Your search resulted in 295 documents. Displaying 25 entries per page.
The effect of chemical changes on the wood-moisture relationships in thermally-modified wood
2009 - IRG/WP 09-40473
Small specimens of three wood species were thermally modified following twenty schedules in the 190-245°C temperature range for treatment times between 0.3 and 16 h. Five wood-moisture relations were subsequently determined, namely: anti-swelling efficiency (ASE), movement, hygroscopicity (adsorption and desorption), transversal swelling (radial and tangential directions), and equilibrium moistur...
M M González-Peña, M D C Hale
Measurements of rot fungal activity as a function of moisture content by isothermal calorimetry
2010 - IRG/WP 10-20428
Measurements of heat production rate have been made on wood samples with the brown rot fungus Postia placenta at different moisture contents. The results clearly indicate that the heat production rate (a measure of respiration rate and activity) is moisture dependent. When the moisture content is decreased, less heat is produced, and when the moisture content is increased, more heat is produced. I...
L Wadsö, A Pilgård, G Alfredsen
Service life prediction of wooden components – Part 1: Determination of dose-response functions for above ground decay
2010 - IRG/WP 10-20439
Scots pine sapwood (Pinus sylvestris L.) and Douglas fir heartwood (Pseudotsuga menziesii Franco) specimens were exposed in double layer field trials at 24 different European test sites under different exposure conditions (in total 28 test sets). The material climate in terms of wood moisture content (MC) and wood temperature was automatically recorded over a period of up to eight years and compar...
C Brischke, A O Rapp
Impact of climate change on wood deterioration - Challenges and solutions for cultural heritage
2010 - IRG/WP 10-20441
Deterioration of wood in cultural assets follows the same physiological mechanisms as in modern structures. Therefore rules and data for prediction of service life derived from old wooden structures can be used to model the service life of recent wooden structures and vice versa. The latter is done in this paper: From experimental test set ups in the field spread over Europe, climatic data, wood t...
C Brischke, A O Rapp, M Hasan, R Despot
A Review on Conditions for Decay Initiation and Progression
2010 - IRG/WP 10-20444
This paper reviews the key publications available on service life prediction of exterior wood applications, critical conditions for decay initiation and progression, and the impact of decay on wood strength. While it is helpful to use climatic data to predict general trend of decay potential, more precise decay initiation and progression information is required by hygrothermal modeling for its dam...
Jieying Wang, P I Morris
Drying Rates and Mold Growth on Various Building Materials under Different Environmental Conditions
2010 - IRG/WP 10-20454
Mold growth on building materials is a major problem for homeowners. The most suitable method to control mold growth on building materials is to utilize design features, construction tools and practices that prevent moisture accumulation, and keep the wood as dry as possible. In order to achieve this, engineers and homebuilders have to know the effects of various temperature and moisture conditi...
Dian-Qing Yang
Finite Element Modelling of the Checking of Wood Exposed to Accelerated Weathering
2010 - IRG/WP 10-20459
The surface checking that develops when wood is exposed to the weather reduces the visual appeal of treated wood products and can reduce the effectiveness of preservative treatments. There is strong interest in developing solutions to this problem and also a growing realization that such solutions may evolve from a deeper understanding of the mechanisms responsible for surface checking. In this pa...
S G Ribarits, P D Evans
Sorption properties of wood impregnated with aqueous solution of boric acid and montan wax emulsion
2010 - IRG/WP 10-40492
Non-biocidal techniques for wood protection become more and more important, nowadays. One of the possible treatments is use of water repellents. In the present research influence of, one of the possible water repellent, the montan wax emulsion, on the moisturizing and the sorption characteristic of impregnated wood was investigated. To achieve a better protection against wood decay fungi, montan w...
B Lesar, M Humar
Impact of wood species on the performance of exterior wood coatings
2010 - IRG/WP 10-40519
To prolong the service life of a wooden construction the protective function of a coating is of utmost importance. The chemical composition as well as the wood-coating interface affects the performance of this protective layer and obviously wood species have an impact too. This paper discusses the influence of wood species on the overall coating performance. Therefore, a range of opaque waterborne...
I De Windt, J Van den Bulcke, J Van Acker
Moisture dynamics of WPC as basis for biological durability
2010 - IRG/WP 10-40520
The largest market for wood-polymer composites (WPCs) is currently decking. Although many products are commercially available, a proper standard for the assessment of the biological durability of WPC does not exist. Recommended standards for testing resistance against basidiomycetes should be completed with a method to bring the specimens in a worst case situation, obtaining a moisture level high ...
N Defoirdt, J Van Acker, J Van den Bulcke
Testing of decay resistance of sapwood and heartwood of thermally modified Scots pine and Norway spruce
2010 - IRG/WP 10-40523
Thermal modification at elevated temperatures changes the chemical, biological and physical properties of wood. One of the main targets of thermal modification is to increase the biological durability and decay resistance of wood. Although the effects of thermal modification on wood have been widely studied, the significance of sapwood and heartwood on the resistance of thermally modified wood has...
H Viitanen, S Metsä-Kortelainen
Effects of global climate change on mould growth - Interactions of concern
2010 - IRG/WP 10-50270
An evident change in climate the last decades has been recorded, and combined effects of increased CO2, elevated temperature and altered precipitation regimes have been observed to represent a change to the fundamental drivers within ecosystems. Growth of moulds, both in nature and on man-made constructions and objects, will most likely increase due to changes in the climate. The survival, the rep...
L Ross Gobakken
Chapter 12 - Treatment Groups of Bamboo
2007 - IRG/WP 07-10635-12
Study on distribution of CCA in three major bamboo species in
Bangladesh, full-cell pressure treated at green and dry conditions
revealed two treatment groups and some treating principles. Higher
adequate treatment for ground and water contact use is only
possible by treating problematic bamboo species pre-kiln dried up to
half of its FSP and non-problematic species pre-dried up to FSP
(20% ...
A K Lahiry
Theoretic discussion on the way and driving forces of moisture migration in wood during vacuum drying
2011 - IRG/WP 10-40538
Most of parameters in conventional drying cannot explain a lot of phenomena appeared in vacuum condition, so it is necessary to further explore the moisture migration way and driving forces in wood under vacuum condition. For the water movement channel in wood is very narrow, the characteristic of heat and mass transfer in wood is similar to that in microscale. This article applies theory of liqui...
Zhengbin He, Xueli Yao, Liqiong Chen, Songlin Yi
Determination of Equilibrium Moisture Content (EMC) of wood in the neighboring Countries of Iran
2011 - IRG/WP 10-40540
The mean value of annual temperature and relative humidity of 33 cities in Azerbaijan, Armenia, Turkmenistan, Afghanistan, Pakistan, Oman, United Arab Emirates, Bahrain, Qatar, Kuwait, Iraq and Turkey were determined using climatic data of the past 11 years.
The EMC values were calculated using the Hailwood-Horrobin sorption model and its annual fluctuation, together with Temperature and relati...
A A Enayati, H Z Hosseinabadi
Growth conditions for fungal decay in wooden constructions – practical experience versus literature
2011 - IRG/WP 11-10758
Data regarding moisture and temperature requirements of decay fungi found in literature have been compared to experience from observations in a large number of Norwegian buildings. A number of selected situations are discussed, among those exposure to high relative humidity, exposure to free water and decay in the supposedly adverse conditions on Svalbard. The moisture content in wood has to be at...
M Sand Sivertsen, J Mattsson
The influence of moisture content and wood pH variation on fungal melanin formation in wood substrates
2011 - IRG/WP 11-10759
Wood decay patterns are strongly influenced by the conditions of the wood substrate, including moisture content and pH. In an antagonistic environment some fungi respond with pigment formation that helps to isolate and protect their mycelium. This is often associated with slower fungal growth and delay of wood mass loss. Dark colored melanin is the most common pigment formed by wood decay fungi, a...
D Tudor, S C Robinson, P A Cooper
Improving our understanding of moisture and other durability-related properties of wood in building envelope performance prediction
2011 - IRG/WP 11-20468
Building science has become an increasingly important field in recent years with rapid changes in construction methods, building materials and consumer expectations. The field has also been brought to prominence by a few large-scale premature building envelope failures in a few regions across the world. Considerable effort has been put into developing hygrothermal models to simulate heat, air, vap...
Jieying Wang, P Morris
Decay initiation in plywood, OSB and solid wood under marginal moisture conditions
2011 - IRG/WP 11-20469
Hygrothermal models are increasingly used as research tools by building scientists and and design tools by designers to simulate heat, air, vapour, and water movements within and through building envelope and even to predict the consequences in terms of mould/decay growth and metal corrosion. This work was designed to generate data on decay initiation under marginal moisture conditions to support...
Jieying Wang, P Morris
Moisture protection and performance during 5 years exposure of 19 wood coating systems on a cladding in Vienna
2011 - IRG/WP 11-40561
A cladding with vertical boards of Norway spruce (Picea abies) comprising different coating systems had been exposed to natural weathering oriented south west in Vienna for 5 years. Weathering behaviour of the boards was assessed in intervals and wood moisture content was measured over the first 22 months of exposure. The moisture protective properties of the coating systems were assessed using la...
G Grüll, I Spitaler, M Truskaller
Long term durability of the heartwood of seven common softwood species in above ground conditions
2012 - IRG/WP 12-10771
The natural durability for wood in above ground use has been evaluated based on results after 11 years of exposure in a test site situated at the Danish Technological Institute in Taastrup, Denmark. Selected results for seven common softwood species exposed horizontally are reported. The test results cover samples with direct rain exposure (use class 3 of the European standard EN335-1:2006) and sa...
E Tang Engelund, M Klamer, T Mark Venås, B Lindegaard
Influence of soil moisture, Sarawak soil types and decay types on decay susceptibility of rubberwood and kelempayan
2012 - IRG/WP 12-10780
Wood and soils are important natural resources of the land, the former widely used as structural supports in contact with the latter. Many low durability wood species exposed to soil contact has reportedly high incidence of decay failures in poorly treated and untreated materials depending on soil types, properties and soil microbial virulence. This paper probes the relationship of the main soil t...
A H.H. Wong, P K.F. Chong, J Sabang
Plywood under the scanner: linking moisture dynamics and 3D structure
2012 - IRG/WP 12-20491
Plywood is highly esteemed as a construction material. Yet, the influence of moisture on both strength and durability are important factors. Especially the dynamics of moisture desorption and absorption should be taken into account when assessing the quality of a panel, which is a fact for all panel materials. This paper therefore focuses on the monitoring of the moisture dynamics of plywood subje...
J Van den Bulcke, I De Windt, N Defoirdt, J Van Acker
Comparative studies on the moisture performance and durability of wooden facades
2012 - IRG/WP 12-20492
Wooden claddings are traditionally used in many parts of the world. Also modern structures are frequently made from timber and timber engineering panel products. However, wood has to compete with other cladding materials and its durability needs to assure sufficient functional and aesthetic service life. Besides many other factors the durability of a wooden facade is dominated by its moisture perf...
T Bornemann, C Brischke, J-M Lück
Moisture performance based wood durability testing
2012 - IRG/WP 12-20495
In the frame of a scientific cooperation within the Swedish research program ‘WoodBuild’ comparative field and laboratory durability studies have been carried out by the Technical Research Institute of Sweden SP and Leibniz University Hannover. One objective was to improve test methods as well as evaluation systems in order to facilitate the use of (field) testing for service life prediction. ...
L Meyer, C Brischke, A Pilgård