Life cycle assessment of open-graded cement-stabilised macadam mixes: a comparative analysis

Conventional open-graded cement-stabilised macadam (OGCSM) layers consume both virgin aggregates and cement, leading to several environmental issues. Utilising recycled and cementitious materials in OGCSM has been instrumental in addressing these concerns. Even though the available literature on bound layers highlights sustainable aspects by incorporating alternative materials, research quantifying the sustainability of OGCSM through life cycle assessments (LCA) is limited. For the present study, comparative LCA was conducted using LCAPave tool developed by Federal Highway Administration to quantify and assess the environmental impacts of selected alternatives for the chosen functional unit and system boundary. The contribution analyses of energy and impacts were carried out for the life cycle stages and processes. The results indicated reductions of 15%–30% in renewable and non-renewable energy, smog formation, acidification, and global warming for alternative 5 than conventional OGCSM. For alternative 5, disposed non-hazardous waste, eutrophication, and ozone depletion were reduced by 45%–60% and a reduction of 70% was observed for disposed hazardous waste compared to conventional OGCSM. Alternative 5 has the best environmental friendly potential among the alternatives.