Abstract:Using reclaimed asphalt pavement (RAP) in pavement projects reduces the amount of virgin materials needed, averts the need to land-fill old materials, and reduces environmental impacts. The environmental and cost benefits of using RAP in asphalt mixes are dependent on multiple factors: the percent RAP content, the properties of the binder and aggregate in the RAP and content in RAP, the amount of virgin binder replacement with RAP binder, hauling distances from the original location to the mixing plant/site, and the amount and type of the rejuvenator that needs to be added. This paper conducted a sensitivity analysis of the changes in life cycle environmental impacts of hot mix asphalt due to different combinations of RAP content, rejuvenator type, and hauling distance. The analysis showed that long hauling distances reduces the environmental benefit of using RAP as measured by the reduction in global warming potential (GWP). For mixes containing 25 percent RAP with no rejuvenator and mixes containing 50 percent RAP with a soybean-derived rejuvenator, it was found out that a hauling distance of 114 miles and 159 miles, respectively, cancels out the reduction in GWP.

Note:Book is the Proccedings of the International Symposium on Pavement. Roadway, and Bridge Life Cycle Assessment 2020 (LCA 2020, Sacramento, CA, 3-6 June 2020)