Abstract:

The molecular simulation method has been widely applied in various fields with the rapid development of computer technology. In this paper, the construction methods of the asphalt molecular model, modifier molecular model, aging asphalt model, aggregate model, as well as verification methods of the base asphalt model were summarized. Through the molecular dynamics (MD) simulation, the properties and performance of asphalt, the diffusion phenomenon of asphalt, the modifying effect of modifiers on asphalt, the aging and regeneration of asphalt and the interface interaction between asphalt and aggregates were discussed. The MD simulation method can forecast the characteristics of asphalt materials, such as the mechanical properties, low-temperature properties, anti-aging properties, self-healing properties of base asphalt, the compatibility between base asphalt and modifier, and the mechanical and adhesion properties of asphalt-aggregate interfaces, which bridged the gap between macroscopic and microscopic behaviors and offered a prescription for the widespread use of MD simulation. However, MD simulation in the asphalt system needed to be improved in areas such as model construction, force field optimization and model validation because the molecular dynamics simulation only focused on the physical interaction between asphalt materials and modifiers. Furthermore, the application of molecular dynamics in the asphalt mixture was currently only limited to the study of the interface between the asphalt and aggregates, and thus it was recommended to combine the finite element simulation and other simulation methods to investigate the asphalt mixture. The final part of the article provided an outlook on the future direction of MD simulation in asphalt systems. In the future, the MD method needed to be used to study the high-temperature rheological properties of asphalt, the simulation of the interface between asphalt and modifiers, and the interaction between various modifiers and asphalt. In addition, it was necessary to investigate the effect of multiple factors (such as crack width, modifier, temperature and rejuvenator) on the self-healing properties of asphalt. In order to investigate the chemical interactions between asphalt and modifiers, it was recommended to combine it with other simulation methods such as quantum mechanics. In the case of asphalt mixture, it was advised to combine it with simulation methods such as finite elements to study the properties of asphalt mixture.

Key words: asphalt, molecular simulation, molecular dynamics (MD), kinetic modeling, asphalt-aggregate interface

摘要：

随着计算机技术的飞速发展，分子模拟方法已被广泛应用于各个领域。本文总结了沥青分子模型、老化沥青模型、集料模型的构建方法以及基质沥青模型的验证方法。通过分子动力学（MD）模拟，探讨了沥青的性质与性能、沥青的扩散现象、改性剂对沥青的改性作用、沥青老化与再生以及沥青与集料的界面相互作用。MD模拟方法能够预测沥青材料的性能，包括基质沥青的力学性能、低温性能、抗老化性能、自愈合性能，基质沥青与改性剂的相容性以及沥青与集料界面的力学性能、黏附性等性能，架起了宏观和微观行为之间的桥梁，为MD模拟在沥青材料的广泛应用提供了指导。但MD模拟在沥青体系中还需要进一步完善，如初始模型的建立、力场的优化和模型验证等，目前分子动力学模拟只关注沥青材料与改性剂之间的物理作用，缺少对两者之间化学作用的研究。此外，分子动力学在沥青混合料中的应用目前只限于沥青与集料界面之间的研究。最后，对MD模拟在沥青体系中的未来发展方向进行了展望，在未来需要使用MD方法来研究沥青的高温流变性能、沥青与改性剂的界面模拟以及多种改性剂与沥青之间的相互作用。此外，还需要探究多种因素（如裂缝宽度、改性剂、温度和再生剂）共同作用下对沥青自愈合性能的影响，为了探究沥青与改性剂之间的化学相互作用，建议结合量子力学等其他模拟方法进行研究，在沥青混合料方面建议结合有限元等模拟方法来研究沥青混合料的性能。

关键词: 沥青, 分子模拟, 分子动力学, 动力学模型, 沥青-集料界面