Incorporation of Recycled Asphalt Shingles in Hot-Mixed Asphalt Pavement Mixtures

Rises in construction and asphalt binder costs, as well as the growing pressures on landfills, have contributed to the increased use of tear-off scrap shingles (TOSS) and manufacturer waste scrap shingles (MWSS) into hot-mixed asphalt (HMA) pavement mixtures. This research project was undertaken to address the responsible incorporation of recycled asphalt shingles (RAS) into HMA pavement mixtures to ensure environmental benefits are realized and pavement durability is retained or improved. The research consisted of a literature review, extensive laboratory testing and field evaluations of in service RAS/RAP HMA pavements. Binder testing established a strong correlation between the new asphalt binder to total asphalt binder ratio and the extracted high/low binder performance grade temperatures. Dynamic modulus testing on HMA mixtures proved to be an invaluable tool in comparing the effects of RAS and RAP on mixture properties across a wide range of temperatures. Field performance appeared to validate the laboratory findings in some instances.