Road LCA: the dedicated ECORCE tool and database

Abstract

This paper presents a specific tool called “ECORCE” (French acronym for ECO-comparator applied to Road Construction and Maintenance) dedicated to the road pavement life cycle assessment. This tool aims to reduce the consumption of materials, water, and energy by means of evaluating impacts. The environmental assessment has been based on the LCA framework established by the SETAC and ISO 14040 series of standards, as well as by NFP 01010 for French products. The pavement life cycle is divided into the initial construction and maintenance operations. Several functional units can be defined in order to compare roads or road layers that have been designed to offer the same service. The system is built by selecting the processes to be considered during the impact assessment; this selection step relies on lists of main processes, such as road materials, road equipment, and material transport. The keys to building this tool were to specifically propose simple functionalities for road engineers and researchers, allow for quick case study implementation, and display a user-friendly interface. Moreover, the tool takes into account civil engineering practices and provides a set of dedicated data related to road materials, road works, and earthworks. ECORCE also allows easily changing input data (geometry, operations, materials, and transport distances); its output screens and tables offer several approaches to investigating environmental LCA results on roads. It becomes possible to compare not only the materials used in a given layer but also the pavement structures composed of several layers using various mixed materials. Lastly, the tool is able to assess initial construction and maintenance policies. Various road structures and their associated traffic conditions may be examined with ECORCE. Results obtained with the tool are detailed in the paper for a highway case study aimed at demonstrating its possible uses. These results highlight that the relative magnitude of impacts from each main process can be analyzed for road design optimization. The tool reveals that road pavement materials have more impact than other processes such as transport and non-road equipment running within the life cycle. The investigation of standard road practices can thus focus on various alternative materials and pavement structures, depending on the configurable functional units already implemented in the tool, as explained in this paper. The highway case study and accompanying sensitivity testing campaign serve to discuss the benefits of this tool.