Sustainable sound absorbers from fruit stones waste

[EN] Ecological and sustainable materials have a growing interest in the field of construction and buildings where recycled materials are being included as constructive solutions. Currently, fruit stones are not used in architectural acoustics and there are no scientific studies that analyse the acoustic insulation of materials manufactured by fruit stones. This work analyses the sound absorption coefficient of panels made of different fruit stones. Four types of fruit stones have been selected with different properties in terms of density, shape and porosity. They are of the hard-stone type so that they have a high durability. To determine the sound absorption coefficient, cylindrical samples with different thicknesses have been manufactured and tested in a standing wave tube. The experimental results showed that the sound absorption varies depending on the type of fruit stone and the thickness of the sample. In the frequency range from 550 Hz to 1500 Hz, some samples reach sound absorption coefficients from 0.7 to 0.95. These panels offer good acoustic insulation properties and an added value from the aesthetics point of view. Gadea Borrell, JM.; Juliá Sanchis, E.; Segura Alcaraz, JG.; Montava-Belda, I. (2020). Sustainable sound absorbers from fruit stones waste. Applied Acoustics. 161:1-9. https://doi.org/10.1016/j.apacoust.2019.107174 Asdrubali, F., Schiavoni, S., & Horoshenkov, K. V. (2012). A Review of Sustainable Materials for Acoustic Applications. Building Acoustics, 19(4), 283-311. doi:10.1260/1351-010x.19.4.283 Panyakaew, S., & Fotios, S. (2011). New thermal insulation boards made from coconut husk and bagasse. Energy and Buildings, 43(7), 1732-1739. doi:10.1016/j.enbuild.2011.03.015 Zach, J., Hroudová, J., Brožovský, J., Krejza, Z., & Gailius, A. (2013). Development of Thermal Insulating Materials on Natural Base for Thermal Insulation Systems. Procedia Engineering, 57, 1288-1294. doi:10.1016/j.proeng.2013.04.162 Barreca, F., & Fichera, C. R. (2013). Use of olive stone as an additive in cement lime mortar to improve thermal insulation. Energy and Buildings, 62, 507-513. doi:10.1016/j.enbuild.2013.03.040 Patnaik, A., Mvubu, M., Muniyasamy, S., Botha, A., & Anandjiwala, R. D. (2015). Thermal and sound insulation materials from waste wool and recycled polyester fibers and their biodegradation studies. Energy and Buildings, 92, 161-169. doi:10.1016/j.enbuild.2015.01.056 Buratti, C., Belloni, E., Lascaro, E., Lopez, G. A., & Ricciardi, P. (2016). Su