Danish Technological Institut


Based on a bibliographic study the paper will deal with different aspects of bond strength. The bond strength is defined as the effect of mortar developing a tensile and shear resistance at the contact surface of masonry units. The bond strength is depending upon the mortar composition, the grain size distribution of the aggregate, the type of binders and the use of admixtures and additions. It is also depending upon the type masonry units, the suction behaviour and the smoothness of the units.
As there is a correlation between the bond strength and the cohesion between mortar and masonry units the bond strength will influence the shear strength of the masonry. There is also a correlation between the bond strength and the flexural strength of the masonry. The size of a masonry panel subjected to lateral loading is of that reason depending on the bond strength. The study has also shown, that masonry build with mortars with a low bond strength has a higher water penetration subjected to wind driven rain compared to masonry build with mortars with a good bond.

Key words
Bond strength, Grain size distribution, Water retentivity, Clay content, Air content, Water penetration