Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Abstract
The use of wood in outdoor constructions has long traditions in Norway. In the last decade, the environmentally demands for wood protective systems has become stricter. At the same time, new design solutions are arising that will challenge the decay protection in outdoor constructions. In this article, the potential for antioxidants as a wood protective agent was tested. Both natural and synthetic antioxidants have been used. All samples achieved a sufficient uptake of impregnation agent, and all the tested products showed a reduction in wood decay rate compared to the control. The protections by the antioxidants are more effective against brown rot fungi, than white rot fungi. The synthetic antioxidants stop the fungal degradation of the brown rot fungi, and should be considered as an additive in future and existing wood protective systems.
Abstract
Wood for outdoor decking has a high market share in the Nordic and Baltic countries among private house owners. Important issues for the consumer are maintenance intervals and aesthetic appearance as well as decay resistance. Knowledge and consumer information about these aspects are required to ensure that wood can compete with alternative decking materials. In this paper an accelerated testing of decking, “stapelbädds metoden”, was evaluated after ten years of exposure at Ås, Norway. The test method covers different hazard situations within use class 3. Different preservatives and wood modification treatments were used in addition to untreated Scots pine (sapwood and heartwood) and larch (heartwood). The samples were treated with two different surface treatments. In addition there was one set without any surface treatment. Fungal discoloration and decay was evaluated. This provided new information about performance both on and above ground for a range of different combinations of preservative/modified systems and surface treatments of wood in decking for outdoor use. Generally, there were no significant differences in performance between the surface treatments, both with regard to surface discolouring fungi and decay fungi. For all surface treatments, the samples with rating 3 (heavy attack) in bottom layer in one or several stacks was: Tanalith M, Tanalith M (c), Gori Pres 10, Scanimp, styren, furfurylation, thermal modification, Ultrawood, larch heartwood, pine heartwood and pine sapwood. For all surface treatments, the samples with mean rating ≤ 2 (evident attack) in top and middle layer in one or several stacks was: ACQ 1900, Wolmanit CX 8, Tanalith E7, Gori SC 100, Royal, Royal with pigment, Scanimp, styrene and larch heartwood
Authors
Andreas TreuAbstract
No abstract has been registered
Authors
Andreas TreuAbstract
Improving wood preservation techniques can contribute substantially to reducing waste and avoiding negative environmental impacts. Dr Andreas Treu outlines a promising technique to dramatically reduce or even stop wood degradation altogether by using electro-osmosis. International Innovation is the leading global dissemination resource for the wider scientific, technology and research communities, dedicated to disseminating the latest science, research and technological innovations on a global level. More information and a complimentary subscription offer to the publication can be found at: www.researchmedia.eu
Abstract
The objective of the project Winfur (within WoodWisdomNet) was the industrial application of furfurylated wood in the window market. Because of promising results concerning the wood species European beech, common ash, radiata pine and Southern yellow pine it was decided to evaluate material from these species.The material exhibits promising wood water related behaviour. Coating tests showed the coatability with selected commercial products. Additionally, outdoor weathering tests were performed. It is also possible to produce 3-layer scantlings with common gluing systems like PVAc. The resistance against wood destroying fungi increased in a way that the material is suitable for the window application. Different investigations were performed to test the furfurylated material and the results are satisfying.The last step in the project was the production of prototypes for different investigations. The window companies reported no differences between using furfurylated wood compared to untreated wood within the production of the windows. The tests of full scale window prototypes according to seven test standards, e.g. repeated opening and closing and water tightness against driving rain were performed.The production and standardised testing of full-scale window prototypes indicates that the use of furfurylated wood will not cause any problems with fulfilling the criteria for the Scandinavian P-mark and the German RAL certificate. The overall conclusion is that furfurylated wood material is suitable for the window production.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The study describes the development of surface mould and blue stain fungi on painted wooden claddings exposed to outdoor weathering. The materials consisted of Norway spruce (Picea abies) claddings that were processed from inner boards, outer boards, and edge-grained boards with known origin. Heartwood proportion, density, annual ring width, knot diameters and relative knot area were measured, and all boards were coated with the same water-borne alkyd modified acrylic paint system. Most of the tangentially sawn boards were coated on the side facing the pith, but a sub-sample was coated on the opposite side for comparison. The specimens were exposed with a 45° angle of inclination facing south in a field trial in Oslo from 2007 to 2011, and mould growth was evaluated visually according to EN 927-3. The development of mould rating was described with an ordinal logistic regression model. The model predicts expected mould rating to follow a sigmoid curve with some deviation in the first part. Neither wood properties nor manufacturing characteristics had any significant effect on the model, and this may in part be due to the use of a high performance coating system.
Abstract
From the range of information published, acetylation appears well suited to provide adequate protection against biological attack for materials derived from typically non-durable wood species. Acetylated wood is now commercially available both in Europe and in the USA. But still there are a lot of unanswered questions related to fungal decay mechanisms in acetylated wood.The paper summarize existing knowledge and highlight future research opportunities related to fungal deterioration of acetic anhydride modified wood. In addition statistical analyses based on previously published data were performed to quantify what factors contribute most to the performance (calculated as test sample/control).The results showed that WPG can explain approximately 50 % of the performance, measured as test sample/control (T/C), for acetic anhydride treated wood. Other of the applied variables, like wood species or type of fungus can reduce the variance in T/C by additional 15 %.
Authors
Christian Brischke Christian Welzbacher Antje Gellerich Susanne Bollmus Katharina Plaschkies Wolfram Scheiding Gry Alfredsen Joris Van Acker Imke De WindtAbstract
Die Dauerhaftigkeit von Holz gegenber Basidiomyceten wird in Europa nach CEN/TS 15083-1 (2005) bestimmt. Die bisherigen Erfahrungen mit diesem Standard sind sehr heterogen, und Ergebnisse frherer Ringversuche teilweise nicht oder nur unvollstndig verffentlicht. Insbesondere die Notwendigkeit einer natrlichen Vorbewitterung der Prfkrper, u.a. mit dem Ziel einer Detoxifizierung des Materials, wird kontrovers diskutiert. Fnf europische Forschungseinrichtungen haben sich deshalb zu einem neuen Ringversuch zusammengeschlossen, in dem die Dauerhaftigkeit gegen holzzerstrende Pilze von fnf Holzarten mit und ohne Auswaschbeanspruchung bzw. 6-monatiger natrlicher Vorbewitterung gegen Coniophora puteana und Trametes versicolor geprft wurden. Es ergaben sich Unterschiede in der Dauerhaftigkeitsklassifizierung zwischen den Prfinstituten (bis zu vier Klassen) sowie in Abhngigkeit von der Vorbeanspruchung und den statistischen Auswertungsgren. Die natrliche Vorbewitterung der Prfkrper hatte teilweise eine Angleichung der Dauerhaftigkeitsklassifizierung zwischen den Prfinstituten zur Folge. In allen Fllen wurde eine Homogenisierung der Dauerhaftigkeitseinschtzung durch Vorbewitterung jedoch nicht erreicht. Generelle Aussagen zum Einfluss der Vorbeanspruchung auf die Klassifizierung der Dauerhaftigkeiten lieen sich somit nicht ableiten, weshalb diese weder zwingend zu empfehlen noch abzulehnen ist.