Seismic Behavior Of Corroded Reinforced Concrete Beams Node

Reinforced concrete structures duing to fatigue loading, environmental corrosion, material damage caused by the accumulation of aging make the bearing capacity and ductility decreased significantly, which led to a significant reduction in seismic performance. In recent years, the durability of concrete structures seismic performance degradation of change is getting more attention by academia. Therefore, the study of seismic behavior of durability of reinforced concrete structures has the major theoretical significance.Based on the steel corrosion rate of the different nodes in the beam under cyclic loading test, we study the performance of steel corrosion on the seismic of concrete structures. Paper are as follows:1 By the electrochemical accelerated corrosion test block test to determine the electrochemical accelerated corrosion test specimens and test block in the corresponding relationship between steel corrosion rate, in order to ensure the beam joint specimen validity of the electrochemical accelerated corrosion tests to provide a guarantee.2 Carried out 5 different rates of steel corrosion in the low beam joints under cyclic loading test.5 beam joint of steel corrosion rates were 0%, 3.19%,5.77%,9.12%,12.21%, the actual rate of corrosion rate and the expected maximum deviation of rust tolerance in the test range.3 Through the corrosion rate of 5 different nodes in the beam under cyclic loading experiment to study the steel corrosion rate on the beam joint failure modes, hysteretic behavior, rules of steel strain. Tests showed that the destruction of the node beam plastic hinge damage to the main beam, and with the improvement of its corrosion crack propagation rate is more rapid, wider crack width; beam hysteretic shape of the curve with the corrosion rate of increase is not corroded by the time of plump spindle become apparent anti-pinch bow or even anti-S shape, surrounded by the hysteresis loop area decreases, the energy dissipation capacity of components decreased; each specimen load-strain hysteresis curve of the slope with the load phase the increase in the amount of corrosion decreases the stiffness of the specimen with the corrosion rate of increase in the lower, and with the increase in the amount of corrosion, surrounded by load-strain curve tends to decrease the area, hysteresis loop even more unstable.4 Beam node by cyclic loading tests of the steel corrosion rate of the bearing capacity and ductility of beam (including the displacement ductility and hysteretic ductility) of. Tests showed that with the increase in the amount of steel corrosion, reinforced concrete beam joint yield load, ultimate load, displacement ductility, energy dissipation capacity were reduced. According to the test data,put forward reflect the impact of steel corrosion rate of bearing capacity and ductility of beam calculation method and modified formula. Formula to better reflect the structure of long-term use in the different stages of the process of the structure of the bearing capacity and ductility changes.