Degradation of Brazilian gypsum exterior walls due to hygrothermal action

Abstract

This work is focused on the evaluation of degradation hazards of Brazilian gypsum exterior walls due to hygrothermal action. An extensive experimental characterization of the thermal conductivity, sorption isotherms, vapour permeability and water absorption coefficient of two different samples of gypsum plasters from the northeast Brazil (plaster pole of Araripe, Pernambuco) was performed. The experimental and analytical procedures followed either international standards or well-established methodologies, supporting the analysis of gypsum walls hygrothermal behaviour.The measured properties were adopted as inputs to hygrothermal simulation software and the analysis of gypsum based exterior walls was conducted for different climate zones and exposure conditions. The study demonstrates the durability issues that may arise in each location, due to differences in hygrothermal action.