A life cycle scenario analysis of different pavement technologies for urban roads.

In the past, lowest price was the award criterion, given that structural capacity and safety were assured. In the last years, environmental, energy, and long-term impacts have been introduced (climate change, resource depletion, energy consumption, generated solid waste, discharged water, and emissions). Unfortunately, the introduction of new pavement technologies and materials (i.e., waste plastics) affects maintenance and rehabilitation processes and call for accurate and timeliness studies and criteria. Consequently, this paper presents an energy and environmental assessment of an Italian urban road and considers different material-related scenarios that fully comply with emerging technologies. A life-cycle approach is applied to assess energy and environmental impacts of a typical Italian urban road, according to the ISO 14040 series. In more detail, the authors assess the energy and environmental profile of different scenarios of bituminous mixtures. The aim of scenario analysis is to identify the less impacting scenario from an energy and environmental point of view. For each analyzed scenario, the contribution of each life-cycle step to the total impacts and the energy and environmental hotspots are identified in order to define suitable options for improvement. The results of the analysis show that step of material production, including raw material extraction and resource supply, is relevant to almost all the assessed impact categories (average contribution higher than 50%). This is mainly due to the production of bitumen, which is a petroleum-based product. Moreover, the scenario analysis highlights that the pavement scenarios that are characterized by the use of recycled materials involve lower energy and environmental impacts, due to the saving of virgin raw materials and avoided impacts for disposal.