Your search resulted in 175 documents. Displaying 25 entries per page.
To decay or not to decay: An accelerated field test of the validity of the Scheffer index
2008 - IRG/WP 08-20392
The Scheffer Index was introduced in 1971 to predict the relative decay hazard of untreated wood exposed above-ground. Precipitation and temperature parameters are used in the calculation. A higher Scheffer Index value implies a greater risk of decay. An accelerated 18-month study using seven field sites with Scheffer Indices ranging from 35 to 400 and two wood types (Populus tremuloides and Pi...
G M Larkin, P E Laks
Field testing in Colombia: Three years of evaluations and experiences
2008 - IRG/WP 08-20394
Two field test sites have been established in Colombia for the evaluation of fungal and termite resistance of treated wood. The combination of elevated temperature, high and stable humidity and high rainfall at the two test sites accelerates microbial and insect activity (Scheffer, 1971; Thornton et al, 1994; Freitag et al, 1995). Tests established include above ground termite tests, ground contac...
Y Cabrera, A Preston
Natural Durability of Some Heartwood from European and Tropical African Trees against Marine Organisms
2009 - IRG/WP 09-10682
This study aims to investigate the natural marine durability of some tropical and domestic wood species in marine environment. A total of 33 tree species, comprising 18 European and 15 tropical originated trees were exposed to marine conditions in 6 meters depth for a period of 14 months at east and west Black sea, Mediterranean, Aegean, and Marmara coasts. The results indicated that wood species...
S Sen, H Sivrikaya, M Yalçın
Dimensional Stability of Nine Tropical Hardwoods from Cameroon
2009 - IRG/WP 09-10687
This study investigated the swelling behavior, rate of swelling and dimensional stability of nine tropical hardwood species from Cameroon, namely ayous (T. scleroxylon), bilinga (N. diderrichii), bubinga (G. tessmannii), iroko (C. excelsa), Makore (M. heckelii), moabi (B. toxisperma), movingui (D. benthamianus), teak (T. grandis) and zingana (M. brazzavillensis). Continuous swelling was monitored ...
S R Shukla, D P Kamdem
Antinomic natural self-protection mechanism in long-lasting woods: a case study with three tropical species from French Guiana
2009 - IRG/WP 09-10696
We demonstrate in this work through 3 examples that Amazonian trees may specialize long-lasting woods by means of at least to different approaches. Wallaba impregnates its wood with large amounts of weakly antifungal compounds acting in synergy, while tatajuba and louro vermelho woods are naturally impregnated with antifungal agents. Comparison of biological activities in vitro and concentrations ...
A Rodrigues, M Royer, N Amusant, J Beauchêne, G Herbette, V Eparvier, A Thibaut, L Salmen Espíndola, B Thibaut, D Stien
Natural Durability Variations of Malaysian Timbers from Sarawak after 26 Years Exposure by Stake Test
2009 - IRG/WP 09-10704
An extensive graveyard stake test site was established in 1977 in Sibu, Sarawak, Malaysia, to evaluate the in-ground durability of 132 Sarawak wood species, mainly hardwoods. Test samples were planted at 100 x 50 cm spacing. Authenticated wood specimens from 3 trees of each of 132 species were processed into 20 replicated outer heartwood (or else undifferentiated heartwood) stakes of 19 x 19 x 457...
A H H Wong, Ling Wang Choon
Accelerated weathering of nine tropical wood species from Cameroon
2009 - IRG/WP 09-10705
The natural durability of tropical species for building components has been a subject of recent concern and questioning, mainly the resistance to weathering. Weathering resistance of nine tropical species from Cameroon, namely Azobe, Bilinga, Bubinga, Teak, Dousie, Moabi, Musanga, Sipo and Padauk were evaluated using an accelerated weatherometer for 2016 hours. Measurement of moisture fluctuation,...
S Pankras, Jinzhen Cao, D P Kamdem
Evaluation of exposure conditions for wooden facades and decking
2009 - IRG/WP 09-20408
During their functional life, building components are exposed to moisture and other environment stress conditions in numerous ways. This is a fact that should be taken into account during manufacture, product development, designing and work execution of building components. For wood material, moisture stress and biological factors like mould and decay fungi are often critical in cladding and decki...
H Viitanen, T Toratti, R Peuhkuri, T Ojanen, L Makkonen
Ensure Durable Wood-Frame Construction under the Climate and Biological Hazards in Shanghai
2009 - IRG/WP 09-20413
This paper provides technical background for developing durability-related provisions for the Shanghai wood-frame construction code. It summarizes the related climate, decay and termite hazards in this area as well as traditional durability solutions used for wood and wood hybrid constructions in China. The overall durability principles or philosophy used throughout this durability chapter are to ...
Jieying Wang, Chun Ni, Jiahua Zhang
Modelling of onset of mould growth for wood exposed to varying climate conditions
2009 - IRG/WP 09-20414
A performance-based service life design format based on climatic exposure on one hand and “resistance” of wood against mould growth on the other hand, is presented in this paper. A limit state for onset of mould growth is defined as the occurrence of traces of mould observed by microscopy. A dose-response model is proposed by which onset of mould growth can be predicted for an arbitrary climat...
S Thelandersson, T Isaksson, A Ekstrand-Tobin, P Johansson
Termite taxonomy and distribution with particular reference to climate change in Africa
2010 - IRG/WP 10-10738
Termites constitute an integral component of various ecosystems in Africa. Termites are also amongst the most difficult of the insects to study because of their cryptic behaviour. There are around 2600 species of termites (Isoptera) in 280 genera which have been described worldwide and about 39% of the total termite species are found in Africa. Some termite species are well known pests of agricul...
P O Y Nkunika, B M Ahmed Shiday, G W Sileshi, J R J French, P Nyeko, S Jain
Fouling and Boring Organisms Deteriorating Various European and Tropical Woods at Turkish Seas
2010 - IRG/WP 10-10741
This study aims to investigate the diversity of fouling and boring organisms damaging wood material at Turkish coasts. Trials were carried out at six harbour sites throughout the seas surrounding Turkey. Wood samples were hanged down at a depth of six meters in the sea, for a period of one year. Identification of the organisms obtained from wood plates revealed the presence of five wood borer and ...
S Şen, H Sivrikaya, M Yalcin, A Kerem Bakır, B Öztürk
Service life prediction of wooden components – Part 1: Determination of dose-response functions for above ground decay
2010 - IRG/WP 10-20439
Scots pine sapwood (Pinus sylvestris L.) and Douglas fir heartwood (Pseudotsuga menziesii Franco) specimens were exposed in double layer field trials at 24 different European test sites under different exposure conditions (in total 28 test sets). The material climate in terms of wood moisture content (MC) and wood temperature was automatically recorded over a period of up to eight years and compar...
C Brischke, A O Rapp
Impact of climate change on wood deterioration - Challenges and solutions for cultural heritage
2010 - IRG/WP 10-20441
Deterioration of wood in cultural assets follows the same physiological mechanisms as in modern structures. Therefore rules and data for prediction of service life derived from old wooden structures can be used to model the service life of recent wooden structures and vice versa. The latter is done in this paper: From experimental test set ups in the field spread over Europe, climatic data, wood t...
C Brischke, A O Rapp, M Hasan, R Despot
Onset of mould growth – the effect of climate variability and different geographic locations
2010 - IRG/WP 10-20446
This paper presents a study on how climate conditions at numerous locations in Sweden affect the risk of onset of mould on wood sheltered outdoors. The results indicate that the risk is clearly higher in the south compared to the north of Sweden. These differences are mainly explained by colder and dryer winter periods in the north which is unfavorable for development of mould. The results also sh...
M Häglund, T Isaksson, S Thelandersson
Improved analysis of field test data related to service life prediction of tropical wood species
2010 - IRG/WP 10-20458
Long field trials of wood in ground contact give valuable data on the natural durability of the material. The European Standard EN 350 gives guidance on how to perform these durability classification, but is limited to the use of averages of in-service life of a set of specimens compared to a reference set. Starting from a database of visual assessment of field stake testing, it is possible to obt...
J Van den Bulcke, A Wong, Ling Wang Choon, Yoon Soo Kim, J Van Acker
Climate change and wood protection, increasing demand of long life wood products and decreasing production of treated wood
2010 - IRG/WP 10-50269
Several new topics related to wood protection sector has appeared in Japan, as the awareness of climate change becomes bigger and bigger. The “Basic act for housing (2006)” and the “Long-life housing promotion act (2009)” were enforced to form a safe and high quality housing stock and to form a long-service-life housing respectively. Despite of the favorable background for wood protection ...
K Yamamoto, H Kato
Effects of global climate change on mould growth - Interactions of concern
2010 - IRG/WP 10-50270
An evident change in climate the last decades has been recorded, and combined effects of increased CO2, elevated temperature and altered precipitation regimes have been observed to represent a change to the fundamental drivers within ecosystems. Growth of moulds, both in nature and on man-made constructions and objects, will most likely increase due to changes in the climate. The survival, the rep...
L Ross Gobakken
Natural durability of wood tested in different environments in Northern Europe
2011 - IRG/WP 11-10747
Moisture is often recognised as a key factor regarding the long time performance of wooden products, and one of the main challenges for timber products is to predict accurate service life in use class 3 (not covered above ground) and use class 4 (in soil or fresh water contact). A range of durability classification studies have been performed both in field and laboratory. But for several wood spec...
P O Flæte, G Alfredsen, F G Evans
Decay hazard mapping for Europe
2011 - IRG/WP 11-20463
In this study, two different dose-response models for above-ground decay as well as a model transferring macro climate data to wood climate data are presented. The models base on data from field trials, which had been conducted at 28 European test sites, and were used to calculate the relative risk for decay caused by climate variability in Europe. The two dose-response models give coherent result...
C Brischke, E Frühwald Hansson, D Kavurmaci, S Thelandersson
The case for using borates in termite control in tropical Australia
2011 - IRG/WP 11-30573
A brief historical overview of boron based wood preservatives efficacy against subterranean termite management worldwide, and in Australia, is presented. The boron based compounds to be used in H2 hazard conditions, may be applied as a surface treatment by dip, flood coat or spray, and rapidly penetrates to the centre of timber substrates, whether containing sapwood or heartwood. However, section ...
B M Ahmed (Shiday), J R J French
Laboratory study of toxicity or tolerance of CCA preservative and heavy metal constituents copper, chromium and arsenic to Malaysian tropical fungi
2011 - IRG/WP 11-30579
CCA preservative and its constituent heavy metal tolerance and toxicity to 3 Malaysian isolates Phialophora fastigiata (soft rot fungus), Paecilomyces variotii (mould fungus) and an unidentified white rot Basidiomycete, was investigated by the modified ‘Strange-Smith’ agar-well-plate technique with 1.6% CCA concentration and the malt-agar-plate bioassay technique with a range of CCA and consti...
A H H Wong, T Mark Venås, N Morsing, C C L Tan, P K F Chong
Evaluation of Five Novel Organotin(IV) Complexes as Wood Preservatives
2012 - IRG/WP 12-30590
Three selected non durable tropical wood species namely Alstonia scholaris (pulai), Macaranga triloba (mahang) and Hevea brasiliensis (rubber) were chemically impregnated with five novel organotin(IV) complexes using vacuum-pressure treatment method. The objectives of this study were to determine the treatability and efficacy of novel organotin(IV) complexes against white and brown rot decay fungi...
M M Rahman, I Jusoh, M A Affan, A Husaini
Effects Of Wood Preservative On Mechanical Properties Of Glulam Manufactured From Lower Density Malaysian Tropical Timber
2012 - IRG/WP 12-40590
This study is to investigate the effect of wood preservative on the mechanical properties of glulam timbers made from low density Malaysian hardwood timbers. Utilization of lower density Malaysian tropical timber for structural applications have not exploited extensively due to their inferior strength. By converting into treated glued laminated (glulam) timbers it could offer the possibility of th...
L Francis, Z Ahmad
Improvement of the biological performance and dimensional stability of two tropical woods by thermal modification
2012 - IRG/WP 12-40605
Pink cedar wood and rubberwood were thermally modified at 230°C in air for 4 h or for 8 h, and then subjected to bending, compression and hardness tests to evaluate the effect of the treatment on these mechanical properties. The biological performance of the modified wood was also determined, according to EN113, and the dimensional stability measured by means of the anti-swelling efficiency. The ...
M M González-Peña