COMPARATIVE ANALYSIS OF DATA ON THE DURATION OF FIRE EXPOSURE BEFORE REACHING THE CRITICAL TEMPERATURE STEEL OBTAINED FOR SAMPLES STANDARDIZED AND SAMPLE SIZE REDUCTION FROM FIREPROOF MATERIALS "ENDOTERM 400202" AND "ENDOTERM 210104"
The results of the determination of the convergence of experimental data on the duration of fire exposure under the standard temperature regime until the critical temperature of steel obtained for standardized samples (columns) and samples of reduced sizes (plates) with the use of the reactive fireproof material "Endoterm 400202", flowing under the thermal influence in fire conditions, and passive fireproof material (plates) «Endoterm 210104». It has been established that the deviation of the values of the duration of fire exposure to achievement the critical temperature of steel, determined for samples of reduced sizes, from the experimental data obtained on standardized samples, is, on average,–9,5% and 4,7% for reactive and passive fireproof materials, respectively. In this case, for a reactive fireproof material the value of this deviation is in the range from -24,0 % to 17,6 %, and most of it (93 %) has negative values (the duration of fire exposure until the critical temperature of steel, determined for most samples reduced sizes does not exceed the experimental data obtained for standardized samples). For a passive fireproof material, the values of deviation are in the range from -24,7 % to 23,1 %, and most of them (75 %) have positive values (the duration of fire exposure until the critical temperature of steel, determined for most samples of reduced sizes, exceeds the experimental data obtained for standardized samples). The average deviation is 12,1 % and 10,8 %, respectively, for reactive and passive fireproof materials. A regularity is established regarding the dependence of the deviation value of the critical temperature of steel. For a reactive fireproof material, with a increase of the critical temperature from 350 °C to 450 °C (and in some samples – up to 500 °C or more) the deviation decreases. With a further increase of this temperature, the deviation increases (up to temperature of 650 °C), and then decreases. For a passive fireproof material with an increase of the critical temperature from 350 °C to 500 °C (and in some samples – up to 550 °C or more) the deviation increases. With a further increase of this temperature the value of the deviation decreases.