Investigation of Aging Behavior of Asphalt under Multiple Environmental Conditions
Yongjie Ding, Danni Li, Hanlin Zhang, Mei Deng, Xinbo Mao, Xuejuan Cao
Abstract
This work investigated the effects of the aging process on the performance of asphalt binder under multiple environmental conditions based on multitechnique experimental results. The aging process of matrix asphalt binder with the increase of temperature for 96 h, 192 h, and 288 h was simulated by an aging oven. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to quantify the microcosmic characteristics of asphalt after aging. The results showed that the aging process of asphalt is an oxidation process, and the oxygen-containing functional groups (C═O and S═O) increased with aging. At the macroscopic level, the changes of adhesion properties and bond strength of asphalt were studied by testing the changes in three major indexes. The penetration and ductility of asphalt decreased, and the softening point increased with aging. The changes of rheological performance were tested by dynamic shear rheometer (DSR) and Brookfield viscometer. Mutual transformation of aromatic phenol, colloid, and asphaltene led to an increase in asphalt viscosity and decrease in workability. Antifatigue performance gradually decreased under the action of load with the extension of time. The elastic properties were finally damaged by fatigue.