Development of Pavement Design Procedures and Construction Specifications for Cold Central Plant Recycling (CCPR) Asphalt Mixtures

Status: Ongoing

Funding Agency: New Jersey Department of Transportation (NJDOT)

Abstract: 

The quantity of stockpiled Reclaimed Asphalt Pavement (RAP) is increasing annually in the United States, with New Jersey reporting one of the highest volumes according to a National Asphalt Pavement Association (NAPA) survey. This highlights the need for sustainable methods to utilize RAP materials instead of allowing them to accumulate in stockpiles or landfills. Cold Central Plant Recycling (CCPR) is a promising technology that enables the reuse of stockpiled RAP in pavement construction through stabilization with foamed or emulsified asphalt recycling agents. CCPR offers several advantages, including reduced greenhouse gas emissions, conservation of natural resources, and decreased environmental impacts. This study aimed to develop construction specifications and a structural design framework for pavements containing CCPR layers suitable for high traffic volume applications in New Jersey. A comprehensive literature review and interviews with Subject Matter Experts (SMEs) from transportation agencies including VDOT, MnDOT, PennDOT, and NYSDOT were conducted to gather information on current practices, materials, mixture design procedures, and construction methods. Based on these findings, draft construction specifications consistent with NJDOT standards were developed. Structural design procedures using both the AASHTO 93 method and AASHTOWare Pavement ME Design were also evaluated, and a CCPR pavement section recommended for Route 34 reconstruction was analyzed, demonstrating comparable performance to conventional pavement over a 50-year design life. Laboratory evaluation of CCPR mixtures using RAP collected from multiple New Jersey stockpiles was conducted in Phase II. Both foamed asphalt and emulsified asphalt stabilized mixtures satisfied specification requirements, with an optimum recycling agent content of approximately 3%. Phase III included the construction of full-scale test sections containing CCPR layers and a control section, followed by instrumentation and pre-testing measurements. Phase IV involves Accelerated Pavement Testing using Heavy Vehicle Simulator (HVS) loading to evaluate long-term pavement performance.

Principal Investigators: Dr. Yusuf Mehta, PhD., Dr. Ayman Ali, PhD., and Dr. Abhary Eleyedath, PhD.

Link to Publications: 

Eleyedath, A., Ali, A., and Mehta, Y. (2025). Cold Central Plant Recycling Mixtures for High-Volume Pavements: Material Design, Performance, and Design Implications. Materials, 18(14), 3345, https://doi.org/10.3390/ma18143345.