DETERMINING THE INFLUENCE OF FAСADE PARAMETERS AND THE WIDTH OF A FIRE-PROOF EAVES ON PREVENTING THE SPREAD OF FIRE THROUGH EXTERNAL VERTICAL STRUCTURES OF BUILDINGS

Abstract

The object of this study is the process of fire propagation through the surface of external wall structures with facade thermal insulation. The paper examines the influence of facade parameters and the width of a fire-proof eaves on preventing the spread of fire by external vertical structures using the example of a residential building. With the use of FDS modeling, the relationships between the parameters of external enclosing structures and the fire-proof eaves on the processes of limiting the spread of fire were investigated. The influence of the minimum parameters of the height of the inter-floor windowsill in the absence of a fireproof eaves on the spread of fire was determined. The dependence of temperature change near the surface of the facade on the width of the fire-proof eaves and the height of the window between floors was established. Based on a series of simulated experiments, it was established that with a height of 1.0 m between floors and the absence of a fire-proof eaves, the critical temperature value is 250 °C. This value corresponds to the destruction temperature of a standard metal-plastic window structure. For the case when the wall height is 1.0 m, and the width of the fire-proof eaves is 0.75 m, the temperature value is 180 °C. That is, the safety condition of 250 °C is met. Based on the research, a dependence was found on the criterion of not exceeding the critical temperature of 250 °C at the level of 1.4 m of the facade of the building floor located above the fire floor. The criterion holds when the width of a fire-proof eaves is at least 0.4 m and the height of the window partition is 1.0 m, as well as when the width of the eaves is 0.5 m, and the height of the window partition is 0.6 m. It was established that the height of a window interfloor partition has a smaller effect than the width of the fire-proof eaves that separates the floors that are located above.