Laboratory Evaluation of Field Produced Hot Mix Asphalt Containing Post-Consumer Recycled Asphalt Shingles and Fractionated Recycled Asphalt Pavement

The research presented in this paper studies the effects of post-consumer recycled asphalt shingles (RAS) on the performance of HMA and its compatibility with fractionated recycled asphalt pavement (FRAP). In the summer of 2009, a field demonstration project was conducted by the Illinois Tollway Authority on Interstate Highway I-90. Eight mix designs containing zero and five percent RAS and varying percentages of FRAP were developed and placed in the pavement shoulder. Production and laboratory samples of the mixes were obtained for dynamic modulus testing, beam fatigue testing, fracture energy testing, binder extraction, and subsequent characterization. From the dynamic modulus testing, master curves were constructed to determine how the behavior of the asphalt materials containing RAS differed from the behavior of the asphalt materials not containing RAS when varying percentages of FRAP were a part of the mix designs. From the extracted binders, a suite of Superpave tests was conducted at different temperatures and frequencies to build master curves for analyzing how the addition of RAS binder affected the rheological properties of the mix binder blend. Fracture energy testing was conducted using the disk-shaped compact tension test to estimate thermal cracking potential. Laboratory test results indicate that the mixes containing five percent RAS with less than 40 percent recycled materials exhibit an increased resistance to permanent deformation while maintaining satisfactory performance in fatigue and low temperature cracking. Although the low temperature binder performance grade increased with the addition of recycled materials, the mix performance test results did not follow that trend, indicating that fibers in the RAS materials likely contributed to the performance of the mixtures.