Study On The Damage Of Corroded RC Beams Based On The Static And Dynamic Characteristics

Steel-bar corrosion is known as one of the important factors affecting concrete durability. As shown in relative research, the deterioration of structural performance of corroded reinforcing steel bar is mainly caused by section loss of corroded reinforcing steel bar, degeneration of bonding property of reinforcing steel bar and concrete and concrete corrosion breakage resulting from rust bilge force of reinforcing steel bar; the paper analyses the residual bearing capacity and service life to provide scientific reference for maintenance, reinforcement and reconstruction after performing damage diagnosis and safety verification on the corroded structure.The paper firstly obtains six segments of reinforced concrete beams corroded at different segments by manually controlling the generation region of steel-bar corrosion according to quick steel-bar corrosion test principle of reinforcing steel bar; the test shows that the corroded segment can be well controlled at the expected position..The damage detection based on vibration test is simple, intact and quick; the paper obtains the vibration signals before and after corrosion of reinforced concrete beam through DH5936 (16CH)_DHDAS dynamic signal test and analysis system in structure vibration test method, and effectively processes and analyses the vibration signals through wavelet analysis processing technology so as to obtain base frequencies of branch beam under different states; the frequency index is applied according to the outline condition of corroded beam for identifying damage existence and damage degree.The paper further verifies and corrects the damage of the corroded beam segment based on static test date on the basis of corroded beam segment damage identified by dynamic test data.Static test is performed on the corroded reinforced concrete beam in three-point concentrated loading mode, recording the load, the flexibility, crack distribution, damage state and concrete stress on spanning section. The test result shows that: under the three-point concentrated loading mode , if the corroded segments of the test beam are situated at the same position, the corrosion rate of the longitudinal rib is larger, and the bearing capacity and the rigidity are reduced more; if the corrosion regions are completely situated between the concentrated loading acting points, the reduction of bearing capacity and the rigidity of the corroded reinforced concrete beam is most obvious; if the corrosion regions are not completely situated between the concentrated loading acting points or beyond the concentrated loading acting points, the reduction of bearing capacity and the rigidity of the corroded reinforced concrete beam is small or even to non-obvious.