Sweet chestnut (Castanea sativa) heartwood is one of the most durable European commercial wood species. Various aspects that could potentially influence the durability were studied in the present research: presence of extractives, ring width and weathering. The properties of wood that had been in outdoor use for 35 years were also examined. The results indicate that ring width and weathering (35 years of outdoor use) did not influence the durability. None of the fungi used were able to degrade sweet chestnut heartwood in a modified EN 113 experiment. After extraction with methanol or water, specimens lost between 11% and 15% of total mass by leaching of extractives. However, extraction only slightly decreased the durability of the leached wood. This indicates that other components (in addition to water and methanol soluble extractives) could be responsible for durability. Furthermore, analysis of 35-year-old wood showed that not all relevant properties of the old sweet chestnut wood deteriorated within the mentioned time frame. This proves that old sweet chestnut hardwood can potentially be reused for a variety of applications.
COBISS.SI-ID: 2266249
Copper-based compounds are some of the most important biocides for the protection of wood in heavy duty applications. In the past, copper was combined with chromium compounds to reduce copper leaching, but a novel generation of copper-based preservatives uses ethanolamine as a fixative. To elucidate the leaching of copper biocides from wood, Norway spruce (Picea abies) wood was treated with a commercial copper-ethanolamine solution with two different copper concentrations (cCu = 0.125% and 0.25%). The aim of this research was to compare the laboratory leaching standards (ENV 1250-2, CEN/TS 15119-1 and CEN/TS 15119-2) with the field leaching studies in ground and above ground. The results indicated that the first leaching peak appears in the initial phases of leaching, both in laboratory and field studies. The degree of copper leaching is also affected by the method of treatment; copper-ethanolamine preservative solutions, when applied with superficial treatments, are more prone to leaching than is vacuum-pressure treated wood. On average, between 25% and 36% of copper was leached from the impregnated wood after 42 months of exposure.
COBISS.SI-ID: 2204809
Consumption of wood based lingo-cellulosic insulating materials in building industry increases from year to year. In spite of increased consumption, there is lack of data on performance of these materials against wood decay fungi. In present research, durability of 12 frequently used materials: five different insulation materials based on wood fibre, hemp fibre insulation, cellulose loose-fill insulation, OSB board, plywood and wood plastic composites were exposed to three brown rot fungi (Antrodia vaillantii, Gloeophyllum trabeum and Serpula lacrymans) and three white rot fungi (Trametes versicolor, Hypoxylon fragiforme and Pleurotus ostreatus) according to EN 113 procedure. Average mass loss of the tested insulation materials after exposure to the fungi is in general higher than mass loss of Norway spruce (Picea abies) and/or beech wood (Fagus sylvatica), indicating that resistance of these materials against fungi is lower than resistance of control spruce or beech wood. Therefore, construction measures have to prevent wetting of these materials in use in order to achieve desired service life. On the other hand the resistance of cellulose loose-fill insulation with added boron salt fulfils the requirements of the EN 113 standard.
COBISS.SI-ID: 2204553