Effects of the anisotropy of extruded earth bricks on their hygrothermal properties

• Unfired clay bricks were made by an extrusion process.
• The hygrothermal properties differed according to the side considered.
• The extrusion process influences clay platelet orientation and hygrothermal properties.

The study focuses on the thermal and hydric properties of extruded earth bricks. The thermal conductivity and water vapour permeability tests highlight anisotropic behaviour of the bricks depending on the extrusion direction during the production process. The results confirm that the extrusion process has a major influence on the orientation of clay layers and has an impact on the hygrothermal properties.