Finite element investigation on the post-fire behavior of reinforced composite NSC-HPC slabs
Abstract
Purpose
Even though it is widely used, reinforced concrete (RC) is susceptible to damage from various environmental factors. The hazard of a fire attack is particularly severe because it may cause the whole structure to collapse. Furthermore, repairing and strengthening existing structures with high-performance concrete (HPC) has become essential from both technical and financial points of view. In particular, studying the postfire behavior of HPC with normal strength concrete substrate requires experimental and numerical investigations. Accordingly, this study aims to numerically investigate the post-fire behavior of reinforced composite RC slabs.
Design/methodology/approach
Consequently, in this study, a numerical analysis was carried out to ascertain the flexural behavior of simply supported RC slabs strengthened with HPC and exposed to a particularly high temperature of 600°C for 2 h. This behavior was investigated and analyzed in the presence of a number of parameters, such as HPC types (fiber-reinforced, 0.5% steel, polypropylene fibers [PPF], hybrid fibers), strengthening side (tension or compression), strengthening layer thickness, slab thickness, boundary conditions, reinforcement ratio and yield strength of reinforcement.
Findings
The results showed that traction-separation and full-bond models can achieve accuracy compared with experimental results. Also, the fiber type significantly affects the postfire performance of RC slab strengthened with HPC, where the inclusion of hybrid fiber recorded the highest ultimate load. While adding PPF to HPC showed a rapid decrease in the load-deflection curve after reaching the ultimate load.
Originality/value
The proposed model accurately predicted the thermomechanical behavior of RC slabs strengthened with HPC after being exposed to the fire regarding load-deflection response, crack pattern and failure mode. Moreover, the considered independent parametric variables significantly affect the composite slabs’ behavior.
Keywords
Acknowledgements
Since submission of this article, the following author has updated their affiliation: Nagat M. Zalhaf is at the Department of Civil Engineering, Kafrelsheikh University, Kafrelsheikh, Egypt.
The authors wish to acknowledge the support of technical staff at the material properties and testing laboratory, and geotechnical engineering laboratory, Faculty of Engineering, Kafrelsheikh University, Egypt, in providing the enabling environment for carrying out the research.
Citation
Zalhaf, N., Ghazy, M., Abdelatty, M. and Zakaria, M.H. (2023), "Finite element investigation on the post-fire behavior of reinforced composite NSC-HPC slabs", World Journal of Engineering, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/WJE-08-2023-0320
Publisher
:Emerald Publishing Limited
Copyright © 2023, Emerald Publishing Limited