Study of the fire resistance of partially encased composite steel-concrete columns according to Eurocode 4

In this paper, the behavior of partially encased steel and concrete composite columns without fire protection exposed on four sides to the standard fire and under axial loading was studied using the simplified calculation model of the Eurocode4 (EC4) method. The main objectives of this study are: first to evaluate the temperature of the different components of the column section as well as the variation in the characteristics of the materials constituting them (strengths and Modulus of elasticity); and then analyze the influence of several parameters, such as the section size, the reinforcement rate, the buckling length and the mechanical strengths of the steel and concrete on the ultimate fire resistance. The results show that the dimensions of the section, the reinforcement rate and the buckling length have a significant influence on the fire resistance. On the other hand, the concrete strength, the structural steel grade and the reinforcing steel grade have a moderate influence.