Hysteresis from Multiscale Porosity: Modeling Water Sorption and Shrinkage in Cement Paste
Name
PhysRevApplied.3.064009.pdf
Size
2.07 MB
Format
Adobe PDF
Checksum (MD5)
32a9cf6d31801fe5a48f4741511cbb8f
Author(s)
Pinson, Matthew B.
Masoero, Enrico
Bonnaud, Patrick A.
Manzano, Hegoi
Ji, Qing
Yip, Sidney
Thomas, Jeffrey J.
Jennings, Hamlin Manson
Bazant, Martin Z
Van Vliet, Krystyn J
Date Issued
June 2015
Journal
Physical Review Applied
Publisher
American Physical Society
Citation
Pinson, Matthew B., et al. "Hysteresis from Multiscale Porosity: Modeling Water Sorption and Shrinkage in Cement Paste." Phys. Rev. Applied 3, 064009 (June 2015). © 2015 American Physical Society
Version
Final published version
Abstract
Cement paste has a complex distribution of pores and molecular-scale spaces. This distribution controls the hysteresis of water sorption isotherms and associated bulk dimensional changes (shrinkage). We focus on two locations of evaporable water within the fine structure of pastes, each having unique properties, and we present applied physics models that capture the hysteresis by dividing drying and rewetting into two related regimes based on relative humidity (RH). We show that a continuum model, incorporating a pore-blocking mechanism for desorption and equilibrium thermodynamics for adsorption, explains well the sorption hysteresis for a paste that remains above approximately 20% RH. In addition, we show with molecular models and experiments that water in spaces of ≲1 nm width evaporates below approximately 20% RH but reenters throughout the entire RH range. This water is responsible for a drying shrinkage hysteresis similar to that of clays but opposite in direction to typical mesoporous glass. Combining the models of these two regimes allows the entire drying and rewetting hysteresis to be reproduced accurately and provides parameters to predict the corresponding dimensional changes. The resulting model can improve the engineering predictions of long-term drying shrinkage accounting also for the history dependence of strain induced by hysteresis. Alternative strategies for quantitative analyses of the microstructure of cement paste based on this mesoscale physical model of water content within porous spaces are discussed.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Massachusetts Institute of Technology. Department of Mathematics
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevApplied.3.064009
