Concentration dependent diffusion in building materials - application of different methods

Abstract

Moisture is an important factor when analyzing the behaviour of building elements and materials. A deeper knowledge on moisture transport under transient conditions of environmental air temperature and humidity is required. In this experimental work, the measurements of moisture diffusion coefficients, D-w, of three different types of building materials commonly used in Portugal (gypsum plasterboard, gypsum plaster and gypsum+lime plaster) were obtained for different values of temperature and relative humidity. The results obtained were in good agreement with the values found in literature and show that the increase in temperature resulted in an increase in the diffusion coefficient and an increase in relative humidity (54% to 69%) resulted in a decrease in D-w.