High Reclaimed Asphalt Pavement (RAP) Asphalt Mixes for Low Volume Roads

US Transportation Collection2018PDFTech ReportArambula-Mercado, EdithChavarro-Munoz, Santiago J.Hu, ShengEpps, Jon A.Park, Eun SugEpps Martin, AmyTexas A&M Transportation InstituteFlorida. Department of TransportationTexas A&M Transportation InstituteUnited StatesFloridaReclaimed asphalt pavementsFoamed materialsEmulsionsAsphalt emulsionsLow volume roadsMix designPerformance testsBinder contentPavement designPavement performanceHot RecyclingCold RecyclingEmulsified BinderFoamingFoamed BinderFDOT-BE194BE194Final Report May 2016-November 2018The Florida Department of Transportation yearly maintenance and rehabilitation activities include milling and resurfacing of approximately 2,000 lane miles of roadway, with an average resurfacing depth of about 2.1 inches (55 mm). These activities result in the generation and accumulation of roughly 1.8 million tons of reclaimed asphalt pavement (RAP) each year. The use of elevated quantities of RAP in low volume roads provides an environmentally responsible solution to the accumulated RAP surplus in some urban areas, while at the same time offering an economical pavement maintenance and rehabilitation option to local agencies facing budget constraints. The objective of this project was to develop mix design guidelines for mixtures with high RAP contents to be used on low volume roads (average daily traffic < 750 vehicles). To accomplish this objective, three types of high RAP mixtures were considered, having RAP contents ranging from 60 percent\u2013100 percent: hot, cold with emulsion, and cold with foamed binder. Performance testing included moisture susceptibility, rutting, intermediate temperature cracking, durability, and stiffness. The hot recycled mixtures showed good moisture susceptibility and cracking resistance, especially when recycling agents were incorporated. The cold recycled mixtures showed poor moisture susceptibility and durability characteristics, which were alleviated when hydrated lime or Portland cement was incorporated in the emulsified and foamed mixtures, respectively. Most hot recycled mixtures, and all the cold recycled mixtures, exhibited poor rutting behavior. A first-cost and life-cycle cost analysis demonstrated significant savings when increased amounts of RAP were incorporated in the recycled mixtures.120