Determination of water permeability for a moisture transport model with minimized batch effect

Abstract

Values of water permeability for cementitious materials reported in the literature show a large scatter. This is partially attributed to the fact that materials used in different studies are different. To eliminate the effects of cements, specimen preparation, curing conditions and other batch effects, this study employs a long cylindrical cement paste to prepare all specimens for a variety of permeability determination methods, such as beam bending, sorptivity, Katz-Thompson and Kozeny-Carman equations. Permeabilities determined by these methods are then used in a moisture transport model. Compared with the measured mass loss curves, we found that permeability determined by the beam bending method provides much closer results to the measured ones than other methods. The difference results from that the saturated specimen is used in the beam bending method while specimens in other methods are dried (or rewetted). As already shown in the literature, the microstructure of the dried or rewetted specimens is altered and different to the original microstructure of the water saturated specimens. . . .

A Dual-Permeability Approach to Study Anomalous Moisture Transport Properties of Cement-Based Materials

“…The first linear stage follows the results of conventional single-porosity model, while the second linear stage deviates from the first linear stage, which is why such a mass change curve is called anomaly. Some other studies reported the anomalous mass change curves which follow the fourth root functions (e.g., Alderete et al 2020), which is certainly different from the most data reported in the literature (Hall et al 1995;Zhou et al 2017;Zhang and Scherer 2018).…”

Modeling Anomalous Moisture Transport in Cement-Based Materials with Kinetic Permeability

“…It has been argued that the measured mass loss alone is not sufficient to identify parameters in the moisture transport model, in particular for models with more than one parameter [18,39]. This is supported by a recent study [40], which has five parameters to be determined.…”

Dynamic effect of water penetration on steel corrosion in carbonated mortar: A neutron imaging, electrochemical, and modeling study

“…In this study, we consider the heterogeneity of concrete microstructure, so K l as a function of porosity is resealable to assume. Following with previous studies [28,54], the Kozeny-Carman (KC) equation is used to calculate K l based on porosity.…”