Experimental and analytical investigation of friction damper in reinforced concrete frames with poor seismic performance

In terms of civil engineering developments, earthquake mitigation methods are a rapidly developing new building rehabilitation concept. According to this concept, some of the earthquake energy acting on the buildings is consumed by additional damping control mechanisms, thus reducing the amount of energy that must be consumed with damage in the building. Rotational friction dampers are one of the passive control mechanisms that attract attention with their large energy dissipation capacity, displacement-independent and frequency-independent operation characteristics. In this thesis, an experimental and analytical study was carried out on the rehabilitation of low-rise reinforced concrete frame buildings with poor seismic performance, which is especially common in the building stock in Turkey, with rotational friction dampers. Experimental and analytical studies were carried out on 1/3 scaled, two-storey and single-span reinforced concrete frames, which have design and construction defects that are frequently seen in buildings in Turkey. The thesis study includes two main research topics. In first part of the study, the friction pads made of Teflon (PTFE), carbonfiber, lead and brass plates, which are intended to be used in two different types of rotational friction dampers, were investigated according to the damper acceptance criteria determined in Fema-356 by conducting cyclic loading experiments at different bolt clamping torques. With carbonfiber, lead and brass friction pads, which are suitable for use in terms of features such as friction behavior, wear, stability and resistance, 3 single-unit Type 1 and Type 2 rotational friction dampers were produced at 100 Nm bolt clamping torque. The characteristics of the produced Type 1 and Type 2 dampers such as slip load and energy consumption were determined by cyclic loading tests. In the second part of the study, static pushover experiments were performed on 7 reinforced concrete frame samples, 3 of which were rehabilitated with Type 1 dampers and 3 of which were rehabilitated with Type 2 dampers, 1 of which was a reference sample of reinforced concrete frame without any dampers. The obtained results were compared in terms of rigidity, ductility and energy consumption. In the analytical part of the study, the analysis of the experimental reinforced concrete frame samples was carried out in the SAP2000 software. At the end of the study, the experimental and analytical results obtained were evaluated and conclusions and suggestions were made.