Electrical resistivity and corrosion potential of reinforced concrete: influencing factors and prediction models

Abstract

This paper presents two models: one for predicting the electrical resistivity of concrete and the other for the corrosion potential of reinforcing steel. The prediction models were developed based on experimental results, considering various influencing factors. The experiment approach included the concrete mix proportion, chloride content, concrete cover thickness and time of exposure as the parameters. The results revealed that fly ash concrete showed significantly high electrical resistivity even in the presence of chloride ions. The effects of fly ash became more significant when the water to binder ratio was lower. Chloride ions also decreased the corrosion potential of steel in both the OPC and fly ash concrete. The corrosion potential was found less negative for fly ash concrete due to higher electrical resistivity. The prediction results show good agreement with the experimental results of this study and some other researchers.

Keywords:

• Concrete durability
• reinforcement
• empirical approach
• nondestructive test

Acknowledgments

The authors would like to acknowledge the National Metal and Materials Technology Center (MTEC) and the Center of Excellence in Material Science, Construction and Maintenance Technology Project, Thammasat University for supporting this research. This study was supported by the Chair Professor Grant (P-19-52302), the National Science and Technology Development Agency (NSTDA), Thailand.

Disclosure statement

No potential conflict of interest was reported by the author(s).