Fatigue Performance Study On Corrosion Steel Bars

The load types of reinforced concrete structure contain not only dead-weight but also vehicle, wind and wave.Reinforced concrete structure under cyclic loading will be destroyed easily, which is called fatigue failure.Studies show that the static performance of structure is influenced small by the corrosion of steel bar, but the fatigue and seismic performance of structure is influenced much more. It is of great both theoretical and practical significance for the research on fatigue performance of corroded reinforced concrete members.Usually the fatigue damage of steel bar leads to the whole damage of the reinforced concrete’s structural members.Reinforcement specimens and corroded reinforcement specimens under constant amplitude axial tensile fatigue loading were tested in this paper. The law of fatigue life degeneration of corroded steel bars was studied.The fatigue performance of the reinforced concrete beam was simulated and calculated. The main work of the thesis were as follows:(l)The reinforcement corrosion work of eight groups of reinforced concrete slab was completed.Indoor electrochemical corrosion rapid method was used.It was verified that the test results have the same action with the actual situation on the corrosion process of steel bars.(2)Seventeen corroded reinforcement specimens were tested under constant amplitude axial tensile fatigue loading.The lodaing and strain performance of six corroded reinforcement specimens after fatigue loading was tested. The law of fatigue life degeneration of steel bars on corrosion,stress ratio and stress magnitude was studied.Regression equa-tion of the fatigue curve and surface were established for corroded steel bars.(3)The finite element models of reinforced concrete beam was establishhed through ANSYS, which the corrosion damage and fatigue damage were considered.The fatigue performance of reinforced concrete beam of different corrosion degrees was further discussed from the analysis.The results of the finite element analysis was compared with that of model experiments.It supported a new method for the anti-fatigue design of structural member.