Your search resulted in 3429 documents. Displaying 25 entries per page.
The susceptibility of 35 Amazon wood species to Cryptotermes brevis (Walker)
1982 - IRG/WP 1160
Laboratory tests were carried to evaluate the susceptibility of 35 Amazon hardwoods to Cryptotermes brevis (Walker). The results were analysed statistically and showed that five wood species were non resistant, nine were resistant and the other twenty-one in between those classes of resistance....
M D Canedo
Criteria for basidiomycetes testing and ways of defining natural durability classes
1998 - IRG/WP 98-20144
Within the framework of a European research project several laboratories have tested a series of 17 wood species covering the total range of natural durability.
Basidiomycete tests are part of the total set up. Although generally based upon standard methods some minor differences in execution of the tests were evaluated for their impact on the results. This variation was superimposed with the fac...
J Van Acker, M Stevens, J K Carey, R Sierra-Alvarez, H Militz, I Le Bayon, G Kleist, R-D Peek
Attempt for developing a new method for above ground field testing of wood durability
2000 - IRG/WP 00-20199
Field testing remains the most appropriate way for evaluation of wood preservatives or natural durability of wood species. Above ground tests are designed to answer specific questions concerning the outdoor utilisation of wood. Such methods supply additional information and confirm or reject preliminary laboratory results. The European standard (ENV 12037, "lap-joint") for assessment of the durabi...
N Terziev, M-L Edlund
The natural durability of wood in different use classes
2003 - IRG/WP 03-10457
The natural durability of important European wood species has been tested on 3970 specimen in field trials. The wood was exposed at five test fields in Germany with different climates at each site in European hazard class 4 and 3 (with and without soil contact). Within EHC 3 it was distinguished between tree different expositions (end grain sheltered, unsheltered and with water trap).
The test is...
U Augusta, A O Rapp
Assessment of wood decay in small-scale unsterile soil-bed tests
1997 - IRG/WP 97-20111
This study is concerned with the investigation of wood decay in small-scale unsterile soil-bed tests. Tests were performed with untreated heartwood samples from five hardwood species of different natural durability classes ranging from highly perishable to very resistant. Our results confirmed the critical role of soil moisture content on wood decay. The highest decay rates were observed at moistu...
L Machek, A M Derksen, R Sierra-Alvarez
The influence of the location of a wood defect on the modulus of elasticity determination in wood durability testing
2004 - IRG/WP 04-20287
This study investigates the influence of the location of a wood failure in stakes upon elastic changes observed in beech specimens with the resonance vibration technique. Natural failures were simulated by artificially created defects at different locations of the test stake. The results indicate that the location of an attack in a stake is important for the measurement outcome. When the attack is...
L Machek, H Militz
A comparison between different accelerated test methods for the determination of the natural durability of wood
1996 - IRG/WP 96-20099
According to the European standard EN 350-1 the natural durability of wood is defined as: "the inherent resistance of wood to attack by wood destroying organisms". This standard also describes how, for certain hazard classes, the durability is determined. The two methods described in this standard are the kolleflask method (EN 113) and the field-stake-test method (EN 252). The EN 113 test gives re...
H Militz, S G L Michon, J E Polman, M Stevens
Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions...
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek
A dynamic approach to assess the modulus of elasticity in wood decay testing
1998 - IRG/WP 98-20139
In this study, the changes in elastic behaviour and mass losses of different hardwood and softwood species exposed to decay in a laboratory soil tests were assessed. Wood decay was monitored using different assessment methods, namely: mass loss and changes in elastic behaviours (MOE) determination. Elastic changes were determined by static and dynamic methods, for the latter, acoustic technique wa...
L Machek, H Militz, R Sierra-Alvarez
A new concept for the evaluation of wood durability for out of ground contact using accelerated L-joint testing
1997 - IRG/WP 97-20123
Since the wood preservation sector is developing in favour of defining exactly the utilization of wood products and preservation techniques as a function of the envisaged hazard class, more in particular the hazard classes 3 and 4 (EN 350) there is obviously a need for a test method evaluating natural durability for out of ground contact applications. Based on the L-joint test as described in the ...
J Van Acker, M Stevens
European standardization for wood preservation. Progress report 91-92
1992 - IRG/WP 92-2398
Since the IRG 22 conference in Kyoto, CEN/TC 38 Plenary met twice in relation with several working group meetings. 5 upon 6 of the interpretative documents have been prepared by adhoc groups of the Standing Committee for Construction within the scope of the 89/106/EEC directive on Construction Products. The expected requirements attached to wood preservation are both requirements 1) and 3): 1) mec...
R Hüe
Variation in field test performance of untreated and CCA-treated lesser-known Surinamese wood species
2000 - IRG/WP 00-20213
In Suriname three different field test sites have been used to verify the biological durability of CCA-treated wood and a range of wood species including lesser-known and lesser-used wood species. In total 37 tropical wood species were tested untreated and for 17 of the less durable species CCA-treatments were included as well. Although the three sites are located in the tropical region they diffe...
J Van Acker, M Stevens, L Comvalius
Testing durability of treated wood according to EN 252. Interpretation of data from Nordic test fields
2006 - IRG/WP 06-20341
To evaluate the effectiveness of new wood preservatives intended for treated wood in ground use there is a European standard, EN 252. The test shall run for five years before any formal interpretation of the results can be made.
Due to environmental concerns, the use of wood preservatives based on copper, chromium and arsenic (CCA) has been restricted in recent years. As a consequence of restrict...
M L Edlund, F G Evans, K Henriksen, T Nilsson
Testing biological durability of wood-plastic composites
2006 - IRG/WP 06-20347
Testing biological durability is inherently different for wood-plastic composites (WPC) compared to solid timber. However there is clearly a need for more information on the durability of WPC’s, on the effect of decay on the material properties of WPC’s and on methods for assessing decay of WPC’s. For the emerging European WPC market there has been some discussions on how to work on these to...
J Van Acker
Durability of some alternatives to preservative-treated wood. Progress report 2: Results from field tests after 5 years’exposure
2007 - IRG/WP 07-30442
A number of alternatives to preservative-treated wood have been tested according to EN 252 (stake test) and a specially designed ground-proximity field test, the latter in Sweden as well as in Hawaii, USA. Seven untreated wood species and four alternative wood treatments labelled as environmentally friendly (acetylation, linseed oil, heat treatment, vinyl polymer) were included in the study. Four ...
M-L Edlund, J Jermer
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
Durability of modified wood in UC3 and UC4. Results from lab tests and 5 years testing in 3 fields
2011 - IRG/WP 11-40562
In 2005 an extensive test program including field tests was set up in order to obtain more data on the durability and long term performance of modified wood and semi-durable wood species. One of the main challenges for modified wood is to predict accurate service life time in UC3 (use class 3, above ground) and UC4 (use class 4, in soil or fresh water contact). So far, data from in-service condi...
M Westin, G Alfredsen
Above Ground Field Evaluation and GC-MS Analysis of Naturally Durable Wood Species
2012 - IRG/WP 12-10764
Nine wood species are being evaluated in above ground field studies in Mississippi and Wisconsin. Candidate naturally durable wood (NDW) species are being rated at yearly intervals for resistance to decay, cupping, and checking. Field ratings after 12 months exposure are presented. To date, Paulownia tomentosa (PAW) and southern yellow pine (SYP) are least durable and cedars are the most durable i...
G T Kirker, A B Blodgett, S T Lebow, C A Clausen
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
Performance testing of DMDHEU-modified wood in Australia
2013 - IRG/WP 13-30613
Chemical wood modification with dimethyloldihydroxy-ethyleneurea (DMDHEU) or its derivatives has been researched for many years and shown to be applicable to improve certain wood properties to both solid lumber and wood-based composites. Earlier research proved a high biological resistance of DMDHEU-modified wood against biological degradation in laboratory and field tests in Europe. Due to the ve...
H Militz, J Norton
Preliminary testing of spiroborate esters as wood preservatives
2013 - IRG/WP 13-30614
Fungicide and insecticide properties of boric acid are known since 30’s of the last century, but high solubility and leachability of inorganic borates limit their use for only applications not directly exposed to liquid water. A number of attempts were made to fixate borate salts into the wood structure but this research topic is still up to date and undiscovered. Water insoluble organoboron est...
D Panov, N Terziev
Durability of alternatives to CCA-treated wood - Results from field tests after 11 years exposure
2013 - IRG/WP 13-30633
The present study was initiated as a consequence of restrictions against the use of CCA-type
wood preservatives in Sweden in the 1990s. New copper-based formulations were introduced on
the market and to some extent, also alternatives to preservative-treated wood, such as thermally
and chemically modified and linseed oil treated wood as well as heartwood of non-tropical
naturally durable wood s...
P Larsson Brelid, M-L Edlund
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
Moisture performance testing of wood – Practical experiences
2014 - IRG/WP 14-20546
Different methods are used to characterize the moisture performance of wood and to quantify the effect of moisture loads on the resulting service life. These methods can be divided into direct and indirect methods. Furthermore they can be distinguished by characteristics like continuous or periodical measurements and measuring local or global moisture content (MC). Furthermore each measuring metho...
L Meyer, C Brischke, M Kasselmann, C Rösmann