Experimental highlight of hygrothermal phenomena in hemp concrete wall: Fid-Bau Portal

Experimental highlight of hygrothermal phenomena in hemp concrete wall

Collet, Florence / Pretot, Sylvie

Abstract This study investigates the hygrothermal behaviour of a timber-framed hemp concrete wall made of precast blocks. Measurements are performed on an uncoated wall as well as on a coated wall. The experimental device consists in two air-conditioned rooms where ambient conditions are selected to induce temperature and/or vapour pressure gradient between the two sides of the wall. The monitoring deals with temperature and relative humidity within the wall. Kinetics of temperature and of vapour pressure are given. Profiles are drawn at several times of the transient phase. In the regular part of the wall, several kinds of hygric behaviours are highlighted such as homogeneous vapour diffusion and huge vapour pressure variations due to evaporation–condensation and/or sorption-desorption phenomena. The results in the line of frame show that the frame doesn't induce disturbances in the hygrothermal behaviour of the wall. It is also shown that the coating reduces and delays vapour diffusion.

Highlights • We report the construction of a hemp concrete test-wall as separating wall of bi-climatic rooms. • The hygrothermal behaviour of the wall is investigated under several hygrothermal stresses. • Vapour diffusion, evaporation–condensation, sorption-desorption phenomena are shown. • It is shown that the frame doesn't disturb the hygrothermal behaviour of the wall. • It is also shown that the coating reduces and delays vapour diffusion.