Environmental assessment of road construction and maintenance policies using LCA

This paper proposes an evaluation of pavement maintenance policies relative to their initial construction, through a Life Cycle Assessment (LCA) and in accordance with the framework established by the Society of Environmental Toxicology and Chemistry as well as in the ISO 14040 Standard. The respective influence of initial construction and maintenance operations is investigated for both asphalt concrete and cement concrete pavement structures. Several case studies are analysed using a specific method and tool, called ECORCE (French acronym for “ECO-comparator applied to Road Construction and Maintenance”), dedicated to road pavement LCA. ECORCE takes into account the materials production, mixing and laying processes, in addition to their transport between the production site and the jobsite. This environmental assessment is based on the principles underlying the life cycle assessment methodology. The chosen Functional Unit only considers the service to road users; heavily-trafficked French motorway structures are thus described over a 30-year service period. A set of overall indicators, consisting of raw material and energy consumption, global warming potential and eutrophication potential, is then calculated for two case studies. These environmental indicators highlight the ability to assess pavement designs along with two maintenance policies considered for each case studied. Results are thus able to expose the relative influence of maintenance (1/3 of the entire life cycle). In conclusion, environmental design principles to achieve a reduction in environmental loads are discussed in considering the entire road life cycle.