Glé Philippe, Gourdon Emmanuel, Arnaud Laurent, Horoshenkov Kirill-V, Khan Amir
Laboratoire Génie Civil et Bâtiment, Ecole Nationale des Travaux Publics de l'Etat, Université de Lyon, 69518 Vaulx-en-Velin Cedex, France.
School of Engineering, University of Bradford, Bradford BD7 1DP, United Kingdom.
J Acoust Soc Am. 2013 Dec;134(6):4698. doi: 10.1121/1.4824931.
Hemp concrete is an attractive alternative to traditional materials used in building construction. It has a very low environmental impact, and it is characterized by high thermal insulation. Hemp aggregate particles are parallelepiped in shape and can be organized in a plurality of ways to create a considerable proportion of open pores with a complex connectivity pattern, the acoustical properties of which have never been examined systematically. Therefore this paper is focused on the fundamental understanding of the relations between the particle shape and size distribution, pore size distribution, and the acoustical properties of the resultant porous material mixture. The sound absorption and the transmission loss of various hemp aggregates is characterized using laboratory experiments and three theoretical models. These models are used to relate the particle size distribution to the pore size distribution. It is shown that the shape of particles and particle size control the pore size distribution and tortuosity in shiv. These properties in turn relate directly to the observed acoustical behavior.
