Your search resulted in 59 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
Biological resistance of wood treated with waterbased resins and drying oils in a mini-block test
1998 - IRG/WP 98-40107
In recent years it was found that the resistance of wood against fungal degradation could be increased by impregnation with an etherificated melamine formaldehyde resin. Using this resin as a reference, a waterbased fatty acid modificated alkyd-resin and two drying-oils were assessed for their biological performance in a mini-block laboratory test. Although drying-oils, like linseed-oil, are often...
M Sailer, A O Rapp, R-D Peek
Influence of different resin treatments on the dimension stability of wood
1997 - IRG/WP 97-40090
The dimension stability of wood is considered to be an important contribution to its durability and its performance in practice. A number of different treatments have been developed to improve the dimension stability of wood. One applied method is the treatment of wood with monomers or resins. The application of appropriate impregnation conditions seemed to be essential to enhance the efficiency o...
M Sailer, A O Rapp
Water-based silicones on wood
1997 - IRG/WP 97-30144
Five waterbased silicones commonly used on masonry where tested as water repellents for wood. The Water Repellent Effectiveness was determined by swellometer-tests and by measuring the water uptake of samples after 24 hours complete immersion and by immersion in a water level of 4 mm for 24 hours. The different methods are compared and discussed. Artificial and natural weathering was performed to ...
D Lukowsky, R D Peek, A O Rapp
Interim balance after 20 months of lap-joint exposure
1999 - IRG/WP 99-20164
The application of natural resins and integrated resin systems to improve the performance of Pinus sylvestris was assessed in a lap-joint test according to DIN V ENV 12037 (1996). Lap-joints of Pinus sapwood were exposed at the test field in Hamburg (Germany) in May 1997. The treated lap-joints were assessed with regard to the performance of the resin treatments out of ground. The exposure of lap-...
M Sailer, A O Rapp, R-D Peek, A J Nurmi, E P J Beckers
Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the...
C Brischke, A O Rapp
Effect of some resin treatments on fungal degradation reactions
1999 - IRG/WP 99-10318
The effect of impregnation of wood with vegetable oil, tall oil and two water soluble on fungal degradation reactions was assessed by hydrolysis and enzyme activity measurements. The experiments were carried out by using isolated enzyme preparations and a living brown-rot fungus Poria placenta. The results indicate that the inhibitory effect of treatments was clearly directec towards the enzymatic...
A-C Ritschkoff, M Rättö, A J Nurmi, H Kokko, A O Rapp, H Militz
Field Trials with mini-stakes
2002 - IRG/WP 02-20244
In 1995 an extensive field test program with wood mini-stakes, 8 x 20 x 200 mm, was started. In these trials a large number of parameters are being evaluated, including several new wood preservatives, differently chemically modified woods and natural durability of various wood species. The test sites are three fields in Sweden for in-ground and “close to ground” testing, one subterranean termi...
M Westin, A O Rapp, Y S Hadi, T Nilsson
New principles for the protection of wood: Impregnation with waterborne resins
1995 - IRG/WP 95-40047
The environmental impact of classical wood preservatives as well as the use of tropical wood species with high natural durability is regarded increasingly critically in the public. Therefore other partially new principles for the protection of wood, like chemical modification, or treatment with resins were examined especially in USA, Japan and in Europe with promising results predominantly in the ...
A O Rapp, R-D Peek
The ecotoxicology assessment of wood preservatives and their active ingredients by means of germination tests using cress - A critical consideration
1999 - IRG/WP 99-50125
With putting the Biocidal Products Directive 98/08/EC (BPD) in place an environmental risk assessment for wood preservatives and impregnated timber is requested. To assess possible risks, suitable test methods are required, which reveal the ecotoxicological profile including environmental fate and behaviour of treated commodities. Germination and growth tests could contribute to the determination ...
P Jüngel, A O Rapp, E Melcher
Method of embedding and staining of wood after biological testing to support the identification of decay type
1998 - IRG/WP 98-20131
A method for preparing wood for microscopic analysis after decay testing is described, with special regard to a novel fast simultaneous staining, which helps to identify different types of decay. The novel staining process is explained as well as the embedding of heavily decayed samples in polyethylene glycol (PEG) and picking up of sections by transparent adhesive tape. Special feature of the int...
A O Rapp
Some fundamental thoughts on the prediction of field performance from lab-testing based on comparison of lab and field test results of some copper-free materials
2003 - IRG/WP 03-20269
In the paper results from lab testing (ENV 807 and EN 113) are compared with field results (EN 252) of differently treated wood. Depending on the type of the organic biocide containing material and depending on type of soil and type of decay differences were found in suitability of the lab methods to predict field performance. The attempt is made to interpret the found differences. Furthermore it ...
A O Rapp, U Augusta
Moisture content and other tested values in. Double layer tests of different size in Lithuania and Germany
2004 - IRG/WP 04-20299
The paper presents measurement results of moisture content and the analysis of durability trial of double layer wood in variants of varying size, conducted in Girionys, Kaunas distr., Lithuania and in Hamburg, Germany. In this trial 3 sample sets of varying size, containing 25, 50 and 100 specimens, are used. The aim of this trial is to ascertain an optimal number of test specimens. The dynamics o...
J Saladis, A O Rapp
Melamine resins as preservatives results of biological testing
1996 - IRG/WP 96-40061
Based on previous work of the authors on resins, the upgrading of wood with a true solution of a methanol etherificated melamine resin in low aqueous concentration was performed. For the relative assessment of the biological resistance against brown and white-rot fungi were used not only untreated controls of pine sapwood (Pinus sylvestris L.), but also heartwood of European larch (Larix decidua M...
A O Rapp, R-D Peek
The natural durability of wood in different use classes - PART II
2006 - IRG/WP 06-10598
The natural durability of important European wood species has been tested on 3970 speci¬mens in field trials. The wood was exposed at five test sites in Germany with different climates, at each site in European use class 4 and 3 (with and without soil contact). Within European use class 3 three different expositions were tested: vertical with sheltered end grain, vertical unsheltered and horizont...
A O Rapp, U Augusta, K Brandt
Biological resistance of didecyl dimethyl ammonium tetrafluoroborate (DBF)-treated wood in soil-bed and Basidiomycetes tests
2006 - IRG/WP 06-30393
This study evaluated the decay resistance of treated wood with a new quaternary ammonia compound, didecyl dimethyl ammonium tetrafluoroborate (DBF) in laboratory soil bed and Basidiomycetes tests. Treated sugi sapwood specimens with DBF at various concentration levels were first subjected to soil bed tests using two types of soil. The specimens subjected to soil bed tests were then used for Basidi...
S N Kartal, C Brischke, A O Rapp, Y Imamura
A roadmap for performance-based specification of wooden components based on service life prediction
2007 - IRG/WP 07-20351
The need for an unified and harmonised system for performance classification and specification of wood and wood-based products in Europe emanates from requirements of users and the European Construction Products Directive, CPD. A road to a feasible specification system is outlined. Exposure-related performance prediction was worked out as a key task on the way to product specification. Therefore s...
C Brischke, A O Rapp
Marine Borer Resistance of Modified Wood - Results from Seven Years in Field
2007 - IRG/WP 07-40375
Wood modified by several methods has been tested for seven years in a marine field with high marine borer activity. Several wood modification methods were included, e.g. thermal modification (with different processes), acetylation, maleoylation, succinylation, furfurylation, treatment with methylated melamine resin and modification with reactive linseed oil derivative. Furthermore, some combinatio...
M Westin, A O Rapp, T Nilsson
Natural Weathering of Coated Oil Heat Treated Wood
2007 - IRG/WP 07-30440
Oil heat-treated (thermally modified) pine wood was coated with 9 different types of solvent- or water-borne exterior finishes. The systems with modified wood substrate as well as unpainted and painted non-modified controls were exposed to weathering (EN 927-3) on two locations with sub-alpine and alpine climate. The influence of natural ageing on surface systems was evaluated after one year of ex...
M Petric, B Kricej, M Pavlic, A Rapp
Impact of decay and blue stain causing fungi on the structural integrity of wood
2009 - IRG/WP 09-10699
The potential influence of diverse decay patterns caused by different brown rot provoking basidiomycetes on the structural integrity of wood was investigated. Additionally the potential impact of blue stain on the structural integrity was examined. Therefore decayed Norway spruce (Picea abies Karst.) specimens representing a wide range of mass loss, caused by four different brown-rot fungi and one...
C Brischke, C Welzbacher, T Huckfeldt, F Schuh
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
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
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
TMT–Interlab–Test to establish suitable quality control techniques - Structure and first results
2010 - IRG/WP 10-40503
As a result of growing quality demands from manufacturers and end-consumers of thermally modified timber (TMT) recent scientific research activities are increasingly focussed on modification mechanisms and by this on the development of suitable quality control methods. To deepen the knowledge in modification mechanisms and to obtain a larger variety of scientific data for TMT depending on the trea...
C R Welzbacher
Methods of field data evaluation - time versus reliability
2011 - IRG/WP 11-20466
Field testing of wood and wood-based products is so far the most reliable way to get information on performance with respect to durability and expected service life. However, field trials are extremely time and cost consuming. The main objective of the present study was to investigate possible correlations between early stages of decay, preferably during the first 5 years, and the actual service l...
P Larsson Brelid, C Brischke, A O Rapp, M Hansson, M Westin, J Jermer, A Pilgård