Influence of mortar coating on the thermal analysis of steel profiles in a fire situation

This article aims to perform the thermal analysis of different welded profiles of the VS and CS series with and without thermal protection subjected to fire action according to the nominal fire curve ISO 834. The fire protection studied was the contour type of constant thickness and the coating material considered was Blaze Shield II mortar. The temperature evolution in the profiles was evaluated using the analytical models prescribed by ABNT NBR 14323:2013 and three-dimensional numerical models using the ABAQUS® software. In general, it was observed that the results obtained by the analytical methods were in agreement with the numerical ones and that the use of mortar as fire protection evaluated in this study proved to be an efficient solution for fire protection. It was also possible to demonstrate that the increase in coating thickness, the reduction in thermal conductivity, and the increase in the specific heat of the constituent material provide a slower evolution of the temperature of the steel structural elements.