Comparison of steel strength retention models for fire exposed concrete slabs

In structural fire engineering, there is a growing trend towards the use of performance based approaches to evaluate structural behaviour during or after a fire. Consequently, there is a need for an increased level of confidence in properties of construction materials used in these performance based approaches. Both steel and concrete have been experimentally observed to show a dispersal in the value of their respective structural strengths, at room temperature, but more significantly at high temperatures. In this paper the influence of three temperature dependent strength retention models for reinforcement steel on the bending moment capacity of simply supported reinforced concrete slabs exposed to a standardized fire is analysed. The results show that the structural response of reinforced concrete slabs strongly depends on the chosen probabilistic model, thus highlighting the importance of appropriate model selection