The structural elements of steel when subjected to the action of a fire suffer degeneration of their physical and chemical characteristics as a consequence of the high thermal effect, decreasing their resistance and rigidity, and causing alterations in the conditions of the initial state of the structure’s tensions and deformations. The stability guarantee of a structural element of steel under the action of a fire is provided by handling time, temperature and resistance. The sizing criteria are established as a function of the temperature curves versus time, which allows the possibility to calculate the effect of thermal action on the structural elements. The objective of this work is to compare the simplified sizing methods for the calculation of the traction of bars under the effect of high thermal gradients as proposed by ABNT NBR 14323: 1999 and the one presented in the most recent version of this guideline, published in 2013.
The structural elements of steel when subjected to the action of a fire suffer degeneration of their physical and chemical characteristics as a consequence of the high thermal effect, decreasing their resistance and rigidity, and causing alterations in the conditions of the initial state of the structure’s tensions and deformations. The stability guarantee of a structural element of steel under the action of a fire is provided by handling time, temperature and resistance. The sizing criteria are established as a function of the temperature curves versus time, which allows the possibility to calculate the effect of thermal action on the structural elements. The objective of this work is to compare the simplified sizing methods for the calculation of the traction of bars under the effect of high thermal gradients as proposed by ABNT NBR 14323: 1999 and the one presented in the most recent version of this guideline, published in 2013.