The paving asphalts have long been recognized to be capable of self-healing. The objective of this study was to evaluate the healing potential of asphalt binders and investigate its relationship with molecular characteristics in terms of composition and structures. Five neat and styrene–butadiene–styrene (SBS) modified asphalt binders were characterized using the recently developed linear amplitude sweep-based healing test. The data were analyzed based on the viscoelastic continuum damage theory to establish healing master curves and determine the healing rate H^R. Chemical evaluation methods included saturates, aromatics, resins, and asphaltenes fractionation, gel permeation chromatography, and nuclear magnetic resonance spectroscopy. Results indicated that the presence of more light/low-polarity fractions of saturates and aromatics or higher concentrations of small molecules promoted healing, as these molecules were expected to have higher mobility facilitating molecular diffusion across crack interfaces. Lower percentages of aromatic ring structures and more aliphatic chains corresponded to higher healing rates. The SBS-modified asphalt binders contained higher concentrations of aromatic rings, but still provided comparable healing potential with the neat asphalts.

中文翻译：

---

净聚合物改性沥青粘合剂的自修复研究

长期以来，人们一直认为铺路沥青能够自我修复。这项研究的目的是评估沥青粘合剂的愈合潜力，并研究其与分子特征在组成和结构方面的关系。使用最近开发的基于线性振幅扫描的愈合测试对五种纯净的和苯乙烯-丁二烯-苯乙烯（SBS）改性的沥青粘合剂进行了表征。基于粘弹性连续体损伤理论对数据进行分析，以建立愈合主曲线并确定愈合速率H ^R。化学评估方法包括饱和油，芳烃，树脂和沥青质分馏，凝胶渗透色谱法和核磁共振波谱法。结果表明，存在更多的光/低极性级分的饱和物和芳族化合物或较高浓度的小分子可促进愈合，因为这些分子有望具有更高的迁移率，从而促进分子在裂纹界面上的扩散。较低的芳香环结构百分比和更多的脂肪链对应于较高的治愈率。SBS改性的沥青粘合剂含有较高浓度的芳环，但仍提供了与纯沥青相当的修复潜力。