Electrochemical Study of Clean and Pre-Corroded Reinforcements Embedded in Mortar Samples with Variable Amounts of Chloride Ions

María de Las Nieves González; María Isabel Prieto; Alfonso Cobo; Fernando Israel Olmedo

doi:10.3390/ma14226883

Electrochemical Study of Clean and Pre-Corroded Reinforcements Embedded in Mortar Samples with Variable Amounts of Chloride Ions

Materials (Basel). 2021 Nov 15;14(22):6883. doi: 10.3390/ma14226883.

Authors

María de Las Nieves González¹, María Isabel Prieto¹, Alfonso Cobo¹, Fernando Israel Olmedo²

Affiliations

¹ Escuela Técnica Superior de Edificación, Universidad Politécnica de Madrid, Avda. Ramiro de Maeztu, 7, 28040 Madrid, Spain.
² Valladares Ingeniería S.L, C/Julián Camarillo, 42, 28037 Madrid, Spain.

Abstract

The present study investigates the possibility of re-surfacing previously corroded reinforcements and the suitability of the two electrochemical techniques that are widely used to determine the state of corrosion of steel (the corrosion potential E_corr and the corrosion rate i_corr). In order to test this, 32 pre-corroded B500SD reinforcing steel bars have been used for one year, where half of the bars have been cleaned to eliminate corrosion products. The other half have been maintained with the generated corrosion products. Subsequently, the bars have been embedded in cement mortar samples with variable amounts of chloride ion, and E_corr and i_corr have been measured for 250 days. The results showed that it is not possible to rework the reinforcement without removing corrosion products and that it is not possible to predict the passive or active state of steel by measuring E_corr only.

Keywords: corrosion; electrochemical techniques; reinforcement; repassivation.