Method of reinforcement for joints between steel roofs and RC columns in existing buildings

The aim of this study was to validate the reinforcement method used for joints connecting a steel roof and a reinforced concrete (RC) frame in existing buildings based on a series of cyclic loading tests. Three reinforcement methods were investigated in the study: one using a steel jacket and high-strength steel rods (Type-1), another using a steel jacket and post-installed adhesive anchors (Type-2), and a third using a steel plate and post-installed adhesive anchors (Type-3). The results obtained show that the Type-1 method is most effective in increasing force, because shear force can be transferred from the RC frame to the steel roof; thus, a steel jacket can support the entire top of the RC column and integrate the roof joints into the RC frame. The Type-2 and Type-3 methods, however, are not effective in the reinforcement of RC columns because shear force cannot be transferred, and concrete failure occurred easily.