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

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 mineralwater-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.

Molecular dynamics investigation of interfacial adhesion between oxidised bitumen and mineral surfaces

“…A C C E P T E D M A N U S C R I P T 5 atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to improve the interfacial adhesion performance of asphalt mixture [32,33]. MD simulations have been used to quantify the adhesion properties and debonding behaviours between a virgin (unaged) bitumen and four different minerals [34]. It was found that the bitumen-mineral interfacial adhesion is primarily attributed to van der Waals force for neutral minerals (quartz) and to electrostatic interaction for alkali minerals (calcite, albite and microcline).…”

“…In order to construct the bitumen-mineral interface system models, the mineral substrate and bitumen layer models are first prepared following the method described in the authors' previous work [34].…”

“…The combination of force field parameters for organics and inorganics makes the COMPASS force field possible to study the interfacial interaction in the mixed systems. The COMPASS force field parameters have been validated using various calculation methods [49] and it has been successfully applied for the study of the bitumen-mineral interfacial systems [34,50,51].…”

“…It is defined as the energy required to separate a unit area of the bitumen-mineral interface into a bitumen surface and a mineral surface. The work of adhesion (W BM ) is expressed as [50,34] W BM = ∆E BM / A (5)…”

Research on Relationships among Different Distress Types of Asphalt Pavements with Semi-Rigid Bases in China Using Association Rule Mining: A Statistical Point of View

“…However, asphalt pavements continuously suffer from combined effects of heavy and repeated traffic loadings and the natural environment during service lives [1]. is will bring about different distress types, such as map cracking caused by repeated traffic loadings, moisture damage, transverse cracking at low temperatures, and rutting at high temperatures [2][3][4][5]. e distresses can significantly reduce performance and shorten service lives of asphalt pavements [6].…”