Performance Evaluation of Cement Mortars Using Iron Ore Tailings as Natural Sand Replacement

The rapid pace of urbanisation has led to a significant rise in the annual production of iron, resulting in the generation of tons of iron ore tailings (IOT). These IOT are typically disposed of in landfills or stored in tailings dams, causing threats to the environment and the ecosystem. This study investigates the utilisation of IOT as a natural sand replacement in mortar mixes, to conserve natural resources. Mortar mixes with the replacement ratios of 0%, 10%, 20%, 30%, 40%, 50%, and 60% were prepared with a water-to-cement ratio of 0.4. Flowability, compressive strength, flexural strength, and water absorption were evaluated for mixes containing different ratios of IOT. The experimental results revealed that the increase in the content of IOT causes a decrease in the flowability of mortars. Moreover, as the IOT ratio increased, the strength showed an increase up to 20% replacement, then decreased for the ratios 20% to 60%. Water absorption results indicated an improvement in the durability of IOT mixes due to their filler effect. The incorporation of IOT as partial natural sand replacement in mortar mixes represents a sustainable construction practice that minimises its environmental impacts and reduces the ongoing depletion of natural resources.