IRG Documents Database and Compendium


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Heat treated timber in Finland
2000 - IRG/WP 00-40158
Heat treatment permanently changes the physical and chemical properties of wood by means of high temperatures (150 - 240°C). Heat treatment darkens the colour of the wood. Heat treatment improves the equilibrium moisture content of the wood and the shrinkage and swelling of the wood is reduced. Very high temperatures improve the resistance to rot and also reduce the susceptibility to fungal decay...
T Syrjänen, E Kangas


An experimental method to simulate incipient decay of wood by basidiomycete fungi
2000 - IRG/WP 00-20200
At very early stages of decay of wood by basidiomycete fungi, strength loss can be measured from wood before any measurable weight loss. Therefore, strength loss is a more efficient measure of incipient decay than weight loss. However, common standard decay tests (e.g. EN 113 or ASTM D2017) use weight loss as the measure of decay. A method was developed that allowed progressive removal of samples ...
S F Curling, J E Winandy, C A Clausen


Ancillary properties of vapor boron-treated composites
2001 - IRG/WP 01-40210
This paper discusses the water absorption, thickness swelling, and internal bond strength of North American composites treated using a vapor boron treatment process. For oriented strandboard, high boron loadings led to lower internal bond strength and lower thickness swelling. Water absorption results were variable but no deleterious effect of treatment was noted. For medium density fiberboard, th...
W A Jones, H M Barnes, R J Murphy


Bibliography: Interactions of wood preservatives with wood, metals, glues, paints and concretes
1983 - IRG/WP 3271
H Becker


A short note on the subject of pretreatment decay in wood
1984 - IRG/WP 1245
The paper reviews five national standards for wood utility poles and some literature that concerns the problems of pretreatment decay. Finally it is proposed to form a new sub-group to study that problem....
J A Taylor


A deflection test for monitoring decay in miniature beams
1986 - IRG/WP 2269
A laboratory apparatus for assessing decay in small stakes is described. It involves the measurement of deflection in a static bending apparatus using a displacement transducer linked to a microcomputer. Measurements are non-destructive, rapid, accurate and automatic and decay can be assessed repeatedly over long time periods....
S M Gray


Methods of assessing decay in poles in service with the Pilodyn wood tester
1978 - IRG/WP 2107 A
H Friis-Hansen


Use of the Pilodyn to assess deterioration of treated aspen waferboard after 30 months of outdoor exposure
1986 - IRG/WP 2254
Samples of preservative treated aspen waferboard exposed outdoors for 30 mo. were compared using pin penetrations of the 6 Joule Pilodyn. These results correlated well with rankings of treatment performance based on more laborious standard mechanical tests, and demonstrate the potential for use of the Pilodyn as a tool to evaluate wood composites in test exposures with minimal destruction....
E L Schmidt, M G Dietz


Dimensional stability, biological resistance, and mechanical properties of phenol-resin-treated particleboard
1990 - IRG/WP 3622
Particleboards were treated with a low molecular-weight phenol-formaldehyde (PF) resin and their enhanced properties were evaluated. Besides dipping of particles in aqeous solutions of resin, and spraying of resin solutions before spray of the conventional phenol-formaldehyde resin for adhesive binder, one step treatment by spraying of the mixture of the low molecular-weight resin and the adhesive...
Y Imamura, H Kajita


Acetylation of lignocellulosic materials
1989 - IRG/WP 3516
A simplified procedure for the acetylation of lignocellulosic materials has been developed. The acetylation is done with a limited amount of liquid acetic anhydride without the addition of a catalyst or an organic co-solvent. Dimensional stability and biological resistance are both much improved by the acetylation. Equilibrium moisture content in acetylated material is considerably lower than in u...
P Larsson, A-M Tillman


An evaluation on durability of untreated mining timber support
1997 - IRG/WP 97-20121
Wedge blocks in dimension of 5 x 7 to 8 x 155 cm3 were cut from indigeneous scots pine pitprops. Each of wedge block pairs were numbered and half of them were placed as the test blocks between the steel arches and the strata in a hard coal pit. Controls in laboratory and test wedge blocks in the mine were then sawn into 20 by 20 by 300 mm standard test sticks. Impact bending, static bending and MO...
A Bobat


Mechanical resistance of Pinus radiata CCA treated and face jointed with PVA adhesive
1999 - IRG/WP 99-40140
Due to the increased use of Pinus radiata timber composites (laminated structural members, panels, etc), its low natural durability and the toxicity of phenol-formaldehyde type adhesives, a PVA (polyvinyl acetate) adhesive was evaluated in machined and rough CCA treated and untreated face joint samples under DIN 68602 (EN 204-205) standard for groups of requirement 3 and 4. The results showed that...
M C Rose, L Reyes, P León


Effect of soft-rot decay on the static bending strength of wood
1991 - IRG/WP 2361
In this study, a modified static bending test has been developed as a method for measuring soft-rot decay in soil bed studies. A good correlation was found between the strength loss of the southern pine test specimens and extent of decay. This data suggests that it may be possible to develop a dynamic test based on stress relaxation that is more sensitive than static bending....
D D Nicholas, J A Wilson, R C Vasishth


A simple non-destructive means of testing poles in situ
1982 - IRG/WP 2167
Anonymous


A Preliminary Report on the Properties of Engineered Wood Composite Panels Treated with Copper Naphthenate
2005 - IRG/WP 05-40294
This paper reports on our preliminary investigation of the properties of randomly oriented strandboard which had waterborne or powdered copper naphthenate (CuN) incorporated into the board during manufacture. When compared to zinc borate-treated controls (ZnB), the mechanical properties of strandboard (MOR, MOE, work-to-maximum load, internal bond strength) were not adversely affected by treatmen...
J W Kirkpatrick, H M Barnes


Decrease of the antidecay resistance of beech wood treated with organotin fungicides after its natural ageing
1998 - IRG/WP 98-30185
The antidecay resistance of beech-wood samples (120 x 8.5 x 8.5 (MM)) treated with tributyltin fungicides gradually decreased due to prolongation of their natural ageing: tributyltin fungicides (TBTO, TBTS, TBTCA, TBT-DEDTK were applied by pressure impregnation technique in ethanole solutions (c = 0. 1%, 0.33% or 1%); treated beech-wood samples were naturally aged without their contact with grou...
L Reinprecht


Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick


Accelerated laboratory soil contact decay test using soil amended with composted wood
2004 - IRG/WP 04-20284
The effect of amending soil with wood compost on the decay rate of wood wafers in contact with the unsterile soil, as measured by radial compression strength loss, was explored. It was found that the addition of composted wood to the soil significantly increased the wood decay rate. The reason for this acceleration in wood decay is not entirely clear, but appears to be at least partially associate...
D D Nicholas, H Borazjani, T Schultz


Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki


Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran


Some experiences with attack of microorganisms on wooden constructions supporting foundations of houses and bridges
1997 - IRG/WP 97-10232
Reconstructions of bridges and public buildings or damage of houses during the construction of subway lines in Berlin have led to a number of inspections of wooden foundations, mostly pine or spruce piles, representing service lives of between ca. 70 and 140 years. In all cases bacterial attack was found both in wood submerged in ground water and in surface water. The extent of deterioration diffe...
M Grinda


The effect of hemicellulose degradation on the mechanical properties of wood during brown rot decay
2001 - IRG/WP 01-20219
Incipient decay of wood by brown rot fungi causes measurable strength losses in wood before measurable weight loss occurs. Previous studies have shown that the high levels of strength loss that occur during incipient brown rot decay may be related to loss in hemicellulose. This paper investigates the effect of decay on hemicellulose composition and the relationship to the mechanical properties of ...
S F Curling, C A Clausen, J E Winandy


Field stake test assessment with the Pilodyn
1980 - IRG/WP 2136
The Pilodyn, which was originally developed to estimate the degree of soft rot in wooden poles, was thought to have potential for giving a quantitative measure of the extent or depth of decay in field test stakes. In the present work a 2-joule Pilodyn with 2.0-mm diameter pin was used in an attempt to limit depth of pin penetration (to 10-15 mm) without reducing scale sensitivity. The results show...
M E Hedley, R W Naish


Paper for discussion - Incising of spruce to improve preservative penetration
1973 - IRG/WP 318
Large quantities of whitewood or Norway spruce (Picea abies) are regularly imported into the United Kingdom from continental Europe. In addition, increasing amounts of Sitka spruce (Picea sitchensis) are likely to become available over the next decade from the Forestry Commission. In many ways spruce is a good structural timber, eg it is relatively cheap and easily available, it has adequate stren...
W B Banks


Acetylated solid wood. Laboratory durability test (part 2) and field trials
1995 - IRG/WP 95-40048
Degradation of acetylated beech, pine and poplar by soft rot fungi was related to strength loss in a laboratory test. No strength loss was noticed for poplar acetylated to a weight percent gain (WPG) of more than 11.2% and beech with a WPG of 12.8%. Several field trials were set up to determine the durability of acetylated products in practice. They included a field test to determine the durabilit...
E P J Beckers, H Militz, M Stevens


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