Your search resulted in 142 documents. Displaying 25 entries per page.
Enhancing the durability of low durability Eucalyptus plantation species: a review of strategies
2020 - IRG/WP 20-40910
Eucalyptus species native to Australia have shown excellent growth rates, good physical properties and resistance to diseases. As a result, they are widely planted globally for a variety of uses. One negative aspect of many of these faster growing species is that they have a high percentage of low durability heartwood that resists preservative treatment. In Australia, large plantations of these sp...
K C Wood, J J Morrell, W Leggate
Effect of a Water Repellent Treatment on Moisture Behavior of Three Australian Hardwoods: A Preliminary Report
2021 - IRG/WP 21-40921
Wood is inherently hygroscopic and will sorb moisture either directly from the atmosphere or via capillary action. Moisture can have marked effects on wood properties and repeated wetting and drying creates dimensional changes that lead to physical damage. Exposure to elevated moisture levels also increases the risk of fungal attack.
Wood preservatives have long been used to minimize the risk of ...
B Hassan, J J Morrell, K Wood
Decay capacity and degradation patterns of Xylaria hypoxylon on different wood species
2022 - IRG/WP 22-10985
A host of physical and environmental factors may influence fungal decay including the wood substrate, temperature, moisture, oxygen, light, pH, and nitrogen. Understanding the effects of these factors on fungal decay is important for the effective utilization of wood decay fungi in biotechnological processes and for understanding the role of these organisms in global carbon cycling. The ascomycete...
E Bari, G Daniel, A Singh, J J Morrell
Post-layup protection of mass timber elements in above ground protected exposures: 2-year results
2022 - IRG/WP 22-30766
Mass timber has seen increased use as a building material for low and mid-rise construction in recent decades. The durability of mass timber elements has not been fully examined and the effects of wood destroying organisms on this these materials merits attention. The effectiveness of currently labeled soil termiticides and passively applied biocides at post-construction or as remedial agents need...
M E Mankowski, T G Shelton, G T Kirker, J J Morrell
Effect of nano-particle characteristics and concentration on UV protection of timber: A field exposure test
2022 - IRG/WP 22-40941
Wood has a well-known susceptibility to ultra-violet light degradation, leading to premature replacement. A variety of products have been developed to protect against this damage, but most provide less than 12 months of protection and must be regularly reapplied. Developing improved coatings would help reduce wood losses and reduce maintenance costs. Nano-particles have a variety of attractive pro...
T Yi, J J Morrell
Effect of densification of Eucalyptus nitens and E. obliqua on moisture uptake, swelling, decay resistance, and fire performance
2022 - IRG/WP 22-40946
Some Australian Eucalyptus species that are abundantly available have low natural durability and poor resistance to fire. These same species are also extremely difficult to treat with preservatives or fire retardants using conventional pressure treatment methods due to a large proportion of refractory heartwood. The aim of this research was to understand whether thermo-mechanical densification had...
B Hassan, J J Morrell, F Wiesner, W Wu, B Belleville, K C Wood
A simple method for assessing the effects of lyctid beetle attack on longitudinal compressive strength of spotted gum sapwood
2023 - IRG/WP 23-20700
Lyctid beetle attack is commonplace in a significant proportion of spotted gum utility poles that are air seasoned prior to chromated copper arsenate (CCA) treatment. While this damage is allowed, there are no reports quantifying the effects of the beetle galleries on pole properties. Full scale testing would require substantial quantities of poles in order to obtain a range of degrees of damage....
M Powell, J J Morrell
Sensitivity of copper indicators for detecting preservative penetration
2023 - IRG/WP 23-20701
Chrome azurol S (CAS), 1-(2-pyridylazo)-2-naphthol (PAN), and rubeanic acid (RA) are the three copper indicators currently used by the timber industry to assess preservative penetration. Although only the American Wood Protection Association (AWPA) standards specify indicator sensitivity, it is unclear how those limits were developed. The sensitivity of each copper indicator was determined in solu...
T Yi, J Norton, S Meldrum, J J Morrell
Establishing the minimum effective penetration of wood preservatives in the refractory heartwood of E. nitens
2023 - IRG/WP 23-30780
Conventional pressure treatment of many Australian hardwoods results in little to no penetration of heartwood and a non-uniform envelope treatment of <5 mm surrounding a mostly untreated core. This is a major issue for many of the low durability plantation hardwood timbers that are grown in Tasmania, which contain high percentages of heartwood. Long term studies on softwoods such as spruce decking...
J R Vargas, J J Morrell, L Yermán, K C Wood
Impacts of elevated moisture levels and subsequent drying on screwed
2023 - IRG/WP 23-40970
Mass timber (glue-laminated timber, cross laminated timber (CLT) and laminated veneer lumber) are increasingly used in mid-to high rise structures in Australia where the climate is mainly sub-tropical with elevated moisture levels and high termite risk. Moisture intrusion poses a major challenge anywhere but becomes more critical under these conditions. Untreated/non-durable materials are consider...
C M T Roder, C D Gerber, J J Morrell
Through-boring to improve the performance of low durability Eucalyptus species for utility poles: 10-year field test results of pole stubs exposed in Southeast Queensland
2023 - IRG/WP 23-40972
An impending shortage of naturally durable hardwood electricity pole timbers in Australia has encouraged investigation of alternatives containing less durable, untreatable heartwood. Through-boring or drilling holes perpendicular to the long axis before treatment, has been used successfully on refractory softwood poles in North America and might have application in Australia. The use of through-bo...
J Norton, L P Francis, J J Morrell
Failure characteristics of thermally modified poplar wood subjected to mechanical tests
2023 - IRG/WP 23-40983
Poplar (Populus spp.) are among the fastest growing timber species and have been widely planted for use in plywood, composites, pallets, furniture components and paper production. However, the low density of the wood limits many structural applications and the wood has little resistance to biodegradation. Thermal modification represents one approach to improving durability by changing the moistur...
E Bari, M Ghorbanian Far, N Moradi, J J Morrell, G Daniel, B Mohebby, R Hosseinpourpia, M Humar
Multi-scale Experimental Study on Self-sustained Smouldering of CCA-treated Timber Poles
2023 - IRG/WP 23-40988
While it is accepted that appropriate treatment with chromated copper arsenate (CCA) will extend the design life of wood markedly, there are concerns regarding the effect of treatment on fire performance. Smouldering combustion in CCA-treated timber infrastructure can self-sustain, destroying the timber elements, as the chromium and copper present in the CCA can act as catalysts of the smouldering...
W Wu, L Yerman, J J Morrell, F Wiesner
Australian timber durability research needs
2023 - IRG/WP 23-50385
Australia was once a world leader in timber durability research, but prolonged disinvestment resulted in a gradual decline in capacity. Forest and Wood Products Australia recognized this problem and supported the development of the Centre for Timber Durability and Design Life to help reverse this decline and begin to educate the next generation of Australian researchers. The Centre is a collabor...
J J Morrell
Comparison of residual Methylisothiocyanate (MITC) in Australian and South American hardwood and softwood treated with a solid compressed Dazomet fumigant stick
2024 - IRG/WP 24-20712
The efficacy of compressed dazomet sticks with or without a copper-based accelerant for control of internal decay of both softwood and hardwood species was examined in multiple field trials. Effective levels of methylisothiocyanate (MITC), the fungitoxic decomposition product of dazomet were found in Australian spotted gum (Corymbia spp) and Guyanese Wallaba (Eperua falcata) as well as in southern...
R Tungal, M Powell, J J Morrell, T Singh
Performance of Douglas-fir cross laminated timber (CLT) subjected to elevated humidity in a ground proximity field test for 6 years
2024 - IRG/WP 24-41010
The ability of insecticidal soil drenches or spray-on insecticide/fungicide treatments to protect mass timber elements exposed in a high moisture environment but out of direct soil contact was assessed using a modified AWPA ground proximity test established in 2017. Three-ply Douglas-fir CLT pieces measuring 305 x 355 x 105 mm (L x H x W) were installed at the Harrison Experimental Forest (HEF) (S...
M E Mankowski, J J Morrell, T G Shelton, G T Kirker
Copper migration from preservative-treated Douglas-fir decking: models vs laboratory leaching data
2024 - IRG/WP 24-50390
The ability of a model to predict copper migration from Douglas-fir treated with organic metallic substances into a freshwater slough was evaluated against data generated through simulated overhead leaching. The model predicted very high loadings of ammoniacal copper zinc arsenate, alkaline copper quaternary or copper azole that had the potential to impact water quality while data from the exper...
M J Konkler, G Presley, J J Morrell, T Singh