Environmental Trade-offs of Different Reclaimed Asphalt Pavement Recycling Strategies for the City of São Paulo, Brazil

Different destination scenarios can be considered to the end-of-life waste materials such as reclaimed asphalt pavement (RAP). In São Paulo city, Brazil, the current practice consists of downcycling the RAP into soil aggregate mix, which can be applied in base layer or into cold asphalt mixture to be applied as base layer in pavement rehabilitation and construction across the city. This study aims to assess the environmental trade-offs of RAP recycling strategies based on the RAP amount available annually. Three different scenarios were evaluated considering the two downcycling strategies currently adopted by the city administration and a third alternative of RAP recycling that has not been in use so far. For the environmental analysis, life cycle stages of raw material production, material transportation, and asphalt mixing were considered. The global warming potential (GWP) is expressed in t CO2 equivalent for each destination scenario. The results of the recycling and downcycling scenarios are compared, showing that RAP recycling can improve the environmental performance of pavement maintenance and construction strategies. If a higher amount of RAP would be available and higher shares of RAP in the asphalt mixture would be considered, the difference between the recycling scenarios could be more pronounced.