Numerical Simulation of Moisture Transport Along Ceramic Bricks

Numerical Simulation of Moisture Transport Along Ceramic Bricks—Wetting Process

Araújo, C. M. / Azevedo, A. C. / Silva, F. A. N.

The moisture transport in brick masonry is an important phenomenon in several deterioration mechanisms. However, is a very complex process and is influenced by many physical phenomena. Investigation of the moisture transfer through a building wall, which in general, consists of multiple layers, presumes knowledge about the continuity between layers. In this study, three types of contact configurations were analysed, as follows: Hydraulic contact, Perfect contact, and Air space. Therefore, to understand the moisture transport in brick masonry the moisture transport through the interface of materials was analyzed. This was done for samples of brick-cement mortar, brick-lime mortar, and air space between brick-layers, as well as for samples with different interface location heights and different mortar thicknesses and air space. Mainly, the present work is concerned to simulate the hygrothermal behaviour across brick–mortar and brick-brick interfaces to compare the results with the laboratory analysis. The numerical simulations of brick–mortar and brick-brick samples were performed with the hygrothermal simulation software WUFI-2D. The data used to run the simulations were taken from the wetting experiments on the samples; the corresponding moisture content profiles were measured using gamma-ray spectrometer. Although the mechanisms of moisture transport in a single building material have been and continue to be extensively studied, the hydraulic characteristics of the interface at different types of contacts between materials are still poorly comprehended and for this reason, the simplified assumption of perfect contact, is widely used in hygrothermal models. In general terms, the assumption of perfect contact implies that the interface will have no effect on moisture transport. In comparison, the imperfect contact assumption implies that the interface between building materials will resist moisture transport. However, comparisons between experimental and numerical results were used to investigate whether the perfect contact assumption is appropriate for real samples.