沥青表面形貌的表征与测试及其对与集料接触特性的影响

采用原子力显微镜对SK90#基质沥青和SBSⅠ-C改性沥青的表面形貌进行了测试,获得了两种沥青的表面形貌参数,并基于此对沥青的表面形貌特性进行了分析;基于沥青表面的高度概率密度曲线和承载面曲线,从界面实际接触面积的角度分析了沥青表面特性对与集料接触特性的影响。结果表明,SBSⅠ-C改性沥青的表面起伏情况高于SK90#基质沥青,具有更大的表面粗糙度。具有更大S_sk(歪斜度)的沥青更有利于形成更好的黏附强度,但也更容易发生磨损而使黏附性能快速降低。沥青与集料间的接触性能受其实际接触面积的影响,SBSⅠ-C改性沥青具有与集料更大的实际接触面积,从而形成更大的摩擦力而具有更优良的黏附性能。

Characterization and Testing of Asphalt Surface Topography and Its Influence on Contact Characteristics with Aggregate

The surface morphology of SK90#matrix asphalt and SBS I-C modified asphalt was tested by atomic force microscopy,and the surface morphology parameters of two kinds of asphalt were obtained.Based on this,the surface morphology characteristics of the asphalt were analyzed.Based on the high probability density curve and the bearing surface curve of the asphalt surface,the actual contact area of the interface was obtained,and the influence of asphalt surface characteristics on contact characteristics with aggregate was analyzed.The results show that the surface undulation of SBS I-C modified asphalt is higher than that of SK90#matrix asphalt,and SBS I-C modified asphalt has greater surface roughness.The larger Ssk is conducive to better adhesion strength between asphalt and aggregate,but it is also easier to wear and reduce the adhesion performance rapidly.The contact performance between the asphalt and the aggregate is influenced by the actual contact area.The SBS I-C modified asphalt has a larger actual contact area with the aggregate,thus forming a greater friction force and having a better adhesion property.