Building structure or element (construction product) ability to carry out forseen functions.
Flammability - what is it?
R Rate defines ability of building supporting structures to withstand the loads during a fire. For example, if the steel supporting constructions has projected fire resistance rate of R30, so these constructions will not loose ability to withstand the loads at least 30 minutes during fire.
E – integrity (tightness), I – insulating properties Together EI - is understood as the minimum time, during which two properties must be met - integrity (tightness) and insulating properties. Thus, the building structure, which has such projected fire resistance criteria, during fire must keep a fire insulating properties (that is not affected construction side during the fire must not heat up to the set temperature) and integrity (tightness) properties (must not disintegrate, must not miss the smoke and fire) during set time. EI criteria is applied to fire protection barriers, partitions, firewalls, fire valves, fire resistant doors, fire sealing systems of communication openings and so on. Thus if fire resistant doors has EI 30 criteria, these doors must meet the above mentioned criteria at least 30 minutes during fire.
Massiveness ratio is used to assess the steel constructions massiveness. Massiveness ratio - open surface area and steel volume ratio. This ratio dimension is mˉ¹̄.
The temperature at which, at a given load level and even distributed temperature, expected steel construction element‘s desintegration, or in other words, temperature at which the steel element looses its ability to withstand the load.
During a fire, fire paint blows, thereby forming an insulating layer. Consequently, the insulating layer protects steel constructions from overheating for some time during a fire.
Fire sealing of communication openings is used to stop the fire, smoke spread and ensure the insulating properties in those areas, where engineering communications passes through fire protection partitions, fire barriers, firewalls and fire protection overlays, i.e., to ensure fire EI criteria of these structures.
This should be evaluated in each case. We need to assess purpose of the building, conditions in which constructions will be exploited and determined anti corrosivity category.
This should be evaluated in each case. We should evaluate fire safety requirements provided in building project, load per roofing constructive, building construction, project author opinion etc.