TY - JOUR
T1 - Water Vapor Sorption in Cementitious Materials-Measurement, Modeling and Interpretation
AU - Kumar, Aditya
AU - Ketel, Sabrina
AU - Vance, Kirk
AU - Oey, Tandre
AU - Neithalath, Narayanan
AU - Sant, Gaurav
N1 - Funding Information:
Acknowledgments The authors acknowledge full financial support for this research provided by the University of California, Los Angeles (UCLA). The authors would like to acknowledge Gwenn Le Saout (École des Mines d’Alès) for quantitative x-ray diffraction analyses (QXRD) of the alite and cement. The contents of this paper reflect the views of the authors who are responsible for the accuracy of datasets presented herein. This research was conducted in the Laboratory for the Chemistry of Construction Materials (LC2) in the Department of Civil and Environmental Engineering and the Molecular Instrumentation Center (MIC) in the Department of Chemistry and Biochemistry at the University of California, Los Angeles (UCLA) and Laboratory for the Science of Sustainable Infrastructural Materials (LS-SIM) at Arizona State University (ASU). The authors acknowledge the support of these laboratories in making this research possible.
PY - 2014/5
Y1 - 2014/5
N2 - The rate and extent of uptake and release of moisture are critical in controlling the behavior of cementitious materials ranging from fluid transport to hygral deformations. While classically determined using an equilibrium (static) salt solution method (Baroghel-Bouny in Cem Concr Res 37:414-437, 2007), advanced capabilities offered by gravimetric dynamic vapor sorption (DVS) analyzers, are now permitting acquisition of sorption spectra at microgram (μg) resolution on the order of a few weeks. This work highlights new multicycle determinations of adsorption/desorption isotherms, acquired using a custom-built DVS analyzer for well-hydrated alite and ordinary portland cement pastes over a range of water-to-solid ratios (w/s, mass basis). Special focus is paid to describe measurement aspects relevant to acquiring reliable spectra, and their interpretation. Sorption isotherms are used to assess transport properties, and sorption hysteresis and its irreversibility following first drying. Based on an optimization-based criterion, the Young-Nelson model is selected to simulate sorption evolutions, including the effects of hysteresis. Sensitivity analyses carried out using this model are used to understand the role of parameters, including porosity and w/s, on the hysteresis that develops from the first to subsequent sorption cycles.
AB - The rate and extent of uptake and release of moisture are critical in controlling the behavior of cementitious materials ranging from fluid transport to hygral deformations. While classically determined using an equilibrium (static) salt solution method (Baroghel-Bouny in Cem Concr Res 37:414-437, 2007), advanced capabilities offered by gravimetric dynamic vapor sorption (DVS) analyzers, are now permitting acquisition of sorption spectra at microgram (μg) resolution on the order of a few weeks. This work highlights new multicycle determinations of adsorption/desorption isotherms, acquired using a custom-built DVS analyzer for well-hydrated alite and ordinary portland cement pastes over a range of water-to-solid ratios (w/s, mass basis). Special focus is paid to describe measurement aspects relevant to acquiring reliable spectra, and their interpretation. Sorption isotherms are used to assess transport properties, and sorption hysteresis and its irreversibility following first drying. Based on an optimization-based criterion, the Young-Nelson model is selected to simulate sorption evolutions, including the effects of hysteresis. Sensitivity analyses carried out using this model are used to understand the role of parameters, including porosity and w/s, on the hysteresis that develops from the first to subsequent sorption cycles.
KW - BET
KW - Desorption
KW - Hysteresis
KW - Sorption
KW - Surface area
KW - Water vapor
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U2 - 10.1007/s11242-014-0288-5
DO - 10.1007/s11242-014-0288-5
M3 - Article
AN - SCOPUS:84897963943
VL - 103
SP - 69
EP - 98
JO - Transport in Porous Media
JF - Transport in Porous Media
SN - 0169-3913
IS - 1
ER -