Your search resulted in 576 documents. Displaying 25 entries per page.
Heat treated timber in Finland
2000 - IRG/WP 00-40158
Heat treatment permanently changes the physical and chemical properties of wood by means of high temperatures (150 - 240°C). Heat treatment darkens the colour of the wood. Heat treatment improves the equilibrium moisture content of the wood and the shrinkage and swelling of the wood is reduced. Very high temperatures improve the resistance to rot and also reduce the susceptibility to fungal decay...
T Syrjänen, E Kangas
An evaluation on durability of untreated mining timber support
1997 - IRG/WP 97-20121
Wedge blocks in dimension of 5 x 7 to 8 x 155 cm3 were cut from indigeneous scots pine pitprops. Each of wedge block pairs were numbered and half of them were placed as the test blocks between the steel arches and the strata in a hard coal pit. Controls in laboratory and test wedge blocks in the mine were then sawn into 20 by 20 by 300 mm standard test sticks. Impact bending, static bending and MO...
A Bobat
Paper for discussion - Incising of spruce to improve preservative penetration
1973 - IRG/WP 318
Large quantities of whitewood or Norway spruce (Picea abies) are regularly imported into the United Kingdom from continental Europe. In addition, increasing amounts of Sitka spruce (Picea sitchensis) are likely to become available over the next decade from the Forestry Commission. In many ways spruce is a good structural timber, eg it is relatively cheap and easily available, it has adequate stren...
W B Banks
The effect of extent and location of decay on strength loss in constructional timber
1994 - IRG/WP 94-30039
Radiata pine heartwood billets, 50 x 100 x 1000 mm³ were end-sealed and treated with copper-chrome-arsenate preservative (NZ Type I) to a range of retentions and penetration patterns. Cross-sections, 10 mm thick, were cut from the centre of each billet and used for determination of preservative distribution, for preservative analysis and for decay tests. The decay test consisted of laying samples...
M E Hedley, H Bier
Standardization of preservative treated timber species for conductor, insulator and transformer packing of REB
1996 - IRG/WP 96-40071
In order to resolve the post landing failure problem of wooden packing for conductor, insulator, transformer of REB, the names of the suitable timber species from different parts of the world, irrespective of countries of origin have been standardized along with their strength and treatability grades. The CCA treatability of some Pakistani timber species have been presented for example which was t...
A K Lahiry
Changes in some important mechanical and physical properties of untreated and treated mining timber after exposure to the conditions of a colliery
1996 - IRG/WP 96-20082
Each of salt treated and untreated mining timber (wedge) pairs with 5x15 cm² cross-section and 155 cm length prepared from Scots pine, Bornmüller's fir and oriental beech was cut in the small standard test specimens to determine changes in some important mechanical and physical properties, 13 month after exposure to the conditions of Kozlu Hard Coal Mines in the depth of 52 m. Thus, the...
A Bobat
Bending strength of heat-treated spruce and pine timber
2002 - IRG/WP 02-40242
Heat-treatment of spruce (Picea abies) and pine (Pinus sylvestris) beams (45 x 145 mm) gave a reduction in bending strength of approximately 50%. The bending stiffness (modulus of elasticity) only decreased by 3.5%. Tests were carried out according to EN 408. Another effect of the heat-treatment was increased variation in bending strength. The 5th percentile value of the bending strength, the so c...
C Bengtsson, J Jermer, F Brem
A questionnaire survey to establish the perceptions of UK specifiers concerning the key material attributes of timer for use in marine and fresh water engineering
2004 - IRG/WP 04-10519
Engineers have a key role in making informed decisions on the type of materials to be used in the schemes they design and construct. Currently, in England and Wales, it is believed that some £500m per year is invested in flood and coastal defence engineering. There is a lack of centralised data in the UK holding information on timber for usage in fluvial and, particularly coastal engineering. A...
J R Williams, G S Sawyer, S M Cragg, J Simm
High-energy multiple impact (HEMI)-test – Part 1: A new tool for quality control of thermally modified timber
2006 - IRG/WP 06-20346
Thermal modification processes improve durability and dimensional stability of wood, but the strength properties, especially the dynamic ones, are compromised and need to be considered with respect to industrial quality control. Results from standard dynamic strength testing, such as impact bending tests, suffer from high variability, and therefore require a high number of replicates. To overcome ...
C Brischke, A O Rapp, C R Welzbacher
Categorization of 300 timber, bamboo and cane grown in Bangladesh based on their families, origins, growths, physical and mechanical properties
2009 - IRG/WP 09-10684
In this study the 300 timber, bamboo and cane plants grown in Bangladesh have been classified into various categories based on their taxonomic families, origin of species, rate of growth, color of wood, texture of wood, shrinkage of wood, equilibrium moisture content (EMC) of wood, flammability of wood, cutting and sawing properties of timber, finishing and polishing qualities of wood, machining p...
A K Lahiry
Influence of heat treatment intensity on the structural integrity of 14 timber species
2012 - IRG/WP 12-40586
Thermally modified timber (TMT) is characterized by improved durability and dimensionally stability, but strength properties, especially the dynamic ones, are compromised at the same time. Because dynamic standard tests require high efforts and time, the high-energy multiple impact (HEMI) –test was developed for the fast and reliable characterisation of the structural integrity of TMT, showing a...
C R Welzbacher, C Brischke, G Maier
Validation by micro-computed tomography of an assessment method to measure the residual strength of anobiids infested timber
2019 - IRG/WP 19-20650
In this article a quantitative correlation study of pine timber structural elements, which have been subject to attack by anobiids, is presented. The main objective of the study was to establish a valid empirical correlation between the lost material percentage (consumed by beetles) and original/residual apparent density. Since the beetles’ attack produces a diffuse damage with a set of tunnels ...
J L Parracha, M F Pereira, A Maurício, P Faria, L Nunes
Experimental study on compressive strength performance of cross laminated timber with biodeterioration damage
2019 - IRG/WP 19-40883
The mass timber construction has attracted attention around the world. The reasons are due to the environmental impacts and the potential of the strength performance and quantity of the wood. Nowadays, CLT is one of the most important materials for the timber constructions. If we use CLT as a building material, we should consider the biodegradation risk for long time use. From an estimation of fut...
T Mori, Y Otsubo, R Inoue, M Ikeda, K Kambara, W Ohmura
Estimation of residual compressive strength on cross laminated timber with biodeterioration damage
2021 - IRG/WP 21-40918
CLT is susceptible to biodeterioration such as fungal decay and termite attack during long-term use for buildings. It is necessary to know the residual strength performance of biodegraded CLT for estimating future performance and aging of CLT. In this study, compression tests of CLT damaged by brown rot fungi and termites were conducted to clarify the relationship between residual strength and mas...
R Inoue, T Mori, K Kambara, W Ohmura
Make do and mend: Re-using timber in Smithfield Market
2022 - IRG/WP 22-50371
Historic buildings are part of our built environment. They are a record of how construction and use of materials have evolved and provide excellent opportunities for regeneration of urban areas. Moreover, re-using these buildings and as much of the material within, contributes to the Green Revolution.
Currently, there is tremendous growth in green construction and as Bob Dylan once said, “the t...
J R Williams
Microbiological degradation of wooden piles in building foundations
1988 - IRG/WP 1370
White rot, soft rot and bacterial attack have been detected in softwood piles under buildings. In some cases bacteria were found to be the main degradation organisms in the studied piles. The water content of degraded piles was very high. The compression strength was quite low also in the piles deteriorated by bacteria. The density of wood was very variable, and the degree of degradation could not...
L Paajanen, H Viitanen
Solvent drying and preservation of timber
1977 - IRG/WP 381
Processes which combine drying and preservation are first reviewed. Some preliminary experiments are then described in which blocks of green Sitka spruce sapwood were immersed, in a solution of tributyltin oxide (TBTO) in methanol at 60°C. Satisfactory penetration of the preservative and exchange of methanol and water occurred in a few hours. The methanol was removed rapidly from the wood by evap...
J A Petty
Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providi...
A J Masuka
Improvements of monitoring the effects of soil organisms on wood in fungal cellar tests
1996 - IRG/WP 96-20093
Accelerated testing the durability of preservative treated timber in a so called "fungal cellar" or "soil-bed" to evaluate its performance in ground contact is widespread practice. In order to obtain a more accurate and reproducible estimate of preservative performance, several institutes, among them the BAM in Berlin, have routinely carried out static bending tests in addition to visual examinati...
I Stephan, S Göller, D Rudolph
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 2: Report of treatment and installation in Australia
1978 - IRG/WP 440
The purpose of this test and the procedures to be followed have been fully set out in documents distributed by the International Research Group on Wood Preservation and numbered IRG/WP/414 and IRG/WP/420. The prescriptions set out in these two documents have been closely followed....
J Beesley
Strength loss associated with steam conditioning and boron treatment of radiata pine framing
1987 - IRG/WP 3438
The combined effect of included defects and wood moisture content on the strength loss of second rotation radiata pine framing following conventional steam conditioning is investigated. The green Modulus of Elasticity (MOE) is reduced by approximately 13% after steaming. When dried after steaming, however, neither the MOE nor MOR is significantly different from unsteamed dried controls....
M J Collins, P Vinden
E.R.C. Pole Tester
1982 - IRG/WP 2190
Operating instructions for the ECRC pole-strength tester 120kNm 'PEST'....
G Elcock
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. 2nd Interim Report
1981 - IRG/WP 477
Three reference wood species - Alstonia scholaris, Fagus sylvatica and Pinus sylvestris, untreated and treated with 3%, 6% and 10% CCA and CCB solutions were supplied to all participants for submergence at local sites. Regular examination of samples is being carried out - 6 months, 12 months and then annually for 7 years....
R A Eaton
Report an some aspects of forest and the timber preservation in Fiji 1999
2000 - IRG/WP 00-40189
This report is divided in two sections. One is the general description of some aspects of the Forest indicating timber availability in Fiji. The other Section is an "Status of Timber Preservation in Fiji in 1999"....
S D Kumar
Manual of a mini treating plant for waterborne preservative treatment of timber and bamboo
1999 - IRG/WP 99-40130
This contributional article includes machinaries and equipments necessary for a small wood treating plant for the pressure treatment of tim bers with waterborne preservatives along with the cost and design. The preservative treatment limitations, treatment schedules and specifications for different products have been described. The cost of a mini treating plant will be 6,00,000 Tk. (13,000 US$), s...
A K Lahiry