分别制备了热氧老化沥青和热氧-紫外老化沥青,构建了新、旧沥青双层扩散模型,并且通过相对浓度与扩散系数的模拟计算、拉拔试验与荧光显微镜试验研究了新、旧沥青扩散融合程度与温度、沥青四组分的关系.结果表明:热氧-紫外老化沥青更不易与基质沥青扩散融合,与基质沥青的黏附性较差;在10~40℃内,新、旧沥青能够快速扩散融合,超过40℃后,升高温度对扩散融合的促进作用逐渐减小,且对热氧-紫外老化沥青与基质沥青的扩散融合促进作用的减小速率更大;沥青四组分扩散系数的大小顺序依次为:饱和分>芳香分≥胶质>沥青质,经紫外老化后,四组分的扩散系数均有所下降,沥青质的降幅最大.
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.