Abstract
The expected impact of this study is to propose a bio-sourced composite material coupling mechanical and hygrothermal performances. This paper deals with the prediction of hygric properties of compacted raw-earth material reinforced with the flax fibers. New experiments have been performed on fibers and earth composite specimens. Then two modeling approaches have been applied using mixing theory and asymptotic homogenization. It was showed, that besides adding flax fibers improves the mechanical behavior of raw earth as strength and shrinkage reduction, their impact on the hygric property as water vapor permeability was also proved. For longitudinal arrangement of flax fibers with different fibers contents, experimental and modeling results are in good agreement.