ENGINEERED WOOD
Taking engineered wood to the top PHILIP HOPKINS
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T’ S appropriate that The
University of Queensland’s (UQ) wood research centre, the Centre for Future Timber Structures (CFTS), is located in the Advanced Engineering Building. The main lecture theatre, made from timber, displays engineered wood in its beauty and functionality as a learning space. That’s what the CFTS, which includes the ARC Future Timber Hub, is all about – research into engineered wood, with a particular emphasis on the development of tall timber buildings in Australia and the Pacific, said Kelly Rischmiller, manager of the CFTS and Hub, which is funded by the Australian Research Council. The Hub emphasises collaboration between its partners – UQ, Queensland’s Department of Agriculture and Fisheries (DAF), Arup, Hyne Timber, Lendlease and the Queensland Fire and Emergency Services. Other backers are Griffith University, New Zealand’s forest research centre Scion NZ, the University of British Columbia and the University of Canterbury. 18
The latter institutions point to the universal spirit of timber research, which is also reflected in many of its researchers at UQ. ‘Australasian Timber’ spoke to three of these – Dr Luis Yerman from Uruguay, and Dr Felix Wiesner and Dr Lisa Ottenhaus, both from Germany. Dr Yerman and Dr Wiesner are part of the National Centre for Timber Durability and Design Life, a collaborative research program between the University of the Sunshine Coast, UQ, and DAF with financial support from Forest and Wood Products Australia. Dr Yerman, a chemical engineer with a background in materials science and waste management who studied in Barcelona, was always interested in bioprocesses, but eventually gravitated towards wood science. “The director of the centre used to say, ‘I can speak several languages’ - biology, chemistry, engineering. I’m expected to be the connection between them!” he quipped.
With emphasis on extending the life span of a timber product, Dr Yerman is studying how the different variables, such as exposure to water – this could include ocean water - can affect timber structures. “Timber connections are in many cases metal. Corrosion will affect the mechanical performance of the connections. We also have fungi and its impact on timber. There is a specifically very Australian aspect – termites. It’s in the (research) queue to start later this year, working with Dr Hassan from the University of the Sunshine Coast,” he said. An immediate project centres on enhancing the effectiveness and long-term preservation of eucalyptus nitens – very important for Tasmania. Dr Yerman’s recent projects include the effects of decay on the flexural behaviour of solid and composite wood products. Dr Wiesner, a lecturer in timber engineering, has a focus on the durability of timber, but within that context, his area of expertise is timber’s traditional bugbear: fire. His background is in structural fire engineering and the fire safety of timber structures, specifically engineered timber structures. AUSTRALASIAN TIMBER May 2021
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The interior of the main lecture theatre at the University of Queensland’s Advanced Engineering Building.
“The drive to build more sustainable buildings means more demand for timber. It can only be sustainable if a building lasts for a long time,” he said. “If a building decays after 10 years, or 20 years if a fire destroys it, that is a problem.” Dr Wiesner’s job is to look at fire performance and fire retardants – “protection measures we can use to help the timber in a fire, and also the interaction regarding durability and fire-retardant treatment”, he said. For example, a fire retardant could reduce durability, such as salts that can reduce the strength and moisture cycle of timber, or durability treatments that could reduce the fire performance of timber through chemical action, acting as an oxidiser, during and after fire. “The silver bullet …. is both to improve the fire performance and the durability,” he said. “To treat timber, you utilise chemical treatment. You have to get the treatment into the timber, and it then has to stay there for the lifetime of the timber.” Dr Wiesner said in a building must be designed so that a fire was constrained in a compartment.
“It’s hard to stop ignition; at some point someone will have a faulty charger. It could light something next to it, and once that grows to a certain size, you get ‘flashover’. Everything in a room that can burn will burn,” he said. “People who build whole timber buildings need to ensure that the fire will go out, especially in higher buildings where the fire service may not be able to intervene. The ideal system is where once you remove all things that can burn – desks, chairs - the timber self-extinguishes.” To achieve that depended on a few conditions – the timber species, the thickness of the timber, the adhesive used. “Large timber buildings are made from multiple board glued together, so there is a lot of research going on in that area,” he said. The fire issue was also relevant for exterior timber such as utility poles and fence posts. It was less a safety issue, more a cost issue for utility companies or private farmers. “You don’t want a small wildfire to take out electricity to a community by taking Continued on page 19 www.timberbiz.com.au
