Evaluation of Aging Characteristics of High-Viscosity Asphalt: Rheological Properties, Rutting Resistance, Temperature Sensitivity, Homogeneity, and Chemical Composition

The purpose of this paper was to study the aging behaviors of high-viscosity asphalt (HVA). Three kinds of asphalt binders [base asphalt, styrene-butadiene-styrene-modified asphalt (SBSMA), and HVA] were treated with rolling thin-film oven test (RTFOT) and pressure aging vessel (PAV). Temperature sweep (TS) test and multiple stress creep recovery (MSCR) tests were conducted on all samples to test the indexes of rheological properties, and chemical compositional changes were monitored by attenuated total reflection (ATR)–Fourier transform infrared spectroscopy (FTIR). The results show that the values of complex modulus (G*), storage modulus (G′), loss modulus (G″), and rutting factor (G*/sinδ) of all asphalt binders increase with the severity of aging. Additionally, after PAV, the values of phase angle (δ), Jnr0.1, and Jnr3.2 of base asphalt gradually decrease, while those of SBSMA and HVA increase. After PAV, the rutting resistance of the base asphalt improves, while that of SBSMA and HVA deteriorates. The aging deteriorates the temperature sensitivity of base asphalt, SBSMA, and HVA but improves their homogeneity. Moreover, the effect of aging on the temperature sensitivity and the micromorphology structure of polymer-modified asphalt (PMA) is greater than that of base asphalt. The rheological aging index and FTIR spectroscopy test result shows that the aging resistance of SBSMA and HVA is better than that of base asphalt. Based on the aging sensitivity analysis and the correlation analysis, the storage modulus is the most sensitive to aging, and the loss modulus aging index could be used for the aging evaluation of HVA.