Michel Dauvergne

Road LCA: the dedicated ECORCE tool and database

PurposeThis 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.MethodsThe 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.Results and discussionIt 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.ConclusionsThe 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.

Environmental and mechanical evaluation of warm mix asphalts in laboratory and on site

Warm asphalt mixes made with ready to use binders or with other types of technology like bitumen foam are commonly used in France and elsewhere. In order to develop knowledge on the different technologies, an experimental trial has been organized in September 2013 in partnership between TOTAL Marketing Services, Eiffage TP and Ifsttar. The purpose of the test was to carry out environmental assessment of the warm mixes comparatively to traditional hot mixes. 4 sections have been realized (hot mix asphalt, warm mix asphalt with respectively ready to use binder, foam, and combination of foam and ready to use binder). The asphalt plant had been equipped in order to record energy consumption and to monitor the chimney emissions. On average the different warm mix technologies lead to savings on energy consumption and on greenhouse effect gases. Extensive asphalt quality data like for example voids contents and macrotexture have also been recorded during the trial. Stiffness tests have also been carried out on cores. Performances of warm mixes are equivalent to the ones obtained with hot mix. A follow-up of the test is planned.