Life-cycle sustainability assessment of pavement maintenance alternatives: Methodology and case study

Modeling life-cycle sustainability assessment (LCSA) for pavement alternatives is still in infant stage. This paper proposes a comprehensive pavement LCSA methodology that integrated life-cycle cost analysis (CLCA), environmental life-cycle assessment (E-LCA), and social life-cycle assessment (S-LCA). A four-step structure was developed for the proposed methodology, including system definition, modeling, unifying, and interpretation. First, the goal and scope were defined and pavement alternatives were identified during the four main life-cycle phases, including raw materials and production, construction, use, and maintenance. Second, pavement C-LCA, E-LCA, and S-LCA were measured in the modeling process, where the foreground project and background inventory data were collected, and the various impact assessment models were proposed. Third, a multi-criteria decision-making model was applied to unify the three sustainability dimensions, and select the appropriated sustainable pavement alternative. Finally, the results were discussed and highlighted in interpretation step, and a sensitivity analysis on weights was carried out. A case study was applied to illustrate the proposed methodology, including thin hot mix asphalt concrete layer (THMACO), hot mix asphalt with warm mix additive Sasobit (HMAW), and hot mix asphalt with reclaimed asphalt pavement (HMAR) in Southeast of China. The results show that the recycling-based HMAR contributed the best economic and social performance, while HMAW achieved the best environmental performance. A combined AHP-VIKOR model was applied, and HMAR was selected as the optimal alternative. In addition, a sensitivity analysis on weights was conducted using 21 cases. (C) 2018 Elsevier Ltd. All rights reserved.