Chloride-induced reinforcement corrosion in cracked concrete: the influence of time of wetness on corrosion propagation

ABSTRACT

Literature data on the influence of concrete cracks on corrosion propagation of reinforcing steel are contradictory. This might be due to very different exposure and test conditions but also to a lack of time-resolved data in cyclic wetting–drying exposure. Here, the influence of the environmental conditions on the corrosion rates in cracked concrete is studied experimentally. The results show that the corrosion rate in cracked concrete depends on the duration of wetting and drying phases and the relative humidity (RH) during the drying phase. The lower the ambient RH in the drying phase, the faster the cracks dry, which depresses the corrosion rate in the periods between the wetting events. A model is proposed to estimate corrosion rates in cracked concrete cyclic wetting/drying exposure.

KEYWORDS:

• Chloride-induced corrosion
• reinforced concrete
• cracks
• macro-cell current
• time of wetness
• RH

Acknowledgement

The authors want to express their sincere appreciation to the Public Road Administration Norway for the funding of this project. Matthias Wielatt helped constructing the formwork. Heinz Richner and Andi Reusser helped casting the specimen. Elizabeth Cabrera partially helped conducting the experiments. Their help is warmly acknowledged by the authors.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Statens vegvesen.