The effect of fire on floor slabs containing enclosed cavities - gently touched or fully explored?

Abstract

Lately, saving weight in concrete structures is getting renewed interest. Different from earlier well-known precast floor types, this time it is about enclosing cavities (or void formers) in concrete structures. The behaviour under fire conditions of floors with enclosed cavities asks for specific attention. At this point there is a proven gap of knowledge. Within this article, the authors explore certain aspects which need to be addressed. Codes on concrete structures contain guidelines to deal with enclosed cavities under normal conditions. The structural effects under fire conditions are, due to the limited research on this topic, not adequately controlled.