Your search resulted in 21 documents.
Rational weight per weight (w/w) qualifying retention from a pole bank in Bangladesh
2000 - IRG/WP 00-40187
Weight per weight (w/w) vs weight per volume (w/v) retention study revealed that the w/w % retention is found to be appropriate and uniform for all timber species in respect of its real effectiveness. The pole species having density below 512 kg/m3 (32pcf.) showing w/v retention below 20kg/m3 (1.25pcf.) have equal w/w retention of 4%. The apparently reduced w/v retention of low density poles will ...
A K Lahiry
Types of decay observed in CCA-treated pine posts in horticultural situations in New Zealand
1984 - IRG/WP 1226
The few reported failures of 11-12-year-old horticultural posts in New Zealand in 1982 were caused by brown-rot. A subsequent survey of CCA-treated posts in all the major horticultural areas has revealed decay of many posts. A microscopic examination of these posts has shown decay by brown-rot, white-rot, soft-rot and bacteria. Several types of bacterial decay have been observed....
J A Drysdale, M E Hedley
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
Premature decay of CCA-treated pine posts in horticultural soils - An overview
1984 - IRG/WP 1241
The recent discovery in New Zealand of early decay in CCA-treated pine posts set in horticultural soils led to the establishment of a comprehensive research programme. The objectives and outline of this programme are presented together with an overview of research progress to date. Results suggest that premature decay of CCA-treated timber is restricted to material placed in highly cultivated soil...
J A Butcher
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
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
A survey of the incidence of decay in copper-chrome-arsenate treated trellis support posts used in horticulture in New Zealand
1984 - IRG/WP 1225
Copper-chrom-arsenate treated softwood posts used as trellis support structures in 5 major horticultural districts of New Zealand were systematically examined for presence of decay. Principal crops on properties examined were grapes and kiwifruit; a minority of properties grew hops, boysenberries, and dwarf apples. Occurrence and severity of decay were variable within specific age classes of posts...
M E Hedley, J A Drysdale
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
Patterns of decay in CCA-treated horticultural post populations - A fungus cellar simulation
1986 - IRG/WP 1286
The distribution of decayed posts in 10-, 14-, and 18-year-old vineyards supported a hypothesis to explain variability in intensity of decay found among posts in New Zealand horticultural properties. The development of decay patterns between samples in a simulated vineyard plot established in the Forest Research Institute fungus cellar gave additional support to the hypothesis that decay within la...
M E Hedley
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
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
Analyses of premature failure of utility poles
2012 - IRG/WP 12-40584
In this study a total number of 18 utility poles of Scots pine (Pinus sylvestris) impregnated with a copper-chromium containing preservative were investigated. They were part of different lower voltage transmission lines in the western part of Germany and failed before predicted minimum service life. All poles in this study were less than 15 years in use. The type of decay and fungi were evaluated...
S Bollmus, N Rangno, H Militz, A Gellerich
Quasi-in-situ durability tests on oak timber bridges
2013 - IRG/WP 13-20510
This study aims on developing a method for determination of wood durability on samples taken from real structures in service. Therefore quasi-in-situ durability tests have been conducted exemplarily on timber bridges made from English oak (Quercus robur L.). Drilling cores were found to be a feasible alternative to standard specimens for laboratory durability tests against pure cultures of Basidio...
C Brischke, C J Behnen, M-T Lenz, K Brandt, E Melcher
Premature failure of wood structures in Use Class 3 caused by decay - some examples from Norway
2018 - RG/WP 18-20643
The Nordic Wood Preservation Council (NWPC) has since 1976 had a standard for classification of preservative treated wood, documents describing conditions for approval of preservatives for industrial use and requirements for quality control of preservative treated wood. Last year, 2017, the NWPC extended the quality system to include natural durability (heartwood) and modified wood.
The objecti...
P-O Flaete
Premature adhesion failure of exterior wood coatings – The influence of substrate temperature at coating application and moisture accumulation during storage
2022 - IRG/WP 22-40937
The present study aimed at extending the knowledge about premature coating failures of industrially finished wood cladding. Two potential factors were studied: the influence of substrate temperature at coating application and moisture accumulation during storage on the adhesion of waterborne coating systems. In the first experiment, 4 batches of wood specimens were submitted to 4 different tempera...
U Hundhausen