Your search resulted in 199 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
High-frequency monitoring of mass loss due to brown rot degradation of modified wood
2016 - IRG/WP 16-10862
Fungi growing in liquid culture undergoes three separate phases in which they i) adapt to the new environment, ii) grow unrestrictedly and exponentially, and iii) are inhibited to increase in number/mass due to lack of nutrients etc. Filamentous fungi have been shown to exhibit similar growth phases in a solid food substrate and have been modelled to grow in this way also in solid wood. In modifie...
R Ringman, A Pilgård, K Richter
Susceptibility of wood substrates to Aurebasidium pullulans at different temperatures
2016 - IRG/WP 16-10863
There is an increasing awareness of how the aesthetical performance of wood exposed outdoors changes over time and especially in the first few years after installation. Mould and blue stain fungi are biological agents that contribute to the weather grey colour on a wooden façade, and the blue stain fungi Aureobasidium pullulans is commonly identified as colonizer on coated and uncoated wood expos...
L Ross Gobakken, G Alfredsen
Durability of a willow/plastic composite mat
2016 - IRG/WP 16-20592
Developing uses for wood wastes could enhance utilization of low value renewable materials while creating opportunities for rural development. Small diameter willow stems have little use in China, but they could be combined with high density polyethylene to create wood plastic composite mats for decorative applications. These mats could be used in exterior, above ground exposures, but would still ...
Li Yan, Haiyan Duan, Beizhan Quan, J Cappellazzi, J J Morrell
Distribution and penetration of the tung oil in wood studied by high-resolution magnetic resonance imaging
2016 - IRG/WP 16-20593
Water repellents as environment-friendly treatments are gaining their popularity as non-biocidal solutions for wood protection. One of the most important water repellents for wood besides waxes and organosilicon compounds are drying oils. Tung oil is one of the best performing oil. However, tung oil, similarly as other oils, does not penetrate deeply into wood, due to its high viscosity. In order...
M Žlahtič, U Mikac, I Serša, M Merela, M Humar
Fabrication and characterization of MicroPCMs filled wood-plastic composites: Effects of polyethylene glycol on melamine–formaldehyde shell material
2016 - IRG/WP 16-40728
Microencapsulated phase change materials (MicroPCMs) containing dodecanol were fabricated using melamine-formaldehyde (MF) or polyethylene glycol 200 modified melamine-formaldehyde (PMF) resin as the shell materials by in situ polymerization. Wood flour/high-density polyethylene (WF/HDPE) composites with MF shell MicroPCMs (MF-MicroPCMs) or PMF shell MicroPCMs (PMF-MicroPCMs) were prepared, respec...
Xi Guo, Jinzhen Cao
The influence of log soaking temperature and thermal modification on the properties of birch veneers
2016 - IRG/WP 16-40749
In veneer manufacture the logs are routinely soaked in heated water baths in order to soften the wood prior to peeling. The temperature of the water may vary greatly between batches; however, the influence of log soaking temperature on veneer properties has had little research attention. Uncontrolled moisture is known to cause problems in wood-based materials, while thermal modification offers a m...
S Källbom, K Laine, M S Moghaddam, A Rohumaa, K Segerholm, M Wålinder
Development of Wood Modification – High melting point wax and hot oil treatments
2016 - IRG/WP 16-40768
This study covers an introduction to the projects where new facilities were created for developing wood modification. In this new research environment it is possible to treat wood with versatile equipment. First modifications with this equipment are going to be done in high temperature and pressure using high melting point waxes and hot oils.
Earlier studies, tests and commercial products show...
H Turunen, L Linkosalmi, J Peura, O Paajanen
Effects of climatic factors and material properties on mould growth on untreated wooden claddings
2017 - IRG/WP 17-10884
Mould growth is an important contributor to colour change of untreated wood exposed outdoors. Predicting the development of mould growth is therefore important to ensure successful use of untreated wood as a façade material. More knowledge about the factors affecting mould growth on outdoor exposed wood is required to give better predictions. In this study, climatic factors and material propertie...
S Karlsen Lie, G I Vestøl, O Høibø, L Ross Gobakken
Moisture behaviour and biological durability of high performance flax fibre reinforced composites
2017 - IRG/WP 17-40803
For natural fibre composites in structural and load bearing applications long reinforcing fibres are required. Therefore, much research is performed on flax fibre reinforced composites to optimize them for high performance use. In most cases such research focuses on the mechanical properties, yet the assessment of moisture behaviour, dimensional stability and biological durability is an important ...
N Defoirdt, J Van den Bulcke, F Bensadoun, J Ivens, I Verpoest, J Van Acker
Influence of hygro-thermal treatment temperature and duration on dimensional stabilisation of wood modified with poly(butylene succinate)
2017 - IRG/WP 17-40813
To improve wood properties, especially dimensional stability, a treatment based on poly(butylene succinate) oligomers (OBS) was experimented. After impregnation in wood, a further hygro-thermal treatment (HTT) was carried out in a pressurized reactor at 100% relative humidity (RH) at differing temperatures for differing durations. The aim of HTT is to induce partial swelling of wood cell walls so ...
C Grosse, M Noël, L Rautkari, P Gérardin
Fipronil Concentrations in Soil after Vertical Termiticide Applications Using the “Termidor®H•P High Precision Injection System”
2017 - IRG/WP 17-20630
Termidor®H•P II High Precision Termiticide concentrations in sandy-loam and sandy-clay-loam building foundation soil were measured 1.0-hour after high-pressure vertical liquid injections into the soil using the Termidor®H•P High Precision Injection System. Cylindrical, vertical 30.5-cm-deep soil cores were extracted and separated into four 7.6-cm-long sequential partitions, and fipronil res...
B M Kard
Impact of temperature and relative humidity on spatio-temporal fungal growth dynamics of Basidiomycetes
2018 - IRG/WP 18-10905
Basidiomycetes can cause considerable damage to wood and other bio-based building materials. Knowing at which environmental conditions these decay fungi generally thrive, and how the environmental conditions affect fungal growth characteristics, is therefore of particular interest. In this paper, we use image analysis to assess the impact of the environmental conditions on the growth dynamics of C...
L De Ligne, G Vidal-Diez de Ulzurrun, J Van den Bulcke, J M Baetens, B De Baets, J Van Acker
Monitoring of the building made of CLT in Ljubljana
2019 - IRG/WP 19-40860
Wood is one of the most important construction materials and its use in building applications has further expanded in recent decades, predominately due to development of the modern composites, like cross-laminated timber. In order to enable even more extensive and reliable use of wood in outdoor applications, factors affecting wood’s service life need to be understood. It is well known that fung...
M Humar, D Krzisnik, B Lesar, N Thaler, B Dujic
Promoting Commercially Available Epoxy Resins for Non-biocidal Wood Preservation
2019 - IRG/WP 19-40877
Commercially available epoxy and polyamine resins were evaluated with the aim of developing new non-biocidal wood preservation treatments. A simple method allowing the impregnation of wood by vacuum double impregnation followed by a curing process was developed for two reference species, beech Fagus sylvatica and Scots pine Pinus sylvestris. The tested products were evaluated for their ability to ...
P Poveda, M Mubarok, S Dumarcay, M Montibus, I Le Bayon, M Kutnik, P Gerardin, F Simon
Wood veneer with high flexible decorated with nanoparticles for highly efficient water treatment
2019 - IRG/WP 19-50347
Natural wood is mainly comprised of numerous long, partially aligned channels (lumens) as well as nanochannels. Wood with these quick and effective passages is suitable for a membrane/separation material. However, a suitable thickness range of wood along its growth direction is essential to effectively separate small molecular, and the wood membrane is too thick to clean easily. In this paper, woo...
S Chang, D Xu, G Liu, J Hu, X Li, Y Liu
Moisture and temperature conditions in an old, highly moisture-loaded timber building in the Røros municipality, Norway
2020 - IRG/WP 20-10966
A 150 years old log building near Røros, Norway, has been in active use as a cowshed since its erection. The animals are kept inside the cowshed all winter and this causes a situation of a high moisture load on the wooden floor, wooden walls and ceiling. Logging of temperature and humidity over one year shows that there are favourable levels of moisture in the wood and air for development of moul...
M Sand Austigard, J Mattsson
Sterilization of Large Timbers during Preservative Treatment: How Quickly We Forget
2020 - IRG/WP 20-40902
Air seasoning is a common method of moisture management in utility poles and is done de facto during pole storage prior to treatment. However, extended air drying prior to treatment encourages fungal attack and can facilitate establishment of decay fungi in poles before a protective preservative barrier is applied. This problem can be mitigated by proper air-seasoning methods coupled with heat ste...
G Presley, J Cappellazzi, M Konkler, K Maguire, R Nelson, J J Morrell
Development of Wooden Fireproof Structures for Mid- and High-rise Buildings in Japan
2021 - IRG/WP 21-30757
When constructing a mid-to-high-rise building more than 4 stories in general in Japan, it is necessary to have a fireproof structure stipulated by the Building Standard Law. The performance required as a fireproof structure in Japan is generally stricter than in other countries, and it is required to be structurally sound after a fire even without fire extinguishing activities. In order to satisfy...
D Kamikawa, M Harada, H Matsunaga, R Takase, N Hattori, Keisuke Ando, M Miyabayashi
Premature adhesion failure of exterior wood coatings – The influence of substrate temperature at coating application and moisture accumulation during storage
2022 - IRG/WP 22-40937
The present study aimed at extending the knowledge about premature coating failures of industrially finished wood cladding. Two potential factors were studied: the influence of substrate temperature at coating application and moisture accumulation during storage on the adhesion of waterborne coating systems. In the first experiment, 4 batches of wood specimens were submitted to 4 different tempera...
U Hundhausen
Joints design considerations in indoor high humidity conditions
2022 - IRG/WP 22-40950
In recent years, a number of cases of degradation by wood destroying fungi have been detected in covered timber structures such as pools, wineries, bathrooms, etc. – in fact, any building where indoor air may reach high humidity values during certain periods of time.
The origin of this kind of decay was not related to water leaks, but to the condensation of the water vapor over the steel connec...
A Lozano, D Lorenzo, M Alonso, F Álvarez, J E Martínez
Starch modified with silanes – high hydrophobic surface treatment for wood protection
2023 - IRG/WP 23-40981
The great potential of silanes for starch modification and their utility as surface wood protection is still not sufficiently assessed. The work aimed to analyze the crosslinking process's effect on starch modification with silane and tested the hydrophobic properties of surface-treated wood. The starch treatment was modified with methyltrimethoxysilane or N-octyltriethoxysilane. SEM-EDX with a cr...
W Perdoch, M Bajstok, B Mazela, I Siemińska, B Peplińska
Manufacturing of bamboo hybrids with high strength, superior fire retardancy, and dimensional stability
2024 - IRG/WP 24-30808
Bamboo, renowned for its rapid growth, high strength-to-weight ratio, and eco-friendly attributes, has found extensive use in decorative building materials and glue-laminated beams. However, the inherent challenges of dimensional instability and flammability in natural bamboo restrict its broad application. This research introduces a range of environmentally friendly techniques aimed at producing ...
W He, Rui Wang, W Li, G Hu, T Singh, Q Fu
Modelling the service life of wood in ground contact – Verification of remotely sensed soil data from the reanalysis dataset ERA5-Land using in-situ measurements at a test site of utility poles in Eastern Norway
2024 - IRG/WP 24-41003
This study compared soil moisture and temperature estimates from the 5th European reanalysis (ERA5-Land) dataset with in-situ measurements to assess the accuracy and applicability of ERA5-Land data for modelling the service life of wood in ground contact. The ERA5-Land soil temperature estimates showed a moderate correlation with the in-situ temperature measurements (Spearman’s ρ of 0.73) and a...
U Hundhausen, P B van Niekerk, B Marais