Environmental life-cycle impacts of bitumen: Systematic review and new Canadian models
系统综述了2024年前沥青生命周期评估文献，构建了加拿大市场模型，发现碳足迹被低估（826-1098 kgCO2 eq/t），原油开采和运输是主要贡献者，呼吁开发高质量清单以支撑绿色路面实践。
• Bitumen LCAs globally lack consistency, high-quality data, and sometimes transparency. • Their GWP are likely underestimated: new Canadian models range 826–1098 kgCO 2 eq/t. • Crude oil is a major contributor, fugitive emissions may raise the GWP to 2680 kgCO 2 eq/t. • Transport impacts vary highly (18–290 kgCO 2 eq/t in Canada): models must be tailored. • Robustly recommend LCA-based pavement green practices requires high-quality bitumen LCIs. Bitumen − or asphalt binder − is a major contributor to pavement environmental impacts. Nevertheless, the literature only counts scarce asphalt binder LCAs, with highly variable results. To better understand bitumen environmental impacts, we review LCAs published before 2024. Then, we build bitumen LCA models for different Canadian markets, using TRACI 2.1 and ecoinvent v3.6. The carbon footprint of Canadian asphalt binders ranges within [826–1098] kgCO 2 eq/t (potentially up to 2680 kgCO 2 eq/t when including fugitive emissions). Crude oil extraction is the main contributor to most life cycle environmental impact categories, but likely still underestimated. Transportation impacts can vary highly ([18–291] kgCO 2 eq/t in Canada). Models for these two hotspots must be tailored. Finally, we critically compare the carbon footprints of all published virgin asphalt binders LCAs: previous carbon footprints range within [143–637] kgCO 2 eq/t and are very likely underestimated. Previous pavement LCA results must be questioned, and higher-quality LCIs urgently developed to produce robust regionalized LCA-based recommendations on pavement green practices.