非线性微分动力学模型的沥青老化行为

为了研究沥青的老化行为及抗老化性能，将沥青进行旋转薄膜烘箱老化（RTFOT）和60℃烘箱老化试验，并从不同使用年限的路面回收老化的沥青，采用非线性微分动力学模型对不同老化方式的沥青粘度进行拟合，根据模型参数讨论了沥青在不同老化条件下的性质变化和老化速率，并分析了老化机理的差异。结果表明，非线性微分模型可以有效地模拟沥青室内和野外老化进程，模型参数L和r可以实现对老化状态和老化速率的量化。不同老化温度下，沥青都有其对应的极限老化状态。RTFOT老化与野外老化的极限老化程度约为60℃烘箱老化的4～5倍，RTFOT老化6h与野外老化6a的老化效果接近，延时的RTFOT老化方法可以模拟实际路面沥青的长期老化。

Aging Behavior Analysis of Asphalt based on Nonlinear Differential Dynamic Model

In order to study aging behavior and anti-aging performance of asphalt, aging tests were carried out with rolling thin film oven test（RTFOT） and oven aging test at 60℃, and aged asphalt was extracted from pavements of different service life. Viscosity of asphalt samples was fitted with nonlinear differential dynamic model. With parameter study, property changes, aging rate of asphalt and the difference of aging mechanism were analysed under different aging conditions. It was shown that the nonlinear differential dynamic model can simulate asphalt aging process in the laboratory or on-site effectively. At the same time, model parameters（L and r） can quantify aging state and aging rate. Asphalt had its limited aging state corresponding with different aging temperature. Ultimate aging degree of RTFOT and field aging were about 4-5 times of that of oven aging test at 60℃. And aging effect of RTFOT for 6h was about equivalent with that of field aging for 6 years. Thus time-delay RTFOT can simulate long-term aging of pavement asphalt.