Moisture Transport in Concrete — Field Tests and Hygrothermal Simulations

Abstract

There is an increasing necessity to apply retrofitting measures to external elements made of concrete employing a wide variety of procedures and materials. In this context, questions regarding moisture behaviour and the related transport processes occurring under natural climatic conditions as well as the risks thus involved always occur. These questions can either be answered with the help of experiments or by numerical simulations. Because experiments are often time-consuming and, in some cases, both problematic and expensive, intensive work has been done over the past few years on the development of mathematical approaches and procedures to evaluate real thermal and moisture transfer processes. The present problem of such calculation methods lies mainly in the availability of the required material properties or transport coefficients. If these are present, moisture calculation procedures can make a considerable contribution towards the estimation, evaluation and optimization of the moisture behaviour of external structural components under real climatic conditions. As far as the moisture properties of concrete as a building material are concerned, a great deal of investigatory work still needs to be done. Within the framework of this study, the material properties and transport coefficients needed to apply moisture calculation procedures to a selected, commonly used type of concrete are to be determined. The moisture transport calculations carried out using these parameters and the PC program WUFI [4] are to be compared, for validation purposes, with laboratory and field measurements.