纳米尺度沥青微观结构特征演化分析

发布时间：2018-06-28 17:37

本文选题：道路工程 + 老化沥青样本　；参考：《中国公路学报》2017年01期

【摘要】：为研究老化引起的沥青纳米尺度微观结构演化特征,建立微观结构演化特征与宏观尺度性能衰变之间的相关关系,分别选取实验室老化和现场老化回收的沥青样本为研究对象,利用原子力显微技术(AFM)和动态剪切流变试验(DSR),对沥青表面微观结构的演变特性和宏观性能的衰变规律进行了研究。研究结果表明:老化对沥青表面微观结构形貌有显著影响,未老化沥青和短期老化(RTFOT)沥青样本表面形貌中存在典型的"蜂相结构",长期老化(PAV)和铣刨料(RAP)中抽提回收的沥青样本其表面形貌仅呈现一些褶皱似的凸起和亮白色斑点;在纳米尺度,老化改变了沥青纳米级相态的空间分布特性,降低了相态之间表面高度差异,表面高度以及表面粗糙度指标可以量化这种空间分布的特征;宏观尺度上,沥青样本黏弹特性发生显著变化,复数剪切模量升高,相位角降低,这种流变响应可以表征老化引起的流变性能的演变。基于此,提出了沥青纳米级形貌特征和流变性能相关关系的量化表征模型。
[Abstract]:In order to study the evolution characteristics of asphalt nanoscale microstructure induced by aging and to establish the correlation between microstructure evolution characteristics and macro-scale performance decay, asphalt samples recovered from laboratory aging and field aging were selected as research objects. Atomic force microscopy (AFM) and dynamic shear rheological test (DSR) were used to study the evolution characteristics of asphalt surface microstructure and the decay law of macroscopic properties. The results show that the aging has a significant effect on the microstructure and morphology of asphalt surface. There are typical "bee phase structures" in the surface morphology of unaged asphalt and short term aging asphalt (RTFOT). The surface morphology of the recovered asphalt samples extracted from long term aging (PAV) and milling planer (rap) only shows some wrinkle protrusions and bright white spots. At nanometer scale, aging changes the spatial distribution characteristics of asphalt nanoscale phase, reduces the difference of surface height between phase states, and the surface height and surface roughness index can quantify the spatial distribution characteristics. The viscoelastic properties of asphalt samples vary significantly, the complex shear modulus increases and the phase angle decreases. This rheological response can characterize the evolution of rheological properties caused by aging. Based on this, a quantitative characterization model of the relationship between the morphology and rheological properties of asphalt was proposed.
【作者单位】：同济大学道路与交通工程教育部重点实验室;
【基金】：国家自然科学基金项目(51678443) 上海市浦江人才计划项目(PJ[2012]0001778) 江西省交通运输厅科技项目(2013C0012)
【分类号】：U414

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