Your search resulted in 97 documents. Displaying 25 entries per page.
Limiting Conditions for Decay in Wood Systems
2002 - IRG/WP 02-10421
Hygrothermal models can predict temperature and moisture conditions in wall components subjected to real weather data, but specific data and a fundamental understanding of how temperature and wood moisture content dictate the progression of decay under these conditions is required for modellers to predict consequences of decay on building performance. It is well understood that wood will decay abo...
P I Morris, J E Winandy
Inadequacies in preservative retention and formulation as contributory causes of premature failure of CCA-treated vineyard posts
1984 - IRG/WP 3280
Analyses of severely decayed or failed vineyard posts and examination of stake test data on effectiveness of copper-chrome-arsenate (CCA) preservatives have suggested two contributory causes of premature failure of vineyard posts: 1. Preservative retentions in posts are such that after 15 years' exposure some decay is inevitable. 2. The high arsenic, low chrome formulations with which the...
M E Hedley
Biostatic film as a primary treatment against pole failure in soil
1995 - IRG/WP 95-40053
Field liners of low density polyethylene (LDPE) film applied as primary treatment of soil-contact surfaces of creosote-treated poles prevented their detoxification and premature failure by establishing hurdles against microbiological colonisation. These hurdles include low water activity, low oxygen tension and nutrient limitations. Moreover, under conditions of high soil moisture, field trials sh...
A A W Baecker, M Behr
Premature failure of treated timber in wharfs in Papua New Guinea, attributed to defects in design
1991 - IRG/WP 4158
The performance of timber in wharfs in Papua New Guinea has been monitored for a number of years. Premature failure of wharf structures was found in many cases to be due to defects in design rather than ineffective preservative treatment. Above-water timbers were found to be prone to severe checking followed by decay. Protection for the end grain of pile tops and the limiting of radial checking in...
S M Cragg
Influence of felling time on the natural durability of norway spruce (Picea abies (L.) Karst.)
1998 - IRG/WP 98-10250
Natural durability was tested in a laboratory test according to EN 113. The test fungi were Coniophora puteana and Poria placenta. Additionally, the test method was modified by using water agar instead of malt agar, so that wood was the only nutrient source for the fungi. In a third attempt the samples were inoculated with Trichoderma harzianum before testing.
The trees were felled on the 22.7.97...
M Hirmke, K Messner, J Fellner, A Teischinger, R Wimmer
Cellular and fractural failure after supercritical fluid impregnation of four wood species
2004 - IRG/WP 04-10503
Supercritical fluids (SCFs) have been investigated for delivering biocides into sawn wood. Pressure differentials during treatment may exceed the compressive or tensile strength perpendicular to grain, creating a potential for transverse deformations that exceed elastic strain limits. Wood treated by SCF processing with CO2, a potential biocide carrier, was inspected macroscopically and microscopi...
M E Anderson, R J Leichti, J J Morrell
Models of the critical time of humidity and temperature conditions for the development of mould fungi in pine and spruce sapwood
1995 - IRG/WP 95-20066
Regression models of the time factor for the growth of mould fungi in pine and spruce sapwood are studied. The first group of models are based on the results of exposures of mould fungi in static humidity and temperature conditions indicating the time for the start of mould growth in wood. The second group of models are based on the exposures of mould fungi in fluctuating or alternating humidity a...
H Viitanen
A non-pressure method of protection based on hurdle theory to control the spectrum of internal environmental factors which affect the decay of poles in soil contact
1993 - IRG/WP 93-20005
A field trial was conducted to establish whether superficial barrier linings on poles in soil contact could function as environmental hurdles against the growth of biological agents and thus provide preventative methodology to preclude premature failure of vineyard poles under flood-irrigation. Assessment after 52 weeks exposure to the prevailing conditions and sub-tropical environment showed that...
A A W Baecker
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative c...
S-E Dahlgren
Non-destructive detection of the presence and behaviour patterns of wood-destroying insects
1988 - IRG/WP 2302
An apparatus, designed for the automatic recognition of the presence and of specific behaviour patterns of wood-boring insects, is introduced. From a wood sample, a mixture of noise and action induced substratum vibrations is picked up, amplified, filtered and translated into a sequence of computer-readable numbers which are passed to a microcomputer-based signal-pattern-recognition. If an incomin...
M Pallaske
Premature failure of CCA treated vineyard posts from brown rot
1993 - IRG/WP 93-10016
A survey of CCA (AWPA Type C) treated posts used as grape vine trellis supports, to determine the extent and type of decay was carried out at a terraced vineyard in the Hawkes Bay region of the North Island of New Zealand. Of 357 posts examined out of a total of 970 in the vineyard, 47% had moderate to severe decay or had failed, 20% had established decay, 10% had a trace of decay and 23% had no s...
R N Wakeling, A P Singh
Preservative treatment of wood by diffusion processes - Simulation of commercial treatment processes
1988 - IRG/WP 3498
Spruce (Picea abies), Scots pine (Pinus sylvestris) and birch (Betula pendula) were preservative treated by diffusion with mixtures of copper sulphate and arsenic pentoxide. The preservative was fixed after a suitable diffusion storage period by soaking in ammonia solution. A high standard of treatment could be achieved in spruce sapwood. This was attributed to its low wood density, and high wood ...
P Vinden
Failure of overhead power transmission and telecommunication poles in Tanzania: Causes, preventive and remedial measures
1988 - IRG/WP 3465
Unless measures are considered urgently to combat massive pole failures occuring in service, it is likely that wooden poles may soon become unpopular. Consequently, pole users may be forced to use costlier alternatives such as underground cables and concrete or steel poles. In trying to countercheck this trend, this paper names the main agents of pole failure, discusses different models of pole fa...
K K Murira
Adequate preservative treatment of kiln dried Eucalyptus camaldulensis and Acacia mangium for tropical and subtropical wood poles
1996 - IRG/WP 96-40075
The Eucalyptus camaldulensis and Acacia mangium round timbers kiln-dried at EMC and full cell pressure treated with CCA-C ensured requisite penetration and adequate dry retention (30 kg/m³ or 4% w/w). The sufficient inherent strength, seasoning property, treatability of sapwood and heartwood equivalent to 44% of radius, natural durability of heartwood, and field investigation on service performan...
A K Lahiry
Time limits for holding logs to achieve successful antisapstain treatment
1997 - IRG/WP 97-30126
The purpose of these trials was to determine the maximum time that logs can be left in winter and summer before treatment if sapstain, caused by pre-treatment infection, was to be prevented. Pre-treatment storage conditions representative of average temperature and humidity for the winter months of June, July and August, and of moderately severe summer conditions, for the Bay of Plenty, New Zealan...
D R Eden, R N Wakeling, C M Chittenden, J G Van der Waals, B Carpenter
Appendage-mediated attachment in spores of lignicolous marine fungi
1982 - IRG/WP 487
The role of appendages in aiding attachment and entrapment of marine fungal spores to wood substrata is described in this paper. Scanning electron microscope (S.E.M.) observations indicated five different classes of attachment or entrapment response in the sixteen species examined. These responses varied -hith the degree to which appendages attached or entrapped spores to wood surfaces. In additio...
G Rees
NMR T1 relaxation time as a non-destructive method for the study of decay in wood
1992 - IRG/WP 92-2406
The NMR spectroscopic technique of measuring the T1 spin-lattice relaxation times has been investigated for its potential in the detection of microbial decay in wood. The T1 NMR analyses were carried out on samples of Scots pine and European beech that had been exposed to decay and non-decay fungi representing each of the important groups colonising wood. Decay in the test material was also assess...
P W McCormack, A E G Cass, R J Murphy
Colonisation of painted wood by Aureobasidium pullulans - Analysis of features and consequences for failure in service
1996 - IRG/WP 96-10144
Wooden blocks of spruce were painted with different paint formulations. Water- and solvent-borne model and commercial paints were used. The painted wooden blocks were inoculated with a spore suspension of Aureobasidium pullulans (de Bary) Berkg. and placed in an environment of high humidity for 14 months. Different colonisation and growth patterns were observed on the different paint surfaces. The...
S L Bardage
Eradication of wood decay fungi by means of radio frequency
1998 - IRG/WP 98-10292
High frequency electromagnetic fields i.e. radio frequency (RF) are used in wood industry for heating, gluing and bending of wood and are also appropriate for eradicating of wood decay fungi and insects. We investigated the effects of RF exposure on wood samples which were in vitro infected by Coniophora puteana, Gloeophyllum trabeum and Lentinus lepideus. For each fungus, the lethal temperature a...
F Pohleven, J Resnik, A Kobe
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
List of fungi in soft-rot tests
1975 - IRG/WP 105
This list gives information on the terrestrial and marine species and strains of fungi tested for soft-rot ability in pure culture with data on their decay activity in untreated wood. An index of the timber species tested is added. The compilation is based on 1) the list of soft-rot fungi of the former OECD Group (Doc.No. 27/DAS/CSI/M/559), Oct. 1968, prepared by R. Rösch and W. Liese, 2) informa...
G Seehann, W Liese, B Kess
An analysis of the effects of some factors on the natural durability of pine (Pinus sylvestris L.) and spruce (Picea abies Karst.)
1986 - IRG/WP 1279
The effects of some factors on the natural resistance of pine and spruce sapwood against fungal decay and against attack of house-longhorn beetle larvae have been studied in laboratory tests and the results are evaluated by analysis of variance and regression analysis. Following conclusions were reached: Wood from summer-felled trees did not have a lower inherent natural durability against fungal ...
J B Boutelje, T Nilsson, S Rasmussen
Quantification of creosote migration down wooden poles and the prevention of its depletion during flood irrigation
1994 - IRG/WP 94-50032
Polyethylene field liners heat-shrunk onto soil-contact surfaces prevented decay of creosote-treated Eucalyptus grandis vineyard poles under flood-irrigation. The present work quantified losses of creosote from these poles after six and 24 months' service. After six months' service the mean creosote retention of unlined poles above the ground line was 12.62% (m/m dry wood), with ...
M Behr, A A W Baecker
The effect of oil-borne preservative treatments on the shear strength of FRP/wood composite adhesive bonds
2003 - IRG/WP 03-40265
Reinforcement of structural wood components with Fiber Reinforced Polymer (FRP) will enhance the beam’s strength, but actual data on long-term durability is sparse, not well documented or not readily accessible. In this study, bond properties of FRP-wood composite materials were investigated following treatment with creosote or copper naphthenate preservatives. The properties investigated inclu...
B Herzog, B Goodell, R Lopez-Anido
Experimental variations in the distribution of CCA preservative in lignin and holocellulose as a function of treating conditions (temperature, concentration, pH, species, and time)
1984 - IRG/WP 3277
The exact distributions between lignin and holocellulose and retentions on wood of copper, chromium and arsenic as a function of various sets of conditions in a 3x3x4x2 factorial experiment in which combinations of three temperatures of treatment, three CCA solution concentrations, four pH's of the initial CCA solution and two timber species, namely Pinus radiata and Eucalyptus grandis, a...
A Pizzi, E Orovan, M Singmin, A Jansen, M C Vogel