Corrosion characteristics of defective reinforced concrete

In order to further understand the corrosion mechanism of reinforcement and simulate the natural corrosion phenomenon, we use X-ray computed tomography (XCT) to nondestructively trace and analyze the corrosion process of the specimens containing the initial defect in protective layer. We compare three-dimensional corrosion morphology and damage of specimens containing interface, middle and surface defects under two accelerated corrosion experiments: the applied current experiment and the wet-dry cycles (W/D) experiment.The results show that W/D tends to produce spatially randomly distributed large pits, while energization produces uniformly distributed tiny pits. W/D corrosion produces generally larger crack widths at similar actual corrosion degree than those with energized accelerated corrosion, which is closer to the natural corrosion. The effects of different defect locations and accelerated corrosion methods on the accumulation of interfacial corrosion products are not obvious, but the cover cracking is obviously related to the defect location, the closer the defect is to the outside of the specimen, the more likely it leads to the cracking of specimen.