Yükleniyor…
Yükleniyor…
Reinforcement bar corrosion occurs in reinforced concrete structures as a result of various environmental effects. Corrosion causes the structures to move away from the performance levels targeted during the design phase and reduces the service life of reinforced concrete structures. Within the scope of the thesis study carried out to investigate the effects of reinforcement corrosion on reinforced concrete frames, 5 reinforced concrete frame specimens were constructed. The corrosion process of reinforced concrete frames was carried out using accelerated corrosion method. The actual corrosion ratio were obtained by gravimetric study after chemical and mechanical cleaning of the reinforcement extracting from the concrete after the loading tests. When the studies carried out on corroded specimens are analyzed, it is seen that researchers consider different corrosion ratio (stirrup corrosion ratio, longitudinal reinforcement corrosion ratio, maximum corrosion ratio, average corrosion ratio, etc.). This situation causes contradictory results in the verification of the models obtained by using corroded specimens. In this context, a total of 13 different corrosion ratio were obtained by considering corrosion ratio on reinforcement (combination of stirrups and longitudinal reinforcement) and specimen basis (combination of column and beam elements). The yield strength, ductility ratio, stiffness degradation and energy dissipation capacity values of the specimens were estimated by considering the experimental models developed from the column and frame studies in the literature. From the results of the experimental study, it was determined that the yield strength, stiffness values and energy absorption capacities of reinforced concrete frame specimens decreased with increasing corrosion rate. In the present study, it was revealed that there are contradictions between the ductility ratios obtained by considering energy-based and actual corrosion ratio and the data obtained by considering displacement-based and theoretical corrosion ratio in the literature.
The negative results resulting from the corrosion of reinforced concrete reinforcement are important for the investigation of corrosion in the reinforced concrete reinforcement. Corrosion affects the performance levels of reinforced concrete structures in addition to shortening the service life of the economic sense, and in the following stages of the destruction of structures can lead to destruction. With the resulting corrosion; the reduction of the reinforcement cross-sectional area leads to negative results such as the volume increase caused by the corrosion product and the decrease in the bond strength between the concrete and the reinforcement. With these results, the bearing capacity, bending and torsional strength of reinforced concrete elements are reduced and the targeted building performance is avoided. Studies on estimating the bending behavior of rusted reinforced concrete elements are sufficiently available in the current literature; The behavior of rusted reinforced concrete elements under the effect of simple torsion has not been studied yet. For this purpose, 6 reinforced concrete beams of C25 concrete class were rusted at different rates by using accelerated corrosion method. In order to obtain the actual corrosion rates, the reinforced concrete beams reinforcements were removed by mechanical and chemical cleaning before the beams were removed after the loading tests. In order to find the actual mass losses of all windings and longitudinal reinforcements, the masses of the reinforcements in the precision balance were recorded and compared with the first masses and the actual corrosion rates were also obtained. At the end of the experiment, the effects of the actual corrosion rates on the torsional moment capacity of the reinforced concrete beams, moment-curvature relations, crack width and distribution were investigated. Corroded reinforced concrete beams torsion behavior by examining; It is thought that torsional strength can be a model for estimating the torsional moments of corroded reinforced concrete beams with the help of emprical model which is developed depending on the corrosion rate and thus to evaluate existing structures.