Heat Transfer in Fire across a Wall in Shallow Floor Structure

Abstract

Shallow floor structures have good inherent fire resistance. With no added protection to the steel section, their fire resistance rating is 1 h. However, when the bottom plate of such sections is exposed directly to fire, heat can be transferred along the steel to adjacent compartments. If the steel is also bare in the adjacent compartments, its temperature will increase. The extent of such a temperature increase is the subject of the present work. Computer modeling based on heat transfer theories has shown that without protection the temperature in bare steel sections in compartments adjacent to the fire may rise significantly to unacceptable levels. With some minimal fire protection for sections near the wall, any temperature rise is much reduced. Therefore, although shallow floor construction does not normally need fire protection, partial shielding at compartment corners is still required. The analysis is based on a previously developed heat transfer model.