Long-Term Performance of Pavement with High Recycled Asphalt Content

This paper summarizes the findings of several case studies on the long-term performance of recycled asphalt pavement (RAP). The goal of these studies was to provide the paving community with documentation on the long-term performance of roadway sections with a high amount of RAP compared with virgin sections on the basis of available information. Roadway sections that contained more than 20% RAP and that had been in place for at least 10 years were identified across the United States with the help of local agencies. The long-term performances of these various recycled sections were compared directly with mixtures made with similar virgin materials via measurements of distress criteria. These distress criteria included rutting, cracking, ride quality, and any overall performance rating that the local agencies used to evaluate their pavement sections. The virgin sections were placed in the same general location and time frame as the recycled sections. The sections with high RAP content, on average, tended to exhibit a lower ride quality, more cracking, and better rutting resistance than the virgin sections, but the differences were not always statistically significant. The differences between the performance ratings for RAP and virgin pavements were within 5% to 10%. Overall, pavement sections with a high RAP content performed at a level comparable to that of virgin sections in these case studies.