Fire Safety Science Digital Archive

A complete concrete model, named the updated Schneider-Concrete-Model which can take into account the transient creep strain and stress history, has been introduced at the 4th IAFSS Symposium in Ottawa 1994 [l]. Though the stress history is taken into account in the updated Schneider-Concrete-Model, the function for the history is simplified in [1]. This paper shows a new approach on how to take into account the stress history in a more accurate way. Sensitivity studies with the new concrete model are also done for different stress history functions by comparing the calculations with fire test results. The results of the study show that the stress level representing the stress history is not an overriding factor. The improved model named Morita-Schneider-Concrete-Model leads to a higher stiffness than the updated Schneider Concrete-Model does, and in the case of a flexural element, the stress history function and the definition of elastic modulus do not indicate much influence on the calculation of structural fire behavior.