AFFORDABLE modifications to steel-framed components in homes, industrial and office buildings can reduce the speed at which fire spreads in those buildings by 25 per cent, Queensland University of Technology structural and fire engineering researchers have found. Mahen Mahendran, from QUT's School of Urban Development, has received funding from the Australian Research Council Discovery grants scheme for a three-year study to develop new steel wall and floor systems with increased fire-rating and associated simple design rules. Mahendran said his group of QUT engineers were testing a variety of plasterboard, insulations and steel frame combinations with a giant $300,000 fire-simulating furnace with a view to finding ways to make ordinary building products work better.

"Our project is to understand how essential building components such as walls and floors work and how they fail under fire conditions. If we know that, then we can develop ways to give them a greater fire rating under load," Mahendran said. "Steel softens and loses its strength and stiffness in intense heat. Steel columns and beams may stretch, crush and buckle under the weight of floors which collapse onto the floors below unless they are properly designed to withstand intense fire conditions. So if we can protect the steel components with innovative combinations of plasterboard and insulation systems it will eliminate premature collapses while giving fire crews more time to evacuate people.

"We are testing individual load-bearing walls and floors to find the best combination of steel members, insulation and linings that will 'buy' that extra time to evacuate the occupants of buildings. Our initial results show we can increase the time before damage to steel walls and floors occurs by 25 per cent with a few modifications. As the steel wall and floor components were protected from buckling and collapse in a fire it was easy to repair fire damage," adds Mahendran.