Método adaptado da análise térmica de estruturas metálicas, aplicado às estruturas de concreto em situação de incêndio

Abstract

In Brazil, the dimensioning of reinforced concrete structures in fire situation is realized in a way simplified tabular. The use of tables in structural designs with different characteristics can generate oversized elements. When the concrete structures are subjected to high temperatures during a fire, its mechanical properties are reduced and lose functionality, and can result in catastrophic situations. It is interesting that the designer can predict the maximum temperature that a structural element is capable of supporting. So, would it be possible to change the dimensions of the elements to the point of reducing the possibilities of structural collapses. Thus the present work aims to address a new method for thermal analysis, seeking other means and paths to find the temperatures in the structural elements of concrete beams. For this we used the simplified method of steel found in NBR 14323:2013, taking into account also the international standards as the EUROCODE. It was observed that, in smaller beams temperatures found by the proposed method are relatively close to the temperatures found in the corresponding abacuses. However, for larger dimensions of the concrete element, the calculated temperatures are lower than temperatures found in European standard, because the heat disperses more robust element and requires a greater amount of heat to warm them up. With that, the improvement of the methods can bring more discussion, and lastly accuracy in thermal analysis processes in the structures.