Determination of the PG binder grade to use in a RAP mix

810999PDFResearch PaperJHR 00-278Project 99-1Recycled materialsHot mix paving mixturesBindersSuperpaveDurabilityTest proceduresConnecticutConnecticut. Dept. of TransportationStephens, Jack E.Mahoney, JamesDippold, CoryConnecticut. Dept. of TransportationUniversity of ConnecticutNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceUS Transportation CollectionThe use of Recycled Asphalt Pavement (RAP) in new Hot Mix Asphalt (HMA) has become routine in the part few years. This practice is spurred by the increased amounts of pavement being milled off prior to overlaying. Using RAP has economical and environmental benefits. The drawback to using RAP in pavements is determining the correct virgin binder grade to add to the asphalt mixture. This problem has been accentuated by using the Superpave System for determining the asphalt binder grade. This asphalt binder in RAP is typically much stiffer than the binder grade required by the Superpave System. Determining the correct virgin binder to use in the HMA is critical to ensure that the pavement will be durable enough to last for its anticipated service life. The current methods of determining the correct virgin binder assumes complete blending of the RAP binder and the virgin binder which does not occur. The simple physical testing procedure presented in this paper does not require the Superpave binder test equipment and could be carried out at the mix plant