Recalculation of Laboratory Tests with the Extended Zone Method


  • Marcus Achenbach
  • Guido Morgenthal



The Advanced Calculation Method given in EN 1992-1-2 is accepted by engineers and building authorities for the determination of the fire resistance of reinforced concrete structures. It has been developed originally for the recalculation of laboratory tests: the time of failure is calculated for a given layout of reinforcement. But in the structural analysis of concrete columns, the area of reinforcement has to be calculated for a desired fire resistance. Design methods and strategies, which are suitable for the design of concrete compression members, require constant material properties and strain limits, which are not given for the Advanced Calculation Method. Therefore Achenbach and Morgenthal have proposed an extension of the Zone Method by Hertz, suitable for the implementation in commercial design software. In this paper, this Extended Zone Method is used to recalculate laboratory tests to determine the accuracy of this method. A statistical analysis of the results is performed to evaluate the statistical key data of the Extended Zone Method.