Viscoelastic Fatigue Damage Properties of Asphalt Mixture with Different Aging Degrees

© 2018, Korean Society of Civil Engineers. In order to reveal the effects of aging on fatigue damage evolution pattern of asphalt mixture, and to reveal the fatigue damage patterns of asphalt pavement during its service life more accurately, the viscoelastic fatigue damage model for the aged asphalt mixtures was proposed based on the Burgers viscoelastic model. The dissipation energy was taken as the damage variable, and the direct tension fatigue tests for asphalt mixture in five different aging degrees were conducted. The viscoelastic parameters of the aged asphalt mixtures were obtained.The calculationmethod of the cumulative fatigue damage was proposed, which considers the aging effects. Moreover, the critical fatigue damage degree and fatigue life calculation equations were derived by employing the fatigue damage model, which were calculated and compared. The calculation errors range from 3% to 18%, which was within an acceptable error range of 30%. The research results show that the aging has a prominent impact on fatigue properties of asphalt mixtures, which could be illustrated by the change of the parameters of the viscoelastic fatigue damage model for the aged asphalt mixtures. The prediction precision of fatigue life is acceptable for using the proposed viscoelastic fatigue damage model