Modeling of room fire growth - Combustible lining materials

A computational procedure has been developed to correlate the room fire test process and results from the proposed IS0 small scale laboratory tests. The analysis assumes that the full scale room fire test follows the proposed ASTM method, implying that the lining material covers ceiling and walls. The procedure requires that the heat release measurement response time of the test room is evaluated and for a specific material linked to results from the ignitability test. From the same test, a value of koc must be calculated. From a small scale rate of heat release test are evaluated specific characteristics describing the RHR-curve. The derived test room and material characteristics are used as input data to an uncomplicated mathematical expression, essentially describing the full scale test fire process as a concurrent flame spread phenomenon. Undetermined parametors in the model have boon derived using regression analysis and results from seven full scale room tests. In these the tested materials were of such thickness that no burning through occurred. The quantitative accuracy was thought acceptable but further experimental confirmation and sensitivity studies are needed to assess the inherent variability. Qualitatively the procedure predicted the same relative ranking of materials as the room test. For thin surface finish materials on a non-combustible base it was possible to derive a radically simple expression to be used as indication of the risk of flashover. Again, the final usefulness can only be evaluated on the basis of further experimental evidence. In summary, it is thought that a first step has been taken in the efforts to use results from small scale tests to rationally predict full scale fire growth (for one specified scenario) and rank materials. (Less)