STUDY OF THE TIME OF DEPENDENCE OF EXFOLIATION OF FIRE-PROTECTIVE MINERALOWOLL COVERING OF STEEL BEAM ON THE CROSS SECTION COEFFICIENT AND LOAD FACTOR
Abstract
This article continues the work on the study of heating of the steel beam and the detachment time of the fire-retardant mineral wool cladding of the steel beam. The dependence of the peeling time on the beam section coefficient and the load coefficient is studied.
Recently, fire protection systems for steel beams based on mineral wool cladding have become widespread. Their feature is the use of high-strength adhesive joints, resistant to temperature. But, at the same time, at mineral-wool panels of small durability there is a high probability of peeling of mineral-wool facing on its layers and as a consequence, loss of fire-retardant ability during time of influence of the standard temperature mode of fire established by the corresponding class of fire resistance. Therefore, the established compliance with a particular fire resistance class must be adjusted.
To calculate the coefficients of the regression model, 8 numerical experimental situations were reproduced. The results of numerical experiments for the implementation of calculations should be obtained according to the orthogonal plan.
To study the influence of the most significant structural parameters of steel beams on the detachment of fire-retardant mineral wool cladding, the interdependencies of structural parameters were constructed under the condition of three possible values of fire-retardant mineral wool cladding thickness: 25 mm, 50 mm and 75 mm.
The regularities are established and the mathematical model of change of time of exfoliation of mineral wool fire-retardant facing depending on their section coefficient A/Vm, thickness of mineral wool facing d and level of loading f is constructed, nomograms for definition of time of exfoliation load level at three values f of thickness of mineral wool fire-retardant facing.
