Effect of Asphalt Mortar Composition on Dynamic Response of Asphalt Mixture

Abstract

To investigate the effect of mortar composition on visco-elastic response of asphalt mixture, The Asphalt Mixture Performance Test (SPT) was conducted on several asphalt mixtures for different ratios of filler to asphalt (F/A) , fiber dosage and proportion of cement instead of mineral powder. The effect of F/A, fiber dosage and and proportion of cement replacement on visco-elastic mechanical parameters (dynamic modulus and phase angle) of asphalt mixtures are analyzed. The results indicate that the dynamic modulus of asphalt mixtures increases first and then decreases with the increases in F/A and fiber dosage. And the more significant differences in these dynamic moduli appear at the higher the load frequency. The asphalt mixture with the lowest F/A has the biggest phase angle, and the difference in the phase angles of those asphalt mixtures is not significant. The changes of phase angle have a close relationship with the load frequency. The resistance to permanent deformation of asphalt mixture can be greatly enhanced by adding fiber. The effect of cement instead of mineral powder on the viscoelastic property of asphalt mixture is relatively small, while the resistance to high-temperature deformation of asphalt mixture can be improved to some extent.