TUAS 2023 Floor Sound Insulation
TTurku University of Applied Sciences (Turku, Finland) was funded in 2020-2023 by the Ministry of the Environment (Finland) for a research project to investigate various aspects related to the impact sound insulation of wooden intermediate floors that are used in multistorey apartment buildings. The research required reliable and reproducible data of impact sound insulation for a broad range of floor constructions. Therefore, large number of floors was built and measured in the building acoustics laboratory of Turku University of Applied Sciences. The data was laborious and expensive to collect because of extensive physical construction work. Therefore, the outcoming data collection is remarkable and unique. Four different load-bearing slabs were inspected (cross-laminated timber slab 140 mm, cross-laminated timber slab 260 mm, open box timber slab 370 mm, steel-reinforced concrete slab 160 mm). The load-bearing slabs were not tested barely since bare slab do not fulfil any sound insulation requirements. Therefore, the tested floors involved at least a floor covering. In addition, the floors involved either floating floor (several alternatives), or a suspended ceiling (several alternatives) or both. The data can serve the development of sound insulation prediction models, experimental analysis of sound insulation, product development of floor construction, and education. The data contains well-documented impact and airborne sound insulation measurement results of 30 wooden floors and 8 concrete floors. The data elucidates, how different floor toppings and suspended ceilings affect the sound insulation. The specialties of these data are: the data were obtained in the same laboratory within a limited period involving the same professional installation team; the measurements were conducted in a broad frequency range (20 to 5000 Hz); detailed structure drawings for each floor construction are given.
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The floor constructions were designed by the researchers but several industrial partners were consulted about them. The constructions were designed so that the single-number values of sound insulation, such as Ln,w and Rw, cover the national target values established in European countries . Therefore, the sound insulation of the studied floors varies very much. Impact sound insulation was measured according to ISO 10140-3  using two standardized impact sources: tapping machine and heavy/soft impact source (rubber ball). Single-number values of ISO 717-2  are reported. The laboratory was accredited by FINAS for the test involving the tapping machine. Airborne sound insulation was measured according to ISO 10140-2 . Single-number values of ISO 717-1  are reported. The laboratory was accredited by FINAS for the test. Measurements within 20-40 Hz are not supported in the standards [2,4] so that the data within 20-40 Hz may contain larger uncertainties than the data within 50-5000 Hz supported in the standards. Dynamic stiffness is reported for resilient materials used under floating floors. Measurements are based on ISO 9052-1 standard . Since all the constructions are described in detail, and the measurements were conducted according to acknowledged international standards, the data is highly reproducible. The lowest measurable impact sound pressure level and the highest measurable sound reduction index is also reported. They set the limits for the constructions that can be reliably measured in this laboratory. None of the studied 38 floors reached that high sound insulation, so that the results are not biased by flanking sound transmission. The laboratory has been described in a congress paper in Finnish . 1. Rasmussen, B. (2019). Sound insulation between dwellings – Comparison of national requirements in Europe and interaction with acoustic classification schemes. Proc. 23rd Int. Congr. Acoust. ICA 2019, pp. 5102–5109. 9–13 Sep 2019, Aachen, Germany. 2. ISO 10140-2:2010 Acoustics – Laboratory measurement of sound insulation of building elements – Part 2: Measurement of airborne sound insulation 3. ISO 717-1:2020 Acoustics – Rating of sound insulation of building elements - Part 1: Airborne sound insulation 4. ISO 10140-3:2021 Acoustics — Laboratory measurement of sound insulation of building elements — Part 3: Measurement of impact sound insulation 5. ISO (2020). International standard ISO 717-2:2020 Acoustics — Rating of sound insulation in buildings and of building elements — Part 2: Impact sound insulation 6. ISO 9052-1:1989 Acoustics — Determination of dynamic stiffness — Part 1: Materials used under floating floors in dwellings. 7. Hongisto, V., Hakala, J., Keränen, J., Alakoivu, R. (2021). Turun uudet akustiikkalaboratoriot. Akustiikkapäivät 2021, ISBN 978-952-69879-0-3, pp. 90-95, 24-25.11.2021, Turku, Finland. Online at: https://www.akustinenseura.fi/wp-content/uploads/2021/11/akustiikkapaivat_2021_s90.pdf.