Your search resulted in 994 documents. Displaying 25 entries per page.
Mould growth on spruce claddings and the effect of selected influencing factors after 4 years of outdoor testing
2015 - IRG/WP 15-30671
Norway spruce (Picea abies) is the most frequently chosen wood species as claddings in façades in Norway, and is used both coated and uncoated. The visual changes that occur during weathering can be colour changes, abrasion or wear, blistering, flaking, and even cracks in the wood or coating, but more often growth of mould and blue stain fungi is the main challenge. A field test with synchronous monitoring of relative humidity, air temperature, material temperature and wood moisture content in Norway spruce claddings has been performed in southern Norway as part of the ClimateLife project. Visual evaluation of blue stain and mould growth according to EN 927-3 was performed, and evaluation data after 46 months exposure is presented. The objectives were to study the effect of 1) environment, 2) cardinal direction and 3) colour of the coated surface on growth of blue stain and mould fungi and to study the variation in relative humidity, air temperature, wood moisture content and material temperature. After 46 months exposure, the red coating system had generally the lowest mould ratings and the uncoated claddings had the highest. Of the white coloured claddings the ones facing south had lower mould ratings than those facing north, but the opposite were found for red coloured claddings. The relative humidity was higher in front of claddings exposed northwards and in a shaded environment compared to an open environment against south. In an open environment red coloured claddings had the lowest wood moisture content and highest material temperature, and red coloured claddings against south had the highest maximum material temperature.
L Ross Gobakken, G I Vestøl
Tall oil – performance after a decade of field exposure
2015 - IRG/WP 15-30672
Water repellents have the potential to enhance biocidal activity by reducing leaching and lowering the moisture levels in wood exposed to rains. A range of studies have been performed in order to evaluate the potentials of tall oils as wood protective systems. The general conclusion has been that tall oil can provide some protection but that they cannot compete with the copper and organic biocide ...
G Alfredsen, P-O Flæte
Indentation and pendulum hardness tests: two convenient assessment methods of the performance of exterior wood coatings
2015 - IRG/WP 15-40689
Developing formulations of exterior wood coatings with long service life is a big challenge. For many years in Europe the performances have been mainly evaluated through weathering tests (within the EN 927 series) followed by visual assessment (blistering, flaking, mould growth, chalking and cracking), colour and gloss measurements, and adhesion tests. Very recently the importance of the mechanica...
L Malassenet, L Podgorski, M Truskaller, G Grüll
Some comments on durability testing of WPC according to EN 15534-1
2015 - IRG/WP 15-40695
The standard EN 15534-1 (2014) gives advice for broad characterization of WPC materials and products. It contains instructions for test procedures concerning different properties e.g. mechanical properties, thermal properties, as well as durability.
In this paper some WPC materials from the market were tested for their resistance against brown rot. Furthermore, the water uptake and bending prope...
S Bollmus, A Gellerich, H Militz
How does the test methodology influence the outcome of durability testing of thermally modified wood
2015 - IRG/WP 15-40699
Thermally modified wood is commercially available on the European market since many years. Today, many production units with various production capacities and different modification processes exist. Industrial scale wood heat treatment processes, under the trade name of ThermoWood were developed in Finland. ThermoWood has two standard treatment classes with different target properties, namely Ther...
A Gellerich, S Bollmus, H Militz
Investigation of Dimensional Stability and Coating Performance of Different Heat-Treated Poplar Wood Before and After Accelerated Aging
2015 - IRG/WP 15-40702
In this investigation, coating performance of heat-treated poplar wood (Populus tremuloioes) in different environments, before and after accelerated aging was studied. Specimens with 150×100×20 mm and 20×20×20 mm in dimensions were prepared. Heat treatments were performed in air, steam and linseed oil media. Specimens were coated by alkyd based stain. Adhesion strength before and after aging, ...
A Talaei, D Ansari Movahed, G Rassam
Termite and insect resistance of acetylated wood
2015 - IRG/WP 15-40703
The benefits from acetylation of wood to enhance resistance against fungal decay and dimensional stability have been known for many years. Since 2007 Accsys Technologies has been commercially producing Accoya® wood that is based on acetylation of radiata pine. A number of studies on the resistance of acetylated wood to attack by wood destroying termites have been conducted, but there is no common...
F Bongers, M Kutnik, I Paulmier, J Alexander, H Militz
Durability of reaction to fire performance of FRT wood products in different end use applications – Methods and results
2015 - IRG/WP 15-40705
Fire retardant treatments (FRT) may considerably improve the reaction to fire properties of wood-based products and the highest fire classifications for combustible products can be reached, but the maintained reaction to fire performance e. g. in exterior applications needs to be addressed in order to form a basis for new and reliable wood products with improved fire performance.
A European Techn...
B Östman, L Tsantaridis
Experimental Measurements of Fire Retardants on Plywood at Fire Test
2015 - IRG/WP 15-40709
The use and development of wood composite materials increased in the past few years. However, in Brazil there are some restrictions on these products regarding their use, since it could be considered a potential risk at a fire situation. Thus, becomes evident the need for researches aiming to fit these in safety standards. This study aims to evaluate the efficiency of two new fire retardant produc...
G C A Martins, L A Marcolin, J M Vidal, C Calil Jr
Shells of Coconut and their Durability against Termite Attack
2015 - IRG 15-10853
All tropical and subtropical areas of the Earth are inhabited by termites. In climates with moderate temperatures, they occur less frequently. Especially wood and non-wood materials that grows in tropical areas and used there in timber constructions and woodworking, wood durability and protection against termites should be researched. This paper reports findings from an experimental “AW011” la...
M Dass, A H H Wong, W Unger
Above-ground performance of a buffered amine oxide treatment system against Mastotermes darwiniensis
2016 - IRG/WP 16-10855
Above-ground H2 field tests against Mastotermes darwiniensis were conducted in far north Queensland to assess the efficacy of buffered amine oxide treatments in the softwoods Pinus sylvestris and P. radiata, and the hardwoods Eucalyptus regnans and E. diversicolor. Untreated hardwoods and slash pine bait wood (P. elliottii) were severely attacked or destroyed, while untreated P. sylvestris was mod...
L J Cookson, R W Clawson Jr
On the effect of climate and exposure conditions on durability indicators and their potential for service life prediction of wood-based products
2016 - IRG/WP 16-20576
In order to encourage increased use of wood, different user groups need to be better informed regarding the variation in performance between different wood materials and the effect of different use classes. It is also important to provide good empirical data on the service life of wood products as input to for example life cycle assessment studies. In the current study the effect of temperature an...
G Alfredsen, C Brischke, P-O Flæte, M Humar, L Meyer-Veltrup
Moisture induced risk and fungal development in various field test set-ups in and above ground
2016 - IRG/WP 16-20577
A high number of studies on the decay performance of wood in outdoor exposure have been conducted in the past. However, no testing methodology for wooden components exposed above ground reflecting the variety of different loads has been established so far. Many test protocols were modified in different ways throughout the years and results were often published in an encoded or incomplete way. This...
L Meyer-Veltrup, C Brischke
Selection of most aggressive test fungi for modified wood - Practical laboratory experience
2016 - IRG/WP 16-20579
One main objective of wood modification processes is the improvement of the durability against wood destroying organisms. Therefore, investigations of the resistance against wood destroying fungi have been one of the main focus within the last years. For the interpretation of the durability results, the selection of suitable test fungi is one of the main questions. A “wrong” fungus species may...
A Gellerich, S Bollmus
Variation in moisture content in field trials according to use class 3.2 conditions
2016 - IRG/WP 16-20580
Different test methods to determine the durability of wood in use class 3 (EN 335:2013) are available. Fungal degradation of wood requires liquid water. Different Standards (EN 335-1:2006; DIN 68 800:2011) specify the risk for decay with moisture content (mc) of above 20%. EN 335 (2013) does not specify moisture content but rather defined limited wetting conditions (use class 3.1) or prolonged wet...
S Bollmus, A Gellerich, H Militz
Bundle tests - Simple alternatives to standard above ground field test methods
2016 - IRG/WP 16-20581
Within this study we applied different new above ground test set ups to untreated Norway spruce (Picea abies Karst.) and Scots pine sapwood (Pinus sylvestris L.) which are frequently used as reference or control species in wood durability field tests. The overall aim of this study was to find a simple alternative method to the few standardized above ground field test methods, such as the L-joint a...
C Brischke, L Meyer-Veltrup
Modelling the performance of bio-based building materials
2016 - IRG/WP 16-20582
The ‘bio-based economy’ represents a growing area of development globally and covers a wide range of building materials including wood and wood-based products. A ‘bio-based’ material is intentionally made from substances derived from living (or once-living) organisms. In this context it means that the materials and products are made from renewable resources, with the criteria that a renewa...
C Brischke
Expert versus multi-sensor evaluation of wood samples after short term weathering
2016 - IRG/WP 16-20587
Understanding the influence of weathering factors and the material degradation mechanisms are fundamental for modelling the weathering process of wood. The goal of this work was to investigate the combined effect of time and exposure on the physical-chemical mechanisms of wood weathering. Four exposure directions (North, South, East and West) were investigated. Experimental tests were performed fo...
A Sandak, J Sandak, I Burud, L Ross Gobakken, M Noël
Evaluation of field test data
2016 - IRG/WP 16-20594
The resistance against fungal decay and insect attack of wood can be highly variable, between boards and even within boards. The variability in durability is not always an issue, but for high demanding applications information about its reliability is required. This comprises the variability of outdoor performance. Durability testing in laboratory and outdoor exposures can provide a good basis to ...
F Bongers, C Brischke, J Van den Bulcke, W Gard, I De Windt, H Militz
Performance of copper treated poles and posts after three to fifteen years of exposure
2016 - IRG/WP 16-20595
Copper based wood preservatives are one of the most important wood preservatives for heavy-duty applications. Wood treated with copper-based preservatives performs excellent if applied according to preservative specifications. If used improperly premature failures might appear. In order to elucidate properties of copper treated wood in use, utility poles and posts treated with copper-based preserv...
M Humar, N Thaler
Engineering for Rural and Civil Development. Uni Performance of wood exterior structures above ground contact in Spain built with softwood species. The situation of cases in northern Spain
2016 - IRG/WP 16-20597
Across Europe is very common to find exterior structures build in sawn and glue-laminated wood. Most of these exterior structures used softwood wood species such as fir, spruce, larch and pine. In Spain wood exterior structures, as for example bridges, became more and more popular since eighties, when sawn and glue-laminated wood were utilized for building exterior wooden structures in overall Spa...
D Lorenzo, J Fernández-Golfín, M Touza
Accelerated Weathering Performance of Impregnated Wood Samples Coated with Zinc by Means of Plasma-Assisted Particle Deposition
2016 - IRG/WP 16-30682
Many different methods are currently applied for wood protection against outdoor conditions. The most important of these is the process of impregnation with liquid substances. However, this kind of wood preservatives cannot provide a long-term protection of wooden surfaces. Weathering-resistant surfaces can be obtained by applying UV absorbing agents. In this study, the influence of zinc particles...
A Can, H Sivrikaya
Anti-Fungal Activity on Some Wood extracts as a Wood Protectant
2016 - IRG/WP 16-30684
In this study, six different wood barks were used, where obtained bark extracts were blended with potato-agar in order to investigate their antifungal properties. To determine the inhibition effectiveness of extractives, two different fungi; Coniophera puteana and Trametes versicolor were selected. Fungal activity was carefully observed for the duration of seven days. Following biological testing,...
Ö Özgenç, S Durmaz
Screening of fastener resistance in contact with untreated wood using different test designs
2016 - IRG/WP 16-30686
The performance of fasteners in wooden constructions is an important aspect especially regarding corrosion resistance. In an early stage corrosion of fasteners in untreated timber becomes often visible as a discoloration on the surface of the timber resulting in bad appearance of the product followed by complaints. In order to develop an accelerated test for the assessment of fastener performance ...
E Melcher, S Wolf, U Cera
Laboratory and Field evaluation on Resistance of Thiacloprid-treated Pine Species to Termites in Mexico
2016 - IRG/WP 16-30687
The usage of Neonicotinoids for wood preservatives is common practice in several countries. Especially the active ingredient Imidacloprid is well established for this application due to its high efficacy against termites. (2Z)-3-(6-chloro-3-pyridylmethyl)-1,3-thiazolidin-2-ylidene-cyanamide, also known as Thiacloprid showed a good efficacy against Reticulitermes santonensis De Feytaud in efficacy ...
P Meckler, T Jaetsch, I Rodriguez