Diffusion behavior of waste soybean oil rejuvenated bitumen based on molecular simulation
To gain insight into the interaction and diffusion behavior of components in waste soybean oil rejuvenated bitumen from a molecular scale,the molecular models of base bitumen,aged bitumen and rejuvenated bitumen were constructed by means of molecular dynamics simulation,and the double-layer bitumen(bitumen-bitumen)models were constructed.The interaction energy and mean square displacement(MSD)were utilized to characterize the diffusion behavior of components in the rejuvenated bitumen models and the binding strength between waste soybean oil and bitumen components.The interfacial interaction energy and molecular diffusion behavior of the double-layer bitumen models were evaluated.The results showed that there was an attractive interaction between the waste soybean oil and bitumen components,and the interaction energy of 5%waste soybean oil rejuvenated bitumen was approximately 95.8%higher than that of 2%waste soybean oil rejuvenated bitumen,indicating that with the increase of the amount of waste soybean oil,the interaction energy gradually increased.By calculating the MSD,it was found that with the increase of the amount of waste soybean oil,the diffusion performance of the bitumen components in the rejuvenated bitumen model gradually increased.The waste soybean oil could effectively improve the molecular migration ability of the bitumen components in the aged bitumen model,while the component migration ability could not fully be restored to the level of base bitumen.The interfacial interaction energy of the base bitumen-aged bitumen model decreased by approximately 8.6%compared with that of base bitumen-base bitumen model,showing that the interfacial interaction ability of the virgin-aged bitumen at the molecular scale was attenuated.With the increase of the amount of waste soybean oil,the van der Waals interaction was gradually enhanced,and the interfacial interaction energy of base bitumen-8%waste soybean oil rejuvenated bitumen was basically the same as that of base bitumen-aged bitumen.The components in the base bitumen-rejuvenated bitumen model had a great diffusion rate when the content of waste soybean oil was 2%—5%.The results provided a theoretical basis for the application of waste soybean oil rejuvenated bitumen from the molecular scale.
rejuvenated bitumenwaste soybean oilmolecular dynamicsmean square displacementinteraction energy
国家科技期刊平台
NSTL
万方数据
