Area: Industrial wood construction
Budget: 830 000 SEK
Timetable: January 2011 - December 2012
Project: Fredrik Ljunggren, Luleå University of Technology
Lightweight construction made of wood suitable for industrial production with a given scale. Today, there are fundamentally two different module versions; volume modules that are normally based on the discs and wooden / laminated beams and plate modules that can be based on glulam structures or boards and battens / studs easily. Build systems have long had difficulty complying with requirements regarding noise and fire, while it is now above all the sound insulation that needs fine-tuning. In many cases, buildings can sound class B (in exceptional cases, Class A), but the margins are still too small, making the soundproofing sometimes fall short of requirements. In such cases, it will be expensive improvements that must be taken afterwards. Experience suggests that the houses that meet modern demands on sound class B, where low frequencies are taken into account, results in satisfied tenants. This conclusion is not scientifically proven, so it will be one of the issues to be investigated in AkuLite project. The weaknesses of the various building systems is somewhat different. The traditional top-beam systems are still often have problems at low frequencies and by flanking transmission. The heavier and more rigid solid systems and the lightweight and rigid light regulatory systems usually have fewer problems at low frequencies, but larger problems at higher frequencies where flanking transmission dominates.
Good sound characteristics is of utmost importance to give full acceptance of wooden structures, but at the same time, the costs kept in check. Good solutions are easy to prove expensive and the housing market is cost sensitive, so solutions must be cost effective. Solutions that are both good and cost costs, however time and advanced technology development.
Division of Sound and Vibration, in the current project part III with Lindbäcks, Martinson and Thyrén (formerly ÅF Ingemansson), developed designs that mostly meets sound class B. However, there is more to be done to really ensure sound class B, to improve insulation at low frequencies, to reduce flanking transmission and to cost-effectively insulate floors.
Continued research and development will be to develop concepts to work even for buildings with six floors (or possibly more), and to develop methods to handle the low frequencies.
The project's focus and goals are:
- Develop solutions that consistently meet sound class B, regardless of room design and floor
- Developing solutions that can be built in six (and possibly more) storey
- Optimize the performance of vibration isolators between the anti-storey
- Identify possible synergies between the volume of construction system and solid system.
The project's long-term objective remains in line with the ongoing work:
a) Industrial Application - to modify existing and develop new innovative and cost effective design solutions that will enable a guaranteed insulation with Class B for all planes in multi-storey buildings with six or more storeys built in both solid wood-based and volume-based designs. In addition, houses more responsive to the subjective requirements for soundproofing.
b) Knowledge Building (to achieve the above) - on the basis of measured data, literature studies, new measurements and calculations to achieve a deeper knowledge of how the volume of modular systems and solid-construction works relating to noise and vibration. It is also important to create a better understanding of what creates subjective acceptability of sound in homes built of lightweight construction.
Collaboration with the National R & D program AkuLite
Since 2007, a national gathering place around the building acoustic research on wood-based home construction. The project has broad participation from both industry and the university with activities relating to noise and vibration in the wooden house. The project is supported by VINNOVA and Formas to that industry provide funding. Most companies in the searched TCN funds count as counter financing and thus exchanged TCN's corporate average up.