Justification of the Efficiency of Application of Plaster for Fire Protection of Concrete Structures

The problem of using concrete for building structures is to ensure their stability and durability during operation within wide limits. Therefore, the object of research was the change in the properties of concrete during a fire and its protection when applying a heat-insulating layer of plaster, which is able to inhibit the temperature when the flame affects the coating. It has been proven that in the process of thermal action on fire-resistant plaster, the process of thermal insulation of concrete consists in the application of materials with low thermal conductivity as part of the plaster on the surface of the material. Similarly, under the influence of the burner flame, a temperature was created on the surface of the sample under the influence of the burner flame with a temperature of more than 800°С for 1800 s, the temperature on the surface of the concrete under the plaster coating did not exceed 120°С, which indicates the formation of a curtain for temperature. In this regard, experimental studies were conducted and it was established that the presence of aluminosilicate microspheres in the plaster leads to the formation of a thermally protective layer on the surface of concrete resistant to mechanical vibrations. According to experimental data, the coefficient of thermal conductivity and thermal conductivity of the plaster was calculated, which is 6.22·10 –7 m 2 /s and 0.142 W/(m∙K), respectively, due to the addition of aluminosilicate microspheres. Thus, there are reasons to assert the possibility of targeted regulation of concrete fire protection processes by using fire-resistant plaster capable of forming a protective layer on the surface of the material, which slows down the rate of heat transfer.