Bitumen is a widely used material employed as a binder in pavement engineering and as a surface sealant in construction. Its surface microstructure and microscale properties have been shown to be temperature‐dependent, with effects manifesting themselves on surface composition and texture, including the formation of the visually striking catana ‘bee’‐like structures. Despite the importance of a good performance of bitumen in subzero environments (<0°C), the behaviour of bitumen surface texture and composition at cold temperatures, affecting cracking, degradation and road icing, has received practically no attention. In particular, such knowledge is relevant to world regions experiencing long periods of subzero temperatures during the year. Employing advanced atomic force microscopy combined with infrared spectroscopy (AFM‐IR) and an environmental chamber, we demonstrate the ability to characterise surface structure and composition with nanoscale precision for a broad range of temperatures. We show that cooling bitumen to subzero temperatures can have several interesting effects on its surface microtexture, nanotexture and composition, especially on its three surface domains, catana, peri and para. We found that the para domain coarsens and extends to form an interfacial transition domain (characterised by increasing surface roughness with peri domain composition) between the para and peri domains. We show that the catana and peri domains have a similar composition, but have different mechanical and chemical properties compared to the para domain. The essential findings of this work improve our understanding of the behaviour of bitumen in subzero environments, aiding us in our quest towards attaining better road and sealant performance.

中文翻译：

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零下环境中沥青表面微结构的演变

沥青是一种广泛使用的材料，用作路面工程中的粘合剂和建筑中的表面密封剂。其表面微观结构和微观特性已被证明与温度有关，其影响表现在表面成分和质地上，包括形成视觉上引人注目的卡塔纳“蜜蜂”状结构。尽管沥青在零下环境 (<0°C) 中的良好性能很重要，但沥青表面质地和成分在低温下的行为会影响开裂、降解和道路结冰，但实际上并未受到关注。特别是，这些知识与一年中经历长期零下温度的世界地区有关。采用先进的原子力显微镜结合红外光谱 (AFM-IR) 和环境室，我们展示了在广泛的温度范围内以纳米级精度表征表面结构和成分的能力。我们表明，将沥青冷却到零度以下的温度可以对其表面微观结构、纳米结构和成分产生多种有趣的影响，尤其是对其三个表面域 catana、peri 和 para。我们发现对域变粗并延伸以在对域和周域之间形成界面过渡域（特征在于随着周域组成增加表面粗糙度）。我们表明 catana 和 peri 域具有相似的组成，但与 para 域相比具有不同的机械和化学性质。