Investigations on the Fundamental Suitability of Sprayed-on and Plaster-covered hygrothermic active Cellulose-Compact-Soundabsorber

Development of a new kind of spray-on and plastered noise absorber on the basis of cellulose from recycled paper. The absorber system preferably attenuates the low-frequency range, that can usually only be controlled with rather complex systems, and can also be used where conventional absorbers could cause problems due to impermissible water vapour condensation.

Content Description

Status

completed

Summary

The increasing awareness with regard to growing burdens on the environment in general and noise in particular - some scientists are already talking about "noise as the pollutant of the decade" - is reflected, among other things, in the increased importance of appropriate acoustic quality of "everyday spaces". Particularly the unreasonably high level of noise in schools and educational facilities but also in office and recreation rooms requires action to be taken by all those involved.

The aim of the project was to develop a completely new kind of spray-on and plastered noise absorber on the basis of cellulose from recycled paper. The absorber system preferably attenuates the low-frequency range, that can usually only be controlled with rather complex systems, and can also be used where conventional absorbers could cause problems due to impermissible water vapour condensation: on the inside of the outside wall. The inexpensive and ecological composite system can also be applied on uneven or curved surfaces.

The innovative absorber system is based on a further development of the "slit absorber" principle. A two-layer plaster system is applied on a flow-optimised, 5 - 6 cm layer of cellulose that is sprayed on in situ. As a complete innovation in slit absorbers, it forms a jointless surface and thus fulfils the demand of many planners for "invisible" acoustic measures while still attenuating low frequencies. At the same time, the system achieves far higher tensile strength perpendicular to the sample plane and compressive strength than is required for insulating materials in composite outside wall thermal insulation systems.

A new levelling system was developed for creation of the cellulose wall coating that, unlike state-of-the-art systems, allows complete independence from levelling devices that usually stay in the finished cellulose layer and therefore the creation of homogeneous in-situ bodies of insulation with a constant thickness and fast work progress.

Although there is still some need to further research the assessment of long-term behaviour, to develop suitable component connectors, and to catalogue acknowledged constructions for application on the inside of outside walls, the present studies have demonstrated the fundamental suitability of the composite system of in-situ spray-on cellulose insulation and special interior plaster as a noise absorber designed primarily to attenuate low-frequency noise.

Project Partners

Project leader:

Ao.Univ.-Prof. DI DDr. Peter Kautsch
Technische Universität Graz - Institut für Architekturtechnologie
A-8010 Graz, Rechbauerstraße 12
Tel.: +43-(0)316 - 873 / 6245; Fax: / 6083
E-Mail: kautsch@tugraz.ac.at
Internet: www.TUgraz.at

Project partners:

Dipl.-Ing. Herwig Hengsberger
el.: +43-(0)316 -873 / 6807; Fax: / 4999
E-Mail: hengsberger@tugraz.at
Ao.Univ.-Prof. DI Dr. Enrico Eustacchio
Technische Universität Graz - Institut für Materialprüfung und Baustofftechnologie mit angeschlossener Technischer Versuchs- und Forschungsanstalt
A-8010 Graz, Stremayrgasse 11
Tel.: +43-(0)316 - 873 / 7152; Fax: / 7650
E-Mail: enrico.eustacchio@tugraz.at
Ao.Univ.-Prof. DI Dr. Gerhard Graber
Technische Universität Graz - Institut für Breitbandkommunikation
A-8010 Graz, Inffeldgasse 12
Tel.: +43-(0)316 - 873 / 7435; Fax: +43-(0)316-463697
E-Mail: graber@tugraz.at
Prof. Dr.-Ing. habil. Peter Häupl
Technische Universität Dresden - Institut für Bauklimatik
D-01069 Dresden, Zellescher Weg 17
Tel.: +49-(0)351 - 4633 / 3171; Fax: / 2627
E-Mail: haeupl@ibk.arch.tu-dresden.de
Martin Kormout
J.W. Bau Ges.m.b.H.
A-1160 Wien, Hasnerstraße 42/18
Tel.: +43-(0)699-14861651; Fax: +43-(0)1-9133234
E-Mail: kormouts@chello.at
Dr.-Ing. Philip Leistner
Fraunhofer Institut für Bauphysik
D-70569 Stuttgart, Nobelstraße 12
Tel.: +49-(0)711 - 970 / 3346; Fax: / 3406
E-Mail: philip.leistner@ibp.fhg.de
Dipl.-Ing. Robert Schmied
Wietersdorfer und Peggauer Zementwerke AG
A-8120 Peggau, Alois-Kern-Straße 1
Tel.: +43-(0)3127 - 201 / 2290; Fax: / 2289
E-Mail: r.schmied@wup.baumit.com