Effects of using recycled asphalt shingles in open-graded friction course on flexible pavement performance

Recycling inert construction wastes is one of the approaches to promote sustainable development. In North America, the majority of steep roofs are covered with asphalt shingles. Re-roofing and manufacturing of asphalt shingles create a large amount of waste. This paper examines the use of recycled asphalt shingles (RAS) in open-graded friction course (OGFC). OGFC mixtures with and without RAS were prepared and tested for rutting resistance, indirect tensile strength, moisture-induced damage, and dynamic modulus. The dynamic modulus was also used to examine the responses of flexible pavement under assumed structures, temperature levels, and loading conditions. In addition, a section of major interstate highway in the United States surfaced with the RAS OGFC mixture of this study was used for performance monitoring. The use of RAS in OGFC was found to enhance its rutting performance, generally increase indirect tensile strengths of the tested specimens, generate pavement structural responses similar to those of a conventional OGFC mixture under the same loading conditions, and improve pavement's fatigue life. Except for clogging, no obvious distress was found in the trial section after being used for two and a half years. Future research is suggested for the development of an appropriate laboratory evaluation method for the assessment of OGFC durability.