Asphalt suffers from a series of aging processes in the natural environment. This is a significant factor in asphalt pavement diseases. Research of the properties of the decay processes in the natural weathering of asphalt will be helpful in distinguishing the characteristics of the various types of asphalt and in the selection of pavement materials. Neat asphalt A70, a styrene-butadiene-styrene- (SBS-) modified asphalt, and crumb-rubber-modified asphalt AR are exposed to outdoor conditions to weather naturally. This process is traced by testing the basic physical properties and the surface free energy of asphalts, using the sessile drop method. Results illustrate that the basic physical properties of asphalt change significantly during the natural weathering process and that the rubber asphalt has the superior aging resistance, while the neat asphalt A70 has a high aging susceptibility. Furthermore, the presence of the SBS and rubber-powder modifiers transforms the change trend of the surface free energy of neat asphalt. The adhesion work between aggregate and asphalt can be used to quantitatively evaluate the adhesive properties between them. Meanwhile, the presence of moisture between the asphalt and aggregate changes cohesive failure into adhesive failure.

中文翻译：

---

天然风化沥青的物理和粘合性能评估

沥青在自然环境中遭受一系列老化过程。这是沥青路面疾病的重要因素。研究沥青自然风化过程中的衰减过程的特性将有助于区分各种类型的沥青的特性和选择路面材料。整洁的沥青A70，苯乙烯-丁二烯-苯乙烯-（SBS-）改性的沥青和碎屑-橡胶改性的沥青AR暴露在室外条件下自然风化。通过使用无滴法测试沥青的基本物理性质和表面自由能，可以追溯该过程。结果表明，沥青的基本物理性能在自然风化过程中发生了显着变化，并且橡胶沥青具有优异的耐老化性，而纯净的沥青A70具有很高的老化敏感性。此外，SBS和橡胶粉末改性剂的存在改变了纯沥青表面自由能的变化趋势。骨料和沥青之间的粘附作用可用于定量评估它们之间的粘附性能。同时，沥青和骨料之间的水分的存在将内聚破坏从粘着破坏变为粘着破坏。