Your search resulted in 284 documents. Displaying 25 entries per page.
Field test design for service life prediction of wooden components
2005 - IRG/WP 05-20308
Wood is predominantly degraded by organisms. Thus, compared to other building materials, service life of wooden material is influenced by many more factors, which are divided into direct and indirect factors. Climate, geographical position, and construction criteria count to the indirect decay factors.
Besides material inherent properties (natural durability, wood preservatives), wood temperature...
A O Rapp, C Brischke
Minimisation of the Environmental Impacts of Coatings on Exterior Wood by Optimisation of their Life Spans
2003 - IRG/WP 03-50197
The study has shown that the environmental impacts from coatings on exterior wood are dependent criteria on their life spans. A minimisation of the environmental impacts can be performed with the help of the integrated design model, which is tested in this study. The optimal life spans, found as reference service lives from the exposure tests, statistical evaluation and the assessment of experts w...
L Strömberg
Service life prediction of wooden components – Part 2: Impact of material, exposure and design details
2010 - IRG/WP 10-20440
Dose-response functions permit to estimate the moisture and temperature induced decay potential for any wooden building component and exposure, and thus the service life to be expected. In part 1 of this series dose-response functions were established as a result of double layer field trials carried out at 24 European test sites over up to eight years. Using them makes it no longer necessary to co...
C Brischke, B Lauenstein, M Bilstein, T Bornemann, A O Rapp
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
Quantitative design guideline for wood outdoors above ground applications
2011 - IRG/WP 11-20465
This paper describes the background and principles behind an engineering design guideline for wood in outdoor above ground applications, i.e. use class 3 according to EN 335. The guideline has been developed in the European research project WoodExter and can be seen as a first prototype for a quantitative design tool in the area of wood durability. It is based on a defined limit state for onset of...
S Thelandersson, T Isaksson, E Suttie, E Frühwald, T Toratti, G Grüll, H Viitanen, J Jermer
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
Non-destructive monitoring of structure and moisture dynamics of plywood exposed outdoors to improve service life prediction and fit-for-purpose design
2015 - IRG/WP 15-20570
Plywood is an important construction material yet prone to water uptake, which can decrease strength and increase decay risk. To predict service life and improve fit-for-purpose design, it is crucial to understand the moisture behavior and structural changes of plywood. In this research, several plywood specimens were exposed outdoors for approximately one year. During this period, the moisture di...
W Li, J Van den Bulcke, I De Windt, M Dierick, J Van Acker
Design and performance prediction of timber structures based on a factorization approach
2017 - IRG/WP 17-20603
Service life of timber structures in outdoor conditions is predominantly affected by the climatic conditions in terms of moisture and temperature over time. On the one hand, the two parameters moisture content and temperature determine the exposure-induced dosage that can lead to fungal infestation and subsequent decay. On the other hand, the material resistance of wood stands in opposition to exp...
L Meyer-Veltrup, C Brischke
Colour changes in unpainted wooden façades – Fifty Shades of Grey
2018 - IRG/WP 18-10903
In Norway the use of weathered unpainted, wooden façades has increased in popularity the last 20 years, both in single family houses as well as in multi-story and non-residential buildings. The benefit of using unpainted wood as façade material can be several: low maintenance costs, low environmental impact and low carbon footprint as well as contemporary and trendy aesthetic appearance.
The va...
K Zimmer, L R Gobakken, O Flindall, M Nygaard
Durability by design – a case study of the performance of wooden decks after 9.5 years of natural weathering
2019 - IRG/WP 19-20648
The service life expected for wood decking manufactured with poorly durable wood species, left untreated and exposed to severe environmental conditions such as high humidity and active biological agents, is usually assumed to be short (less than 10 years). The current classification of wood’s natural durability is based on EN standardised tests which do not fully reflect the real end-use conditi...
M Kutnik, M Montibus
Performance based specification of wood – Introducing project CLICKdesign
2019 - IRG/WP 19-20661
This paper introduces the new ForestValue research project CLICKdesign – delivering fingertip knowledge to enable service life performance specification of wood. This European consortium is working on the primary innovation to move from the complex, fragmented and general to the easy-to-use, consolidated and specific by provision of an accessible digital tool for specifiers. Competing materials ...
E Suttie, C Brischke, E Frühwald Hansson, S Fortino, J Sandak, M Kutnik, G Alfredsen, C Lucas, R Stirling
Service life planning of wooden structures: Mathematical prediction models versus professional experience
2019 - IRG/WP 19-20663
During the last 15 years, enormous efforts have been made in developing models for predicting the service life of wooden structures and components. Currently, a framework of how exposure, dimension, design details and the material-intrinsic and the ability to take up and release water can be linked to model the moisture risk in wood products is in principle available.
The aim of this study was to...
C Brischke, J Niklewski, M Humar, G Alfredsen
Significance of the thermal design and the sorption isotherm shape in hygroscopic wood moisture dynamics and service life
2022 - IRG/WP 22-20682
Moisture dynamics are considered important for predicting the service performance of wood in exterior applications. Above a critical moisture content, water acts a softener on the structural polymer matrix of the wood cell wall, enabling the necessary diffusion of molecular species involved in the fungal degradation mechanism of wood. Water may enter solid wood in either liquid form or in vapor fo...
W Willems
How to Document the Performance of Super-Critical Treated Wood in above Ground Situations?
2005 - IRG/WP 05-20316
The paper presents practical experiences from the preparation of a new preservative treated wood product for introduction to the market. The product in question is Superwood™, which is treated with organic biocides using CO2 in a supercritical state as a solvent.
The question is how to evaluate the performance of a new product such as Superwood™ in order to get an acceptance on the market a...
N Morsing, A H H Wong, F Imsgard, O Henriksen
Inspection results of preservative treated stakes, maximum 33 years in field
1992 - IRG/WP 92-3690
Since in 1958, we have undertaken field experiments in Japan. For these field experiments, we used sapwoods of Japanese cedar called Sugi (Cryptomeria japonica) because of majority of plantation forest soft wood species in Japan. For some preservatives, we added sapwood of Japanese beech called Buna (Fagus crenata), a main Japanese hard wood species. Dimensions of these specimens were 30 x 30 x 60...
K Suzuki, K Yamamoto, M Inoue, S Matsuoka
Extending the useful life of creosoted electricity distribution poles in service
1993 - IRG/WP 93-50001-16
Creosoted transmission poles have provided good service over many decades in a whole range of environments. The use of save biocides for secondary treatments has the potential to extend the life of such poles. These techniques, together with a full understanding of the modes of failure, make it possible to establish new strategies to further improve the environmental benefits of treated wooden pol...
D J Dickinson, B Calver
Effect of a penta emulsion on the service life of Douglas fir, heartwood posts
1978 - IRG/WP 3112
C S Walters
Scientific development for prolonging the service life of timbers by impregnating with creosote or organic solvent type preservatives in which additive has been incorporated
1977 - IRG/WP 382
Chemically impregnated wood has played a prominent part in the Telephone and Electricity Distribution Industry during the past century and there is no doubt that it will play an equally prominent part in the future. The reasons why wood poles and wooden, structures predominate, are that when adequately chemically impregnated with a recognised timber preservative to ensure the expected service life...
P R B D De Bruin
Reliability-based service life prediction methodology for assessment of water protection efficiency for coatings on wood
2003 - IRG/WP 03-20268
Assessment of water protection efficiency according to EN 927-5 has been shown to give significant differences in water absorption values for different types of coatings on wood. It is shown that the combination of EN 927-5 and an artificial weathering procedure gives more information regarding expected durability and long-term performance than a single measurement of water absorption on fresh, un...
J Ekstedt
An approach to testing the preventive effectiveness of preservative treatments for wooden joinery
1981 - IRG/WP 2156
The ecological sequence established in field trial samples exposed out of ground contact has shown the need for outdoor exposure in testing potential joinery preservative pretreatments. A system of exposure of L-joint units is proposed. Data obtained by examining samples destructively show promise as the basis for predicting service life after relatively short exposure periods (within 2 years)....
J K Carey, A F Bravery, J G Savory
The performance of glue laminated railway ties after 40 years of service in the main line track
1989 - IRG/WP 2325
Two series of horizontally glue laminated ties made of a softwood body and topped with a hardwood lamination were creosoted and installed in 1947 in a tangent and a curved main line track. The tests are now 40 years old and the excellent condition of the ties of these two series suggest that a service life of 50-60 years can be expected....
J P Hösli, E E Doyle, C P Bird, T Lee
Estimation of service life of durable timber species by accelerated decay test and fungal cellar test
2002 - IRG/WP 02-20249
Many kinds of durable wood species for outdoor uses has been imported from all over the world to Japan. However information on the natural durability of these species is not sufficient to estimate the service life of them in the climate of Japan. Highly durable species such as Jarrh, Teak, Ipe, Ekki, Selangan batu, Red wood, Western red cedar showed no significant percent mass losses by accelerate...
K Yamamoto, I Momohara
Thirty-four year test of on-site preservative treatments to control decay in wood above ground
1993 - IRG/WP 93-30015
This research was initiated in 1958 to investigate efficacy of various preservatives and treating methods for new lumber going into exterior structures of buildings. Post-rail units (2x4 inches) constructed of Southern Pine sapwood, Douglas-fir heartwood, and mill run western hemlock were dip- or brush-treated before or after assembly. Units were trested with pentachlorophenol in various petroleum...
T L Highley, T C Scheffer
The effect of service life and preservative treatment on the hardness of wooden poles
1989 - IRG/WP 3537
The surface hardness of utility poles is an important parameter which effects the acceptability of the pole as being safe to climb during line maintenance. The current investigation was designed to evaluate how the surface hardness of preservative treated utility poles is effected by the type of preservative, and the age of the poles. Chromated-copper-arsenate (CCA) treated red pine and jack pine ...
E B Jonsson, E M A Nilsson, J N R Ruddick
HCB - a new preservative combination for wood pole maintenance
1996 - IRG/WP 96-30122
New combination of heavy creosoted boron (HCB) applied on hardwood and softwood logs at different moisture content revealed successful diffusion of boron in all sapwoods within 7 days and in all sapwoods plus hardwoods within 15 days. The new cost effective paste sterilizes wood through diffusion and suitable for pole maintenance at groundline and above groundline e.g. cut ends, drilled holes, woo...
A K Lahiry