Influence of the properties of an asphalt binder on the rheological performance of mastic

Abstract

Four asphalt and one filler were selected to fabricate mastics with four filler volume fractions. Amplitude sweeps were carried out to determine the linear viscoelastic (LVE) strain limits, and frequency sweeps were applied to obtain the complex shear modulus and phase angles of the 20 specimens. The Christensen-Anderson-Marasteanu (CAM) model was employed to fit the complex shear modulus master curves. Functional group indexes were then applied to characterize the chemical contents of the asphalt, according to the results of Fourier transform infrared spectroscopy. Based on grey relational analysis (GRA), the influence of asphalt properties on the rheological index of mastics was qualitatively analyzed. The results showed that the LVE limit strain decreased as the filler volume fraction increased, and the LVE strain limit of asphalt mastic approached the SHRP LVE strain limit of asphalt binder as the filler volume fraction increased. Values of the CAM model parameters showed that conventional asphalt mastics had better cracking resistance than the modified asphalt mastics with the same filler volume fraction. The modified asphalt mastics were more prone to translate from viscoelastic to elastic than the conventional asphalt mastics, and therefore the modified asphalt mastics were less susceptible to high temperatures than the conventional asphalt mastics. The GRA results indicated that the influence of filler on the crack resistance of mastics depended on the asphalts performance when the filler volume fraction was 0.23. However, this influence depended largely on the chemical composition of asphalt binder when filler volume fraction was more than 0.38.