Fire resistance test requirements for composite floor slabs

Composite floor slabs are more and more widely used in engineering, and based on safety considerations composite floor slabs fire resistance requirements have been the concern of owners and architects.

In general, composite floor fire-resistant recognized in two ways: a. composite floor fire-resistant calculations recognized by the structural designer; b. after the fire test to achieve a certain fire-resistant time. And what are the conditions to meet the test to reach the fire-resistant aging?

load-bearing capacity

In the fire resistance test, composite metal decking manufacturer needs to propose the amount of loading required to carry out the test, for example, Solideck in the fire resistance test loading for 550 Kn/m², when in the case of loading, in the fire resistance test to reach the age of the deflection does not exceed the standard, and the floor slab did not collapse, that is, considered to be the test is qualified, the maker’s composite metal decking can achieve a certain age of fire resistance.

Integrity

A critical characteristic of a composite floor slab losing its integrity during fire resistance testing is the development of cracks in the slab. The disadvantage of cracks for fire resistance is that they may cause “cross fires”, that is, a fire on one floor may ignite the upper floor through cracks, or increase the temperature of the upper floor，which will cause the overall fire hazard of the building and cause harm to people and property safety. Therefore, integrity is a necessary condition for fire resistance testing.

Thermal insulation

Thermal insulation is another requirement for fire resistance testing of composite floor slabs. The requirement for thermal insulation is to control that in the event of a fire, the temperature will not be so high as to trigger the combustion of furniture and other items in the room that would cause a fire on this floor. The fire resistance test requires that the maximum interior temperature does not exceed 180° and the average temperature does not exceed 140°. If the temperature of these two items exceeds the requirements, the test is considered to be unqualified.

When the composite floor slabs in the fire resistance test, load-bearing capacity, Integrity and Thermal insulation all meet the requirements, it is considered that this composite metal decking in a particular working condition (steel deck thickness, composite floor slab thickness, loading quantity) to achieve a certain amount of fire resistance aging.