* Professor and Martini, Mascarin and George Chair in Masonry Design,Dept. of Civil Eng., McMaster Univ., Hamilton, ON, L8S 4L7 Canada.E-mail:** Post-doctoral Fellow, Dept. of Civil Eng., McMaster Univ.,Hamilton, ON, L8S 4L7 Canada.On leave, Structural Eng. Dept., Ain Shams University, Cairo, Egypt.E-mail:*** Deceased, Ph.D. graduate, Dept. of Civil Eng., McMaster Univ.,Hamilton, ON, L8S 4L7 Canada

Eighty-seven assemblies were tested to investigate the inplane behaviour of grouted concrete masonry under different combinations of shear, compression and tension loading. In these tests, stresses are explicitly defined without the need to adopt any assumption of isotropic or elastic behaviour. Thus, these tests are shown to be suited to the study of the anisotropic characteristics of masonry. The variables considered include the bed joint orientation, the grout continuity and the stress levels. Modes of failure, strength, and stress-strain relationships were found to depend on the bed-joint orientation. The degree of anisotropy varied depending on the continuity of the grout normal and parallel to the bed joints. The tests showed that using blocks with knocked-out webs, resulting in continuous grout both normal and parallel to bed joints, helps reduce the anisotropic characteristics of masonry. Within a range of low compressive stresses, the relationship between the shear strength and the compressive stress was found to be almost linear, and can be predicted by linear superposition of the shear capacities of the grout and mortar components across the joint.
Key words
Anisotropy; Compression; Concrete block; Grout;