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Yayın Seismic behavior of an ordinary RC structure exposed to corrosion(Işık Üniversitesi, 2019-01-18) Türkmen, Gizem Ceren; Karadoğan, Hüseyin Faruk; Işık Üniversitesi, Fen Bilimleri Enstitüsü, İnşaat Mühendisliği Yüksek Lisans ProgramıWithin the scope of this thesis, seismic behavior of a 15 years old, approximately ½ scale, one storey, one bay frame which has concrete made of sea sand, mild reinforcing steel, and which was exposed to outdoor conditions for 15 years that resulted in a certain amount of corrosion of reinforcement, subjected to constant axial load and displacement reversals was examined analytically and experimentally. This frame represents the building stock with insu?cient seismic details in Turkey which is built without conforming the existing design codes. Analytical part of the study consists of two approaches; distributed plasticity approach and concentrated plasticity approach. Parameters such as unit deformation and strength of materials were obtained by the axial tension and compression tests for the steel and concrete, respectively. A reference frame having same dimensions and characteristics with the corroded frame except for compressive strength of concrete, was tested 9 years ago with the same experimental procedure also takes a part of this study for comparisons. Experimental results of corroded frame were compared with analytical results which are obtained by nonlinear static time history analysis and pushover analysis. Besides, a retro?tting technique that is RC jacketing is assumed to be applied on the columns of the frame and in?uence of this technique on the seismic behavior of the frame was examined for several assumptions with static pushover analysis and the obtaining the capacity curves for each assumption, comparisons were done. Moreover, a parametric study which involves the increase in the amount of corrosion of the specimen tested, was performed to have the insight about the effect of diameter loss of reinforcement due to corrosion on the lateral load carrying capacity and deformation capacity of the structure. The experiment was ended at %3 drift ratio and bending and shear cracks were observed at the ends of columns. Structure elements underwent excessive loading which is beyond their load carrying capacity and had plastic deformation at the column ends which refers to strong beam weak column analogy. Furthermore, implementation of RC jacketing as a retro?tting technique analytically, led the plastic deformation to occur at the beam ends instead of column top end which complies with the proposal of TEC known as strong column-weak beam situation. According to the experimental and analytical studies, seismic behavior of the frame which is presented by capacity curve is modeled better with concentrated plasticity approach. Secondly, load carrying capacity, energy dissipation, cumulative energy dissipation of recently tested frame is higher than the reference frame which has lower compressive strength of concrete. Also, when comparing capacity curves,the frame has quite similar behavior when the concrete is 32 days old. Furthermore increasing corrosion rates of column reinforcements leads lower lateral load carrying capacity and ductility under lateral loading. As it is expected, it was observed that retro?tting of the columns by RC thin jacketing like 4-6 cm thickness is an e?ective and useful method to increase sectional and hence the displacement ductility and the lateral strength of the frame. Self-leveling and self-compact special concrete can be used for those thin jackets.
