From Waste to Resource: Evaluation of the Technical and Environmental Performance of Concrete Blocks Made from Iron Ore Tailings

Abstract

This study investigates the use of iron ore tailings (IOTs) as recycled aggregates in segmental blocks, focusing on technical performance, CO2 emissions, and embodied energy using the cradle-to-gate approach. IOTs replaced fine aggregates in concrete at 25%, 50%, and 75% by volume, achieving compressive strengths of 16.23 MPa, 10.02 MPa, and 3.93 MPa, respectively. Raw material production accounted for 98% of CO2 emissions and 86% of embodied energy. Producing blocks at mining sites offered limited environmental benefits due to longer transport distances. Despite this, the results showed a 6% reduction in CO2 emissions and a 35% improvement in mechanical–environmental performance (CO2 emissions weighted by compressive strength) compared to traditional concrete. These findings underscore the potential of IOT-based concrete for segmental block production.