Effect of macrocell currents on rebar corrosion in reinforced concrete structures exposed to a marine environment

Autonomous corrosion monitoring systems in reinforced concrete structures tend to use sensors that are electrically isolated from rebars. This strategy ignores the macrocell currents take place between active and passive areas of reinforcement. The effect these has been studied on rebar exposed a marine environment. results showed existence generates greater anodic polarisation rebars’ areas, which favours chloride migration towards steel surface. As result, onset takes sooner, concentration chlorides is higher, rate increases. When state, mass loss negligible due currents. However, after onset, influence worse quality is, smaller cover is. differences almost two orders magnitude C30 one order C50. total determined only by measuring microcell currents, obtained values underestimate 90%. Conversely, when analysis includes good fit theoretical real obtained. • Macrocell increase diffusion process. reduce favour kinetics. Estimations considering gravimetric tests. Corrosion must consider both processes.