Influence of calcined laterite on the physico-mechanical, durability and microstructure characteristics of portland cement mortar

Most investigations in the literature concerning cement replacement with supplementary cementitious materials (SCMs) have predominantly focused on the utilization of fly ash and slag, which are not universally available. Laterite soil presents itself as a potential alternative to these commonly used SCMs, particularly where availability is an issue. Commonly found in tropical and subtropical regions, laterite soils have been extensively employed in building construction. Therefore, the present study aims to explore the incorporation of laterite soil calcined at 600 °C as a substitute for Portland cement (PC) in mortars, with the objective of producing sustainable construction materials. The effect of calcined laterite (CL) passing 75 μm sieves as 10, 30 and 50% replacement of Portland cement (PC) on the fresh and hardened properties of mortars was investigated. Mortars were cured at room temperature, and subjected to setting time, flowability, ASR, mechanical strength, porosity, water absorption, bulk density test along with scanning electron microscopy analysis at 28 days. The obtained result revealed the reduction in mechanical properties with the incorporation of CL up to 50 wt% compared to the reference sample only used OPC. As incorporation rates of calcined increased, the flow and setting times (initial and final) values decreased from 197 to 138 mm and 156 to 24 min and 341 to 77 min, respectively.