SOUND ABSORPTION ON BOARD CONSTRUCTION MATERIALs USED IN WOOD BUILDINGS

Abstract

When the sound wave touches the material (wall), some fraction reflex the wall, other fraction is absorbed and the rest fraction of the sound wave will go through the wall. So, in every enclosed space we can say about sound absorption, transformation of sound energy into some other energy. Sound absorption coefficient α (-) can be mentioned as criteria for the standard of sound absorption by the material. The article deals with the evaluation of sound absorption in the chosen materials which are utilised in wooden buildings, construction parts of partition walls and ceilings, floors and walls cover. There were used the following materials which are applied in the construction of wood buildings: particleboard (DTD), oriented strand board (OSB), beech plywood (PDP_BK), poplar plywood (PDP_TO), tetra pak recycled board (TETRA K), gypsum fibreboard (Fermacell), cement chipboard (CTD), plasterboard (Rigips) and medium-density fibreboard (MDF). The measurement was performed by the transfer function method in accordance with the standard ISO 10534-2. Under the frequency in the range 200 Hz – 2.0 kHz, the highest values of sound absorption coefficient were measured in CTD, PDP_TO, DTD and OSB within the interval from 0.05 to 0.53. Fermacell and Rigips have the highest values of sound absorption coefficient (0.3 – 0.4) within the frequency from 2.5 kHz to 4 kHz. At the same time, Fermacell, Rigips, but also MDF and TETRA K boards reached the lowest sound absorption (0 – 0.21) within the frequency interval 50 Hz – 2.0 kHz. Sound absorption assessed on the base of NRC coefficient was measured as very low (under 0.2) for all assessed materials, except of CTD. The tested board materials according to the standard ISO 11654 can be included among sound reflective material and little sound absorptive material. The highest level of noise reduction coefficient αNRC was measured at cement chipboard CTD (αNRC = 0.3) which can be included among absorptive materials. The results should be transformed into predictions in room and building acoustics, particularly in the design and projection of partition wall constructions in ultra-low energy buildings but also in the entire interior equipment.