Cargando…
Multiscale poromechanics of wet cement paste
Capillary effects, such as imbibition drying cycles, impact the mechanics of granular systems over time. A multiscale poromechanics framework was applied to cement paste, which is the most common building material, experiencing broad humidity variations over the lifetime of infrastructure. First, th...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
National Academy of Sciences
2019
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561161/ https://www.ncbi.nlm.nih.gov/pubmed/31072922 http://dx.doi.org/10.1073/pnas.1901160116 |
_version_ | 1783426093445808128 |
---|---|
author | Zhou, Tingtao Ioannidou, Katerina Ulm, Franz-Josef Bazant, Martin Z. Pellenq, R. J.-M. |
author_facet | Zhou, Tingtao Ioannidou, Katerina Ulm, Franz-Josef Bazant, Martin Z. Pellenq, R. J.-M. |
author_sort | Zhou, Tingtao |
collection | PubMed |
description | Capillary effects, such as imbibition drying cycles, impact the mechanics of granular systems over time. A multiscale poromechanics framework was applied to cement paste, which is the most common building material, experiencing broad humidity variations over the lifetime of infrastructure. First, the liquid density distribution at intermediate to high relative humidity is obtained using a lattice gas density functional method together with a realistic nanogranular model of cement hydrates. The calculated adsorption/desorption isotherms and pore size distributions are discussed and compare well with nitrogen and water experiments. The standard method for pore size distribution determination from desorption data is evaluated. Second, the integration of the Korteweg liquid stress field around each cement hydrate particle provided the capillary forces at the nanoscale. The cement mesoscale structure was relaxed under the action of the capillary forces. Local irreversible deformations of the cement nanograins assembly were identified due to liquid–solid interactions. The spatial correlations of the nonaffine displacements extend to a few tens of nanometers. Third, the Love–Weber method provided the homogenized liquid stress at the micrometer scale. The homogenization length coincided with the spatial correlation length of nonaffine displacements. Our results on the solid response to capillary stress field suggest that the micrometer-scale texture is not affected by mild drying, while nanoscale irreversible deformations still occur. These results pave the way for understanding capillary phenomena-induced stresses in heterogeneous porous media ranging from construction materials to hydrogels and living systems. |
format | Online Article Text |
id | pubmed-6561161 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | National Academy of Sciences |
record_format | MEDLINE/PubMed |
spelling | pubmed-65611612019-06-17 Multiscale poromechanics of wet cement paste Zhou, Tingtao Ioannidou, Katerina Ulm, Franz-Josef Bazant, Martin Z. Pellenq, R. J.-M. Proc Natl Acad Sci U S A Physical Sciences Capillary effects, such as imbibition drying cycles, impact the mechanics of granular systems over time. A multiscale poromechanics framework was applied to cement paste, which is the most common building material, experiencing broad humidity variations over the lifetime of infrastructure. First, the liquid density distribution at intermediate to high relative humidity is obtained using a lattice gas density functional method together with a realistic nanogranular model of cement hydrates. The calculated adsorption/desorption isotherms and pore size distributions are discussed and compare well with nitrogen and water experiments. The standard method for pore size distribution determination from desorption data is evaluated. Second, the integration of the Korteweg liquid stress field around each cement hydrate particle provided the capillary forces at the nanoscale. The cement mesoscale structure was relaxed under the action of the capillary forces. Local irreversible deformations of the cement nanograins assembly were identified due to liquid–solid interactions. The spatial correlations of the nonaffine displacements extend to a few tens of nanometers. Third, the Love–Weber method provided the homogenized liquid stress at the micrometer scale. The homogenization length coincided with the spatial correlation length of nonaffine displacements. Our results on the solid response to capillary stress field suggest that the micrometer-scale texture is not affected by mild drying, while nanoscale irreversible deformations still occur. These results pave the way for understanding capillary phenomena-induced stresses in heterogeneous porous media ranging from construction materials to hydrogels and living systems. National Academy of Sciences 2019-05-28 2019-05-09 /pmc/articles/PMC6561161/ /pubmed/31072922 http://dx.doi.org/10.1073/pnas.1901160116 Text en Copyright © 2019 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/ https://creativecommons.org/licenses/by-nc-nd/4.0/This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) . |
spellingShingle | Physical Sciences Zhou, Tingtao Ioannidou, Katerina Ulm, Franz-Josef Bazant, Martin Z. Pellenq, R. J.-M. Multiscale poromechanics of wet cement paste |
title | Multiscale poromechanics of wet cement paste |
title_full | Multiscale poromechanics of wet cement paste |
title_fullStr | Multiscale poromechanics of wet cement paste |
title_full_unstemmed | Multiscale poromechanics of wet cement paste |
title_short | Multiscale poromechanics of wet cement paste |
title_sort | multiscale poromechanics of wet cement paste |
topic | Physical Sciences |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561161/ https://www.ncbi.nlm.nih.gov/pubmed/31072922 http://dx.doi.org/10.1073/pnas.1901160116 |
work_keys_str_mv | AT zhoutingtao multiscaleporomechanicsofwetcementpaste AT ioannidoukaterina multiscaleporomechanicsofwetcementpaste AT ulmfranzjosef multiscaleporomechanicsofwetcementpaste AT bazantmartinz multiscaleporomechanicsofwetcementpaste AT pellenqrjm multiscaleporomechanicsofwetcementpaste |