Enhancing bond strength and characteristics of soil-cement block masonry

Soil-cement blocks are used for the load bearing masonry of 2-3-story buildings. Flexural and shear strength of such walls greatly depend upon the bond strength between the block and the mortar. This paper deals with the methods of improving the shear-bond strength of soil-cement block masonry (without altering the mortar characteristics) and the influence of shear-bond strength on masonry compressive strength. Altering the texture of bed faces of the block, size and area of the frog, and certain surface coatings have been attempted to enhance the shear-bond strength. The results indicate that: (1) rough textured bed face of the blocks yields higher shear-bond strength than the plain surface; (2) use of fresh cement-slurry coating on the bed faces improves the shear-bond strength considerably; (3) no significant changes are noticed in the compressive strength and stress-strain characteristics of soil-cement block masonry due to changes in shear-bond strength; and (4) masonry has a higher straining capacity than that of the block and the mortar.