Bench-scale reaction-to-fire test

Bench-scale reaction-to-fire tests are used to characterize the behavior of materials under more severe thermal exposure conditions that are representative of the growing pre-flashover stage of a compartment fire. These tests essentially determine how a material responds to the temperatures and heat fluxes in a growing fire. In these tests, the fire conditions are simulated with a radiant panel or by inserting the specimen into a small furnace. A pilot may be used to ignite the flammable gases and vapors that are generated as a result of thermal decomposition of the... 

The purpose of bench-scale reaction-to-fire tests is to measure the flammability characteristics of materials, i.e., ease of ignition, flame spread propensity, heat release, and production of smoke and toxic combustion products. Some tests are designed to measure only one of these characteristics. Other tests are more sophisticated and can be used to measure several characteristics at the same time. 

Often it is very difficult to determine the burning behavior of complex objects on the basis of the performance of its individual components in bench-scale reaction-to-fire tests. It is much more practical to measure the heat release rate and related properties for the complete object. This requires a large-scale test. In other cases, it is not possible to capture certain aspects of real fire behavior such as melting, delamination, joint effects, etc., in a bench-scale test. A large-scale test is needed to assess these effects. Two commonly used large-scale reaction-to-fire tests are test methods are discussed as follows. 

In some cases, it is not possible to evaluate a material or product (combination of materials) in a bench-scale test in a manner that is representative of its end-use. For example, it is difficult to use a bench-scale test method to evaluate the effect of joints on the fire performance of a thick sandwich panel that consists of a plastic foam core and metal skins. In this case, a room test is used to assess the reaction to fire of the materials. It is also very difficult to assess the fire performance of complex objects such as upholstered furniture based on the reaction-to-hre characteristics of the object s components. Large-scale reaction-to-hre tests have been developed to evaluate these complex objects. 

Empirical approaches are useful when macroscale HRR measurements are available but little or no information is available regarding the thermophysical properties, kinetic parameters, and heats of reaction that would be necessary to apply a more comprehensive pyrolysis model. Although these modeling approaches are crude in comparison with some of the more refined solid-phase treatments, one advantage is that all required input parameters can be obtained from widely used bench-scale fire tests using well-established data reduction techniques. As greater levels of complexity are added, establishing the required input parameters (or material properties ) for different materials becomes an onerous task. 

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