Diffusion of Virgin and Aging Asphalt in Different Aging Methods
Thermo-oxygen aging asphalt and thermal oxygen-ultraviolet aging asphalt were prepared.The double-layers diffusion model of virgin and aging asphalt was constructed.Through the simulation calculation of relative concentration and diffusion coefficient,verification of pull-off tensile test and fluorescence microscope test,the relationship of diffusion degree with temperature and four components was analyzed.The results show that the thermal oxygen-ultraviolet aging asphalt is more difficult to diffusion with the virgin asphalt,and the adhesion with the virgin asphalt is poor.In the range of 10℃to 40℃,the virgin and aging asphalt can diffuse rapidly.When the temperature is over 40℃,the promoting effect of increasing temperature on diffusion gradually decreases.The decreasing rate of promoting effect is greater for the diffusion of thermal oxygen-ultraviolet asphalt and virgin asphalt.The diffusion coefficients of four components of asphalt from large to small are in the order:saturate>aromatic≥resin>asphaltene.After ultraviolet aging,the diffusion coefficients of the four components decrease.Among them,asphaltene declines most significantly.
road engineeringdouble-layers diffusion model of virgin and aging asphaltmolecular dynamicaging asphaltrelative concentrationdiffusion coefficientpull-off tensile test