A life cycle assessment model for pavement management: Road pavement construction and management in Portugal

Improving the sustainability of road pavements requires road agencies and construction companies to identify, by means of appropriate methodologies and tools, the priority areas of action. The life cycle assessment method has gradually become a versatile tool capable of informing decisions on resource and process selection to better understand, measure and reduce the environmental impacts of a system. This article presents the results of a study aimed at estimating and comparing the life cycle impacts of the flexible pavement structures defined in the Portuguese pavement design catalogue. The analysis assessed the functional units over a 40-year project analysis period (PAP), considering all pavement life cycle phases: extraction of raw materials and production; transportation of materials; construction, maintenance and rehabilitation; work zone traffic management; usage and end-of-life. The results of the case study showed that for the less demanding traffic classes the materials phase is the main contributor to the road pavement's overall life cycle environmental impact. However, if the road pavement is expected to carry significant volumes of traffic over its PAP, then the usage phase dominates the road pavement's overall environmental performance. The analysis also showed that, as expected, the foundation class impacts the environmental performance of the pavement under high traffic volumes. Stronger pavement foundations require thinner pavement, resulting in lower overall environmental burdens.