Entwicklung vereinfachter Materialgesetze in Form von temperaturabhängigen Spannungs-Dehnungs-Beziehungen für ultrahochfesten Beton

Developing simplified materials laws in the form of temperature-dependent stress-strain relations for ultra high performance concrete.

The behaviour of concrete as a building material at temperatures in the region of q ≤ 1200 °C is normally investigated using steady state and transient creep tests. The various experimental methods are described in detail in the RILEM recommendations. The results of the experiments are then displayed in the form of temperature-dependent stress-strain diagrams. These diagrams represent the basis for the numerical calculation of the load-bearing and deformation behaviour of components exposed to fire. When such diagrams are used, the boundary conditions must also be considered, such as the heating rate. The example of normal concrete has already been used to show how simplified temperature-dependent stress-strain diagrams may be derived from experimental findings. The present paper applies the same procedure to ultra high performance concrete. As an example, the theoretical considerations and the derivation of building material-specific parameters are applied to one concrete mix composition.