Sustainability comparison between pavements with conventional and recycled hot mix asphalt

Abstract

The conscience that the world resources are not unlimited has led to the implementation of more sustainable practices. Taking into consideration that road pavements are infrastructures that cause significant environmental impacts during their construction, operation and rehabilitation stages, it is essential to search for new techniques and processes for the mitigation of these consequences, which are analyzed using life cycle assessment (LCA) tools. The fundamental objective of any LCA methodology is to evaluate a product or service throughout its life, considering the direct and indirect impacts. Although this seems a simple concept, its application becomes more complicated due to lack of understanding of the system under study and the difficulty of obtaining relevant data. This paper presents the findings of a study using a methodology of life cycle assessment that has been developed and used to compare the sustainability of two pavement structures, more specifically a conventional flexible pavement and a pavement that incorporates reclaimed asphalt pavement (RAP) material. In addition to the benefits of reusing the RAP material, namely the waste minimization and the lower need of virgin aggregates, the results indicate the existence of other environmental benefits such as reduced energy consumption and emissions, including the greenhouse gas emissions, having thus a lower global warming potential (GWP) compared with the conventional solution.