Your search resulted in 55 documents. Displaying 25 entries per page.
Improvements of monitoring the effects of soil organisms on wood in fungal cellar tests
1996 - IRG/WP 96-20093
Accelerated testing the durability of preservative treated timber in a so called "fungal cellar" or "soil-bed" to evaluate its performance in ground contact is widespread practice. In order to obtain a more accurate and reproducible estimate of preservative performance, several institutes, among them the BAM in Berlin, have routinely carried out static bending tests in addition to visual examinati...
I Stephan, S Göller, D Rudolph
An attempt to evaluate wood resistance against fungal decay in non-sterile conditions by measuring the variation of resistance to bending test
1988 - IRG/WP 2308
The main object of this work was to determine the variation of strength on large test specimens of wood (800 x 45 x 45 mm³) when exposed to accelerated fungal attacks close to natural conditions, out of test vessels. The modulus of elasticity (MOE) and the modulus of rupture (MOR) have been assessed. Thereby, the natural resistance of the wood species to fungal decay, the efficiency of preservati...
L N Trong
A direct method for testing plywood and particle boards against fungal decay
1984 - IRG/WP 2214
A method directly inspired from the French standard testing method of the resistance of particle boards against fungal decay (AFNOR N° 51.295 May 1980) is described. But in that experimentation, the infestation is localized and realized in non sterile conditions. Small blocks of Fagus sylvatica (60 x 20 x 10 mm³) used as " inoculates " are infested with basidiomycetes, in Kolle flask for 4 to 6 ...
L N Trong
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
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
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
Bending Properties of FRT OSB
2012 - IRG/WP 12-40600
Fire retardant treated (FRT) oriented strandboard (OSB) and plywood of different widths were tested in static bending to determine width effects. Results were consistent with previous width effect studies and showed that increasing specimen width results in a decrease in sample MOR properties among all the sample groups tested in this study. Increasing sample width for OSB samples leads to more ...
J M Hill, H M Barnes, S Q Shi
Bending properties of treated western hemlock plywood
1996 - IRG/WP 96-40064
This study investigated the mechanical properties of western hemlock plywood after treatment with waterborne preservatives and redrying. Unlike previously reported results for southern pine plywood, western hemlock plywood was more sensitive to redrying temperature than to preservative treatment. Generally, western hemlock plywood was affected by temperature and other variables. Losses in mechanic...
H M Barnes, A Khouadja, D E Lyon
Bending creep test of plywoods under long term exposure to fungal attack
1981 - IRG/WP 2163
Bending creep test and decay test were coupled in order to evaluate the durability of structural plywoods and preservative efficacy. Experimental blocks, 5.0 x 1.2 cm² section x 35.0 cm length, were impregnated with distilled water and inoculated with mycelial fragments of test fungus. Polyethylene bags stretched with metal frame were used as decay chambers. The chambers containing inoculated blo...
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
Bending properties of TCMTB-treated Southern pine sapwood using supercritical carbon dioxide impregnation process
1997 - IRG/WP 97-40080
The effects of elevated pressure and treatment with thiocyanomethylthiobenzothiazole (TCMTB) on the bending properties of Southern pine sapwood were evaluated at pressures ranging from 1,800 to 3,600 psi. All bending properties were affected to some extent by supercritical fluid treatment. Modulus of elasticity and work to maximum load were not significantly affected by pressure levels. Modulus of...
Gyu-Hyeok Kim, S Kumar, E S Demessie, K L Levien, J J Morrell
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...
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
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
Bending & tensile properties of vapor boron-treated composites
2002 - IRG/WP 02-40228
North American composites including laminated veneer lumber, oriented strandboard, and medium density fiberboard were treated by vapor boron technology and subsequently tested in static bending. Tensile properties were also determined for the two composite boards. The study was designed as 3 x 2 factorial with three treatment levels and two mill locations for each composite type. In general, mil...
H M Barnes, R J Murphy, B K Via
Strength properties of preservative treated pine and spruce wood after super-heated steaming
1984 - IRG/WP 3313
Possible changes of strength properties of CCF pressure impregnated pine and spruce with subsequent steaming at 110°C respective 120°C for 30 min were examined. For spruce analysis of variance indicated that none of the processes had a significant effect on bending strength, compression strength and the corresponding modulus of elasticity as well as on impact bending strength and shear strength ...
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
Statistical evaluation of 'micro-bending' samples for classification of wood attacking fungi
1992 - IRG/WP 92-1544
Micro-specimens from both hardwood and softwood were exposed to selected species of field isolated fungi. The strength reduction and weight loss caused by these fungi were determined. A statistical procedure was then developed to classify the fungi into brown-, white-rot, or non-decay fungal categories based on these data. The procedure reveals the extent of hazard a fungus poses to wood members. ...
B Goodell, Jing Liu, A Homola, J Jellison, J Shottafer
A laboratory technique to measure the performance of preservative treated hardwoods in ground contact
1982 - IRG/WP 2172
A laboratory technique to measure the performance of preservative treated timber in ground contact is described. It uses partially sealed blocks of timber which are treated, leached and sawn into small stakelets for soil exposure in a fungal cellar. Performance is monitored by the loss of static bending strength with time, and a simple apparatus for measuring the deflection of a stakelet under a l...
E F Baines
In-ground field test of scots pine (Pinus sylvestris L.) sapwood and heartwood
2004 - IRG/WP 04-30336
Scots pine (Pinus sylvestris L.) sapwood and heartwood stakes treated with CCA-C and creosote were tested for one- year in a field plot in Bartın region in Turkey. Scots pine heartwood stakes had lower preservative retention than sapwood stakes. Bending strength of the stakes was decreased after impregnation and one-year field test. While the bending strength of untreated sapwood was 93....
H Sivrikaya, H Hafizoglu
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
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of ...
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
Supercritical fluid treatment: Effects on bending strength of white spruce heartwood
1993 - IRG/WP 93-20008
The effects of supercritical carbon dioxide on wood strength were evaluated using white spruce heartwood, a species known to be especially susceptible to collapse during exposure to higher pressures. The effects of pressures of 2000 or 3600 psig and temperatures of 40 or 80°C were evaluated using 30 or 60 minute exposure periods. No significant differences were noted in modulus of rupture or modu...
S M Smith, J J Morrell, E Sahle-Demessie, K L Levien
Resistance to decay of particle boards: Presentation of a test method
1986 - IRG/WP 2260
The experimentations were undertaken on particle boards 35 and 50 mm thick. The rot resistance tests were carried out on specimens whose dimensions were 600 x 75 x 35 mm³ for particle boards 35 mm thick and 800 x 75 x 50 mm³ for particle boards 50 mm thick according to a method derived from the one described in the documents IRG/WP/2214 and IRG/WP/2243. Two exposure periods were used: 12 and 16 ...
G R Y Déon, N Trong
An attempt to grow dry rot fungus Serpula lacrymans on mortar substrate in non-sterile conditions
1989 - IRG/WP 1385
According to many experts, Serpula lacrymans is probably the most dangerous wood destroying fungus in houses. Investigations of KOCH, A.P. (2) showed that incidence of this fungus in percent was around 20% when the frequency of some other standard fungi was far below (Coriolus versicolor: 0.2% for example). The work presented here is a part of a program carried out at CTFT for assessing the resist...
L N Trong