2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

Performance-Based Design of RC Beams Exposed to Natural Fire: A Case Study

Mr. Robert Kuehnen, Western University (Presenter)
Dr. Maged Youssef, The University of Western Ontario
Dr. Salah El-Fitiany, Alexandria University, Egypt

In North America, the current practice for structural fire safety involves the implementation of prescriptive methods, requiring compliance with passive fire-resistance barriers and active suppression systems.  Although this approach has been largely successful in delaying the propagation of fire, which allows for the safe evacuation of occupants, it provides limited knowledge about expected structural behavior during fire.  To ensure structural integrity, the North American industry is moving towards performance-based structural fire design, focusing on structural elements that can achieve specific performance objectives during fire exposure.  Buildings can thus be designed with greater flexibility, reduced construction costs, and improved occupancy safety.  Given the intrinsic fire-resistant properties of concrete, performance-based design is particularly powerful in the case of reinforced concrete (RC) structures. 


In this paper, a case study is presented demonstrating a simplified approach to undertake performance-based flexural fire design of RC beams.  The case study highlights the three main steps in the design process: (i) determination of the natural fire severity, (ii) calculation of element internal temperatures, and (iii) sectional flexure analysis.  In each part, the process is performed using simplified analysis methods, which are validated against results obtained using experimental tests or computational finite element simulations.  Using the outlined approach, engineers can design RC beams to withstand natural fire events.