Preliminary Results of Interlaboratory Tests on Hygrothermal Properties of CEB

Determining the hygrothermal properties of earth-based building materials on a material scale is a major challenge in order to highlight and guarantee their performance. This data is also essential to feed models at wall and building scales for prediction and optimization of their contribution to energy consumption and user’s comfort. In the context of the activities of the French National Project on earth construction (PN Terre), one round robin campaign has been launched to measure the following hygrothermal properties of compressed earth bricks (CEB): dry density, thermal conductivity, specific heat capacity, ad- and desorption isotherms and water vapor permeability. The analysis of the preliminary results from six participating laboratories in France highlighted the main sources of discrepancy and of uncertainties. First recommentions are proposed to improve the accuracy of the measurements.