Bending analysis of beams affected by fires

Abstract

The fire resistance of reinforced concrete elements can be determined by simple isotherm methods or detailed analyses using a full finite element model. Many design offices do not have sufficient resources to make use of finite element methods and currently must rely on the crude isotherm method.  A new methodology of intermediate complexity is presented that determines rapidly the strength of RC beams affected by fire.  It is considerably more accurate than existing simple performance based methods, yet is implemented in spreadsheet software that is available to all engineers. Any cross-sectional temperature field can be considered and the method accounts for non-linear and temperature dependent material behaviour in both steel and concrete. It can handle concrete sections of arbitrary cross-section.  Results can be numeric or displayed graphically.