Sustainable utilization of iron ore tailings as an alternative material in asphalt pavements: A systematic review

Using iron ore tailings (IOT) in asphalt pavement construction enables large-scale utilization of industrial solid waste, conserves non-renewable resources, and reduces carbon emissions. However, the unique physicochemical properties and low pozzolanic activity of IOT pose challenges to its effective application. This review categorizes IOT according to particle size distribution and summarizes the performance and underlying mechanisms in both cementitious systems and asphalt mixtures. The performance of cement-stabilized IOT materials and corresponding improvement strategies are reviewed, alongside the hydration mechanisms and related property developments of IOT-based cementitious materials. Finally, the advantages and limitations of asphalt mixtures containing IOT are discussed, highlighting implications for waste utilization and low-carbon pavement construction. Insufficient early-age strength of cement-stabilized IOT can be effectively improved by slag incorporation, which promotes hydration while reducing overall costs compared to external additives and fiber addition. The low pozzolanic reactivity of IOT, particularly those with high iron content, remains a major limitation for cementitious materials. Activation methods should be adapted to material properties, yet standardized procedures are lacking. Optimizing activation methods and raw material proportions based on hydration progress and pore structure is essential for enhancing the performance of IOT-based cementitious materials. In asphalt mixtures, the acidic surface of IOT reduces adhesion, but the use of anti-stripping agents or alkaline additives can effectively improve low-temperature cracking resistance. Addressing these challenges in activation and interfacial bonding is critical to advancing the application of IOT-based materials in sustainable, low-carbon road engineering. • The use of iron ore tailings (IOT) in road construction is reviewed. • The physicochemical properties of IOT and its performance in cement-based and asphalt-based systems are systematically analyzed. • Key challenges limiting the large-scale utilization of IOT are identified. • Strategies for enhancing the performance of IOT-based road materials are proposed.