Your search resulted in 501 documents. Displaying 25 entries per page.
Modelling of moisture content in timber bridge details
2017 - IRG/WP 17-20613
The design of details is an important aspect in durability design of timber bridges. Details are often considered the weakest points in bridges due to their tendency to trap and accumulate moisture and thus facilitate decay. When designing maintenance plans and inspection intervals, it is important to know how design choices will come to influence the service life. Moreover, service life and wood ...
J Niklewski, C Brischke, E Frühwald Hansson, L Meyer-Veltrup
Comparative Durability of Timber Bridges in the USA
2017 - IRG/WP 17-20615
As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was jointly administered by the ...
J P Wacker, B K Brashaw
Moisture content as a quality control parameter in thermally modified timber production
2017 - IRG/WP 17-20622
Quality assurance (QA) or factory production control (FPC) is necessary to ensure a proper production process. The requirements of QA/FPC can result from EN and national standards, quality assurance systems, or producer-specific rules.
TMT producers must ensure that the process was correct, and to ensure traceability of products. In addition to the electronic records, the material should be che...
W Scheiding, H Turkulin, S Stein
An experimental study of mould growth and wood decay in timber frame walls
2017 - IRG/WP 17-20623
This paper deals with parameters related to the occurrence of mould growth and wood decay in timber frame walls. In a first part, the hygrothermal conditions inside a timber frame wall finished with brick veneer cladding are analysed to get an idea of possible moisture related problems. It is shown that, based on the VTT mould prediction model, there is a mould risk on the interface between the in...
M Vanpachtenbeke, J Van den Bulcke, I De Windt, J Langmans, S Roels, J Van Acker
Efficacy of Erythropleum suaveolens (potrodom) and Distemonanthus benthamianus (bonsamdua) water extractives on the durability of five Ghanaian less used timber species of varying perviousness and retentiveness
2017 - IRG/WP 17-30705
Conventional wood preservatives are not only toxic to target bio-deterioration organisms but also to humans, other organisms and the environment. In an effort to find preservatives that are less toxic or non-toxic to man, other organisms and the environment, efficacy of branch bark and heartwood water extracts (0.65 g/ml) of Erythropleum suaveolens (potrodom) and Distemonanthus benthamianus (bonsa...
A Asamoah, K Frimpong-Mensah, C Antwi-Boasiako
Copolymers of tannin extracts as wood protection agents
2017 - IRG/WP 17-30709
Wouldn´t be a dream to preserve wood with the substances which the nature already synthesizes for protecting itself? The idea we would like to pursue is simple: Increase the concentration of these substances, the tannins, trying to fix them properly in wood. It appears easy but it is not. Sensibility against leaching, fungal decay and weathering were observed. In this paper new flavonoid co-polym...
G Tondi, L Sommerauer, A Oberle, A Petutschnigg, M-F Thevenon
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
Prefacricated modular wooden bridges
2017 - IRG/WP 17-40785
The bridge consists of simple, identical pre-fabricated triangular wooden panels joined top and bottom to make up trusses. These trusses are in turn joined together side by side in pairs and are braced to one another to create a girder construction. The deck is carried on top of the trusses, an arrangement which has several advantages for such an uncomplicated structure. It is built up on site, af...
L Jayanetti
Solid Timber Bridges – Latest Developments
2017 - IRG/WP 17-40788
The technology of gluing in wood construction has evolved considerably in recent years. This has been shown especially in timber bridges that Glulam is now the main building material. A further development is the so-called block gluing, which provides a good basis for supporting structures. Numerous bridges, especially in central Europe, appeal by unique design and monolithic and solid construction. These structures base on two main developments: block lamination of glulam and the composite of timber and concrete to one structural system.
F Miebach
The potential and the challenges of acetylated wood in timber bridges - experiences from an ongoing project
2017 - IRG/WP 17-40792
Acetylated wood is known to be a durable and dimensional stable alternative for high performance materials, and has high potential for exterior timber structures. Research has shown that acetylated wood can be effectively bonded by various adhesive types. However, one of the most common used adhesives for timber constructions, Melamine Urea Formaldehyde (MUF), shows a high degree of delamination o...
A Treu, R Bredesen, F Bongers
A summary of history and use of timber bridges in New Zealand
2017 - IRG/WP 17-40801
Wooden bridges have been an important part of road and rail networks in New Zealand. While wooden structures have largely been replaced by concrete and steel on major arteries they still have a place where lightweight, easily assembled structures are needed. These timber bridges may also be a cheaper alternative to other materials in roads which carry relatively low traffic loads. In the last ten ...
D Page, T Singh
Durability of energy efficient wooden buildings: a building physical point of view
2017 - IRG/WP 17-40812
The drive for more energy efficient and sustainable buildings resulted in an increased popularity of wooden buildings, even in countries with a masonry tradition. Often guidelines and prescriptions then are copied from other countries. Different climatic boundary conditions and tradition of finishing, though, do require different moisture tolerance criteria. This is clearly the case for water vapo...
S Roels, J Langmans
Review of Leaching Experiments of CCA-Treated Wood and Wood Treated with Copper-based Alternatives
2017 - IRG/WP 17-50330
The objective of this study was to compare leaching rates of various wood preservatives from treated wood and the tests used to gather this information. The preservatives compared included CCA and the copper-based alternatives, MCQ, ACQ, and MCA. The tests compared included AWPA E11, SPLP, TCLP, and environmental leaching tests. Among all of the tests evaluated, environmental tests most closely si...
A Jones, J Marini, H Solo-Gabriele
Corrosion verification experiment of the screw driven into CLT
2017 - IRG/WP 17-40816
Japan has abundant forest resources, but we depend on import for 70 percent of the consumed timber. Japan has the vision which promotes the timber self-sufficiency rate 30% to 50% by 2020. Therefore CLT attracts attention as a new timber material. Japan has a climate with high temperature and humidity, and wooden buildings are often treated with chemicals as a measure against biological deteriorat...
N Wada, H Ishiyama, S Yamamoto
Influence of sea water on timber and metal joints
2017 - IRG/WP 17-40818
In the Great East Japan Earthquake that occurred in March 2011, many buildings suffered from seawater immersion caused by the tsunami. Saito's study revealed that corrosion progresses on metal plate that experienced seawater immersion 1). However, the detailed mechanism of corrosion progresses has not yet been clarified. Therefore, in this study, salinity which is one of causes of corrosion w...
T Nishimura, H Ishiyama, F Hirose, N Wada
Elimination of colonies belonging to higher termite group using insecticide bait: A short review
2018 - IRG/WP 18-10908
Controlling termite infestation by using baiting method is gaining popularity around the world. Lower group of termites particularly belonging to the genus Coptotermes have proven to be easy to control by this method due to their nature of feeding. However termites belonging to higher group, such as those under Termitidae were initially thought to be a challenge as they mostly fed on fungal garden...
P Dhang
Above-ground testing methods – review of Rotorua, New Zealand test site results after ten years
2018 - RG/WP 18-20642
A series of seven different types of above ground durability tests were initially conducted over four years to determine which type of tests would give the fastest, most consistent results. Five types of test; ground proximity, two types of decking, flat panels and double layer, were reassessed after ten years. Exposure conditions varied between tests with ground proximity producing close to groun...
D Page, T Singh
Self-Extinguishment Phenomena of Mass Timber in Medium-Scale Compartment Fires
2018 - IRG/WP 18-30729
This paper presents a review of the fire safety risks that mass timber construction may introduce in buildings, with special consideration to medium- and high-rise buildings. These main risks are represented by an effect to the classical fire safety strategy for buildings: (1) Compartmentalisation, to ensure that the fire will not spread farther than the compartment of origin, (2) Preventing verti...
C Gorska, J P Hidalgo
Resistance of modified wood to termite attack assessed in laboratory and field testing: A review of internal research
2018 - IRG/WP 18-40824
Within the past decades, new wood modification technologies have been investigated in order to improve certain wood characteristics and enable the use of timber products for outdoor applications. Some of these non-biocidal technologies have been developed and commercialized recently. Thus, various material properties were studied intensively and shown to be improved. To a great extent, previous re...
L Emmerich, P Gascón-Garrido, H Militz
A Conceptual Review of Young People’s Perceptions about Wood
2018 - IRG/WP 18-40836
This article was adapted from the previous study “Young People’s Perceptions about Wood” prepared by Usta (2017), and extended through the development and evaluation of the initial data in terms of the conceptual framework regarding the descriptions of wood by young people. Because it was highlighted by previous study that the university students as the full members of society have the aware...
I Usta
Thermally modified timber treated with methacrylate
2018 - IRG/WP 18-40849
Thermally modified timber (TMT) from Scots pine sapwood similar to Thermo-D quality was impregnated with methacrylate resin by the hot-and-cold method and subsequently cured at elevated temperatures. The results showed that methacrylate resin could be used to reduce colouring of painted TMT wood during accelerated weathering probably by hindering the migration of extractives. The resin itself did ...
O Karlsson, O Myronycheva, DJones, D Elustondo, D Sandberg
Determining the natural durability on xylarium samples: mini-block test, wood powder and chemical profiling
2019 - IRG/WP 19-10944
Xylaria, or wood collections, can be considered sleeping beauties in terms of wood technological and biological output. In this study we focus on determining the natural durability of xylarium specimens from the Federal Xylarium in the Royal Museum for Central Africa. The Federal Xylarium contains over 80,000 specimens, covering more than 13,000 species, mainly from Central Africa. These specimens...
V Deklerck, L De Ligne, J Van den Bulcke, E Espinoza, H Beeckman, J Van Acker
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
Visual assessment of longitudinal wheel timbers and assessing the feasibility of extending wheel timber service life in the UK railway network
2019 - IRG/WP 19-20651
Timber has been a versatile building material for centuries and during the start of the Railway Age in the nineteenth century it was in considerable demand for use in the railway network, particularly bridge building. Timber is still in service and widely used throughout the UK railway network. The resilience and favourable strength to weight ratio and its relative ease of fabrication make it an...
J R Williams
Hydroxyl accessibility - A brief review of deuterium exchange studies on modified wood
2019 - IRG/WP 19-20656
Wood modification imparts dimensional stability and decay resistance. The mechanism(s) by which this occurs are thought to be related to the bulking of the wood cell wall and subsequent moisture exclusion. Hence, quantification of accessible hydroxyl (OH) groups is of great interest when evaluating and increasing the understanding of the performance of modified wood. The aim of this study was to b...
G Beck, C Hill, G Alfredsen