Life-cycle assessment of road pavements containing marginal materials: Comparative analysis based on a real case study

The Life-Cycle Assessment (LCA) is a standardized procedure generally used, in Italy, in industrial engineering to evaluate the economic-environmental efficiency of production processes. LCA is aimed at optimizing the design, with special emphasis on environmental sustainability. Also in the construction sector, LCA has recently gained a fundamental role as a quantitative measurement tool able to take into account correctly the environmental and economic benefits achievable adopting different alternatives (most of them uncommon) based on the entire service life, maintenance and end-of-life procedures included. As far as pavement engineering is concerned, the use of marginal materials (such as, for example, reclaimed asphalt pavement, crumb rubber, slags, etc.) is becoming of strategic importance due to the decreasing availability of virgin natural resources and the consequent increasing public consciousness addressed to environmental protection and preservation. In this regard, the LCA applied to road pavements constructed using marginal aggregates probably represents the only effective tool able to evidence the crucial aspects on which the design choices should be based, taking also into account long-term parameters. Given this background, the present research illustrates one real case study of LCA analysis applied to asphalt pavements of a motorway. The use of industrial by-products (i.e. steel slags) instead of natural mineral aggregates is considered. Comparative evaluation of different scenarios has been carried out using specifically developed spreadsheets. The research study demonstrates that LCA is able to highlight potentialities and issues related to the different analyzed scenarios, representing a valid tool for designers and decision-makers. Moreover, the obtained results contribute to enlarge the worldwide database about the implementation of LCA for pavements.