(Image: Getty)
Wood could hold up the skyscrapers of the future 鈥� now that it鈥檚 stronger and more versatile than ever before
As populations around the world grow and cities burgeon, more and more of us will be adopting a high-rise lifestyle. Perhaps the skyscrapers of the future will be built with our two conventional, energy-guzzling construction materials, cement and steel. Or perhaps they will be made from some lab-derived wonder stuff. Maybe graphene 鈥� that much-feted, carbon-based material whose strength, weight for weight, is 100 or more times that of steel. Or some other exotic nano-material, skilfully crafted atom by atom to optimise its strength.
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Possibly. Or perhaps they鈥檒l be made of wood.
This oldest of construction materials is easy to come by, produces little waste and is renewable if harvested the right way. Where it has fallen down is on strength: it simply doesn鈥檛 have what it takes to support tall buildings.
That is now changing. Wood-derived materials such as , in which softwood is glued together in a specific way to make a light, strong material, are leading to a wave of ever-taller wood-based buildings. block completed in 2012 at Victoria Harbour in Melbourne, Australia, is currently the record-holder for an inhabited building, but will soon be usurped by a 14-storey timber apartment building under construction in Bergen, Norway. will be 49 metres tall when it is finished in late 2015.
Plyscrapers
Last year the international architectural practice Skidmore, Owings & Merrill concluded that a 125-metre tall skyscraper made mainly of wood, using reinforced concrete only for connecting joints, , and have a construction carbon footprint between 25 and 40 per cent that of concrete and steel. In March this year, the US Department of Agriculture together with the , a US-Canadian outfit, competition to demonstrate the viability of 鈥減lyscrapers鈥�.
, a plant biochemist at the University of Cambridge, thinks that more could be done to press wood鈥檚 case. Wood gets much of its strength from the rigid walls that surround each cell, but our knowledge of where that strength comes from at the molecular level is sketchy. 鈥淲e know there is cellulose and a range of other polysaccharides and we know there is lignin, too,鈥� he says. 鈥淏ut it鈥檚 not clear how it鈥檚 all arranged.鈥�
Dupree and his colleagues, who include architects and polymer chemists, by the charitable Leverhulme Trust to start changing that. Their work will involve looking at molecular structure by placing bits of different tree species in a nuclear magnetic resonance machine, a device more commonly used to determine the atomic structure of the likes of components of batteries and solar cells. In the short term, this may allow the development of polymers that could be added to wood to strengthen it. Longer term, deciphering cell wall molecular structure may reveal ways to genetically engineer stronger trees primed to make bigger buildings.
And it鈥檚 not just construction. Wood and its derivatives are also being touted as biofuels and even in the form of paper as a flexible, cheap substrate to replace silicon in electronics. With a bit of 21st century know-how, the material past is being reinvented as the future.
Read more: 鈥�Wonder stuff: Seven new materials to change the world鈥�
This article appeared in print under the headline 鈥淔uture stuff: Wood鈥�
