Stabilization effects on the thermal conductivity and sorption behavior of earth bricks

Abstract

The renaissance of earth building is mainly motivated by the thermal and hygric properties of the material. These earthen materials qualities lead to improve the hygrothermal conditions in indoor environment. Today, stabilization of earth bricks by addition of chemical stabilizers is a common approach used to maintain and improve its use for construction. Although the addition of cementitious stabilizing agents enhances the engineering properties of soil, it is not the case for their hygrothermal properties. In this work, an experimental investigation is performed on stabilizers effects on thermal conductivity and moisture sorption isotherms of compressed earth bricks. Four water vapor sorption models are evaluated by fitting the sorption isotherms data of un-stabilized and stabilized compressed earth bricks. Soil blocks have been manufacturing with locally material. They are stabilized with cement or lime contents of 5%, 8%, 10% and 12%.The results show that the thermal conductivity increases as a function of stabilizers contents. The measuredsorption data of earth bricks showed that stabilization induces a reduction of material water vapor permeability. It’s found that Henderson model is the best for fitting sorption isotherms data over the studied range of relative humidity.