Токсичность продуктов термолиза и дымообразующая способность огнезащитных вспучивающихся покрытий для стальных конструкций

Abstract

PURPOSE. The work considers intumescent fire-proof coatings for steel building structures of various component compositions, as well as the fire-proof action mechanism of intumescent systems. Taking into account the results of previous researches and our own experience in the development of fire-proof materials for steel structures, chemically balanced formulations of intumescent coatings have been formed. Based on the study of smoke-generating ability and thermolysis products toxicity of intumescent fire-proof coatings, the possibility of their participation in changing the general toxicological situation when exposed to high temperatures (fire), as well as in the formation of smoke is noted. The main objective of the work is to study the dynamics of thermolysis toxic products release during thermal decomposition of intumescent coatings, their smoke-generating ability, as well as to establish the possibility of reducing density of the released thermolysis products and the smoke generation coefficient when using combinations of intumescent coatings. METHODS. As part of the work an express assessment of the fire-proof effectiveness of various intumescent coatings has been carried out using an experimental radiant heating installation, as well as dynamics of thermolysis products release under thermal influence on steel samples with fire protection. In addition, to study the smoke-generating ability of intumescent fire-proof systems, a method of experimental determining the smoke generation coefficient of solids and materials has been used. FINDINGS. According to the express assessment results of fire-proof efficiency the time to reach the critical temperature of steel samples with the studied intumescent coatings is at least 30 minutes. It has been found that when using an original type of fire protection(a combination of intumescent coatings), it is possible to reduce the density of the released gaseous thermolysis products, as well as the value of smoke generation coefficient. RESEARCH APPLICATION FIELD. The results of the study can be used to predict the dynamics of hazardous factors development during a fire in a building or a structure, taking into account the contribution of the developed intumescent fire-proof coatings to the general toxicological situation. CONCLUSIONS. As part of the work an original type of fire protection for steel structures, including combinations of intumescent fire-proof coatings, has been proposed. A synergistic effect has been discovered as a result of intumescent systems combination use in comparison with the results obtained for the corresponding individual compositions that are part of these combined coatings layer by layer. The effect of filtration in reducing thermolysis toxic products yield and smoke generation of fire protection, which is based on the filtering effect of the outer intumescent layer of the combined system, has been established.