Preparation and properties of a newly developed devulcanized and pyrolytic crumb rubber modified asphalt

Purpose The purpose of this article is to determine the parameters of the preparation process for devulcanized and pyrolytic crumb rubber modified asphalt (DCRMA) and then study the rheological and microscopic properties of DCRMA through experiments. Design/methodology/approach In this study, a new preparation process for DCRMA was developed, then the penetration, softening point and viscosity tests were employed to determine the parameters of the preparation process. The crumb rubber (CR) solubility, Fluorescence microscopy (FM), Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric analysis tests were conducted to verify the devulcanized and pyrolytic effectiveness of the preparation process. Furthermore, dynamic shear rheometer and bending beam rheometer were used to characterize the high and low-temperature rheological properties of DCRMA. Findings The results showed that the penetration balanced the CR degradation and the virgin asphalt aging well and thus could be used as a main parameters control indicator. The CR solubility, FM and FTIR tests proved that the CR has been fully devulcanized and pyrolytic via the preparation process. The DCRMA exhibited better low-temperature and fatigue performance and lower rutting performance than the conventional crumb rubber modified asphalt (CRMA) with the same CR content. Finally, the time–temperature superposition principle could be employed for all binders in this study. Originality/value A new preparation process for DCRMA was developed.