FIRE RESISTANCE ASSESSMENT METHOD OF BUILDINGS FROM FIRE-PROOF BUILDING STRUCTURES
Abstract
An assessment of the fire resistance of the building made of building structures protected from fire by fire-resistant coatings was carried out. This technique is based on the use of a mathematical model and a calculation-experimental method to determine the fire resistance of reinforced concrete structures. A computer model was also created to analyze the thermal and stress-strain state of a building made of fire-resistant constructions (using the example of a three-story parking lot for cars).
The model takes into account the properties of fire-resistant coatings, thermophysical and mechanical characteristics of materials used in the structure, as well as nonlinear laws of deformation of materials at high temperatures and under the influence of force loads. The model allows you to determine the fire resistance class of building structures with the use of fire-resistant coatings of various types. An analysis of fire variants was carried out to study the fire resistance (stability) of the building depending on the place of origin and fire load on the reinforced concrete structures of the car parking building.
Evaluation of the fire resistance of the fire-resistant building structure was carried out using the developed models. An assessment of the fire resistance of the building made of fire-resistant constructions was carried out. Measures to increase the fire resistance limits of structures, consisting in the use of fire-resistant coatings with scientifically based parameters, are proposed. The thickness of the passive fire-resistant coating, thermal conductivity coefficient, specific heat capacity, which must be set when evaluating the fire resistance of a fire-resistant reinforced concrete column and increasing the limits of fire resistance to 180 min, are substantiated. In numerical calculations of non-stationary heating of a fire-resistant reinforced concrete column of a parking lot (coating thickness 11 mm) under conditions of exposure to a standard fire for 180 min. it was established that the temperature on the reinforcing rods reached 213 °C, which is 4 times less than the heating of an unprotected column.
