Energy efficiency of a novel low carbon bio-based material for building

A novel low carbon bio-based building material is developed using cob under the framework of CobBauge project. Experimental and numerical studies are conducted to characterize thermal behavior of cob building. The studied mixes are: structural mixes S3, S9 and S12 made of 2.5 % hemp straw, 2.5% flux straw and 5% wheat straw respectively, and the insulation samples T5 and T6 containing 25% of hemp shiv and reed. The results are analyzed and compared for different structural and insulation materials. The selected optimal cob mixes are the French soil-wheat straw fibber mix S12 and the French soil-Reed mix T5 thanks to their low mean thermal conductivities 0.24 W/m.K and 0.19 W/m.K respectively. Afterwards, a comparative study between conventional and cob construction is conducted through an energy performance simulation of a typical French house in Caen city. Results show that cob is a good and promising alternative for ecological construction.