Design-based life cycle assessment of flexible pavements to evaluate embodied carbon footprint

Material-intensive infrastructure systems, such as flexible pavements, offer significant opportunities for reducing resource consumption and associated life-cycle environmental impacts through design-level interventions. This study integrates structural performance metrics, specifically modulus improvement factor (MIF), into life cycle assessment (LCA) decision-making for pavements. The life cycle carbon emissions of conventional and sustainably reinforced pavements were evaluated. Besides, the inclusion of acidification potential and abiotic fossil resource depletion was evaluated for pavement at the material stage. Further, sensitivity analysis and field verification were performed. Results reveal that material production and manufacturing contribute more than half of total emissions, while transportation contributes to one-third, with the least at the construction stage. A carbon emission reduction factor (CERF) was formulated to compare reinforced and unreinforced materials, demonstrating that geogrid inclusion reduces embodied carbon across all subgrade conditions. The proposed LCA framework demonstrates a practical pathway for structural benefits along with sustainability evaluation into pavement design.