Fire resistance design of composite slabs in building structures: From research to practice

Many modern fire safety codes for building structures use either a prescriptive approach or a performance-based approach. It is widely recognised that performance-based approaches provide great advantages over prescriptive approaches as they allow designers to use rational fire engineering methods to assess structural fire safety. However, performance assessments of entire structures are not straightforward, so the majority of modern fire codes still adopt either a prescriptive approach or a combination of prescriptive and performance-based approaches. In Hong Kong, the prescriptive approach is still widely regarded as the fundamental method assuring fire resisting construction, and assuring building compartmentation. However, there is growing interest in the practical application of structural fire engineering, and with this technique, it is essential to recognise that the key feature for implementing performance-based structural fire engineering is the assessment of a structure's fire resistance under specific fire exposures. This paper presents an overview of well established analysis methods for the assessment of building structure fire resistance. All the basic principles of these methods are presented and discussed through their application in assessing the performance of composite slabs under fire. Structural engineers are strongly recommended to recognise and acquire the skills of fire resistant design so that they can proactively contribute to fire resisting construction in practice.