Establishment of fire protective effectiveness of reed treated with an impregnating solution and coatings

Abstract

An analysis of techniques for determining the fire protective effectiveness of reed was performed; the need to develop reliable methods for studying the process of ignition and flame propagation around the surface of the building structure, required to create new types of fireproof materials, was established. Estimation of ignition time and time of passing the surface area by the flame front revealed the unreliability of the actual values of the flammability index. The method for determining the process of ignition and propagation of flame of fire protected materials was substantiated and, taking into account the permanent conditions of heat and mass exchange in the course of testing, the setup was developed. Determining the flammability index implies the impact on sample of the heat flux of the electric radiation plane and the sample ignition by the burner. In also involves determining the thermal coefficient of the plant, measurement of the maximum temperature of combustion products and the time of its achievement, ignition time and the time of passing the surface sections by the flame front, the length of the burnt part of the sample and calculation of flammability index. The conducted research into the process of ignition and flame propagation along the reed surface using a given technique showed that the raw sample under thermal influence ignited at second 52, the flame propagated across the whole sample over 100 s. The fire protected sample, treated with the impregnating solution based on the mixture of inorganic and organic substances, specifically the mixture of urea and phosphoric acids and natural polymer in the amount of 47.1 g/m 2 , ignited at second 595, flame propagation along the surface occurred only at the first section, the maximum temperature of flue gases was 114 °C, flammability index decreased to 0.42. The results of determining the flammability index showed that under the influence of high temperature flow on the coating in the amount of 46.2 g/м 2 , ignition and flame propagation did not occur, flammability index was 0. Due to intense swelling, there occurred a slight increase in temperature in the vent pipe. A decrease in the flame retardant in the composition by two times at the same consumption resulted in an increase in flammability index for the roofing impregnating solution up to 5.8, and for the swelling coating up to 0.96, respectively. The above results make it possible to establish the ratio of flame retardants and polymers in these compositions and their required quantity