Abstract
The mechanical and physical properties of modified timber were assessed by experimental work. The timber was modified using three different methods: acetylation with acetic anhydride, modification with methylated melamine formaldehyde resin and heat treatment in an oil bath. The wood material was sapwood of Scots pine (Pinus sylvestris) with dimensions of 45×70×1100 mm. A total of 99 specimens were included in this study. The following properties and their inter-relations were studied: density, modulus of elasticity (MOE), bending creep deflection and relative creep. It was found that all the modifications successfully reduced the relative creep. However, the performance properties of modified timber ought not to be calculated on the basis of density, as is the case for untreated wood. On the other hand, the long-term performance of modified timber can be assessed by its initial MOE and the difference in equilibrium moisture content (EMC) between two climates.
Zusammenfassung
Die mechanischen und physikalischen Eigenschaften von modifziertem Kiefernschnittholz wurden experimentell bestimmt. Das Schnittholz wurde mit drei verschiedenen Methoden modifiziert: Acetylierung mit Essigsäureanhydrid, Modifizierung mit methyliertem Melaminformaldehydharz und Hitzebehandlung im Ölbad. Das Probematerial war Kiefernsplintholz (Pinus sylvestris) mit den Abmessungen 45×70×1100 mm. Insgesamt wurden 99 Proben getestet. Die folgenden Eigenschaften und deren Korrelationen wurden untersucht: Dichte, dynamischer und statischer Elastizitätsmodul, Kriechverformung im Biegeversuch und relatives Kriechen. Alle Modifikationen reduzierten das relative Kriechen erheblich. Verwendungsrelevante Eigenschaften von modifiziertem Holz sollten nicht anhand der Dichte bewertet werden wie bei unbehandeltem Holz. Andererseits kann die Kriechverformung von modifiziertem Holz anhand seines Elastizitätsmoduls und dem Unterschied in der Ausgleichsholzfeuchte zwischen zwei Klimata abgeschätzt werden.
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Epmeier, H., Kliger, R. Experimental study of material properties of modified Scots pine. Holz Roh Werkst 63, 430–436 (2005). https://doi.org/10.1007/s00107-005-0019-2
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DOI: https://doi.org/10.1007/s00107-005-0019-2