Comparative Life Cycle Assessment of Structural Filling Materials for Sustainable Roads

Mine tailings are solid wastes after a valuable fraction of the ore gets extracted. This study aims to explore the possibility of using iron tailing waste in the development of road subgrade and its environmental implications. The study uses the Life Cycle Assessment (LCA) methodology to quantify and compare the environmental impacts generated by the conventional sand subgrade and tailing subgrade for a 1 km stretch of road with a width of 8 meters. The study also conducted a sensitivity analysis to show the impact of transportation distance on the environmental impacts of iron tailing using the Monte Carlo Simulation technique. The study has used six midpoint impact assessment categories, namely climate change, water depletion, fossil depletion, freshwater eutrophication, terrestrial acidification, and marine ecotoxicity, to show the comparative environmental impacts and sensitivity analysis. The study results indicate that road subgrades developed by iron tailing waste are more environmentally beneficial than sand subgrades. The sensitivity analysis results indicate that tailing transportation reduces the environmental benefits if transported over long distances, but still, the utilization is helpful for environmental sustainability. The study is a novel contribution highlighting the sequestration potential of iron tailing waste utilization using the midpoint environmental impact categories.