Structure fireproofingStudying the effects of fire on steel structures, nuclear plants
Building fires may reach temperatures of 1,000 degrees Celsius, or more than 1,800 degrees Fahrenheit, and the strength of steel structures drops by about 40 percent when exposed to temperatures exceeding 500 degrees Celsius; scientists study precisely what happens to the connections between a floor’s steel beams and the building columns when these connections are exposed to intense heat
Ten years after 9/11, researchers at Purdue University are continuing work that could lead to safer steel structures such as buildings and bridges and also an emerging type of nuclear power plant design.
“I want people to understand that in the last ten years we’ve not been quiet,” said Amit Varma, a Purdue associate professor of civil engineering. “We’ve been working to make structures better and safer.”
The researchers are using a custom heating system and a specialized laboratory for testing large beams and other components and have created models that could be used in designs to improve fire safety.
New findings are detailed in two research papers appearing this month as part of a special 9/11 issue of the American Society of Civil Engineers’ Journal of Structural Engineering. The work has been led by Varma, doctoral student Lisa Choe and graduate student Emily Wellman.
Data will be used to update design codes for steel structures and to test and verify computational building-design models.
A Purdue University release reports that the work is funded by the National Science Foundation, the U.S. Department of Commerce’s National Institute of Standards and Technology, the American Institute of Steel Construction, and the American Iron and Steel Institute.
Building fires may reach temperatures of 1,000 degrees Celsius, or more than 1,800 degrees Fahrenheit, and the strength of steel structures drops by about 40 percent when exposed to temperatures exceeding 500 degrees Celsius.
Steel components in buildings are covered with fireproofing materials to resist the effects of extreme heating. “So the air could be 1,000 degrees in a fire, but the insulated steel might be 500 degrees or less,” Varma said. “However, once the steel gets beyond 600 degrees Celsius, there can be some major problems.”
The Purdue researchers designed a system made up of heating panels to simulate the effects of fire. The heating system is being used to test full-scale steel columns at Purdue’s Robert L. and Terry L. Bowen Laboratory for Large-Scale Civil Engineering Research. The panels have electrical coils, like giant toaster ovens, and are placed close to surfaces being studied. As the system is used to simulate the effects of fire, test structures are subjected to forces with hydraulic equipment to mimic the loads experienced in real structures.
“We wanted to build an experimental method that engineers can use to study the behavior of buildings in fire using a structures laboratory,” he said. “Most of the
