Quantifying Weathering-Aging Test Parameters of High Viscosity–Modified Asphalt by Establishing a Conversion Relationship with Standard PAV Aging

Abstract

The purpose of this study was to quantify the weathering-aging degree by establishing a conversion relationship with standard pressure-aging vessel (PAV) aging, thus guiding the selection of environmental parameters in the weathering-aging test. First, the orthogonal test was used to determine the most severe weathering-aging combination. Then the rheological property and chemical composition of high viscosity–modified asphalt (HVMA) after weathering-aging and standard PAV aging were investigated by dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC) tests. Afterward, the radar figure was used to establish the conversion relationship between weathering aging and standard PAV aging. The results show that the most severe weathering-aging condition combination is 70°C, 1,000 W/m2, and 70% relative humidity (RH). The molecules from the polymer, asphaltene, and maltene phase exhibit dynamic migration processes of molecular weight during aging, thus leading to the transition from a viscous component to an elastic component in HVMA. Compared with PAV aging, HVMA has more significant chemical changes during weathering aging due to the coupling effect of solar radiation and heat. Most of the performance changes of HVMA are similar in weathering aging and standard PAV aging except for functional groups and R3.2. The 4 days of weathering aging at 70°C, 1,000 W/m2, and 70% RH shows the best accordance to the standard PAV aging.