Hygroscopic and mechanical behaviour of earth bricks

Considering the challenges imposed by the current movement towards green development, earth construction appears to offer promising possibilities for improving thermal comfort, energy consumption and indoor humidity regulation. However, the difficulties in predicting the behaviour of earth as a construction material is an obstacle to the development of this technique. The principal objective of this study is to establish the scientific bases needed to predict its hygroscopic and mechanical behaviour as a function of the relative humidity that is one of the main factors controlling the home confort. For this purpose, it is necessary to find correlations between the variability of the soils (density, pore size distribution, chemical and mineralogical composition) and the hygromechanical behaviour of the earth bricks (adsorption, hydric buffering and compressive strength). The results, in terms of hydric and mechanical behaviour specific to each brick, show that the behaviour of this material depends on several factors, namely, the SiO2/Al2O3 ratio, the porosity rate, the pore size distribution, the nature of the clay minerals, and their content.