EVALUATION OF FIRE RESISTANCE OF FIRE PROTECTED STEEL STRUCTURES BY CALCULATION AND EXPERIMENTAL METHOD

Abstract

Based on the developed geometric, physical, computer and finite element model, the fire resistance of fire-resistant steel structures was evaluated by calculation and experimental method. The adequacy of the developed computational-experimental method for assessing the fire resistance of fire-resistant steel structures in assessing the fire resistance of a fire-resistant I-beam steel column was verified. The results of tests for fire resistance of steel columns with fire-retardant coating at standard temperature of the fire without the load applied to them (temperature in the furnace, temperature in certain places on the surface of fire-retardant steel columns, the behavior of the investigated fire-retardant coating). The analysis of tests on fire resistance of fire-resistant steel columns exposed to fire at standard temperature (temperature in the furnace, temperature in places of measurement of temperature on a surface of columns, behavior of a fire-retardant covering) is carried out. A computer model of the «steel column – reactive flame retardant coating» system has been built for numerical simulation of non-stationary heating of such a system. Simulation of non-stationary heating of the system «steel column – fire-retardant coating» in the software package FRIEND with the specified parameters (geometric model, thermal effects, initial and boundary conditions, properties of system materials). The reliability of the results of numerical modeling with real experimental data on the duration of fire exposure at the standard temperature of the fire to reach the critical temperature of steel. Based on the comparison of experimental results and numerical simulations, a conclusion is made about the adequacy of the developed model to the real processes that occur when heating fire-retardant steel columns without applying a load under fire conditions at standard fire temperature. The efficiency of the proposed calculation and experimental method for assessing the fire resistance of fire-resistant steel structures has been confirmed.