Utilization of Stone Quarry Sludge in the Development of Environmentally Friendly High-Strength Concrete

This study explores a sustainable strategy for enhancing high-strength concrete (HSC) by partially replacing natural fine aggregates with stone quarry sludge (SQS), a byproduct of quarrying operations. The aim is to promote environmental conservation and waste valorization while maintaining or improving concrete performance. Concrete mixes were prepared by substituting fine sand with SQS at incremental levels of 10%, 20%, 30%, 40%, and 50%. Mechanical properties were assessed through specific weight measurements, compressive strength tests, and three-point bending evaluations. FTIR analysis was conducted to investigate microstructural changes, and a carbon footprint assessment was performed to quantify environmental benefits. The mix containing 20% SQS exhibited optimal performance, achieving a compressive strength of 61 MPa and a bending strength of 5.1 MPa. FTIR results confirmed enhanced C–S–H gel formation, indicating improved microstructural integrity. Carbon footprint analysis revealed that moderate SQS substitution significantly reduces embodied carbon. These findings support the use of quarry sludge as a viable component in eco-friendly HSC, with potential for further optimization and long-term durability studies.