Molecular dynamics simulation of nano-crack formation in asphalt binder with different SARA fractions

Wei Sun, Hao Wang

Research output: Contribution to journalArticlepeer-review

Abstract

It is challenging to understand crack formation at the nanoscale in asphalt that is invisible from the surface owing to experimental limitations. This study investigated the initiation and nucleation of nanovoids underlying the cracking process of asphalt binder using molecular dynamics simulation. The strain-induced tensile test was simulated to observe the cavity morphology and atomic forces in the asphalt binder. The effect of chemical composition of the asphalt binder was investigated through three asphalt models with different saturate, aromatic, resin, and asphaltene (SARA) fractions. The results indicated that the SARA fractions affected the nanovoids evolution process with respect to the volume and surface area of nanovoids. Fibrillar structures were observed at a higher strain level, and the asphaltene molecules were less possible to appear at the fibrils and the asphalt binder with higher asphaltene content had less fibrils. The initiation location of nanovoids was notably correlated with local chemical composition, indicating that nanovoids tended to initiate at the location with less concentration of asphaltene molecules and heteroatoms. In addition, asphaltene experienced a slightly higher atomic force than that of maltene. However, local force concentration was not able to be observed. The findings provided fundamental insights into the chemo-mechanics of asphalt binder in terms of crack behaviour.

Original languageEnglish (US)
Pages (from-to)789-800
Number of pages12
JournalMolecular Simulation
Volume48
Issue number9
DOIs
StatePublished - 2022

ASJC Scopus subject areas

  • General Chemistry
  • Information Systems
  • Modeling and Simulation
  • General Chemical Engineering
  • General Materials Science
  • Condensed Matter Physics

Keywords

  • Molecular dynamics simulation
  • asphalt binder
  • atomic force
  • chemical composition
  • nano-crack

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