Influence of reinforcement properties on the failure of composite slabs in fire

Abstract

This paper examines the influence of the properties of steel reinforcement on the response of composite floor slabs under idealised fire conditions, with emphasis on ultimate failure considerations. An experimental investigation into the effect of elevated temperatures on the mechanical characteristics of steel reinforcement is firstly described. The study includes tests carried out at ambient temperature as well as under steady state and transient elevated temperature conditions. Apart from the evaluation of stress-strain response and degradation of stiffness and strength properties, particular emphasis is given to assessing the influence of elevated temperature on enhancing the ductility of steel reinforcement. The implications of the specific reinforcement properties on the ultimate behaviour of composite floor elements and assemblages in fire are then discussed. For this purpose, novel analytical models are used to assess the ultimate behaviour of members incorporating different types of reinforcement.