Lateral rigidity improvement of deficient reinforced concrete structures with the use of user friendly systems

The existing building stock in Turkey consist of reinforced concrete (RC) framed structures. Those structures completed before 2000's, do not have enough earthquake resistance and subjected to massive failure or heavy damage. The life looses after earthquakes showed that, existing structures must be strengthened for future sismic activities. In the current knowledge and literature there are numereous strengthening methods. The seismic performance improvement methods must be effective, economical and also must have minimum time duration of construction. In this study, an inovative method is proposed to strengthen reinforced concrete framed structures with low lateral rigidity. The method is proposed to be applied externally to the structure. A strong steel frame is supposed to be fixed to the external facade of the RC frame. The fixing will be done between RC columns and steel beam or columns. The external steel frame will contribute to the lateral rigidity of the system as well as lateral load carrying capacity. The steel frames will be intended to be placed at the corners. The rigidity and strength contribution of the steel system is analysed in the study. For this aim a 6 storey, RC structure is modelled and strengthening alternative are applied to the model structure. Linear and nonlinear analysis are carried out. The lateral rigidty and lateral load carrying capacity increment levels are determined and also internal force levels are compared with capacities. In the study, the apperance of the structure after the strengthening application is evaluated with render images.