Fire Behaviour of Concrete Columns with Restrained Thermal Elongation

This paper presents the results of an experimental and numerical study to clarify the influence of the surrounding building structure in the fire behaviour of reinforced concrete columns with restrained thermal elongation. The parameters studied were: the longitudinal reinforcement ratio, the slenderness of the column and the stiffness of the surrounding structure to the column in fire. The experimental study was complemented by a numerical study carried out using the finite element program SAFIR. Simplified calculation methods proposed in EN1992-1-2 were also used to evaluate the fire resistance of the tested columns. From the application of the 500°C isotherm method, proposed in EN1992-1-2, it can be noticed that this method led to smaller values of the fire resistance than those obtained in the experimental tests. The tabulated data method A, proposed in EN1992-1-2, proved to be very conservative.