ABSTRACT
The history of asphalt pavement recycling dates back to the early 1900s. Recycling asphalt pavements first became popular in the U.S. in the 1970s during the oil embargo when the cost of crude oil skyrocketed. Today, the two primary factors that influence the use of reclaimed asphalt pavement (RAP) in asphalt pavements are economic savings and environmental benefits (Newcomb et al. 2007). RAP is a useful alternative to virgin materials because it reduces the use of virgin aggregate and the amount of virgin asphalt binder required in the production of hot mix asphalt (HMA) (Copeland 2011). For higher RAP content (above 25%), design and production takes extra effort, but the savings in using the higher RAP contents significantly outweigh the added costs. Blending to meet gradation and the appropriate binder grade in the final product are keys to successful mix design, production, and performance (Newcomb et al. 2007).
