive evidence to show which unit, mortar and masonry properties are the most important. Tests were performed to determine the effect of these on bond strength. The results of bivariate tests were similar to those observed previously by others. A multivariate test revealed that joint thickness was the most important characteristic. Thinner joints provide higher bond strengths. Of the unit properties, porosity and pore size distribution could be important.