Physical, Mechanical, and Microstructural Performance of Soil–Cement Bricks with Mineral and Ceramic Waste

The reuse of industrial residues in construction materials is a key strategy for promoting sustainability and reducing natural resource consumption. This study evaluated the physical, mechanical, and microstructural performance of soil–cement bricks produced with iron ore tailings, red ceramic waste, and crushed sand. The soil was previously corrected with crushed sand to optimize particle size distribution. Bricks were produced with 10% cement by mass, varying the proportion of residues, and cured for 7 and 28 days. Physical properties (water absorption), mechanical performance (compressive strength), durability (wetting–drying cycles), and microstructural characteristics (X-ray diffraction) were assessed. Results indicate that the incorporation of iron ore tailings and ceramic waste improves matrix densification, reduces water absorption, and enhances compressive strength. Small additions of residues minimized mass loss during durability tests. Microstructural analysis revealed that quartz, feldspars, kaolinite, hematite, mullite, and cristobalite interact with cement hydration products, contributing to performance gains through filler effect, structural stiffness, and efficient particle packing. The findings demonstrate the technical feasibility of producing eco-efficient soil–cement bricks using these residues, providing environmental benefits and meeting Brazilian standards for strength and durability. Future work should explore long-term durability, pilot-scale production, and detailed microstructural investigations.