FIRE TESTS AND CLASSIFICIATION IN SANDWICH PANELS

Many countries have introduced regulatory requirements with an aim to determine the acceptable minimum level for fire protection. These requirements serving as guidelines may not answer all questions of the designers; however, they provide insights. Fire regulations are considered crucial for EU whereas it is not paid enough attention in Turkey. To sum up, regulatory provisions related to fire safety have been drafted based on the following requirements (without limitation):

Fire outbreak and spread of fire and fumes inside the building should be limited (Reaction to Fire). Load bearing capacity of the constructed building should not be decreased for a certain period (Fire Resistance). Spread of fire to surrounding buildings should be limited (Active Safety Systems). Building occupants should be able to evacuate the building or rescued by various means (Fire Detection Systems). The safety of rescue teams should be taken into consideration.

Each of fire safety parameters before and after fire plays a crucial role in taking necessary measures. However, the reaction to fire properties (Fire Performance) of building materials included in the architectural discipline should be evaluated in particular. The contribution of the material to spreading fire or even the fire resistance of the material is defined as fire performance.

Reaction to Fire testing is performed using small-scale models suitable for final use. Exterior wall and roof lines where the fire spreads the most in the building are modeled and subjected to fire testing. All standards and test methods for polyurethane (PUR) sandwich panels are set out in detail in TS EN 14509. In this standard in which fire performance is also included, building materials have been classified under 6 different classes from A1 to F. Other classes of the material are also determined based on the amount of smoke and burning droplets resulting from fire in line with the test reports of the material as follows:

TS EN ISO 11925-2: Small Flame Test (SFI): This fire test method consists of simulating a fire by placing a lighter-sized flame source on a corner or surface of the sample for 15 or 30 seconds. The time until ignition or until the fire exceeds 150 mm is documented. Based on the test results, the fire class is determined as D, E, or potentially F. The fire classes of materials for B, C, and D are not determined only using this test method. In addition to this test, SBI test is also required.