Simplified fire design for composite hollow-section columns

Abstract

In the context of Eurocode 4 Design of Composite Steel and Concrete Structures, Part 1-2: Structural fire design, this paper proposes a new simplified design method to determine the fire resistance of columns with concrete-filled steel hollow sections. This method was introduced into the French national annex of the Eurocode in October 2007 in place of the informative Annex H. After mentioning several theoretical shortcomings of Annex H and its lack of accuracy leading to unsafe design of columns with usual slenderness, an advanced finite-element model already developed by the current authors is briefly presented. A comparison with fire tests carried out in France, Germany and Canada illustrates the good accuracy of the model. The new design method is then explained progressively.