Comparative analysis of rheological and microscopic performance of SBS modified asphalt based on field aging and laboratory aging

In this study, the correlation and difference of Styrene-Butadiene-Styrene (SBS) modified asphalt rheological and microscopic performance under field aging and laboratory aging were analyzed. The asphalt recovery experiment obtained SBS modified asphalt after construction aging (CA), 1 year field aging (1A), and 5 years field aging (5A) as field aging samples. The SBS modified asphalt samples were obtained by laboratory aging methods: ultraviolet aging (UV), rotating film oven test (RTFOT), and pressure aging vessel (PAV). Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) experiments were applied to test the SBS modified asphalt rheological performance, and infrared spectroscopy (IR) and fluorescence microscopy (FM) were applied to test the SBS modified asphalt microscopic performance. By contrasting the SBS modified asphalt correlation and difference in rheological and microscopic performance during field aging and laboratory aging, the conclusion demonstrates that the degree of rheological and microscopic performance after CA treatment is not significantly different from that after RTFOT treatment. However, from the micro performance analysis, the micro performance indexes of PAV (10H) and PAV (20H) were significantly lower than those of 1A and 5A, and the rheological and micro properties are different after accelerated aging. This suggests that accelerated aging can recover and simulate the behavior in the early stages of field aging, but with increasing age, accelerated aging cannot fully simulate the aging behavior in more complex situations, resulting in a lower degree of accelerated aging than in the mid- to late-stage field aging.