To investigate the effect of recycled engine oil bottoms (REOB) as a compatibilizer on the properties of styrene–butadiene–styrene-modified bitumen (SBS-PMB), this paper studied the preparation method, properties, and micro-mechanism of composite modification of matrix bitumen with SBS and REOB. Firstly, a multi-factor orthogonal experiment determined the optimal preparation scheme of REOB/SBS composite-modified bitumen (REOB/SBS-PMB). Then, the high-temperature stability rheological properties, and anti-aging performance of REOB-PMB were studied by testing Brookfield viscosity, elasticity recovery, and dynamic shear rheology (DSR) and by short-term aging simulation (TFOT). Finally, the microstructure, fraction content, and SBS particle dispersion of 70# matrix bitumen (70-MB), SBS-PMB, and REOB/SBS-PMB were compared and analyzed by tests of Fourier transform infrared spectroscopy (FTIR), rod-shaped thin-layer chromatography, and fluorescence microscopy to reveal the micro-mechanism of REOB improving SBS and bitumen compatibility. The research results showed that the mixing form of SBS and REOB in bitumen was mainly physical swelling and blending, with chemical changes also present that have a minor impact. The light fraction in REOB increased the flowability of bitumen, promoted the swelling of SBS, improved the compatibility between SBS and bitumen, and improved the high-temperature stability and rheological properties while reducing the impact of aging.

Self-melting ice asphalt pavement materials inhibit pavement freezing and improve driving safety. This paper aims to study the long-term salt release characteristics of self-melting ice asphalt mixtures and the impact on pavement after complete salt release. Firstly, a method to accelerate the rapid release of salt based on the Los Angeles abrasion tester. Then, long-term salt release patterns were elucidated under the influence of deicing agent dosage, type of asphalt, and type of gradation. Finally, a quantitative analysis of the pavement performance after complete salt release is conducted. The results indicate that the release efficiency of the Los Angeles abrasion tester method has increased by 91 times compared to the magnetic stirrer immersion flushing method and by 114 times compared to the natural soaking method. The SBS-modified self-melting ice asphalt mixture possesses a longer duration of salt release, but the uniformity of salt release is inferior. Salt release duration is directly proportional to the dosage of deicing agents. SMA-13 self-melting ice asphalt mixture exhibits poorer uniformity in salt release. After complete salt release, high-temperature stability of self-melting ice asphalt mixtures decreased by 31.6%, low-temperature performance decreased by 15.4%, water stability decreased by 26.7%, and fatigue life decreased by 35.9%.