Corrosion Behavior of Reinforcing Steel Undergoing Stray Current and Anodic Polarization

Corrosion Behavior of Reinforcing Steel Undergoing Stray Current and Anodic Polarization

Chen, Zhipei (TU Delft Materials and Environment)
Koleva, D.A. (TU Delft Materials and Environment)

2021

Different concrete structures (viaducts, bridges, or tunnels) in the neighborhoods of railways may be subject to the stray current leaking from the rails. In these cases, the reinforcing rebars embedded in concrete act as conductors, “pick up” the stray current, and can corrode. For simulating the stray current-induced corrosion of metals, most researchers just supplied anodic polarization on samples. However, stray current induces both cathodic polarization and anodic polarization. This work experimentally justifies the different effects of stray current and anodic polarization on reinforcing steel embedded in mortar. A comparison between stray current and anodic polarization effects on the corrosion behavior of embedded steel is performed for both fresh (24 hour-cured) and hardened matrix (28 day-cured) in chloride-free (Cl-free) and chloride-containing (Cl-containing) environments. It is found that in all studied conditions, anodic polarization leads to a significantly different electrochemical performance of the steel rebar compared to the stray current. Hence, anodic polarization cannot reflect all the effects of stray current, and therefore, it has limited significance for simulating stray current. It is also clarified that the curing regimes and starting time of the stray current play significant roles in the formation of a corrosion product layer on the steel surface.

Anodic polarization
Corrosion
Mortar
Steel
Stray current

http://resolver.tudelft.nl/uuid:8590cd61-8baf-49de-beb0-7a9671842e4d

https://doi.org/10.3390/ma14020261

1996-1944

Materials, 14 (2), 1-23

Institutional Repository

journal article

© 2021 Zhipei Chen, D.A. Koleva