Composite Columns Made of Partially Encased Steel Sections Subjected to Fire

The behaviour of composite steel-concrete columns in comparison to bare steel columns subjected to fire is in general much better. The stiffness of the surrounding structure plays an important role in this behaviour. Therefore, a set of fire resistance tests on composite steel-concrete columns with restrained thermal elongation were carried out at the University of Coimbra, in Portugal, and the Federal Institute for Materials Research and Testing, in Berlin, Germany. Especially the influence of the restraining stiffness of the surrounding structure on the fire resistance of the columns was analyzed. The conclusions drawn in this study intended to show how the fire resistance of composite steel-concrete columns is influenced by their interaction with the building structure in a fire event.