Sustainable?Pavement?Design?Using?Recycled?Plastic?Waste?for? Enhanced?Mechanical?Performance?and?Reduced?Environmental? Footprint

Abstract

Mounting plastic pollution and shrinking virgin bitumen reserves spur interest in polymer-modified asphalt derived from post-consumer waste. This study formulates a design methodology blending shred-to-aggregate plastic at 6?%, 8?%, and 10?% by weight with 60?70 penetration grade bitumen. Laboratory tests—Marshall Stability, indirect tensile strength, four-point bending fatigue, and Hamburg wheel-tracking—are complemented by life-cycle assessment (LCA) following ISO 14?040. Results reveal that an 8?% plastic blend increases stability by 22?%, doubles fatigue life, and decreases rut depth by 47?% relative to control mixes. Cradle-to-gate LCA shows a 14?% reduction in global warming potential and a 19?% drop in cumulative energy demand due to virgin material substitution and avoided land filling. Field performance of a 1?km trial stretch is tracked for 24?months, indicating negligible stiffness degradation and no visible distress.