Reducing the environmental impacts associated with road infrastructure is a key challenge in the transition toward more sustainable construction practices. Asphalt pavements, due to their extensive material use and energy demand over long service periods, offer significant opportunities for improvement through innovative materials and production technologies. This study evaluates the environmental performance of an asphalt pavement incorporating recycled tire crumb rubber and a warm mix asphalt additive (CR + WMA) in comparison with a conventional hot mix asphalt (HMA) pavement. A comprehensive cradle-to-grave life cycle assessment (LCA) was conducted in accordance with ISO 14040/44 standards, encompassing material production, construction, maintenance, and end-of-life stages. Different pavement service life scenarios were considered, and environmental impacts were quantified using sixteen midpoint categories of the environmental footprint (EF) 2.0 method. To enable a consistent comparison between pavement alternatives with different durability, results were normalized using a functional unit of 1 m2·year. The results show that the CR + WMA pavement consistently exhibits lower environmental impacts than the conventional HMA pavement across all impact categories. When identical service lives are assumed, impact reductions are primarily associated with lower production temperatures, partial substitution of virgin bitumen with recycled crumb rubber, reduced maintenance needs, and the normalization of life cycle impacts when results are expressed per m2·year. Overall, the CR + WMA pavement reduces life cycle environmental impacts by approximately 45%–60% across all EF midpoint categories compared to the conventional HMA pavement, depending on the impact category and service life scenario considered. These findings demonstrate the importance of explicitly accounting for service life and maintenance in pavement LCAs and highlight the potential of CR + WMA technology to reduce the life cycle environmental footprint of asphalt pavements, supporting more informed infrastructure design decisions and the development of more sustainable road pavement solutions.
Rodríguez-Alloza et al. (Wed,) studied this question.