Anwendung der Zonenmethode für brandbeanspruchte Stahlbetonstützen

Use of a Simplified Method (Zone Method) for Concrete Columns Exposed to Fire

Eurocode 2 provides a fire resistance check for concrete columns called zone method (simplified calculation method). Some European countries already allow this check. Germany will probably reject this method for concrete columns, as the results from the zone method partly differ from the accepted advanced method. In the authors' opinion, one reason for the differences might be lack of documentation or lack of detailed rules for the zone method. Using the zone method as a nonlinear method - even though it is based on the assumptions of plastic theory - already lead to decisive misinterpretations or misunderstandings. Hence, this article shows briefly the original assumptions and derivation of basic formulas for the zone method according to Hertz.
The use of the zone method for compression members is demonstrated with documented calibrating examples. It is displayed, how to calculate the ultimate load and the load-bearingbehaviour with adequate accuracy.