ANALYSIS OF HOLLOWCORE CONCRETE FLOOR SLABS UNDER FIRE

The aim of this paper is to provide recommendations to designers, and to propose a simple method for designers to model the structural behaviour of hollowcore concrete floor slabs in fire. The proposed finite-element model incorporates a grillage system using beam elements to capture the thermal expansion of the precast units in both directions, with the topping concrete over several precast units modelled by shell elements. The research reported herein compares the proposed model with various fire test results of hollowcore concrete slabs. The simulation outcomes show good agreement with the experimental results. Several hollowcore concrete slab flooring systems tested previously at the University of Canterbury for seismic purposes were simulated using this modelling scheme. Various supporting schemes have been considered, and the results show that different arrangements of axial and rotational restraint at the supports can significantly influence the fire performance of the concrete slab floors.