Performance Evaluation of Hot Mix Asphalt Containing Recycled Asphalt Shingles in Washington State

Due to the increasing cost of asphalt binder and also due to environmental considerations, recycled asphalt shingles (RAS) are now allowed to be added into hot mix asphalt (HMA). RAS have been incorporated into HMA with the intent to achieve the potential benefits of cost-effectiveness and environmental sustainability without compromising the performance of the HMA. This study investigates the performance of HMA with and without RAS based on the evaluation of field cores drilled from four experimental pavement sections that were constructed in 2009 in King County of Washington State. The performance of the asphalt mixtures and the recovered asphalt binders are evaluated with respect to rutting, fatigue, and thermal cracking resistance via laboratory experiments. The test results show that the rutting resistance of the mixtures as well as the recovered binders is improved by the addition of RAS. However, the fatigue and thermal cracking resistance of the mixtures is not significantly affected by the addition of RAS. The field performance survey indicates excellent conditions for all test sections after three years of service.