Comparison of the hygric behaviour of three hemp concretes

Florence Collet (1) , Julien Chamoin (1) , Sylvie Prétot (1) , Christophe Lanos (1)

1 LGCGM - Laboratoire de Génie Civil et Génie Mécanique

Hemp concrete is a bio-based building material the main qualities of which are its low environmental impact and its hygrothermal behaviour. Even for one kind of application (for example: wall), several compositions and manufacturing methods are encountered in the market. This study compares the hygroscopic behaviour of three hemp concretes used for building walls to identify whether composition and manufacturing have an impact on hygric properties. The investigations are based on the measurement of the sorption curve, of the water vapour permeability versus humidity and of the moisture buffer value. Moisture diffusivity is calculated from the sorption curve and from the water vapour permeability. The results underline the high transfer and storage capacities of these materials; they are classified as excellent (or nearly excellent) hygric regulators. A slight effect of porosity, connected with composition and manufacturing method, is observed.

Mots clés: Bio-based material; Sorption isotherm; Water vapour permeability; Moisture diffusivity; Moisture buffer value

Domaines: Thermique [physics.class-ph]; Thermique [physics.class-ph]

Florence Collet, Julien Chamoin, Sylvie Prétot, Christophe Lanos. Comparison of the hygric behaviour of three hemp concretes. Energy and Buildings, 2013, 62, pp.294-303. ⟨10.1016/j.enbuild.2013.03.010⟩. ⟨hal-00810372⟩