Liu, Cheng;
Zhang, Mingzhong;
(2022)
Multiscale modelling of ionic diffusivity in unsaturated concrete accounting for its hierarchical microstructure.
Cement and Concrete Research
, 156
, Article 106766. 10.1016/j.cemconres.2022.106766.
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Abstract
This study presents an integrated multiscale framework for modelling ionic diffusivity in unsaturated concrete accounting for its microstructural features and 3D moisture distribution. The hierarchical microstructure of concrete at multiscale from nano- to meso-scale is mimicked, based on which the fluid-solid interaction and moisture distribution in pore network of concrete with various saturation levels are simulated using a lattice Boltzmann multiphase model. A lattice Boltzmann-finite difference model for diffusion is developed to mimic the ionic diffusion and predict the ionic diffusivity in unsaturated concrete. Results indicate that ionic diffusivity in unsaturated concrete highly depends on moisture content and distribution, pore structure, and aggregate content. As the water saturation level drops to around 90%, interfacial transition zone starts to retard ionic diffusion. Voids have a great contribution to water saturation level but less effect on ionic diffusivity. The simulation results of ionic diffusivity at each scale agree well with experimental data.
| Type: | Article |
|---|---|
| Title: | Multiscale modelling of ionic diffusivity in unsaturated concrete accounting for its hierarchical microstructure |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.cemconres.2022.106766 |
| Publisher version: | https://doi.org/10.1016/j.cemconres.2022.106766 |
| Language: | English |
| Additional information: | © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
| Keywords: | Partial saturation, C-S-H, Pore structure, Diffusion coefficient, Lattice Boltzmann method |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Civil, Environ and Geomatic Eng UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10144655 |
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