Research heating of the steel i-beam rods with mineral wool coating under the conditions of standard temperature fire regime

Abstract

In the article, experimental fire tests on establishing maximum fire resistance of the steel columns with fire-retardant mineral wool covering are analyzed. The scientific novelty of this study are the new method developed for manufacturing and shaping samples of the steel columns with fire-retardant mineral wool covering, and the method developed for conducting fire tests on establishing patterns of dependence of the moment when steel columns with the fire-retardant cladding lose their bearing capacity down to the limit. The subject of the study was an influence of design parameters of the fire-retardant cladding on the results of the estimated fire resistance of the steel columns under the influence of the standard fire temperature mode. The main task of the research described in this article was to determine a moment of the peak critical temperature of fire-retardant steel structure depending on the thickness of the mineral wool covering. The test results of samples of steel columns with different thickness of fire-retardant cladding based on mineral wool covering are also described in the article; the tests were carried out in accordance with the developed methodology of experimental studies. The repeatability of the time indicators of the bearing capacity loss by the tested samples of steel columns with fire-retardant cladding depending on the duration of the sample exposure to the action of the fire standard temperature is shown. The obtained research results will allow to create a mathematical model for predicting a dependence of the moment when a steel structure reaches its critical temperature depending on the thickness of the fire-retardant cladding. The constructed mathematical model can be considered as a scientific basis for the creation of new engineering methods of calculation for assessing fire resistance of the steel structures with fire-retardant mineral wool covering. These engineering and calculation methods allow improving the regulatory acts for designing of the fire-resistant steel structures.