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There is a scarcity of natural river sand due to the ban on mining of sand from riverbeds, attributed to environmental and ecological issues. Therefore, there are attempts to use nonorganic solid wastes and industrial by-products as sand substitutes. The paper reports experimental studies on the suitability of processed granulated blast furnace slag (PGBS) as fine aggregate in the mortars used in masonry construction. The physical and chemical characteristics of the PGBS and the properties of mortars made with PGBS, such as workability, compressive strength, water retentivity, drying shrinkage, and elastic properties, were examined. The masonry properties such as compressive strength, flexure bond strength, and stress-strain characteristics were investigated using PGBS- and sand-based mortars. The investigations show that PGBS can be a potential substitute to river sand in the masonry application. The addition of PGBS was beneficial in terms of mortar and masonry characteristics. In the case of lean mortars, the addition of PGBS showed 30% to 45% spike in compressive strength. Thermogravimetry was used to quantify hydration products formed in PGBS-based and river sand–based mortars. The experimental outcomes indicate that (1) the physical and chemical properties of PGBS were similar to those of river sand except that the PGBS may show mild pozzolanic activity and higher water absorption; and (2) the masonry compressive strength increased by ∼22% , and the flexure bond strength nearly doubled when PGBS-based mortars were used. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]