Uptake of water (and therefore ions) by unsaturated, hardened concrete may be characterised by the sorptivity. This is a simple parameter to determine and is increasingly being used as a measure of concrete resistance to exposure in aggressive environments. The complete process is described by a nonlinear diffusion equation, with the hydraulic diffusivity a strongly nonlinear function of the degree of saturation of the concrete. Accurate analytical approximations to the solution of this equation, as well as numerical solutions for general conditions, exist when the diffusivity function is known. Unfortunately, it is not an easy function to determine, requiring accurate information on the water penetration profile. A simple alternative which estimates the diffusivity from sorptivity and porosity measurements is presented for an assumed exponential dependence of diffusivity on water saturation. Predicted water penetration profiles corresponding to this estimated diffusivity are shown to be accurate by comparison with published experimental results.
RESUMg
This report is one of a continuing series of Research Reports published by the Department of Civil Engineering at the University of Queensland. This Department also publishes a continuing series of Bulletins. Lists of recently published titles in both of these series are provided inside the back cover of this report. Requests for copies of any of these documents should be addressed to the Departmental Secretary. The interpretations and opinions expressed herein are solely those of the author(s). Considerable care has been taken to ensure the accuracy of the material presented. Nevertheless, responsibility for the use of this material rests with the user.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.