Stray Current Corrosion Of Reinforced Concrete Bearing Capacity Relationship Of Fatigue

With the growing population of cities, traffic pressure increasing and light rail and metro gradually as the main means to alleviate traffic pressure. However, after years of use of light and the subway use fixed number of years. The study found that the use of the reinforced concrete structures in the normal use of underground projects affected complicatedly by stray current, corrosion and fatigue. This article, as a part of initial study project of national key development program for fundamental research (973 Program 2009CB623203-3)" Stray current - chlorine salt - the fatigue of the reinforced concrete under the synergy Corrosion damage and failure mechanism", make a research on the law and mechanism of reinforced concrete structures under corrosion and fatigue condition.Based on the experimental results, it gives the law of damage of reinforced concrete structures in fatigue corrosion and analyzes the mechanism. Briefly the main work and achievements follows.(1) Electrochemical tests on components and specimen of concrete were both carried out. Anodic polarization curve and corrosion potential explain the mechanism of corroded steel bar and the effect of fatigue in corrosions(2) Experimental investigation of beam specimens is carried out subjected to cyclic loading under the conditions of stray current, saltsolutions and its couple effect. It revealed the law of the damage of the stiffness of concrete structures and showed different damages in all conditions.(3) Micro-analysis of fatigue corrosion showed initiation and development of steel crack and explained the reasons of the damage of structures.Through electrochemical corrosion test of three specimen and static, corrosion fatigue test and micro test of five reinforced concrete beams, results show that: (1) multi-element coupled electrochemical corrosion caused the most significant effect. fatigue factors can promote corrosive effect it explains the decrease of the mechanical properties on the concrete structures (2) the mechanical properties of concrete beams changes significantly in different corrosion factors, its deflection and stiffness have the same trend in damage (3) micro-crack of steel bar analyzes that all kinds of corrosive environment in fatigue influence the mechanical properties of steel, and further explained the reasons for reduced mechanical properties of structures.