Wang Ming, Wang Yuxuan, Guo Jingxuan, Xing Chengwei, Zou Lingyun, Tian Shuaituan
School of Transportation Science and Engineering, Civil Aviation University of China, Tianjin 300300, China.
Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang'an University, South 2nd Ring Road Middle Section, Xi'an 710064, China.
Polymers (Basel). 2024 Sep 7;16(17):2537. doi: 10.3390/polym16172537.
The objective of this study is to recognize and characterize the nanoscale phase modulus mapping of the asphalt film in pavement mixture cores using atomic force microscopy quantitative nanomechanical technology. The pavement core samples from the upper and middle layers of four highways and laboratory samples were taken as the research object. The phase modulus-macro property correlation of recovered asphalt was analyzed using mathematical statistics. The results showed that the pavement core samples had more significant multi-phase and diversified phase characteristics compared to lab samples. This indicated that the asphalt in the pavement core had an obvious phase separation phenomenon due to aging. The phase modulus of each sample was distributed across a relatively wide numerical range, and there were also many numerical points with large fluctuations. Especially for the mixture sample containing SBS (Styrene-Butadiene-Styrene)-modified asphalt, the phase modulus distribution mappings presented a multi-peak phenomenon. Hence, considering the distribution characteristics of the data, the box plot method was introduced. Compared with quantified results from laboratory samples, the phase modulus of SBS-modified asphalt increased by 0.96 times, 1.18 times and 1.15 times, and that of base asphalt increased by 0.59 times, 0.56 times, 0.42 times, 1.24 times and 0.39 times, respectively. This indicates that the aging degree of asphalt in the upper layer was generally greater than that of the asphalt in the middle layer and that there was an aging gradient in the direction of pavement depth. All points were within the 95% confidence band in terms of correlation fitting, indicating a better fitting effect between phase modulus and complex shear modulus, as well as between phase modulus and penetration. This research provides innovative ideas for future multi-scale numerical simulation and cross-scale performance model development of asphalt binders.
本研究的目的是利用原子力显微镜定量纳米力学技术识别并表征路面混合料芯样中沥青膜的纳米级相模量映射。以四条高速公路上、中层的路面芯样和实验室样品为研究对象。运用数理统计方法分析了回收沥青的相模量与宏观性能的相关性。结果表明，与实验室样品相比，路面芯样具有更显著的多相性和多样化的相特征。这表明路面芯样中的沥青由于老化而出现明显的相分离现象。每个样品的相模量分布在相对较宽的数值范围内，也有许多波动较大的数值点。特别是对于含有SBS（苯乙烯-丁二烯-苯乙烯）改性沥青的混合料样品，相模量分布图呈现出多峰现象。因此，考虑到数据的分布特征，引入了箱线图法。与实验室样品的量化结果相比，SBS改性沥青的相模量分别提高了0.96倍、1.18倍和1.15倍，基质沥青的相模量分别提高了0.59倍、0.56倍、0.42倍、1.24倍和0.39倍。这表明上层沥青的老化程度总体上大于中层沥青，且在路面深度方向上存在老化梯度。在相关性拟合方面，所有点均在95%置信带内，表明相模量与复剪切模量以及相模量与针入度之间具有较好的拟合效果。本研究为今后沥青结合料的多尺度数值模拟和跨尺度性能模型开发提供了创新思路。
