Sustainable Utilization of Granite Waste for Improving the Mechanical Properties of Fired Clay Bricks

Objectives In this work, the utilization of granite waste from the Shada Mountain area in Saudi Arabia as an additive to enhance the mechanical and microstructural properties of clay bricks. Material and Methods Clay and granite mixtures containing 0, 15, 30, and 45 wt% of granite were prepared, shaped, and fired at 900 -1000°C. The physicochemical and microstructural features were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM) analysis. Results An evaluation of the ceramic characteristics of the bricks indicates that increasing the granite content decreased the linear shrinkage, water absorption, and apparent porosity, while enhancing the bulk density. At 1000°C, the compressive strength significantly increased for compositions containing up to 30 wt% granite due to enhanced vitrification and densification of the ceramic matrix. Microstructural analysis suggests that granite particles act as stable inclusions and could potentially serve as nucleation sites, which may contribute to the formation of a compact ceramic matrix. However, excessive granite content (45 wt%) led to a reduction in mechanical strength due to insufficient clay bonding phases. Conclusion The results demonstrate that granite waste can be effectively utilized as an effective fluxing agent in clay brick production, improving performance while reducing reliance on natural clay resources.