Synthesis of the Current Knowledge Concerning the Construction of French Traditional Cob Building for Giving Recommendations
The museum of the “Bourrine du bois Juquaud” is a tourist site located in the town of Saint Hilaire de Riez in France. It presents the daily life of the inhabitants of the marsh in the early twentieth century and their traditional earthen houses called Bourrine. The Bourrine is a cob construction with reed roof. The earth used for walls is soil from marshlands added with dune sand and straw fibres but some part are without fibres like coating applied on walls. By now, the knowledge acquired on the implementation of these mixtures for the lifting of the walls are oral knowledge and it is necessary to ensure the preservation of this traditional heritage. Currently the done reparations present cracks due to shrinkage. This study aims at well defining the mixtures by a scientific approach. The earth and dune sand were analyzed by taking cores from different existing bourrines and also by extracting soil on site. Different mixtures were produced by varying the proportion of earth sand and water. The linear shrinkage were measured. Corrections were done to get the best mixture for manufacturing and repairing the Bourrines.