Acoustic and thermal properties of hemp-cement building materials

Abstract

Abstract The present research aims to analyze the sound absorption coefficient and the thermal conductivity of the building materials based on hemp. Nowadays, two main problems affect the characteristics of the space where people live and work: the unwanted sounds and the thermal insulation. On the materials building market there are products which can reach these parameters, but separately. For this reason this study looks at more in-depth constructive solutions of the hemp-based composite materials, which can respond at the same time to the acoustic and thermal properties of the space where people are. The experimental program was based on the study of hemp based building materials divided in two categories: monolayer and multilayer samples. For obtaining the building materials the hemp elements used were the fiber and shiv, produced in Romania. The binder which connected the hemp elements was the white cement. The sound absorption coefficients were analyzed using the impedance tube and for the thermal conductivity the Fox200 device was used. It was noticed, in the first situation, that the recipe which was made only from one layer of fiber had better acoustic and thermal properties than the shiv monolayer recipe. In the second situation the samples with triple layer compositions presented a difference of 25% for the sound absorption coefficient and 20% for the thermal conductivity coefficient depending of the layer composition of the samples.