Use of Recycled Materials in Pavement Preservation

Surface treatments such as chip seals and slurry surfacing systems are among the most popular preservation options available for flexible pavements. While the use of these treatments has been widely adopted by many state and local agencies, design and construction have typically been performed using virgin materials. To further enhance the benefits of pavement preservation, recycled materials may be incorporated into chip seal or slurry surfacing treatments (slurry seals and micro surfacing) to replace all or part of the virgin materials. Sources of recycled materials may include reclaimed asphalt pavement (RAP), recycled tire rubber (RTR), and recycled plastic. Some agencies have adopted this practice, most notably in the case of RAP, but the use of recycled materials is still limited due to a lack of information related to this topic. The objective of this study is to evaluate the potential use of recycled materials as substitutes for aggregate and/or as emulsified asphalt binder additives in terms of design implications, laboratory testing and relationship to field performance, and environmental and economic benefits.