Comparative study of LightWeight and Normal Concrete composite slabs behaviour under fire conditions

Abstract

This paper presents the experimental study of lightweight concrete (LWC) and normal concrete (NC) composite slabs with steel decking profile exposed to standard time-temperature curve. LWC composite slabs are very efficient in terms of energy savings and sustainability due to their low values of thermal transmittance. In this study NC is used to compare the fire behaviour of LWC composite slabs. Dimensions of the slab are 160 mm thick, 1120 mm wide and 2030 mm long. In order to perform fire tests in the intermediate-scale samples, a non-standard furnace was designed and assembled. The furnace is composed of a heating chamber, a gas evacuation system and a portal frame. The heating chamber is made of a steel framework and refractory layers. The evacuation system, which has an auxiliary vein with a fan to introduce air, extracts hot gases. The portal frame is composed of steel profiles with a rotating beam equipped with a linear actuator to apply the load on the samples. This beam is opened to allow the slabs to be placed and closed during the test. Finally, experimental results show that the time of fire resistance is close to 30 min for both types of slabs. Free water within the slabs affects the temperature increase of concrete. Thus, the temperature distribution inside the slab follows a non-constant trend, due to the movement and evaporation of the free water. Furthermore, although there is de-bonding between the steel and the slabs, no spalling is detected.