CONSTITUTIVE MODEL OF STEEL FIBRE REINFORCED CONCRETE SUBJECTED TO HIGH TEMPERATURES

Abstract

Research on structural load-bearing systems exposed to elevated temperatures is an active topic in civil engineering. Carrying out a full-size experiment of a specimen exposed to fire is a challenging task considering not only the preparation labour but also the necessary costs. Therefore, such experiments are simulated using various software and computational models in order to predict the structural behaviour as exactly as possible. In this paper such a procedure, focusing on software simulation, is described in detail. The proposed constitutive model is based on the stress-strain curve and allows predicting SFRC material behaviour in bending at ambient and elevated temperature. SFRC material is represented by the initial linear behaviour, an instantaneous drop of stress after the initial crack occurs and its consequent specific ductility, which influences the overall modelled specimen behaviour under subjected loading. The model is calibrated with ATENA FEM software using experimental results.