Your search resulted in 37 documents. Displaying 25 entries per page.
Evaluation of timber bridges with special consideration of detail design
2017 - IRG/WP 17-40781
Since 1997 the use of wood in bridge construction has been increasingly criticized by the Hamburg federal state authority supposedly because of shortened service life due to decay. With regard to wood research, however, it is often suggested that use of timber is suitable for weathered structures as long as constructive protection measures will be observed. In order to unravel the reasons for the ...
K Robbers, J Fromm, E Melcher
Extending the useful life of creosoted electricity distribution poles in service
1993 - IRG/WP 93-50001-16
Creosoted transmission poles have provided good service over many decades in a whole range of environments. The use of save biocides for secondary treatments has the potential to extend the life of such poles. These techniques, together with a full understanding of the modes of failure, make it possible to establish new strategies to further improve the environmental benefits of treated wooden pol...
D J Dickinson, B Calver
Some observations on causes of failure of preservative treated natural round transmission poles in Nigeria
1977 - IRG/WP 291
Treated natural round transmission poles in Nigeria have been discovered to be attacked underground as early as two years after planting. Termites and rot fungi attack the inner tissues and leave a pattern characteristic for the species of the pole. Tectona grandis, Nauclea diderrichii and Wide Pore pine, the major species for transmission poles in Nigeria show these attacks. A form of termite shi...
M A Odeyinde
Observations on the failure of anti-sapstain treated timber under non-drying conditions
1990 - IRG/WP 1437
A range of bacteria and yeasts were isolated from antisapstain treated timber and fresh sawdust. Solution samples containing 100 ppm of TCMTB in a nutrient medium were inoculated with these organisms and incubated at 25°C for 5 days. The levels of TCMTB remaining in solution were determined by HPLC analysis after this time. Results indicated high losses of active ingredient for a range of organis...
G R Williams
Conservation of wooden cultural property
1994 - IRG/WP 94-30038
A survey of the conservation of wooden archtitectual monuments, art objects and archaeological finds is presented. Each of the three areas has typical conservation problems which reqire the use of selected wood preservatives and consolidation agents. Furthermore specific protection and consolidation methods are necessary. A precise damage diagnosis with non-destructive testing methods is the first...
A Unger, W Unger
Soil-bed studies (Part 3): A cause of failure of multisalt preservatives following soil-bed exposure
1983 - IRG/WP 3261
P Vinden, J F Levy, D J Dickinson
Polyflavonoid tannins - From a cause of CCA soft-rot failure to the "missing link" between lignin and microdistribution theories
1986 - IRG/WP 3359
Polyflavonoid tannins are proven to be fast-reacting with CCA solutions and hence, to be strong competitors of the structural wood constituents for fixation of CCA preservatives. The consequence of this effect is that even relatively small amounts of tannin cause severe undertreatment of the structural wood constituents which in turn badly affects the long term durability of CCA-treated timber. Th...
A Pizzi, W E Conradie, M Bariska
HCB - a new preservative combination for wood pole maintenance
1996 - IRG/WP 96-30122
New combination of heavy creosoted boron (HCB) applied on hardwood and softwood logs at different moisture content revealed successful diffusion of boron in all sapwoods within 7 days and in all sapwoods plus hardwoods within 15 days. The new cost effective paste sterilizes wood through diffusion and suitable for pole maintenance at groundline and above groundline e.g. cut ends, drilled holes, woo...
A K Lahiry
Analysis of volatile emissions as an aid in the diagnosis of dry rot
1992 - IRG/WP 92-2393
The dry rot fungus, Serpula lacrymans was grown in pure culture on malt extract and on sapwood of pine. The volatile compounds emitted from the cultures were determined by diffusion sampling on tubes filled with Tenax TA, thermal desorption and gas-chromatography-mass-spectrometry in order to find markers for attack of the fungus....
J Bjurman, J Kristensson
The possible significance of the lignin content and lignin type on the performance of CCA-treated timber in ground contact
1988 - IRG/WP 1357
The lignin in wood samples of Alstonia scholaris, Octomeles sumatrana and a Simaruba species have been analysed. These timbers are characterised by a high lignin content and low syringyl:guaiacyl ratios. Decay tests with two soft rot fungi showed that the timbers were less susceptible than timbers with a low lignin content and higher syringyl:guaiacyl ratios. Numerous data for field performance of...
T Nilsson, J R Obst, G F Daniel
Morphological and Molecular Diagnosis of Leptographium spp. in Canadian Softwoods
2003 - IRG/WP 03-10479
Sapstaining fungi that affect commercially important softwood species mainly belong to the genera Ceratocystis, Ophiostoma and Leptographium. Our 1997-1999 fungal surveys confirmed that this is the case in Canada. The work reported here addresses identifying the morphologically plastic Leptographium at the species level, which is difficult using conventional methods. We assessed the morphologic...
S Alamouti, Jae-Jin Kim, A Uzunovic, C Breuil
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
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
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
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
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
rDNA-ITS sequence of Serpula lacrymans and other important indoor rot fungi and taxon-specific priming PCR for their detection
1999 - IRG/WP 99-10298
Taxon-specific priming polymerase chain reaction (TSPP) is a powerful molecular tool for fungal diagnosis. For its application to indoor rot fungi, the internal transcribed spacer (ITS) of the ribosomal DNA (rDNA) of the main fungal species causing wood rot in European buildings was amplified with the polymerase chain reaction (PCR). The ITS region was sequenced. The complete sequences are present...
O Schmidt, U Moreth
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
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
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
Continuous moisture measurement (CMM) to detect failure of moisture resistance
2009 - IRG/WP 09-20422
A wood coating system will fail to perform properly after a certain time of weathering. From that moment, the substrate is especially prone to fungal attack. Moisture plays a key role on weathering performance, wood protection efficacy and decay susceptibility of wood. Therefore, knowledge of the moisture dynamics of the applied wood protection is of significant importance in the prediction of the...
I De Windt, J Van den Bulcke, J Van Acker