Your search resulted in 363 documents. Displaying 25 entries per page.
Surface moulds and staining fungi on acetylated wood – effect of increasing acetyl content
2013 - IRG/WP 13-10797
Wood used in outside applications is susceptible to weathering and photo degradation, which often leads to surface discoloration, loss of brightness and surface deterioration. Research has shown that acetylated wood is more resistant against brown rot, white rot and soft rot, and more dimensionally stable than untreated wood. However, acetylated wood seems still to be disfigured by surface moulds ...
L Ross Gobakken, S Bardage, C J Long II
Inhibitory extractives or nutrients? Mould growth on coated heartwood and sapwood of Pinus sylvestris and Gleditsia triacanthos
2013 - IRG/WP 13-10806
Sometimes mould fungi grow over weathered coated sapwood, whereas the coated heartwood is not colonised. Two factors may be responsible for these differences: Either the larger content of nutrients in the sapwood, or the content of biocidal extractives in the heartwood. In this study the factors for the difference in mould growth on coated heartwood and sapwood of Pinus sylvestris (Scots Pine) and...
D Lukowsky, N Buddruhs
Statistical analysis of durability tests - Part 1: Principles of distribution fitting and application on laboratory tests
2013 - IRG/WP 13-20504
Service life prediction is an important topic in wood research, especially with regard to the Construction Products Regulation (CPR). Both laboratory tests as well as in-service performance testing are therefore essential in combination with proper monitoring and analysis tools. A crucial concept is variability in testing and analysis, especially for a biological material such as wood. The larger ...
I De Windt, J Van den Bulcke, C Brischke, C R Welzbacher, A Gellerich, S Bollmus, M Humar,
A critical view on early indicators for above ground field performance of wood
2013 - IRG/WP 13-20509
Above ground field tests are quite often a balancing act between the provision of realistic test conditions, reliable statistics, and acceptable long test durations. Within this study we therefore reviewed 543 data sets from above ground field tests performed at 36 different test sites in 8 countries in Australia and Europe. The main objective was to investigate possible correlations between early...
C Brischke, L Meyer, G Alfredsen, P-O Flæte, L Francis, M Hansson, P Larsson Brelid, J Jermer
Statistical analysis of durability tests - Part 2: Principles of time-to-failure and application on field test data
2013 - IRG/WP 13-20512
Service life prediction is an important topic in wood research, especially with regard to the Construction Products Regulation (CPR). Both laboratory tests as well as in-service performance testing is therefore essential, in combination with proper monitoring and analysis tools. A crucial concept is variability and the incorporation of variability in tests and analysis. In this paper we focus on t...
J Van den Bulcke, I De Windt, C Brischke, C R Welzbacher, A O Rapp, J Van Acker
The assessment by visual grading, change of color and ergosterol content ratings, the resistance to mould fungi of treated with wood preservative Scots pine sapwood
2013 - IRG/WP 13-20514
The filamentous (mould) fungi belonging to Ascomycetes, Deuteromycetes group are an cosmopolitan organisms which attacks wooden elements disfiguring them, dropping their value and causing environmental and health hazard. The fungi in a short time cause mainly disfigurement of wood does not effect on strength properties of wood, but with strong prolongation of duration of conditions favourable for ...
A Fojutowski, A Koziróg, A Kropacz
Service life evaluation of wood - an engineering approach
2013 - IRG/WP 13-20515
A performance-based service life design format based on climatic exposure on one hand and “biological wood resistance” on the other hand is presented in this paper. Important concepts are the introduction of limit states as well as reliable performance models for the biological processes, by which onset of deterioration can be predicted for arbitrary climate histories. Examples of applications...
S Thelandersson
Extraction and analysis of DNA from green and seasoned timber as basic methods for determination of wood species and origin
2013 - IRG/WP 13-20523
Against the background of the European timber trade regulation EUTR, commenced to law by March 2013, the determination of wood species and tracing of its origin is getting a great importance. A promising approach for establishing fast and reliable tracking systems for wood products is DNA analysis. A critical point is the extraction of analysable DNA from the wood and its lignified cell walls. Thu...
K Jacobs, H Mende, W Scheiding
Method for determining the critical moisture level for mould growth on building materials
2013 - IRG/WP 13-20530
The natural conditions of relative humidity (RH) and temperature (T) in different parts of a building is rarely constant over time. Instead, RH and T often vary cyclically and may pose a risk of mould growth as these conditions are the two key environmental parameters that controls mould growth. Consideration to both humidity and temperature conditions and the susceptibility to mould in a material...
A Ekstrand-Tobin, P Johansson, G Bok
Quantification of copper and chromium in field stakes after different exposure times: Remaining metal content and distribution
2013 - IRG/WP 13-50291
In order to determine the distribution of copper and chromium as well as their remaining concentration EN 252 specimens and thicker pine sapwood stakes (non standard format) were treated with a commercial CC salt in a vacuum pressure process. The stakes were installed in the test field of the Institute of Wood Research, Hamburg, in August 2010. In all cases three stakes were removed after 4, 8, 12...
T Liese, M Bahmani, E Melcher
Modelling the risk for mould growth on timber stored outdoors protected from rain
2013 - IRG/WP 13-20529
A mould resistance design (MRD) model was used to calculate the maximum duration of storage of timber outdoors under cover (protected from rain) before the onset of mould growth on the surface of wood. The prediction model is based on laboratory tests performed in constant and cyclic climates and were also confirmed against exposure tests in attics and crawl spaces. The prediction model presented ...
E Frühwald Hansson, S Bardage, S Thelandersson
Critical moisture levels and mould resistance of five different wood treatments
2013 - IRG/WP 13-30632
Mould resistance of five different treatments were tested using two methods, a recently
developed method for the determination of critical moisture levels of building materials (RHcrit),
and ASTM D3273-94. The critical moisture level method exposed samples at 22 °C and 98, 92,
86 and 82% relative humidity (RH) for 12 weeks. ASTM D3273-94 was performed at 29 °C and
about 95% RH.
Treatments c...
G Bok, P Johansson, A Ekstrand Tobin, S Bardage
Using hyperspectral imaging to detect and quantify mould and blue stain on coated and uncoated wood
2014 - IRG/WP 14-10822
Hyperspectral imaging has been applied on the surface of samples of coated and uncoated Norway spruce (Picea abies) as a new technique to detect and quantify growth of mould and blue stain fungi. Principal Component Analysis of the hyperspectral images resulted in a clear visualization of the fungi and the amount of mould coverage could be estimated. This indicates that NIR hyperspectral imaging c...
L Ross Gobakken, I Burud, A Flø, K Kvaal, T K Thiis
Identification of soft-rot fungi existed in the samples from the galley excavated at Yenikapi
2014 - IRG/WP 14-10833
The shipwrecks of the Middle Byzantine period were excavated during the construction of the Marmaray railway and metro station in Yenikapı between 2004 and 2012. This has become the largest investigations because of the size and the number of the shipwrecks and its associated artifacts. In the previous report, the electron micrographs of the samples revealed that a wide range in the degree of...
T Wada, C Köse, K Igarashi
Microbial Community Analysis of Naturally Durable Wood in an Above Ground Field Test
2014 - IRG/WP 14-10826
This paper presents preliminary results of an above ground field test wherein eight naturally durable wood species were exposed concurrently at two sites in North America. Surface samples were taken at regular intervals from non-durable controls and compared to their more durable counterparts. Terminal Restriction Fragment Length Polymorphism was performed to characterize the microbial (bacteria, ...
G T Kirker, S V Diehl, P K Lebow
Statistical analysis of 40 years of preservative in-ground stake testing in Australia
2014 - IRG/WP 14-20552
Wood is widely recognized as a valuable material, yet the natural durability of some wood species limits its use for certain outdoor purposes. For decades, a wide range of methods and chemicals have been developed to increase the resistance of wood against degrading microorganisms and termites. Preservative treatment has a long and widespread tradition in wood protection. Proper testing of the eff...
J Van den Bulcke, L J Cookson, I De Windt, W Li, J Van Acker
VOC-free remedial treatment agent on organic solvent basis with surface cleaning by photocatalysis using titanium dioxide
2014 - IRG/WP 14-40651
Due to the EU Regulations according to the harmonisation of the European market of biocidal products and the EU Regulations regarding emissions of volatile organic compounds in residential properties a new VOC free yet organic solvent based remedial treatment agent is introduced including a potential method to clean up the wooden surface of remaining biocides after a remedial treatment using photo...
H Ahl, J Fromm, P Jüngel, E Melcher, M Pallaske
Dynamic mechanical analysis (DMA) of nano cupric oxide (CuO) modified aqueous phenol formaldehyde (PF) resin
2014 - IRG/WP 14-40654
Phenol formaldehyde (PF) resins, modified by nano CuO incorporating alkane surfactant and polyvinyl alcohol (PVA) 17-99, were analyzed by dynamic mechanical analysis (DMA). The mechanical properties of its bonded plywood including tensile strength, modulus of rupture (MOR), modulus of elasticity (MOE) and shear strength under five test conditions were evaluated. Results indicated that the incorpor...
Wei Gao, Guanben Du
Modern Instrumental Methods to Investigate the Mechanism of Biological Decay in Wood Plastic Composites
2014 - IRG/WP 14-40674
Various instrumental techniques were used to study the fungal decay process in wood plastic composite (WPC) boards. Commercial boards exposed near Hilo, Hawaii (HI) for eight years in both sun and shadow locations were inspected and tested periodically. After eight years of exposure, both boards were evaluated using magnetic resonance imaging (MRI), while a selected area of the board exposed in sh...
G Sun, R Ibach, M Gnatowski, J Glaeser, M Leung, J Haight
Compatibility of Acetylated Wood and Wet Concrete
2014 - IRG/WP 14-40673
One of the newer commercial technologies to provide stability and durability to wood and wood composites is the process of acetylation (the reaction of acetic anhydride with wood). Wood is often used in contact with concrete, although only a very limited amount of species are suitable for this type of application because of durability issues. From this perspective durability class 1 timber such ...
R Rowell, C Lankveld, J Alexander
Effects of UV Radiation on Melanization and Growth of Fungi Isolated from Weathered Wood Surfaces
2015 - IRG/WP 15-10842
This research tests the hypothesis that fungi isolated from weathered wood will respond to elevated levels of UV radiation by increasing their melanin production. To test this hypothesis, we measured the melanin production and mycelial color of Aureobasidium pullulans and Cladosporium cladosporioides, before and after the fungi were grown under artificial UV, visible light and complete darkness. T...
V A Hernández, P D Evans
Short-term protection of palm wood against moulds and decay fungi by environment-friendly organic acids
2015 - IRG/WP 15-10843
Felled palm trunks are susceptible to fungi as long as their moisture content is above fibre saturation. During this period, it has to be protected against moulds and decay fungi. The study tested environmental-friendly organic acids for their protecting efficiency. Small samples of Date palm (Phoenix dactylifera) and Oil palm (Elaeis guineensis) wood were treated with weak organic acids and subse...
M Bahmani, O Schmidt
The whitening cause of Korean wooden heritage by flame retardant treatment
2015 - IRG/WP 15-20560
Korean wooden heritage used to treat by flame retardants in order to protect fire. There are 2 types flame retardant using for wooden heritage. These flame retardants treatment are basic measure that apply to wooden heritage along with other fire protection. The flame retardants cause white stains by reacting with Korean traditional wood painting (Dancheong) and increase wood humidity. The Korean ...
Jin Qyu Kim, Gyu-Seong Han, Yong Jae Chung, Hwa Soo Lee, Dong Won Son
Development of a rapid screening method to determine the susceptibility to mould growth of novel construction and insulation products
2015 - IRG/WP 15-20562
Wood-based materials are commonly used in building construction/insulation as a replacement for solid timber. However, these materials are susceptible to microbiological growth and different environmental conditions influence the vulnerability of wood-based materials. Moulds are a common problem found within homes and cause aesthetic damage, health problems and can increase material vulnerability ...
B K Stefanowski, S F Curling, E Mansour, G A Ormondroyd
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