Long-term strength development and durability assessment of cement-stabilized carbonate-based aggregate quarry by-products: Potential role of hydrotalcite

Quarry by-products (QBs) are residual materials generated during aggregate quarrying operations. QBs present promising sustainable alternatives for use as pavement foundation layers. Carbonate aggregates account for a significant portion of crushed stone production in the United States, resulting in substantial quantities of QB materials. Among these, dolomitic QB materials stabilized with a small amount of cement have demonstrated superior performance in field tests compared to cement-stabilized limestone QBs. Although several studies have explored the improved strength of cement matrices containing dolomite compared to limestone, the findings remained inconclusive in explaining the performance differences. Addressing these inconsistencies, this study examines the effect of the mineralogical composition of carbonate aggregate QB materials —ranging from dolomite to limestone—on strength development and freeze–thaw durability in QB specimens stabilized with 3 % cement. The analysis revealed a strong correlation (R² = 0.98) between hydrotalcite formation and strength gain per fine fraction in cement-stabilized QB specimens subjected to long-term curing. Raman imaging confirmed that hydrotalcite forms near dolomite grains, refining the microstructure and contributing to strength development. Furthermore, the findings indicate that the enhanced strength of dolomitic QBs compared to limestone QBs is associated with improved freeze–thaw performance. This study highlights the potential utilization of surplus dolomitic QB materials in pavement geotechnical applications, offering a sustainable solution that leverages their mineralogical properties to enhance performance and consequently extend the service life of pavement foundations.