基于原子力显微镜技术的沥青与矿料表面粗糙度及黏附特性
Characterization of surface roughness and adhesive mechanism of asphalt and mineral aggregate based on atomic force microscopy method

采用原子力显微镜技术（AFM）的轻敲和力曲线模式，在微观尺度下对沥青与矿料表面的二维图像和三维形貌信息进行采集和分析，并测试和计算表征材料物理黏结特性的表面能。测试和分析结果显示，不同油源的沥青具有明显不同的化学组分和表面粗糙度，具有蜂形结构的沥青表面粗糙度更大。老化将明显减少沥青的表面粗糙度，降低其表面能，进而对沥青与矿料的黏附产生不利影响。结合宏观的黏附拉拔力学试验，对沥青和矿料表面粗糙度、表面能与宏观拉拔强度间的关联进行统计分析。结果表明，对于含蜂形结构的沥青，沥青和矿料表面粗糙度对黏附力学性能较为重要；而对于不含蜂形结构的沥青，其与矿料的黏附性更决定于所选材料的表面能，即两种材料间的物理黏结作用。 The 2-D picture and 3-D topography for asphalt and mineral aggregate were firstly scanned with the tapping mode of atomic force microscope (AFM). Then the surface energies of asphalt and mineral aggregates were measured with the force-curve mode of AFM and calculated to represent their physical bonding performance. The results indicate that the asphalt binders made with various crude oils have different chemical compositions and surface roughness. The asphalt binder with bee-structure has a larger roughness compared with asphalt binder without bee-structure. Ageing can reduce the surface roughness and surface energy of asphalt, then weaken the adhesive bonding between asphalt and mineral aggregate. Finally the relationships among the surface roughness and surface energies of asphalt and mineral aggregate, and the adhesive tensile strength of asphalt/mineral aggregate system were analyzed, based on the adhesive tensile test results at the macro-scale. It is found that the roughness of asphalt and mineral aggregate play a key role in determining their adhesion, when the asphalt has bee-structures. However, for the asphalt which has no bee-structures, the adhesion between asphalt and mineral aggregate is more dependent on the surface energies of materials, which actually represents the physical bond performances of materials. 国家自然科学基金（51408154）；中国博士后科学基金特别资助（2015T80357）；中央高校基本科研业务费专项资金（HIT.NSRIF.2017043）