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Earthquakes often escalate into disasters due to structures that have not undergone proper engineering evaluations, leading not only to loss of life but also to significant economic, social, and psychological impacts on society. The high number of casualties and property damage resulting from recent major earthquakes in our country, which lies within an active seismic zone, has raised numerous questions regarding the current state of existing structures. Demolishing and rebuilding all structures identified as seismically inadequate is not an economically viable solution. The Textile Reinforced Mortar (TRM) method has gained popularity in the seismic retrofitting of masonry structures. For the accurate assessment of the overall performance criteria of a TRM-based strengthening detail, understanding the bond stress-slip displacement material model at the interface between TRM strips and the masonry surface is crucial. This thesis aims to experimentally investigate the bond -slip material model at the interface between TRM strips and various masonry wall (aerated concrete, hollow clay bricks, and solid clay bricks) and to develop a generalized material model. The experimental study considers variables such as the type of mortar used for bonding the TRM strips to the surface, the width of the TRM strips attached to the masonry surfaces, and the bond length as experimental parameters. Additionally, the use of fan-type carbon fiber reinforced polymer (CFRP) anchors to delay the debonding of TRM strips from the surface is also examined. Based on the results obtained from a comprehensive experimental study, a generalized bond -slip material model for the interface is developed.
Due to the reinforcement corrosion that occurs in reinforced concrete elements, the targeted performance levels of the structures are negatively affected. The main negative effects of corrosion on reinforced concrete elements are the decrease in the area of the reinforcement, the volumetric expansion of the corrosion products and the cracking of the concrete, the decrease in the adherence force between the concrete and the reinforcement. In this context, the researches conducted to evaluate the structural performance of rusted reinforced concrete columns are still important. Within the scope of this thesis study, 5 reinforced concrete columns were tested in order to examine the effect of high levels of reinforcement corrosion on the structural behavior of reinforced concrete columns. One reinforced concrete column was not exposed to corrosion as a reference sample, and accelerated corrosion processes were applied to other specimens at different levels in the corrosion pool. After the rusting process, the width of primary cracks caused by corrosion on the specimens was measured with the help of a microscope and crack maps were created. With the obtained crack width values, empirical models predicting the corrosion rate from primary crack widths in the literature were verified. Reinforced concrete column specimens were tested under constant axial load by applying incremental reversible repetitive lateral load. After the loading tests, the samples were broken, the longitudinal reinforcements and winding fittings were removed and mechanically cleaned of corrosion residues. Final weights of the rebars were recorded with precision scales and the actual corrosion rates of the samples were calculated. In the light of all experimental data obtained, energy-based empirical models have been proposed to determine the seismic performance levels of reinforced concrete columns exposed to corrosion.