Experimental Study on Fatigue Performance of Reinforced Concrete Beams in Corrosive Environment with Cyclic Loads

In marine environments, reinforced concrete bridge structures are subjected to cyclic loads and chloride ingress, which results in corrosion of the reinforcing bars, early deterioration, durability loss, and a considerable reduction in the fatigue strength. Owing to the complexity of the problem and the difficulty of testing, there are few studies on the fatigue performance of concrete structures under the combined action of corrosion environment and cyclic load. Therefore, a coupling test device for corrosion and cyclic load is designed and fatigue tests of reinforced concrete beams in air environments and chlorine salt corrosive environments are carried out. The fatigue corrosion process, damage mode, and corrosion features of the test beams as well as chloride ion content in concrete are analyzed. The relationships of deflection, crack, and number of cycles in the different environments are given. Results show that the fatigue life of the beam is greatly reduced under coupled effects of the cyclic load and corrosive environment, the failure form of the beam is corrosion fatigue damage. The deflection and crack keeps growing with the increase in loading cycles. Under the coupling of cyclic load and corrosion environment, the content of chloride ion in concrete is low and there is less variety along the direction of penetration.