Behavior of Structural Lightweight Polystyrene Foam Concrete Flat Slabs When Exposed to Fire

Abstract

Background: Reinforced concrete flat slab is used in a wide range of applications. In addition, reduction of the weight of the concrete used increases the advantages of the flat slab. Objective: The main objective of this work is to study the performance of structurally reinforced foam concrete flat slab exposed to fire under eccentric and concentric loads. Methods: The experimental specimens included eleven tested square slabs with typical dimensions of 150 mm thickness and 1750 mm total length. The column cross section was 200 × 200 mm at the center of the slab. The density of the used lightweight polystyrene foam concrete was 1820 kg/m3. The crack patterns, load-deflection curves, steel strains, deflection during the fire, reduction in deflection during cooling by air, and residual deflection after fire and cooling were investigated. Results: The experimental results showed that the cracking load and maximum load of the tested slab with foam concrete were reduced compared to those of normal concrete. Conclusion: From the analysis of the results, it was found that the fire caused a reduction in the ultimate loads in the case of tested foam concrete slabs compared to that of normal-weight concrete slab. And also, the deformation of the tested foam concrete slab during the fire was increased comparing with normal-weight concrete slab. In a theoretical study, the modification factor for calculating the maximum allowable punching force was evaluated according to the ACI-318 and BS-8110 codes, and the reduction factors of compressive strength during the fire was done.