Moisture effect on nanostructure and adhesion energy of asphalt on aggregate surface: A molecular dynamics study

Wei Sun, Hao Wang

Research output: Contribution to journalArticle

Abstract

This study aims at investigating the moisture effect on nanostructure and adhesive energy of asphalt-aggregate interface in asphalt mixture at atomistic scale. Molecular Dynamics (MD) simulations were conducted to study the molecular interaction between virgin and aged asphalt binder with silica and calcite. The MD simulation results were used to investigate the effect of water intrusion on the nanostructure of virgin and aged asphalt binder on aggregate surface. The adhesion energy and debonding energy of asphalt-aggregate interface were compared at dry and wet conditions. In particular, the contributions of saturate, aromatic, resin, and asphaltene (SARA) components of asphalt binder to total adhesion energy were decomposed and analyzed. It was found that the existence of interfacial water changed the nanostructure of asphalt binder, including the self-aggregation of asphaltene and the distribution characteristics of SARA components. Although oxidative aging had different influences on adhesion energy of asphalt binder with silica and calcite, the interfacial water reduced adhesion energy regardless of aggregate type. The SARA components of asphalt binder exhibited different bonding ability with aggregate. The moisture effect on adhesion energy of SARA components varied in different trends, different from the overall adhesion energy.

Original languageEnglish (US)
Article number145435
JournalApplied Surface Science
Volume510
DOIs
Publication statusPublished - Apr 30 2020

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

Keywords

  • Adhesion energy
  • Asphalt-aggregate interface
  • Debonding
  • Moisture effect
  • Molecular dynamics
  • Nanostructure

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