摘要
沥青混合料在外界环境的影响下很容易发生氧化老化,且沥青内部化学组分众多,对宏观性能均有一定的影响。本研究基于分子动力学模拟等手段,从微观的角度研究紫外光对沥青膜老化梯度行为的影响。通过建立集料—沥青—集料三层模型,模拟了不同温度下氧气在沥青膜中的扩散行为;通过傅里叶红外光谱测试及原子力学显微镜测试,分析了老化后试件化学组分的变化情况并通过力曲线图计算研究了试样微观力学的变化。结果表明,氧分子在沥青膜内的活性会随着温度升高而提高,氧分子浓度的增加使沥青发生氧化反应的概率增加。温度较低时,沥青路面的老化主要受紫外老化的影响。随着老化时间的增加,沥青膜内部会随老化程度差异的增大而发生流动混合,表层的老化程度最大甚至可以下降约30%,老化程度会随老化天数进行一定的重分布。
The asphalt mixtures are susceptible to oxidative ageing due to their various properties under the influence of the external environment,and there are many chemical components within asphalt that have an influence on the macroscopic properties.Based on molecular dynamics simulation and other means,this paper investigated the effect of UV light on the ageing gradient behavior of asphalt films from both a macroscopic and microscopic perspective.This paper firstly simulated the diffusion behavior of oxygen in the asphalt film at different temperatures by establishing a three-layer model of aggregate asphalt aggregate;the asphalt specimens after UV aging were layered and encapsulated,and tested by Fourier infrared spectroscopy and atomic force microscopy.The changes of chemical components of the specimens after aging were analyzed by infrared spectrograms as well as the changes of micromechanics of the specimens were studied by force diagram calculations,so as to analyze the effect of UV light on the aging gradient.The results show that the activity of oxygen molecules in asphalt film will increase with the increase of temperature,and the increase of oxygen molecule concentration will increase the probability of asphalt oxidation reaction.At low temperature,the aging of asphalt pavement is mainly affected by UV aging.With the increase of aging time,the asphalt film will flow and mix internally with the increase of aging degree difference.The aging degree of the surface layer can even drop by about 30%at most,and the aging degree will redistribute to some extent with the aging days.
作者
方珑
李政
王伟成
毛自根
刘奇
于斌
FANG Long;LI Zheng;WANG Weicheng;MAO Zigen;LIU Qi;YU Bin(Zhangjiagang Municipal Transportation Bureau,Zhangjiagang Jiangsu 215638,China;Huashe Design Group Co.,Ltd.,Nanjing Jiangsu 210014,China;Anji County Transportation Investment and Development Group Co.,Ltd.,Huzhou Zhejiang 313399,China;School of Transportation,Southeast University,Nanjing Jiangsu 210018,China)
出处
《交通节能与环保》
2024年第1期141-146,共6页
Transport Energy Conservation & Environmental Protection
关键词
紫外老化
沥青膜
老化梯度
分子动力学模拟
UV ageing
asphalt film
ageing gradient
molecular dynamics simulation
