Concrete offers good protection against high temperatures thanks to its comparably low thermal conductivity and high specific heat. The concrete cover, which is required anyway for other reasons (durability, bond), protects the reinforcement from excessive heating and, consequently, loss of strength and stiffness due to fire. Hence, the fire resistance of concrete structures may be guaranteed in most cases by conceptual decisions and quick verifications using tabulated design data. However, for buildings with a high risk of damage or personal injury, detailed studies on the fire behaviour of a concrete structure may be necessary.
This chapter introduces the thermal and mechanical behaviour of concrete and reinforcement exposed to fire, discusses the issue of explosive fire spalling of concrete, shows structural actions and deformations specifically occurring in the case of fire, and introduces /evaluates design methods provided in SIA 262/ SN EN 1992-1-2.