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

Gao, Yangming, Zhang, Yuqing, Gu, Fan, Xu, Tao and Wang, Hao (2018). Impact of minerals and water on bitumen-mineral adhesion and debonding behaviours using molecular dynamics simulations. Construction and Building Materials, 171 , pp. 214-222.

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.

Publication DOI: https://doi.org/10.1016/j.conbuildmat.2018.03.136
Divisions: Engineering & Applied Sciences > Aston Institute of Materials Research (AIMR)
Additional Information: © 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).
Uncontrolled Keywords: Adhesion,Aggregate minerals,Bitumen-mineral interface,Debonding,Molecular dynamics,Stripping mechanism,Civil and Structural Engineering,Building and Construction,Materials Science(all)
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
https://www.sci ... 950061818306330 (Publisher URL)
Published Date: 2018-05-20
Authors: Gao, Yangming
Zhang, Yuqing ( 0000-0001-5825-0131)
Gu, Fan
Xu, Tao
Wang, Hao

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