多尺度分析复合高黏改性沥青–集料界面黏附性能

Multi-Scale Analysis of the Adhesion Properties of Composite High-Viscosity Modified Asphalt-Aggregate Interface

摘要: 针对目前排水沥青路面长期处于有水条件下容易出现沥青–集料界面黏附性能不足的问题，为提高黏附性能与水稳定性能，研发复合高黏改性沥青(High Viscosity Modified Asphalt, HVMA)，通过自主设计的扫刷和动水冲刷试验、接触角测定实验和分子动力学模拟从宏观、微观和分子层面多尺度阐释沥青–集料界面作用机理及高黏改性沥青界面黏附性能。结果表明：通过扫刷和动水冲刷实验得出，HVM改性剂显著降低沥青–集料间的扫刷损失率与动水冲刷前后飞散损失率；在接触角试验中，HVM改性剂大幅提高沥青–集料的色散分量，降低沥青–集料的极性分量；在分子动力学模拟中，发现HVM改性剂提高了沥青与集料间的界面能，降低沥青与集料间的剥落能。综上分析改性剂的作用机理，HVM改性剂中SBS组分增强了沥青与集料之间的黏结强度，在混合料的内部形成较稳定的网状结构，改性剂中SBR和EVA组分加强了较稳定的网状结构，且EVA具有较大的比表面积，可提高对沥青轻质组分的吸收作用，进一步增强沥青–集料间黏附性能。

Abstract: In light of the current issue that permeable asphalt pavements often suffer from insufficient adhesion performance at the asphalt-aggregate interface under continuously wet conditions, efforts have been made to enhance the adhesion and water stability by developing composite high-viscosity modified asphalt (HVMA). Through independently designed sweep tests and dynamic water scouring tests, contact angle measurement experiments, and molecular dynamics simulations, the study elucidates the multi-scale mechanisms of the asphalt-aggregate interface from macroscopic, microscopic, and molecular perspectives, as well as the adhesion properties of high-viscosity modified asphalt at the interface. The results indicate that: the sweep and dynamic water scouring tests demonstrate that the HVMA modifier significantly reduces the sweep loss rate and the scattering loss rate before and after dynamic water scouring between asphalt and aggregates; in the contact angle experiments, the HVMA modifier notably increases the dispersive component of the asphalt-aggregate interaction while decreasing the polar component; in molecular dynamics simulations, it is observed that the HVMA modifier enhances the interfacial energy between asphalt and aggregates and reduces the debonding energy between them. In summary, the analysis of the modifier’s mechanism of action reveals that the SBS component in the HVMA modifier enhances the cohesive strength between the asphalt and aggregates, forming a more stable network structure within the mixture. The SBR and EVA components in the modifier strengthen the stable network structure, and EVA has a large specific surface area, which can improve the absorption of asphalt light components, and further enhance the adhesion between asphalt and aggregate.