Author
DAVID M F ORR AND JOHN COSTELLOE, University College Cork

Abstract
A bond wrench apparatus has been developed for testing bed joints between solid concrete block masonry units. The apparatus has been used to obtain data for an investigation into the effect of the eccentricity at which the load is applied to the wrench on the indicated tensile bond strength. It is concluded that the tensile bond strength calculated from bond wrench tests on the basis of simple linear elastic distribution of stress, depends significantly upon the eccentricity at which the bond wrench load is applied and that lower strengths are given by shorter eccentricities.