The international regulations in force provide two foundamental aspects:
– the fire reaction, or rather the partecipation degree of combustible material to witch it is subjected;
– fire resistance, or rather the capacity of a costruction, of a part of this or a costruction element to keep it, for a fixed time:
R = resistance: attitude to conserve the meccanic resistance below the fire action.
E = tightness: attitude not to let pass, neither produce, if subjected to the action of fire on one side, flames, vapos or hot gas on the not exposed side.
I = thermal insulation: attitude to reduce the calor trasmission.
REACTION TO FIRE
The european standards UNI EN 13501-1 regulates the fire reaction classification of products and building elements. Even in the presence of a Europen classification, in Italy is still necessary the Ministerial approval, except prodcuts to whom exist an european harmonized standard, or for CE materials. The building materials, except floors, are classified in according to the A1, A2, B, C, D, E, F european standards.
The A1 material classification are incombustible while A2, B, C, D, E materials tend to be combustible in increasing order, the F class concern materials for which the fire reaction is not determined. The european classification expected for the A2, B, C, D classes also the classification of fumes and dipping.
Example: B-s1, d0, where s is for smoke and d is for drops. The classification goes from 0 (absent) to 3 (high).
The 16 Febraury 2007 Ministerial Decree, expected that the building elements are must be certified in accordance with UNI EN13501-2 standard.
The resistance fire classes are the following: 15, 20, 30, 45, 60, 90, 120, 180, 240 e 360, and express the time, in minutes, during wich the fire reaction must be garanteed. Performance requirerments and classes: in general, the performance requirerments are the following:
R: the rispect of this parameter garanted the load-bearing capacity of structures wich pillars and beams, but also of slabs and load-bearing walls that do not have a compartmentalization function.
REI: the rispect of this parameter garanteed the load-bearing capacity, the stability and the insulation of loadbearing structures, that have compartmentalization function, wich slabs and load-bearing walls.
RE: the rispect of this parameter garanteed the load-bearing capacity and the stability of load-bearing structure, that have also compartimentalization function, wich slabs and load-bearing walls.
EI: the rispect of this parameter garanteed the stability and the insulation of not-load-bearing structure, that have compartmentalization function wich not-load-bearing walls, membrane false ceilings, crossings, joints, canalizations, etc..