Tensile Bond Strength of Soil-Cement Block Masonry Couplets Using Cement-Soil Mortars

Abstract

Soil-cement blocks and cement-soil mortars are used for the load bearing masonry. The paper deals with the scantily explored area of tensile bond strength of soil-cement block masonry using cement-soil mortars. Influence of initial moisture content of the block and block characteristics (strength, cement content, and surface characteristics) as well as composition and workability of cement-soil mortar on direct tensile strength of masonry couplets has been explored. Major findings of this study are (1) initial moisture content of the block at the time of construction affects bond strength and use of partially saturated blocks is better than dry or fully saturated blocks; (2) as the cement content of the block increases, its strength increases, and surface pore size decreases leading to higher bond strength irrespective of the type of mortar; (3) cement-soil mortar gives 15–50% more bond strength when compared to cement mortar and cement-lime mortar; and (4) bond strength of cement-soil mortar decreases with increase in clay content of the mortar. The study clearly demonstrates the superiority of cement-soil mortar over other conventional mortar such as cement mortar. The results of this paper can be conveniently used to select a proportion for cement-soil mortar for soil-cement block masonry structures.