With this translation of the original post written in spanish «¿Es adecuado el ensayo del SBI?», I gonna present you a new section on the Fire safety blog called «English corner». In this section you will find a posts selection made by me in English. So, I hope you enjoy it !!!.
This post has its origin in the erroneous comments and statements that for many years I have listened about the suitability of the SBI test (EN 13823) as a test to evaluate the reaction to fire. It should take into account that this test represents an advance with respect to the old Spanish legislation, due to SBI test allows us to know new parameters that were previously not considered.
At present, Euroclasses are required by our legislation to fulfill the requirements associated with the reaction to fire. The most representative test and one that gives us more information is called SBI (Single Burning Item, EN 13823). This test consists of simulating a burning object in the corner of a room in order to evaluate the fire behavior of the room’s cladding product. The SBI test is based on the so-called large-scale reference test ISO 9705 «Room corner test». Between the two tests, the differences are very remarkable and affect, among other aspects, the dimensions of specimens, dimensions of the test room, heat output from the burner, test procedure, etc.
This reference test was used to define the boundaries of the Euroclass based on the possible occurrence of flashover. The correlation between the two tests was carried out through the evaluation of 30 construction products analyzing the FIGRA (Fire Growth Rate). FIGRA is the rate of heat release of a product or material. The correlation showed very good results because of the 30 evaluated products, for 26 of them the result was satisfactory. However, there were 4 products that the correlation through FIGRA was not desired. These 4 groups of products were EPS sandwich panels, polycarbonate panels, PVC profiles and electric cables. To this product group was called the «exotic products».
In this respect, it should be noted that the correlation was not as desired due to the ISO 9705 test is intended to know the contribution to fire of a surface product. Obviously, exotic products are not designed to use as surface product . For this reason, this reference test is not suitable for this type of products.
However, it should be noted that 90% of the construction products considered in this correlation exercise got a good estimation of their behaviour through the SBI test. Therefore, the validity of this test to evaluate the products of construction in case of fire should be recognized, since it also allows to test the products according to their end use application including for example both horizontal and / or vertical joints, substrates as well as different fixing and assembly techniques. This is a great step with respect to old classification standard (UNE 23727), which did not provide the necessary versatility in the evaluation of the behaviour in case of fire.