Your search resulted in 54 documents. Displaying 25 entries per page.
The kinetics of anhydride modification reactions of wood. Experimental results and theoretical modelling
1998 - IRG/WP 98-40125
Although the chemical modification of wood remains a fertile area for research, there has been little work performed on the kinetics of the modification process. The reaction kinetics of a series of linear chain and cyclic anhydrides has been studied and activation energies of the reaction determined. The reaction kinetic profiles are determined by the relative rates of reaction of the reagent wit...
C A S Hill, J G Hillier
Modelling of copper emission fron treated wood leached according to NEN 7345 and ENV 1250.2
1996 - IRG/WP 96-20097
A series of water leaching experiments is carried out investigating pine and spruce treated and fixed using different copper-containing preservative solutions and process technologies. Water changes took place as prescribed in the Dutch standard NEN 7345 and the European test method ENV 1250.2, each of the leachates being chemically analysed for their copper content. Irrespective of the preservati...
G M F Van Eetvelde, S G L Michon, M Stevens
Accelerated anti-termite laboratory tests, simulation of field conditions and assessment of results for service life
1994 - IRG/WP 94-20034
Termites are one of the most serious biodegrading agents in the tropics. Though some species of termites occur in the warmer temperate regions, only a few species can withstand the rigours of colder regions. Testing of termite resistance of material is done either by field tests or by accelerated laboratory tests. Field tests, though realistic to assess service life, are elaborate, take a long tim...
P K Sen-Sarma
Three-dimensional modeling of fumigant distribution in wood poles
1993 - IRG/WP 93-30025
The practice of using fumigants to control internal decay has been widely accepted in the United States and has shown to be effect in control internal decay in transmission poles and other large wood timbers. Mathematical models were developed to simulate the chloropicrin movement in utility poles after treatment. The simulation results indicated that treatment of utility poles, using either tradi...
Jing Liu, B Goodell
Predicting the decay resistance of timber above-ground: 1. Climate effects
2006 - IRG/WP 06-20330
Despite the benefits of using timber as a building product, it is disadvantaged by current Australian Standard durability classifications which lack the sensitivity desired by engineers and architects. To address the need for more sensitive timber service-life information in Australia, an above-ground durability research program was established in 1987. One focus of research is the relationship be...
L P Francis, J Norton
Fire Safety of Wood Floor Assembly: Model and Full-scale Test
2007 - IRG/WP 07-20375
The present paper describes the model for the prediction of fire safety of wood floor assemblies. The model includes heat transfer model for the calculation of the flow of heat in floor assembly and structural model for the analysis of the mechanical performance of wood joists. The floor assemblies considered in this paper are constructed with nominal 2x10 (38x241mm) wood joists lined by Type X ...
H Takeda
Field Liners as physical barriers to prevent wooden utility pole decay in soil: An accelerated field simulation trial
2008 - IRG/WP 08-20384
Field Liners (FL’s), plastic sleeves used to protect in-ground wooden poles from fungal and termite damage, have been tested before as physical barriers to prevent contact between soil and wood and to retain wood preservative treatment. These earlier studies concentrated mostly on creosote preserved poles and early generation FL’s which were cumbersome in their application. The newer generatio...
A R Howgrave-Graham, L J Cookson, T Hale
Service life prediction of wood: scale-dependent tools within a bio-engineering framework
2008 - IRG/WP 08-20387
Service life prediction (SLP) is a complex yet essential method for the building industry. Accurate and precise assessment of the components is crucial for a strong position of wood on the market. As it is a biological material, wood has an inherent variability and is susceptible to fungal attack. Therefore a profound knowledge of these characteristics is the corner stone of SLP for wood products....
J Van den Bulcke, J Van Acker, M Stevens
Evaluation of exposure conditions for wooden facades and decking
2009 - IRG/WP 09-20408
During their functional life, building components are exposed to moisture and other environment stress conditions in numerous ways. This is a fact that should be taken into account during manufacture, product development, designing and work execution of building components. For wood material, moisture stress and biological factors like mould and decay fungi are often critical in cladding and decki...
H Viitanen, T Toratti, R Peuhkuri, T Ojanen, L Makkonen
Modelling of onset of mould growth for wood exposed to varying climate conditions
2009 - IRG/WP 09-20414
A performance-based service life design format based on climatic exposure on one hand and “resistance” of wood against mould growth on the other hand, is presented in this paper. A limit state for onset of mould growth is defined as the occurrence of traces of mould observed by microscopy. A dose-response model is proposed by which onset of mould growth can be predicted for an arbitrary climat...
S Thelandersson, T Isaksson, A Ekstrand-Tobin, P Johansson
Modelling hyphal growth of the bio-incising fungus Physisporinus vitreus
2010 - IRG/WP 10-10710
The white-rot fungus Physisporinus vitreus preferentially degrades the pit membranes of bordered pits in tracheids and subsequently enhances wood permeability. Thus, P. vitreus can be used to improve the uptake of wood preservatives and environmentally-benign wood modification substances. This process can be used to enhance the use and sustainability of native conifer wood species by the wood indu...
M Fuhr, C Stührk, F W M R Schwarze, M Schubert, H J Herrmann
Simulation and Investigation of Wood Degradation by Erosion Bacteria in Laboratory Experiments
2010 - IRG/WP 10-20431
A Microcosm experiment was successfully set up to establish, monitor and manipulate bacterial wood degradation under low oxygen conditions. Sound pine sticks were placed in waterlogged sediment from a heavily decayed pine pile foundation site in Amsterdam. The system was subject to different gassing treatment regimes in order to investigate the role of oxygen in the bacterial degradation process o...
J Gelbrich, E I Kretschmar, N Lamersdorf, H Militz
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
Decay hazard mapping for Europe
2011 - IRG/WP 11-20463
In this study, two different dose-response models for above-ground decay as well as a model transferring macro climate data to wood climate data are presented. The models base on data from field trials, which had been conducted at 28 European test sites, and were used to calculate the relative risk for decay caused by climate variability in Europe. The two dose-response models give coherent result...
C Brischke, E Frühwald Hansson, D Kavurmaci, S Thelandersson
Service life prediction of wooden components - Part 3: Approaching a comprehensive test methodology
2011 - IRG/WP 11-20464
This paper is the third in a series on 'service life prediction' of wooden components and should be considered as a discussion paper. The authors tried to analyze the topic with a look from a distance and comment sometimes with a smile on the current controversial discussion about SLP issues. Nevertheless, the viewpoints of different groups, such as natural scientists, engineers, approva...
C Brischke, C R Welzbacher, L Meyer, T Bornemann, P Larsson Brelid, A Pilgård, E Frühwald-Hansson, M Westin, A O Rapp, S Thelandersson, J Jermer
Aesthetic service life of coated and uncoated wooden cladding - influencing factors and modelling
2011 - IRG/WP 11-20470
Mould growth on exterior coated cladding façades is an undesirable element and will often shorten the aesthetical service life. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood substrate itself, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within...
L Ross Gobakken, O A Høibø
Cell wall properties of softwood deteriorated by fungi: combined chemical analyses, FT-IR spectroscopy, nanoindentation and micromechanical modelling
2013 - IRG/WP 13-20527
Mechanical properties of wood are determined by its inherent hierarchical microstructure, starting at the nanometer scale, where the elementary components cellulose, hemicelluloses, and lignin build up the wood cell wall material. Fungi cause degradation and decomposition of these components and, thus, alter the mechanical properties of wood. The aim of this study is to gain new insight into these...
L Wagner, T K Bader, K de Borst, T Ters, K Fackler
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
Acceptance levels of surface disfigurement - tolerance to defects of coated wood
2015 - IRG/WP 15-20564
Service life planning (PSL) has become an important issue in performance based building and substantial progress has been made in recent years. The role of predicting the aesthetical service life of wooden building components has been underestimated for quite long time but is recently attracting more and more notice. It is influenced by numerous factors such as discoloration, fading, flaking, crac...
C Brischke, P Kaudewitz
Global survey on durability variation – on the effect of the reference species
2016 - IRG/WP 16-20573
Climate change due to anthropogenic emissions is the largest environmental challenge of our time. Forest-based value chains play an important role in reducing the accumulation of CO2 in the atmosphere. Maximizing the use of wood to tackle climate change requires improved understanding of the service life of timber products. This information can best be obtained from field testing and while there i...
R Stirling, G Alfredsen, C Brischke, I De Windt, L P Francis, E Frühwald Hansson, M Humar, J Jermer, M Klamer, M Kutnik, P Laks, I Le Bayon, S Metsä-Kortelainen, L Meyer-Veltrup, P I Morris, J Norton, T Singh, J Van Acker, J Van den Bulcke, T M Venås, H Viitanen, A H H Wong
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
Simulation of surface climate and mould growth on wooden façades
2016 - IRG/WP 16-20585
The weathering of wooden surfaces is normally caused by mould growth, lignin deterioration and leaching of extractives. For well insulated buildings, the effect of the interior climate on the outer surface is small and sometimes negligible. This paper describes simple models for surface temperature and moisture conditions on a wooden façade that can further be used to model weather degradation an...
T K Thiis, I Burud, D Kraniotis, L Ross Gobakken
Studying fungal growth using automated image analysis and computer simulations
2016 - IRG/WP 16-20590
Wooden materials are prone to fungal attack resulting in damage and economic losses. Therefore many efforts have been made to understand the degradation of wood and to avoid the adverse effect of fungi. Even though the extent of degradation of a material is inversely proportional to the extension of the fungi attacking it, most researchers focus mainly on the former, leaving the study of the latte...
G Vidal-Diez de Ulzurrun, J M Baetens, J Van den Bulcke, B De Baets
Modelling of moisture content in timber bridge details
2017 - IRG/WP 17-20613
The design of details is an important aspect in durability design of timber bridges. Details are often considered the weakest points in bridges due to their tendency to trap and accumulate moisture and thus facilitate decay. When designing maintenance plans and inspection intervals, it is important to know how design choices will come to influence the service life. Moreover, service life and wood ...
J Niklewski, C Brischke, E Frühwald Hansson, L Meyer-Veltrup
Comparative performance of wood/wood-based claddings predicted by four hygrothermal simulation tools
2019 - IRG/WP 19-20646
A number of hygrothermal numerical simulation packages are available, either wholly or partially dedicated to heat, air and moisture transfer simulations of building materials and wall assemblies. The objective of this work was to compare the hygrothermal responses and the moisture performance of western red cedar and composite wood claddings of a wood frame wall as predicted by four hygrothermal ...
M Defo, M Lacasse, A Laouadi