6533b7d5fe1ef96bd1263e48
RESEARCH PRODUCT
Experimental investigation of the effect of moisture on the acoustic properties of lightweight substrates used in green envelopes
Yorick Buot De L’epineNicolas DauchezEmmanuel AttalEmmanuel AttalBertrand Dubussubject
010302 applied physics[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph]Materials scienceAcoustics and UltrasonicsMacroporeMoistureAcoustic porous mediumLightweight substrateSound absorption;Lightweight substrate;Acoustic porous medium;Moisture;Green envelopeGreen envelope01 natural sciencesCharacteristic impedance[SPI.MAT]Engineering Sciences [physics]/MaterialsSubstrate (building)Speed of sound0103 physical sciencesPerliteSound absorptionComposite material[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/MicroelectronicsPorosity010301 acousticsMicroscale chemistryMoisturedescription
International audience; Substrates are used in green walls and roofs to supply air and water to the roots of the growing plants. These substrates are porous with micropores which store water and macropores which facilitate drainage and air entry. Effect of moisture on acoustic absorption is studied for two lightweight substrates: coir dust and perlite. Measurement of dry and moistened substrates are conducted to evaluate their effective speed of sound, attenuation, characteristic impedance, compressibility and density between 100 Hz and 1000 Hz using an impedance tube and the three microphone-two load method. Effect of moisture on these quantities is found to depend strongly upon the interaction between water and substrate particles at the microscale. Performance of rigid-frame and limp frame porous models is evaluated when applied to the characterization of dry and moistened lightweight substrates. Finally, sound absorption of substrate layers and composite plant-substrate samples is analyzed for different moisture contents.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2021-09-01 |