Moisture transport in concrete during wetting/drying cycles

Abstract

An accurate description of moisture transport in concrete is significant to determine the service life of a concrete structure. Many authors managed to describe the global moisture transport in concrete during wetting/drying cycles by using Fick’s laws of diffusion. The difference between the models of the various authors lies in the use of the diffusion coefficient. There are authors who are convinced that by using two different diffusion coefficients, one for wetting and the other for drying, a better description of the moisture transport in concrete can be obtained. In this paper, this approach is examined by simulating and comparing two models, one with a single diffusion coefficient and the other with two diffusion coefficients. A comparison is made between the results of a model with two diffusion coefficients and a model with a single diffusion coefficient, where the diffusion coefficient is the average of the wetting and drying diffusion coefficient. The result is computed for one cycle of wetting and drying. The simulations show that there are differences in the results of the models. In order to validate the model and to investigate which of the models describes the moisture transport most accurately, experimental work is needed.