The influence of defects at the steel/concrete interface for chloride-induced pitting corrosion of naturally-deteriorated 20-years-old specimens studied through X-ray Computed Tomography

•Eight 20-years-old corroding reinforced concrete cores are studied through X-ray CT.•OPC-specimens had lower corrosion resistance than blended-cement specimens.•The deepest pits are found at the outer side of the steel and close to interfacial voids.•Interfacial voids should be considered the locations where pits propagate the most. Although reinforcement corrosion is a well-known issue, which are the locations of the steel/concrete interface most sensitive to pitting corrosion is still an unclear issue. In this study, X-ray computed tomography is used to characterize eight 20-years-old reinforced concrete cores naturally deteriorated due to chloride-induced corrosion. The deepest and most frequent corrosion pits were observed at the portion of the reinforcement oriented to the outdoor environment and in proximity to interfacial air voids. Therefore, the presence of interfacial air voids should be considered as a relevant factor when assessing the risk of corrosion of reinforced concrete structures.