基于表面润湿理论的再生剂-老化沥青界面扩散行为评价

为研究再生剂-老化沥青界面扩散行为及其影响因素，采用Wilhelmy吊片法测试了不同温度下再生剂的表面张力及其与老化沥青间的接触角，计算得到润湿过程中的热力学参数浸润功和动力学参数润湿速度（润湿时间），研究了再生剂自身性质、环境温度及沥青老化程度对界面扩散行为的影响。结果表明：环氧大豆油（ESO）的掺入降低了再生剂的接触角，增大了浸润功，加快了润湿速度，缩短了润湿时间，提升了再生剂的润湿性能，促进了再生剂-老化沥青的界面扩散，而十二烷基苯磺酸（DBSA）的掺入则对再生剂-老化沥青的界面扩散有不利影响；温度对再生剂-老化沥青界面扩散行为影响显著，随着温度升高，再生剂的黏度降低，接触角减小，润湿速度加快，再生剂在较短时间内即可充分包裹老化沥青表面；再生剂表面张力越大，其在老化沥青表面浸润功越大，界面扩散动力越大，扩散过程更易自发进行；再生剂在老化沥青表面的接触角越小，其在老化沥青表面的润湿速度越快，再生剂液滴更容易形成包裹老化沥青表面的再生剂膜；再生剂的黏度越低，流动性越好，其在老化沥青表面的润湿速度越快，有利于再生剂-老化沥青界面的扩散；沥青的老化对再生剂-老化沥青的界面扩散有不利影响，随沥青老化程度的加深，再生剂在其表面的润湿性能下降，界面扩散程度降低。故为保证再生剂对老化沥青的再生效果，在再生剂选择及研发时，应优先选用表面张力更大、黏度更低且与老化沥青间接触角更小的再生剂。

Evaluation of Interface Diffusion Behavior Between Rejuvenator and Aged Asphalt Based on Surface Wettability Theory

To study the interface diffusion behavior between rejuvenator and aged asphalt and its influencing factors, the surface tension of the rejuvenator at different temperatures and its contact angle with the aging asphalt was tested using Wilhelmy pendant method. The thermodynamic parameters-wetting work and kinetic parameters-wetting speed (wetting time) during the wetting process were calculated. Based on this, the effects of the regenerator's properties, environmental temperature, and aging degree of asphalt on the interface diffusion behavior were studied. The results show that the incorporation of epoxy soybean oil (ESO) reduces the contact angle of the rejuvenator, increases the wetting work, accelerates the wetting speed, shortens the wetting time, improves the wetting performance of the rejuvenator on aged asphalt, and promotes the interfacial diffusion between rejuvenator and aging asphalt. Moreover, the incorporation of dodecyl benzene sulfonic acid (DBSA) adversely affect the interfacial diffusion of the regenerant. Temperature has a significant effect on the interface diffusion behavior; as the temperature increases, the viscosity of the rejuvenator decreases, the contact angle decreases, and the wetting speed is accelerated. The rejuvenator can fully wrap the surface of aged asphalt in a short time. The higher the surface tension of the rejuvenator, the higher the wetting work on the surface of the aging asphalt, and the higher the interface diffusion power, the easier the diffusion process to proceed. The smaller the contact angle of rejuvenator on the surface of aged asphalt, the higher the wetting speed on the surface of the aging asphalt, and the easier it is for the rejuvenator droplets to form a film of rejuvenator that covers the aged asphalt surface. The lower the viscosity of the rejuvenator, the better the fluidity. It has a higher wetting speed on the surface of aged asphalt, which is beneficial to the interface diffusion between rejuvenator and aged asphalt. The aging of asphalt is detrimental to the interface diffusion between rejuvenator and aged asphalt. With the increase in the aging degree of asphalt, the wettability of rejuvenator on the surface of asphalt decreases, which reduces the degree of interface diffusion. Therefore, to ensure the effect of the rejuvenator on the aged asphalt, it is necessary to select a rejuvenator with higher surface tension, lower viscosity, and smaller contact angle with the aged asphalt when developing the rejuvenator.