摘要
为探讨沥青化学组成对其蜂状结构的影响,针对3种常用直馏沥青,考虑沥青中普遍存在的长链烷烃类、硫化物、稠环芳烃及沥青质类化合物的分布特性,进行了沥青微观相态组成成因的分子动力学模拟及试验研究。借助已知代表性化合物组装沥青分子模型,通过沥青元素组成、四组分分布、平均分子量及原子力显微镜形貌观测验证沥青分子模型的有效性。利用分子模型原子体积与表面特性势能场分布图及分子动力学轨迹图研究了不同分子对沥青微观相态组成的贡献。结果表明:沥青质是形成蜂状结构中高度较高的白色区的原因之一;长的烷基侧链尾部穿插在沥青质分子层间或大沥青质分子卷曲空白处,形成蜂状沉陷区;而极性大且空间位阻小的硫化物和稠环芳烃吸附在沥青质芳香环微区形成黏附力大但弹性模量低的沉陷区。
To investigate the effect of the chemical composition of asphalt binders on its bee-like structure,aimed at three common direct distillation asphalt,considering the distribution characteristics of alkane with long chain,sulfide,condensed aromatics,and asphaltenes compounds,molecular dynamics simulation and test study of the formation mechanism of the microcosmic phase state of asphalt binders were carried out.Combining assembled asphalt molecular models using known representative components,the effectiveness of models was verified in element asphalt component,the distribution of four components,average molecular weight,and the micro morphology by atomic force microscope（AFM）.The images of potential field of atom volume and surface characteristic from molecular models,as well as the trajectory charts of molecular dynamic were used to investigate the contribution of different molecules to the microcosmic phase state of asphalt binders.The results show that asphaltenes are one of the reasons for the white district formation in relatively high height of bee-like structure.Alkane with long chain can insert into the layers of asphaltene molecules or the gap of large curlingasphaltene molecules which form subsidence area in honeycomb.However,sulfide and condensed aromatics with high polar and small steric hindrance can attach to the aromatic segments of asphaltene and lead to a subsidence areas with high value of adhesive force but low value of elastic modulus.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2016年第3期9-16,共8页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51278159
51478154)
关键词
道路工程
直馏沥青
分子模拟
蜂状结构
微观相态
化学组成
road engineering
direct distillation asphalt
molecular simulation
bee-like structures
microcosmic phase state
chemical component
