The assessment of the performance of building materials exposed to harmful environments is an important challenge within the framework of service life prediction of structures, durability of materials and building maintenance. Indeed, in order to establish the right diagnosis of deterioration and to apply the right methods for preventing or at least containing building deterioration, we need to analyze its causes and mechanisms responsible for its process. Since water is often a major factor for damage or decay in buildings, the study of liquid water and water vapor transport is of great practical importance, in particular to the knowledge of transport properties.

In general, these properties (permeability, diffusivity) are easily measured experimentally for dry materials. However, it would be an advantage if they could be derived from microstructures and water content. Thus, it would be possible, on one hand, to explain experimental results and, on the other hand, to design virtual materials with desired engineering properties.

In the first part of the paper, the measured transport properties of building materials are compared to those computed based on microstructural information, consisting of 3D images simulated from 2D scanned electron microscopy images (2D-SEM). The computed values compare favorably to those measured experimentally, thus demonstrating the capability of utilizing microstructural characterizations to predict transport properties.

In order to validate this method, in the second part of the paper, we compare 3D images, obtained by modeling 2D-SEM images, with X-ray computed microtomography (CMT) images. CMT has been performed using the beam line ID19 at ESRF (European Synchrotron Research Facilities:Grenoble).