Poroelasticity and acoustic properties of bio-based materials : from characterization to the understanding of mechanical dissipation effects

The building sector is a key element in reducing the effects of climate change. To operate sustainably and efficiently, solutions based on building materials having a low environmental impact, such as bio-based materials, are needed. In fact, they present high-level multi-functional properties and they capture atmospheric carbon dioxide. However, even if a number of works has examined visco-thermal dissipation effects, the understanding of the mechanical dissipation effects on the acoustic performances of bio-based materials is still incomplete and little data are available in the literature. Therefore, it seems particularly relevant to investigate by experimental characterizations and modelling methods the effects of mechanical dissipation on the acoustic properties of a representative variety of bio-based materials such as vegetal wools, vegetal aggregate stacks and vegetal concretes. To do this, Young's modulus, Poisson's ratio and structural damping were measured on the various typology of materials by a quasi-static analysis method. The non-linear elastic behaviour in compression of bio-based samples is analyzed. Finally, the influence of Young's modulus and structural damping on the acoustic absorption and attenuation properties of bio-based materials is described using modelling approaches.