MOISTURE TRANSPORT IN POROUS BUILDING MATERIALS

Abstract

Since complex phenomena of moisture transport play a striking role in brick masonry, because of blemishing by efflorescences and damage caused by the crystallization processes, experimental studies on the laboratory scale should give insight into the dynamics of capillary suction and evaporation as well. A special test set-up, for stacks of bricks each having uniform characteristics, allows the monitoring of moisture rise in the material column, by weighing at intervals. So, two regression functions could be established having strict validity for differing brick types, test liquids and ambient climates and being furthermore transferable to masonry sections. Contrary to the evaporation formula, all terms of the fitted model for suction can readily be related to parameters which describe physical processes. These findings may serve as an approach to a better understanding of the transport of rising moisture in historical monuments.