Impact of minerals and water on bitumen-mineral adhesion and debonding behaviours using molecular dynamics simulations

Yangming Gao, Yuqing Zhang*, Fan Gu, Tao Xu, Hao Wang

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

This study aims to evaluate the effects of mineral types and water on the adhesion properties and debonding behaviours of bitumen-mineral interface systems. A molecular dynamics modelling approach was employed to simulate the interactions between minerals and bitumen with and without the presence of water. Four representative minerals (quartz, calcite, albite and microcline) were selected to build the mineral-bitumen interface systems and the mineral-water-bitumen interface systems in the molecular dynamics models. The adhesion property between minerals and bitumen was quantified by work of adhesion, defined as the energy required to separate a unit area of the bitumen-mineral interface. The debonding behaviour between minerals and bitumen is characterised by work of debonding, defined as the energy required to displace bitumen by water at the mineral-bitumen interface. The simulation results were validated by available experimental results reported in the literature. It was found that the work of adhesion and the work of debonding for the four bitumen-minerals interface systems are ranked microcline > albite > calcite > quartz at both dry and wet conditions. Moisture can reduce the adhesion between minerals and bitumen by 82%, 84%, 18% and 1% for the quartz, calcite, albite and microcline, respectively. The adhesion between minerals and bitumen is attributed to the non-bond interaction energy, in which the major component is van der Waals interaction for neutral minerals (e.g., quartz) and the electrostatic interaction for the alkali minerals (e.g., calcite, albite and microcline). The bitumen-mineral debonding is a thermodynamically favourable process with reduced total potential energy of the system. It is concluded that the bitumen-mineral adhesion and debonding behaviours strongly depends on the chemistry and mineralogical properties of the minerals. This work provides a fundamental understanding of the adhesion and debonding behaviours of the bitumen-mineral interface at the atomistic scale.

Original languageEnglish
Pages (from-to)214-222
Number of pages9
JournalConstruction and Building Materials
Volume171
Early online date18 Apr 2018
DOIs
Publication statusPublished - 20 May 2018

Bibliographical note

© 2018, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

Funding: European Union’s Horizon 2020 programme via a Marie S. Curie Individual Fellowship project (Grant No. 749232 - AMAM).

Keywords

  • Adhesion
  • Aggregate minerals
  • Bitumen-mineral interface
  • Debonding
  • Molecular dynamics
  • Stripping mechanism

Fingerprint Dive into the research topics of 'Impact of minerals and water on bitumen-mineral adhesion and debonding behaviours using molecular dynamics simulations'. Together they form a unique fingerprint.

  • Cite this