Realistic Modeling of Composite and Reinforced Concrete Floor Slabs under Extreme Loading. II: Verification and Application

Abstract

This paper deals with the large displacement behavior of floor slab systems under extreme loading conditions. The analytical model, presented in the companion paper, is verified through comparisons against existing experimental results on both reinforced concrete and composite slabs, with flat or ribbed profiles. The new model incorporates a novel shell element and accounts for material and geometric nonlinearities under ambient as well as elevated temperatures. The verification studies examine the response of reinforced concrete slabs under unrestrained and restrained edge conditions. An assessment of the behavior of ribbed floor slabs is also undertaken, in addition to simulation of the structural response of a full-scale composite beam-slab floor system under a realistic compartment fire situation. The results show good correlation between the experimental findings and numerical predictions, and demonstrate the reliability and robustness of the proposed analytical model. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of floor slabs under extreme conditions. In particular, the significance of compressive arching and tensile membrane actions, under various boundary conditions, is illustrated. Also, the importance of adopting a realistic representation of the composite slab geometry is highlighted. The proposed analytical model is of particular relevance to developments in performance-based structural fire design, where realistic assessment of the floor slab response is of paramount importance.