Open AccessEffect of air pressure on moisture transfer inside porous building materials
Author(s) -
Fukui Kazuma,
Iba Chiemi,
Hokoi Shuichi,
Ogura Daisuke
Publication year - 2018
Publication title -
japan architectural review
Language(s) - English
Resource type - Journals
ISSN - 2475-8876
DOI - 10.1002/2475-8876.12047
Subject(s) - moisture , materials science , porous medium , airflow , porosity , brick , composite material , compressed air , atmospheric pressure , absorption (acoustics) , air water , mechanics , thermodynamics , meteorology , physics
The effect of air pressure on moisture transfer inside porous building materials cannot be omitted in cases where air cannot escape through the surface of the materials; in such cases, air is compressed by the movement of moisture. In this study, we conducted water‐absorption tests on a brick specimen. By comparing the result of the experiment on a specimen whose side surfaces were sealed with that of a specimen whose bottom surface was additionally sealed, it was demonstrated that the water‐absorption was evidently delayed in the latter case, wherein air could not escape from the specimen except for the top surface, through which water was absorbed. We also developed a numerical model based on the equations for simultaneous air and moisture transfer. The calculated result is reasonably consistent with the experimental result, which supports the validity of the model that includes the change in air pressure in the material and air loss through the top surface as air bubbles. By using this model, the behavior of the air and water inside the specimen was investigated in detail.