Your search resulted in 388 documents. Displaying 25 entries per page.
The effect of initial moisture content on wood decay at different levels of gaseous oxygen concentration
1999 - IRG/WP 99-10316
The influence of initial moisture content on wood decay at different levels of atmospheric oxygen concentration was studied. Three fungi, Coriolus versicolor a white rot, Coniophora puteana a brown rot, and Chaetomium globosum a soft rot, were chosen. The mycelia of the fungi were inoculated on mini blocks of Fagus sylvatica (beech) and Pinus sylvestris (Scots pine). Incubations were under four le...
S M Kazemi, D J Dickinson, R J Murphy
Service Life Prediction of Wood Claddings by in-situ Measurement of Wood Moisture Content
2004 - IRG/WP 04-20304
The Danish Technological Institute is in co-operation with industry partners running a project aiming at predicting the service life of different wood protecting systems.
The project focuses on examining the moisture reducing effect of different wood claddings and the ability to maintain the appearance of the surfaces, when the wood is used in service class 3.
A façade construction is exposed t...
B Lindegaard, N Morsing
Estimation of the impregnation degree of pine wood by the distribution analysis of active ions concentration in the cross-section
1999 - IRG/WP 99-20174
Samples in the form of pine wood rollers of diversified moisture content of ca. 50, 28 and 12% were impregnated with a water solution of the mixture type CCB with the use of the full-cell process. Moisture content was determined in individual layers from the girth to the pith. In the same way the concentrations of copper and chromium ions with the use of the spectrophotometric method and recalcula...
K Lutomski, B Mazela
Standardization of CCA treated 45 hardwood species grown in Bangladesh for REB crossarms
1995 - IRG/WP 95-20059
Researches on 45 hardwood species grown in Bangladesh regarding density, moduli of rupture (MOR), colour and treatability of sapwood and heartwood, seasoning property and natural durability of heartwood revealed that both sapwood and heartwood of 17 species could be full cell pressure treated with CCA at impregnation pressure of 14-18 kg/cm² and only sapwood of rest 28 species could be pressure t...
A K Lahiry
The effect of heat treatment on the properties of spruce
1994 - IRG/WP 94-40032
The effect of high temperature treatment (above 150°C) on the wood quality is studied at the VTT. Improved dimensional stability, lower equilibrium moisture content and increased durability against biodeterioration is achieved, depending on the environmental factors. The biodeterioration resistance of spruce is improved due to changes in chemical composition and lower equilibrium moisture content...
H Viitanen, S Jämsä, L Paajanen, A J Nurmi, P Viitaniemi
Limitations of the Pilodyn when assessing decay in graveyard test stakes
1982 - IRG/WP 2168
The following examination was designed to evaluate more precisely the usefulness of the Pilodyn for routine, objective assessments of the condition of field test stakes and to examine its limitations, particularly in respect to: 1.) The importance of variables other than extent of decay which may affect Pilodyn readings; 2.) Practicality of obtaining multiple readings in decayed and non-decayed re...
M E Hedley
Moisture distribution in coated wooden panels. Studies of moisture dynamics by computerized axial tomography
1992 - IRG/WP 92-2413
Certain modern coatings have been held responsible for the rot damages in wood sidings, which have, during the past few years, appeared at an increasing extent in Scandinavia and which have occurred rather soon after the application of the coating. In this study, the moisture excluding effect of different coating systems intended for sidings have been studied with the help of an X-ray technique, c...
J Ekstedt, L O Lindgren, S Grundberg
Co-operative research project on L-joint testing. Sampling after 4 years exposure
1987 - IRG/WP 2274
In September 1983, Document No: IRG/WP/2208 was distributed giving guidance on sampling after 8 months exposure and including tables on which to record the test results. Similarly in September 1984, Document No: IRG/WP/2233 was distributed concerning sampling after 18 months exposure. No major problems have been notified to Princes Risborough Laboratory concerning the sampling method. It is theref...
J K Carey, A F Bravery
Treatment groups and remedies for CCA treated hardwood and softwood poles
1999 - IRG/WP 99-40142
Different hardwood and softwood species from Bangladesh and Bhutan was investigated regarding density, green fiber stress, natural durability of heartwood and CCA treated sapwood, CCA treatability grades, sapwood thickness, and kiln-drying properties for long term use as electric poles. These properties along with the past service records for nineteen years, separated ten heardwood and five softwo...
A K Lahiry
The movement of iron into field test stakes
1987 - IRG/WP 2284
Failed and sacrificial stakes recovered from the Westham Island field test site were examined for their iron content. Varying amounts were recorded, which were greatest in the failed stakes. The possible role of the iron taken up by the below ground portion of the stakes, in accelerating the decay process and/or the preservative leaching is under investigation. The reaction of the iron with the ch...
J N R Ruddick, P I Morris
A technique for determining the efficacy of water diffusible preservative plugs for implanting in joinery in service
1987 - IRG/WP 2291
A technique is described for determining the efficacy of soluble, diffusible preservative plugs for eradicating decay in joinery. It uses blocks of Scots pine sapwood or heartwood adjusted to known moisture contents prior to the establishment of the test fungus Coniophora puteana, from a single longitudinal dowel and the subsequent introduction of the preservative plugs. Prevention of decay, eradi...
J K Carey, A F Bravery
Application of oscillating pressure to improve treatability of refractory species
1987 - IRG/WP 3449
Under practical conditions a minimum moisture content of 80% demande by the German quality standard RAL-RG 411 can not be guaranteed throughout the year. Storage of logs with bark prolonges the drying process; a storage without bark must be avoided. A sufficient penetration according the standard can be achieved at least with a moisture content of 60%, optimal conditions may prevail between 100% a...
R-D Peek
The effect of moisture content on the electrical resistance of timber as detected by a pulsed current reistance meter (Shigometer)
1984 - IRG/WP 2212
The literature concerning the use of the Shigometer® for detecting decay in standing trees and wood poles is reviewed and the differences of opinion over the effect of timber moisture content on electrical resistance are highlighted. A simple experiment designed to test this effect is described and the implications of the results for testing poles in service are discussed. There was a large diffe...
P I Morris, D J Dickinson
Moisture content of logs under sprinklers
2000 - IRG/WP 00-40157
Logs are kept under sprinklers during storage for avoiding the development of sapstain fungi. According to literature, sapstain fungi do not develop if the moisture content is above 120%. It is supposed that, the water sprinklers maintain the log's moisture content above this value, but, very often, sapstain is found on sawn lumber cut from these logs. Logs are harvested and transported t...
M C Rose, A M Briones, M Fernández
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
Whitewood - An external joinery timber?
1975 - IRG/WP 253
The timber used traditionally for softwood joinery in the UK is redwood (Pinus sylvestris). In the past its ready availability in the desired sizes and quality and its durability in service encouraged little competition. However, the past decade has seen some erosion of this position, particularly through the increased proportion of sapwood in redwood supplies. Since the sapwood is less durable th...
J W W Morgan
The use of lap-joints in natural durability testing: moisture content development during 36 months outside exposure trials
2000 - IRG/WP 00-20217
Lap-joint trials (following European Standard ENV 12037) were set up with 11 different softwood and hardwood species. The main aim was to evaluate the suitability of this test standard (developed for testing wood preservative effectiveness) for natural durability testing. The moisture development has been followed during a 36 months period. In this paper, the outcomes of different moisture content...
H Militz, C J Bloom
Why don't more people work with Serpula lacrymans nowadays? A discussion of some of the different approaches to experimenting with this unique fungus
1989 - IRG/WP 1383
Remarkably few laboratories are currently investigating this well-known fungus. Not only has it failed to gain acceptance as a standard test organism (for wood preservative evaluation) in many countries, but is also sometimes excluded from pure research studies when it ought to be an obvious first choice as a representative basidiomycete. This paper discusses some different approaches that have be...
J D Thornton
Suitability of different termite species for laboratory testing
1982 - IRG/WP 1159
Different termite species were tested in the laboratory to evaluate the effectiveness of insecticides and wood preservatives in wood against termite attack. Determined were the optimum group size and composition, the matrix (vermiculite) volume and its moisture content. Choice feeding tests with fully impregnated wood blocks which are carried out according to a modified EN 117 procedure for Reticu...
U Kny, H Kühne
Penetration of oil-borne preservatives in American elm
1975 - IRG/WP 355
Pressure treatment of elm posts and cants by Rueping schedules resulted in erratic penetration. Instead of the expected gradual decrease in retention from surface inward in posts, inner zones frequently contained more preservative than the surface quarter inch. Heartwood was found penetrated when sapwood was not. There were numerous skips in treated zones. The prevalence and possible causes were i...
E A Behr
Protection of pine sawtimber and sawn timber against blue stain in Poland
1983 - IRG/WP 3193
The purpose of this paper is the synthesis of more important results of basic and applied research that have been grouped in the following problems: 1.: Fungi causing blue stain in the pine wood, occurring in Poland. 2.: Moisture content changes of pine sawtimber and sawn timber as the factor of blue stain producing fungi development. 3.: Effect of sapwood moisture content on the degree of wood st...
E Tarocinski, M H Zielinski
Factors affecting the resistance of fibre building boards to fungal attack
1975 - IRG/WP 252
Fungal decay is initiated at lower moisture contents in standard and tempered hardboards (18%) than in pine sapwood (26%). In contrast, in a saturated atmosphere, the equilibrium moisture contents of standard hardboard (14%) and of tempered hardboard (12.5%) are much lower than the moisture content permitting decay initiation whilst the equilibrium moisture content of pine sapwood (25.1%) approach...
C Grant, J G Savory
Effects of the delay in the beginning of treatment on absorption and distribution of water-soluble salts in posts treated by sap-replacement method
1992 - IRG/WP 92-3719
One of the most important matters in green wood treatments, such as sap-replacement method, is knowing the longest time available for beginning treatment without losing efficacy. In this paper, the influence of this factor on absorptions and distribution of the preservative into the wood is analized. Tree start-up times were first chosen: 3-6 hours, 48 h and 120 h after being cut down. The treatme...
M V Baonza Merino
Moisture correction for ultrasonic MOE measurements above fibre saturation point in Scots pine sapwood
2006 - IRG/WP 06-20333
There is a high correlation between methods for dynamic modulus of elasticity (MOEdyn) and static modulus of elasticity (MOEstat). MOEdyn methods have been found sensitive to detect early stages of decay and may be seen as an option for non-destructive wood durability testing. As the MOEstat measurements do not change after reaching the fibre saturation point, the uncorrected MOEdyn data from ultr...
E Larnøy, G Alfredsen, H Militz
Laboratory methods for assessing the resistance of wood plastic composites to fungal attack.
2006 - IRG/WP 06-20340
Wood plastic composites (WPC’s) have many attractive material features including dimensional stability and resistance to moisture, but the wood in these materials remains susceptible to fungal attack. Assessing WPC decay resistance in laboratory trials has proven difficult because the slow moisture sorption characteristics of this material do not allow for sufficient fungal attack over the trad...
J J Morrell