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沥青-集料界面粘附机理的分子动力学模拟
Molecular Dynamics Simulation of Adhesion Mechanism of Asphalt-aggregate Interface
【摘要】 采用分子动力学方法研究不同集料的化学成分和温度对沥青-集料界面的粘附性能的影响,计算沥青的粘聚功和沥青-集料界面的粘附功。结果表明,沥青密度、表面自由能、内聚能密度和溶解度等的模拟值与试验测量值一致;当温度为273 K时,沥青的表面自由能和粘聚功最大,之后随温度升高而减小;范德华力对沥青混合料的粘聚和粘附性能起主要作用。氧化物与沥青之间的粘附功从大到小依次为:CaO>Al2O3>MgO>Fe2O3>SiO2;三种集料与沥青之间的粘附功从大到小依次为:粗闪长岩>辉长岩>花岗岩,碱性集料与沥青的粘附强度比酸性集料的大。当温度为298 K时,沥青-集料界面粘附功最大,与沥青的粘聚功相近,容易同时发生粘附破坏和粘聚破坏;在其他温度时,沥青的粘聚功大于界面粘附功,主要发生粘附破坏。
【Abstract】 Molecular dynamics simulation is adopted to investigate the influence of chemical composition and temperature of different aggregates on the adhesion performance of asphalt-aggregate interface. The adhesion work of asphalt and asphalt-aggregate interface was calculated. The simulated values of asphalt density, surface free energy, cohesive energy density and solubility are consistent with the experiments. The results show that both the surface free energy and cohesion work of asphalt reach the maximum at 273 K, and then decrease with the increasing temperature. Van der Waals force plays an important role in the cohesion and adhesion of asphalt mixture. The adhesion works between five oxides and asphalt are successively decreasing, CaO>Al2O3>MgO>Fe2O3>SiO2. The adhesion works between the three aggregates and asphalt are successively reduced, Coarse diorite > gabbro > granite. The adhesion strength of basic aggregate to asphalt is higher than that of acid aggregate to asphalt. The asphalt-aggregate interface adhesion work reaches the maximum at 298 K, which is close to the asphalt cohesive work, causing the adhesion and cohesive failure more likely to happen at the same time. The cohesive work of asphalt is higher than the interface adhesion work at other temperature, which mainly results in the adhesion damage.
【Key words】 Asphalt-aggregate interface; Cohesive work; Adhesive work; Adhesive failure; Molecular dynamics simulation;
- 【文献出处】 材料科学与工程学报 ,Journal of Materials Science and Engineering , 编辑部邮箱 ,2022年05期
- 【分类号】U414
- 【下载频次】255