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A platform for research: civil engineering, architecture and urbanism
Water diffusion mechanisms in bitumen studied through molecular dynamics simulations
https://orcid.org/0000-0002-4036-3629
https://orcid.org/0000-0001-6745-163X
https://orcid.org/0000-0001-7477-9684
https://orcid.org/0000-0002-8830-9437
Abstract Water transport is one of the major factors responsible for moisture damage in asphalt pavements. To study the thermodynamics and kinetics of water transport in bitumen and to uncover microscale mechanisms of moisture-induced damage, molecular dynamics simulations were performed for up to 600 ns for water–bitumen systems with realistic water contents that varied from 0 to 1.76 wt%. Hydrogen bonding interactions and clustering of water molecules at various combinations of temperature and water content were investigated, and their effects on the self-diffusion coefficient of water and bitumen properties are computed and discussed. It is shown that the saturated water concentration in bitumen is small, especially at low temperatures, and additional water molecules tend to form large water clusters via hydrogen bonding, indicating micro-phase separation of the water and bitumen phases inside the simulation box. Hydrogen bonding and water clustering play a crucial role on the magnitude of the self-diffusion coefficient of water. Physical properties of bitumen that include viscosity and cohesive energy are affected by water. The presence of large water clusters is indicative of how degradation in cohesion is observed on the microscale.
Graphical abstract Display Omitted
Highlights Molecular simulations of water-bitumen systems conducted with durations up to 600 ns. Water at low concentrations is free, hydrogen bonded to bitumen, or in small clusters. Water at higher concentrations forms large clusters that indicate phase separation. Self diffusion coefficient for free water is 100x higher than for water in clusters. Presence of water in bitumen can lead to decreases in viscosity and cohesive energy.
Water diffusion mechanisms in bitumen studied through molecular dynamics simulations
https://orcid.org/0000-0002-4036-3629
https://orcid.org/0000-0001-6745-163X
https://orcid.org/0000-0001-7477-9684
https://orcid.org/0000-0002-8830-9437
Abstract Water transport is one of the major factors responsible for moisture damage in asphalt pavements. To study the thermodynamics and kinetics of water transport in bitumen and to uncover microscale mechanisms of moisture-induced damage, molecular dynamics simulations were performed for up to 600 ns for water–bitumen systems with realistic water contents that varied from 0 to 1.76 wt%. Hydrogen bonding interactions and clustering of water molecules at various combinations of temperature and water content were investigated, and their effects on the self-diffusion coefficient of water and bitumen properties are computed and discussed. It is shown that the saturated water concentration in bitumen is small, especially at low temperatures, and additional water molecules tend to form large water clusters via hydrogen bonding, indicating micro-phase separation of the water and bitumen phases inside the simulation box. Hydrogen bonding and water clustering play a crucial role on the magnitude of the self-diffusion coefficient of water. Physical properties of bitumen that include viscosity and cohesive energy are affected by water. The presence of large water clusters is indicative of how degradation in cohesion is observed on the microscale.
Graphical abstract Display Omitted
Highlights Molecular simulations of water-bitumen systems conducted with durations up to 600 ns. Water at low concentrations is free, hydrogen bonded to bitumen, or in small clusters. Water at higher concentrations forms large clusters that indicate phase separation. Self diffusion coefficient for free water is 100x higher than for water in clusters. Presence of water in bitumen can lead to decreases in viscosity and cohesive energy.
Water diffusion mechanisms in bitumen studied through molecular dynamics simulations
https://orcid.org/0000-0002-4036-3629
https://orcid.org/0000-0001-6745-163X
https://orcid.org/0000-0001-7477-9684
https://orcid.org/0000-0002-8830-9437
Abstract Water transport is one of the major factors responsible for moisture damage in asphalt pavements. To study the thermodynamics and kinetics of water transport in bitumen and to uncover microscale mechanisms of moisture-induced damage, molecular dynamics simulations were performed for up to 600 ns for water–bitumen systems with realistic water contents that varied from 0 to 1.76 wt%. Hydrogen bonding interactions and clustering of water molecules at various combinations of temperature and water content were investigated, and their effects on the self-diffusion coefficient of water and bitumen properties are computed and discussed. It is shown that the saturated water concentration in bitumen is small, especially at low temperatures, and additional water molecules tend to form large water clusters via hydrogen bonding, indicating micro-phase separation of the water and bitumen phases inside the simulation box. Hydrogen bonding and water clustering play a crucial role on the magnitude of the self-diffusion coefficient of water. Physical properties of bitumen that include viscosity and cohesive energy are affected by water. The presence of large water clusters is indicative of how degradation in cohesion is observed on the microscale.
Graphical abstract Display Omitted
Highlights Molecular simulations of water-bitumen systems conducted with durations up to 600 ns. Water at low concentrations is free, hydrogen bonded to bitumen, or in small clusters. Water at higher concentrations forms large clusters that indicate phase separation. Self diffusion coefficient for free water is 100x higher than for water in clusters. Presence of water in bitumen can lead to decreases in viscosity and cohesive energy.
Water diffusion mechanisms in bitumen studied through molecular dynamics simulations
Ma, Lili (author) / Salehi, Hirad S. (author) / Jing, Ruxin (author) / Erkens, Sandra (author) / Vlugt, Thijs J.H. (author) / Moultos, Othonas A. (author) / Greenfield, Michael L. (author) / Varveri, Aikaterini (author)
2023-10-13
Article (Journal)
Electronic Resource
English
Water diffusion in bitumen films
| Elsevier | 2021
| British Library Online Contents | 2018
| British Library Online Contents | 2018