Performance and Fatigue Analysis of High Reclaimed Asphalt Pavement Content and Warm-Mix Asphalt Test Sections

The use of warm-mix asphalt and reclaimed asphalt pavement is gaining wider acceptance across the United States. Though they are commonly used, there is a need to better characterize their laboratory properties and field performance to achieve optimal flexible pavement structures in the future. To meet this need, the National Center for Asphalt Technology began a study in 2009 that featured five sections using warm-mix asphalt technologies and high reclaimed asphalt pavement contents. The sections were expected to fail within 10 million equivalent single-axle load applications according to past experience but they performed well until 14 million equivalent single-axle loads, at which point fatigue cracking developed. A variety of fatigue cracking performance tests were conducted in the laboratory to develop correlations between laboratory and field performance. The laboratory results yielded different predictions, with the modified overlay tester showing the best correlation to field performance.