Mechanical Properties of Low Plasticity Clay Soil Stabilized with Iron Ore Mine Tailing and Portland Cement

Due to the economic and environmental issues, utilization of mineral wastes, e.g. iron ore mine tailing (IOMT), as road materials can be recommended as a sustainable alternative. In the present work, the mechanical properties as well as the resistance to freezing and thawing (F-T) cycles of low plasticity clay soil stabilized with different percentages of Portland cement (0%, 6%, 9%, 12%, and 15%) and different percentages of IOMT content (0%, 10%, 20%, 30 %, and 40%) are investigated. To this end, the unconfined compressive strength (UCS), initial elastic modulus (E0), and indirect tensile strength (ITS) at different curing times of 7, 14, 18, and 56 days for different admixtures are determined to select the optimum mix design for stabilization of clayey subgrade soil. This work shows that with increase in the percentage of cement, the strength parameters such as UCS, E0, and ITS increase, while increasing IOMT does not show a specific trend to increase the strength parameters. Evaluation of the strength parameters at different curing times shows that in the short-term curing times (7 and 14 days), the iron ore mine tailing has a positive effect on the strength parameters, while in the long-term curing times (28 and 56 days), the iron ore mine tailing has a negative effect on the strength parameters. In total, it was found that 12% of the Portland cement and 10-40% of IOMT passes the UCS and F-T criteria for stabilization of low plasticity clay soils, while clay soil (without IOMT) requires at least 15% of Portland cement for stabilization.