Civil Engineering Research Helps Innovation in Steel Construction
19 April 2006
The world's housing is undergoing a gradual revolution, due to the thinnest of materials: steel sheets less than half a millimetre thick.
Research breakthroughs in cold-formed steel structures, largely spearheaded by the University's Dean of the Faculty of Engineering, Professor Greg Hancock, are transforming the way that dwellings are being built in Australia and the region.
During his time as BlueScope Steel (formerly BHP Steel) Professor of Steel Structures in the School of Civil Engineering, Professor Hancock and his team developed high strength cold-formed steel sections (G550 for houses and G450 for buildings) withbuilt-in stiffeners which prevent them from twisting or buckling. He is currently introducing the technology to China and India; a move which will see new buildings less susceptible to earthquakes and other natural disasters.
A significant proportion of Australian buildings contain steel members, columns, beams and sheeting; sixty per cent of those use cold-formed rather than hot-rolled steel structures. Unlike timber, steel measurements are precise and the material is not vulnerable to white ants when used for housing. Cold-formed steel is light in weight, and can be pre-produced, thereby cutting manufacturing and instalment costs. "In the case of G550, it is also extremely strong," said Professor Hancock.
"Cold-formed steel products are made by bending a flat sheet of steel at room temperature into a shape that will support more load than the flat sheet itself," he explained. This is as opposed to hot-rolled steel which involves handling heavy billets and reheating them at 2300 degrees Fahrenheit. Cold-formed structures can be manipulated to further increase their strength; the G550 product has been shaped to do just that.
Professor Hancock has recently returned from co-chairing a two day workshop in India with academics from Australia and from the Indian Institute of Technology -Madras (ITT-M) in Chennai as well as leading structural engineers from all over India; a partnership cemented by an MOU signed by Pro-Vice-Chancellor Professor Beryl Hesketh and ITT-M last year. One of the issues explored was how Indian people can build traditional homes which are simultaneously structurally sound.
"After an earthquake destroys houses, people want their homes back just the way they were. Like honeybees creating an exact replica of the hive, people systematically rebuild their houses with the same design, using the same materials," said Professor Hancock. Problems arise when traditional homes continue to collapse in an earthquake. Indian buildings can benefit from the G550 high strength steel as it provides a means to reinforce the structures without changing their façades. Most houses in India are made from concrete, bricks and stone.
"A frame made from G550 steel, which is extremely light and strong, and with ductility , will be able to act as a skeleton - unseen from the outside - to prevent the house from falling down," he explained.
Professor Hancock is working with engineers in India and China to assist in the development of a Cold-Formed Steel Structures Standards in both countries. "Eventually, as traditional building resources begin to die out - bricks and stone in India, timber in China - people will necessarily turn to steel more and more," he said.