再生剂通过扩散、混溶对老化沥青进行组分调节，从而使其路用性能恢复并满 足应用要求，因此再生剂的扩散是反映老化沥青再生效果的主要技术问题。首先通过傅 里叶变换红外光谱技术，以特征吸收峰面积为测量基准，建立再生剂扩散系数分析方 法，然后以端羧基丁腈橡胶 ( CTBN) 为示踪剂，采用自行设计的扩散试验，以特征吸 收峰强度定量分析再生剂扩散量，并对再生剂扩散系数进行计算。结果表明: CTBN 标 记后再生剂红外波谱 1739 cm － 1 处特征峰变化显著，峰面积与 CTBN 含量变化呈线性关 系，通过建立标准曲线能够有效反映再生剂在老化沥青中的扩散量; 以峰面积比 D1739 / D1458为测量基准，建立再生剂扩散系数理论分析方法，具有一定的可靠性，扩散系数与 浓度变化密切相关，可有效反映老化沥青再生程度; 扩散系数与累积扩散量随温度变化 均呈正比关系，且两者增长速率基本相同，同一温度下扩散速率随竖向深度增大呈递减 趋势，与再生剂扩散量变化趋势一致，符合 Fick 第二定律。

Ｒejuvenator adjusts the components of the aged asphalt through diffusion and miscibility，so as to restore its road performance and make it meet the application requirements． Therefore，the diffusion of rejuvenator is the main technical problem influencing the regeneration effect of aging asphalt． Firstly，an analysis method of rejuvenator diffusion coefficient was established by using Fourier transform infrared spectroscopy technique and taking the characteristic absorption peak area as the measurement standard． Then，using CTBN as a tracer，a self-designed diffusion test was used to quantitatively analyze the diffusion amount of the rejuvenator with the characteristic absorption peak intensity，and calculate the rejuvenator diffusion coefficient． The results show that the characteristic peak at 1739cm － 1 of the infrared spectrum of the rejuvenator change significantly after CTBN labeling，and the peak area shows a linear relationship with the change of CTBN content． The diffusion amount of rejuvenator in aged asphalt can be effectively reflected by establishing a standard curve． Taking the peak area ratio D1739 /D1458 as the measurement standard，the established theoretical analysis method of the rejuvenator diffusion coefficient has certain reliability． The diffusion coefficient is closely related to the concentration change，and can effectively reflect the degree of aging asphalt regeneration． The diffusion coefficient and the cumulative diffusion amount are proportional to the temperature change，and the growth rate of the two is basically the same． The diffusion rate at the same temperature shows a decreasing trend with the increase of the vertical depth． It is consistent with the change trend of the rejuvenator diffusion amount，and is in compliance with Fick’s second law．