Earthen-based building: In-situ drying kinetics and shrinkage

Present work focuses on the study of drying and shrinkage kinetics in cob and light earth layers constituting a hybrid walling system. In-situ measurements were performed on the walls of a CobBauge prototype building under construction in Saint-André-de-Bohon (France). To do so, an adapted monitoring system has been designed and implemented. Thus, volumetric water content sensors and dial indicators were immersed and placed in different positions in different walls of the building. Drying kinetic and shrinkage rate in both layers have been measured. Results show that drying and shrinking processes follow an exponential decay in both structural and thermal layers. Correlations between water content and materials shrinkage have been found and discussed. This study will contribute to the optimization of earth construction times in general, and in particular, form-stripping times.