Acoustical properties of hemp concretes for buildings thermal insulation
Résumé
This presentation deals with the acoustical performance of hemp-lime and hemp-clay dedicated tobuilding thermal insulation. The work is based on statistically robust experimental results frommore than 100 hemp-clay samples, together with the analysis of a large hemp-lime database. Amodelling approach is also developed to provide a general overview of the materials. In hemp-claymixes, our experimental results show the concentration of hemp in a mix has a first order effect onthe acoustical performance, while binder fluidity and clay type have no significant effect. Anotherconclusion of this study is that hemp-clay and hemp-lime behave acoustically in a same way. Forboth materials, experimental sound absorption and transmission curves can be modelled with aphysical-based four-parameters approach. The close agreement between experimental measurementsand modelling highlights the good level of understanding of the physical phenomena responsible forthe acoustical behavior of hemp concrete. A classification is finally proposed in terms of density tobe used as a general guideline to evaluate or optimize the acoustical performances of hemp-basedconcrete.