Using Rejuvenating Agents to Improve Hot Mix Asphalt Performance Incorporating Reclaimed Asphalt Pavement (RAP)

摘要

Reclaimed Asphalt Pavement (RAP) continues to be the most recycled product in America. In 2018, the National Asphalt Pavement Association (NAPA) determined that 82.2 million tons of RAP was reused in new Hot Mix Asphalt (HMA). The average RAP content was 21 percent, which is similar to estimates in Canada where 15 to 20 percent of RAP is typically reused. However, the same survey highlighted that in 2018 approximately 110 million tons of RAP was left unused in stockpiles, which is problematic from a sustainability perspective. Properly engineered asphalt mixtures incorporating RAP have been shown to perform as well as virgin HMA. Rejuvenating agents such as organic compounds generated from petroleum processing have been utilized to achieve the desired quality while ongoing evaluation of newer recycling agents such as waste or vegetable oil derivatives shows considerable promise. The focus of this paper is to provide a better understanding of how to engineer and produce mixtures containing various proportions of RAP (and potentially Reclaimed Asphalt Shingles, RAS) while improving cracking performance. The development of a potential framework for the use of rejuvenating agents is presented along with a discussion on the proper design and production of durable quality mixtures using RAP.