Construction and field performance of hot mix asphalt with moderate and high RAP contents

Reclaimed asphalt pavement (RAP) can be used to replace a portion of the virgin materials in asphalt pavements. The use of RAP reduces material costs and demands on natural resources. RAP typically replaces 10 to 20 percent of virgin material in hot mix asphalt (HMA). In some regions, a surplus of RAP materials is available which could be used to further reduce costs. Often the percentage of RAP is not increased because of uncer- tainties about the performance and constructability of higher RAP content mixes. In 2006, research was initiated to investigate the feasibility of designing, producing, and constructing quality mixes containing moderate to high RAP percentages. Seven 200-foot test sections were built at the National Center for Asphalt Technology Pavement Test Track in September 2006. Since trafficking started in November 2006, over 10 million ESALs have been applied to these test sections. This paper discusses the construction and field performance of these RAP experiment sections.