Marble Waste as a Sustainable Sand Substitute in Mortar: Investigating Mechanical and Durability Performances

Increased marble consumption in construction depletes natural resources and generates significant waste. Utilizing this waste as an aggregate replacement conserves material and protects the environment. To address these issues, efforts have been made to use marble waste sand (MS) as an alternative to natural sand (NS) to study its impact on designed mortar by testing the mechanical performance, thermal conductivity, and acid resistance. Six mixes were prepared by replacing NS with MS at intervals of 20% (0–100%). Experimental results indicated an enhancement in strength properties as the percentage of MS replacement increased up to 100% compared to the control mortar. Thermal conductivity increased slightly with a higher MS percentage, correlating with an increase in hardened density and a reduction in porosity due to densification of the mortar. The specimens exhibited enhanced chemical resistance when exposed to sulphate solution and showed reduced damage from sulfuric acid exposure compared to NS mortar. The findings suggest that a 60% replacement of MS is optimal across all conducted tests, indicating that incorporating marble waste can enhance the mechanical and durability performance of mortar, making it a viable, sustainable construction material, which is one of the pillars of Vision Oman 2040.