Effect of aging on damping properties of rubberized asphalt binder and rubberized porous asphalt mixture

Abstract

The purpose of the study is to explore the effect of aging on the damping properties of rubberized asphalt binder and rubberized porous asphalt mixture (RPAM), and to reveal the attenuation mechanism of damping properties. The effect of aging on the damping properties of asphalt binder was analyzed through temperature scanning test. Fourier transform infrared spectroscopy, gel permeation chromatography, and fluorescence microscopic test were conducted to analyze the aging mechanism of damping properties from the perspectives of chemical composition and morphology. The dynamic modulus test and free vibration damping test were used to investigate the effect of aging on the damping properties of asphalt mixtures. Results showed that aging led to a decrease in the damping properties of asphalt mixtures. Compared to porous asphalt mixture, RPAM had lower sensitivity to aging, so its damping properties was less prone to decay. The effect of aging on asphalt binders obtained from the temperature scanning test was consistent with the results of asphalt mixtures, indicating that the decrease in damping properties of asphalt mixtures was attributed to the deterioration of damping properties of asphalt binders. The results of chemical composition and phase morphology indicated that the proportion of large molecules in the asphalt binder increased significantly during the aging process. The decrease in intermolecular mobility led to a decrease in the damping properties of asphalt binder. Significantly, crumb rubber can prevent the aging of asphalt binder, thereby delaying the attenuation of damping properties of RPAM.