Fire prevention
The main purpose of fire prevention is to prevent fires from starting and then to stop them from spreading and finally to stop reaction by rapid quenching methods.
Fire protection is ideally divided into active and passive fire protection.
Active protection measures aim at reducing the frequency and intensity of fire through early detection and suppression when the fire is still in its initial phase.
Passive protection measures, the heart of Marvon production, aim at:
- Limiting damages to structures
- Avoiding or limiting the harmful effects of the productions of combustion.
This is achieved through compartmentalization, ventilation systems, emergency evacuation plans and other measures.
Therefore, both the structural elements and those used for completion not only perform an essential function but also a second function of no less importance, adhering to the regulations in the field of fire prevention.
The structural elements are: foundations, load-bearing walls, beams, slabs, roofs, etc…
Completion items are on the other hand: cladding materials, walls, windows, etc.
The characteristics of all the elements, for the purposes of the fire prevention provisions, are expressed in terms of performance determined by regulation and standardized technical procedures.
Such performance fundamentally regards two aspects: the reaction to fire of the materials and the fire resistance of the products.
The reaction of materials to fire regards the participation of a material with the fire to which it is exposed. It essentially expresses the ability of a material to feed and propagate a fire, depending on its physical and chemical characteristics.
If a material is fireproof, that is, not likely to burn, it is clear that the degree of participation with the fire will be inexistent. If it is flammable, that is, likely to burn, therefore to allow the fire to ignite and develop, its degree of participation in the fire will be positive.
In view of the difficulty in defining a real fire, from its outbreak to the complete development of the same, the degree of participation of a material in the fire, that is its reaction to fire, is assessed on the basis of empirical evidence that refers to a conventional fire model. In Italy, such tests are performed in accordance with the procedures and classification criteria established in the Ministerial Decree of 26 June 1984.
The decree identifies six classes of reaction to fire, varying from 0, for incombustible materials, to 5 for combustible materials in relation to their greater susceptibility to trigger, propagate and maintain combustion.
Unlike reaction to fire, resistance to fire expresses a characteristic that does not relate to the materials but to a building component, regardless of the materials used.
Such a characteristic is identified in the capacity of the component to preserve, in the event of fire, the functions for which it was designed, created and installed.
Depending on the functions, fire resistance ratings are designated by certain criteria:
Fire stability(R)
The ability for a building element to maintain its mechanical resistance when exposed to fire.
Fire resistance integrity(E)
The ability of a construction element, when exposed to fire on one side, to prevent the passage though it of flames and hot gases and to prevent the occurrence of flames on the unexposed side.
Insulation(I)
The ability of a construction element to restrict the transmission of heat within specified levels.
Fire resistance is normally expressed with the symbols R, RE, REI followed by the time limit during which the elements retain the requirements indicated by the terms.
The time, expressed in minutes, is determined based on the presumed potential of the fire by means of the estimation of the so-called fire load and the definition of the building class.