Your search resulted in 433 documents. Displaying 25 entries per page.
Durability of timber products –Part 1: Inventory and evaluation of above ground data
2012 - IRG/WP12-20498
The material-inherent resistance of wood is one of the most important qualities influencing the durability of timber. Hence, it has also a major effect on the service life to be expected from a timber construction. In addition, design details and the respective climatic conditions determine durability and make it impossible to treat wood durability as an absolute value. Moreover, the reference mag...
C Brischke, L Meyer, G Alfredsen, M Humar, L Francis, P O Flæte, P Larsson Brelid
Testing service life for use class 3: accelerated L-joint performance of commodities
2012 - IRG/WP 12-20500
Above ground testing is considered important for the assessment of treated wood intended for use class 3. Laboratory testing of efficacy of biocides as well as of natural durability focussing on such applications has to be linked to performance and service life. An accelerated L-joint test was some 15 years ago developed at the Ghent University to allow worst case assessment under semi-controlled ...
J Van Acker, J Van den Bulcke, I De Windt, L De Vetter
Tannin resin-boron associations: Leaching and biological resistance
2012 - IRG/WP 12-30587
The easy leaching of boron in wood preservation formulations has allowed to use this fungicide only for short term applications. The recently discovered adduct with flavonoids allows boron to resist longer periods of time within wood and consequently extend its life. Two different leaching treatments were compared and the fungal and termite decay was examined. The biological tests have shown extre...
G Tondi, S Wieland, N Lemenager, A Petutschnigg, A Pizzi, M-F Thevenon
WOOD: its importance in our life
2012 - IRG/WP 12-40583
As it is described by Hoadley (1980) and Tsoumis (1991), wood is an organic material yielded by trees which increase in diameter by the formation of new woody layers which envelop the entire stem. Wood has served man since he appeared on Earth (as a fuel and/or as a construction material for making houses, tools, weapons, furniture, packaging, paper, and artworks). It is important to appreciate th...
I Usta
Chemical Analysis of Hydrothermally Treated Beech Wood in Buffered Mediums
2012 - IRG/WP 12-40604
Hydrothermal treatment of beech wood in buffered mediums was carried out to study the effect of different mediums of heat treatment on crystallinity index of treated specimens due to degradation of carbohydrates. Different mediums (water, buffer5, 7 and 8) and temperatures (160 and 180 °C) were used. ATR spectra focusing on indexes of carbohydrates degradation obtained and analyzed. Results showe...
A Talaei, A Karimi
Initial investigations into the spalting potential of Peruvian hardwoods
2014 - IRG/WP 14-10813
This study was performed to determine if several moderately-utilized Peruvian hardwoods had potential for spalting applications. We applied a modified decay jar methodology with six native Peruvian woods and three moulds, with a period of incubation of six weeks. Results showed that Nigrospora sphaerica and Marupa (Simarouba amara) resulted on the highest significant internal pigmentation (black),...
S M Vega Gutiérrez, S C Robinson
Analysis of decay progress anisotropy by X-ray computer tomography
2012 - IRG/WP 12-20501
Wood has a serious handicap as structural materials that it is vulnerable to decay by fungi. A weather exposed bridge has a possibility of an abrupt fall down, and wooden houses with heavily decayed structural members are easily destroyed by large earthquakes. To avoid such damages, a new predicting method on the decay progress in timber structures, and also its strength losing behavior along with...
K Maeda, M Ohta
Effectiveness of CCA-C and CCB preservatives after a 30 years stake test
2012 - IRG/WP 12-30606
The objective of this experiment was to assess the durability of four pine species treated with waterborne preservatives. In order to determinate this, a stake field test, following the IUFRO (International Union of Forestry Research Organizations) recommendations, was installed at Experimental Station of Luiz Antonio (21º 32’ S and 47º 42’ W), State of São Paulo, Brazil.
Species under t...
I PJankowsky, E S Lepage, C Salvela, J M Vidal, S Takeshita
The effect on moisture content of water trapped in wood joints
2012 - IRG/WP 12-40613
To predict the service life of a structure, a model where the exposure of a structure is compared to its resistance can be used. Which exposure and resistance parameters that are relevant depend on which materials the structure consist of. This approach, with an exposure and a resistance parameter, is similar to the one used in structural engineering where a load (exposure) is compared to the bear...
M Fredriksson, L Wadsö, P Johansson
An assessment of soft rot in preservative-treated poles in two test sites and two network areas in New South Wales
2013 - IRG/WP 13-10801
This document presents an extended summary of recent investigations into soft rot attack of preservative treated power poles from the re-inspection of samples selected from two field sites and two in-service trials located in New South Wales, Australia. The in-ground sapwood of selected poles was assessed by probing and, after core sampling, by microscopy to determine the severity and extent of s...
W D Gardner, M A Powell, C Kirton
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,
Quasi-in-situ durability tests on oak timber bridges
2013 - IRG/WP 13-20510
This study aims on developing a method for determination of wood durability on samples taken from real structures in service. Therefore quasi-in-situ durability tests have been conducted exemplarily on timber bridges made from English oak (Quercus robur L.). Drilling cores were found to be a feasible alternative to standard specimens for laboratory durability tests against pure cultures of Basidio...
C Brischke, C J Behnen, M-T Lenz, K Brandt, E Melcher
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
Changes of fungicidal, mechanical and sorption properties of wood during above ground outdoor exposure
2013 - IRG/WP 13-20513
The aim of this preliminary study was to investigate differences in mechanical, fungicidal, and sorption properties of four different wood species (sweet chestnut (Castanea sativa), common beach (Fagus sylvatica), Norway spruce (Picea abies), and copper-ethanolamine (CuE) impregnated Norway spruce (Picea abies)) that were exposed in the 3rd use class (CEN, 1992) for periods between 4 and 30 months...
N Thaler, M Humar
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
Climatic impacts on the moisture performance of wooden decking and facades
2013 - IRG/WP 13-20518
In outdoor usage wood is exposed to a variety of influences, which reduce its durability against biological deterioration and wetting. Besides many other factors the service life of wooden facades and cladding is dominated by occurring moisture loads on the one hand and their capability to withstand moisture on the other hand. Hence, climatic factors have a direct impact on the material climate an...
T Bornemann, C Brischke, G Alfredsen
Image analysis for mould and sapstain detection on wood
2013 - IRG/WP 13-20519
Laboratory tests for mould growth on wood products are time consuming and rely on visual assessments of specimens utilizing subjective rating systems. Accelerated laboratory methods are needed that can provide rapid, quantitative assessment of mould and sapstain growth on solid and composite wood products. Image analysis of scanned spore imprints from southern pine or oriented strandboard (OSB) sp...
C A Clausen, V W Yang
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
Moisture distribution in glulam beams with natural cracks observed with CT Scanning before and after rain
2013 - IRG/WP 13-20534
The way cracks in outdoor wooden constructions affect durability is an interesting topic, since a certain amount of cracks can always be found naturally in wood and glued laminated wood. The question in this was, can cracks lead water into the wood and thereby increase the risk for decay and reduce strength and service life. Moisture balance, i.e., water absorption and water distribution were stud...
K Sandberg
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
Estimation of service life of treated wood in ground contact based on early indicators
2013 - IRG/WP 13-20536
A well-known problem with field testing is that it takes a long time before meaningful and reliable results are achieved. Only when a trial has come to an end the so called average life for the samples in a group can be calculated and compared with other samples. The aim of the present study was to investigate if it is possible to get a reasonable and good estimation of the average life long befor...
M Hansson, J Jermer, P Larsson Brelid, N Terziev
Performance standards for wood in construction – delivering customer service life requirements
2013 - IRG/WP 13-20537
There is increasing need for consideration of performance classification for wood products in construction, as evidenced by the CPR, warranty providers and end user demands for information. This means we need to radically consider how the tests we conduct on wood for durability (especially biological durability) can inform on service life and how they might if possible be translated into a perform...
E Suttie, C Brischke, F Englund, E Heisel, J Jermer, D Lorenzo, M Polášek, S Thelandersson, J Van Acker
Performance of recent and old Sweet chestnut (Castanea sativa) wood
2014 - IRG/WP 14-10816
Sweet chestnut (Castanea sativa) hardwood is one of the most durable European wood species. In the present research, various aspects that could potentially influence the durability were elucidated, namely: presence of extractives, ring width, and weathering. Simultaneously, properties of wood, which was in outdoor use for 35 years, were elucidated as well. The results indicate that ring width and ...
M Humar, M Žlahtič, N Thaler
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