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Fireprotection of steel
LOADBEARING STEEL BEAMS AND COLUMNS The fire resistance requirement for a building is defined in terms of fire resistance period and stated in terms of minutes (15, 30, 45, 60, 75, 90, 120, etc. up to 240 minutes).
This information is usually given in local building regulations and it depends on the height, occupants and type of the building. In practice it means that the building frame has to maintain its load bearing capacity during the fire until everybody has left the burning building. It is the responsibility of the design engineer, using design codes such as ENV1993-1-2, to specify the appropriate limiting or failure temperature for a given section.
Different load bearing materials have different fire resistance periods. These materials are usually tested by using a standard fire curve which demonstrates development of a real fire.The temperature in a standard fire rises rather quickly and then increases indefinitely. Fire resistance test results are expressed in terms of time of failure against one or more of three criteria:
• Load bearing capacity (R)
• Integrity (passage of hot gases/fames) (E)
• Insulation (temperature raise on the cold side of the structural element, usually max. 140 °C) (I)
In some building constructions all of these are needed but for the steel frames only load bearing capacity is required e.g. R120.
PAROC FPS 17 has a density of ~170 kg/m3. The right product for the application will be chosen based on the system provider's approval.
3D
PAROC FPS 17 has ETA approval for fire protection for steel structures. The product is easy to handle and install for different kinds of fire applications.
This software is designed to help choosing the right thickness of Fire protection slab PAROC FPS 17. It´s a non-combustible stone wool insulation for use as fire protection for steel structures, chimneys, doors, furnaces and ovens. Stone wool insulation has varying fire protection abilities that are largely dependant on the density of the material as well as the used insulation thickness. Generally speaking, the higher the density, the longer the fire protection time.
Material
PAROC FPS 17 is delivered as a slab in format 600x1200. Depending on the type of beam and the thickness of the insulation, the consumption needs to be calculated for each individual case. For example, for HEA beam that is insulated>
as a box, you need to calculate like this: (h + thickness + thickness x2) + (b x2).
Se projekteringsanvisning för detaljerad monteringsbeskrivning.
A/V
The rate of increase in temperature of a steel cross-section is determined by the ratio of the heated surface area (Am) to the volume (V). This ratio, (Am /V), has units of m-1 and is known as the section factor. Members with low section factors will heat up more slowly. The section factor is thus a measure of the rate at which a section will heat up in a fire and the higher its value, the greater will be the protection thickness required.
