Recycling industrial tailings sands for transportation infrastructure: A review of sustainable approaches

Tailings sand (TS) is a globally abundant industrial by-product; however, its widespread underutilization results in resource waste and environmental burdens. As natural sand resources are increasingly depleted, sustainable recycling of TS has drawn growing interest, particularly in transportation geotechnical engineering. This review systematically examines the physical, chemical, and geotechnical characteristics of TS and employs CiteSpace software to analyze recent research trends and emerging hotspots. Current engineering applications of TS mainly include road base construction, subgrade improvement, and the development of geopolymer binders. When used in conjunction with stabilizers such as cement, lime, or alkaline activators, and further blended with industrial by-products like fly ash or rubber, TS significantly improves the mechanical performance, durability, and long-term stability of geomaterials. These hybrid approaches not only lower construction costs but also promote environmental sustainability by diverting waste from landfills and reducing the carbon footprint of conventional materials. The review also assesses the practical feasibility of TS through engineering case studies. Key future research directions are identified, including performance optimization, large-scale field application, durability assessment, and life-cycle sustainability analysis. Overall, TS demonstrates strong potential as a sustainable substitute for natural sand in transportation infrastructure, delivering both economic and ecological benefits. This study provides updated insights into industrial waste valorization and supports the transition toward more environmentally responsible geotechnical practices.