Pilot Study in Florida: Rejuvenator Application for 100% RAP in Cold Mix Asphalt

Abstract: As sustainable road construction increasingly addresses environmental challenges, utilizing 100% reclaimed asphalt pavement (RAP) cold mix with a rejuvenator presents a viable and cost-effective solution by reducing the use of virgin materials and energy while minimizing ecological impacts. Collaborating with industry, local government, and academia, this pilot study investigates the performance of 100% RAP cold mix asphalt combined with a bio-based rejuvenator for a low-volume road in Walton County, Florida. The study was divided into two phases: (1) determining the optimal dosage of the rejuvenator for 100% RAP cold mix asphalt, using cracking, rutting, and durability testing; various moisture contents of RAP were also considered at the optimal rejuvenator dosage; (2) constructing an overlay project using this dosage. Results indicated that a dosage of up to 0.75% rejuvenator consistently delivered balanced performance across key metrics, although higher moisture content reduced air voids and rutting resistance. Field construction on a 600-foot section of Sea Oats Road demonstrated how to best incorporate blending rejuvenator into RAP, as well as the appropriate field compaction efforts. Field surveys were also conducted to monitor performance. Initial findings suggest that 100% RAP cold mix asphalt with a rejuvenator is a promising option for low-volume roads in warm coastal regions.