Electrochemical study of inhibitors to improve the anti‐corrosion performance of reinforced bar in the concrete

Abstract

Purpose

The purpose of this paper is to consider the use and application of the “wire‐beam electrode” method to evaluate the effectiveness of corrosion inhibitors used in concrete.

Design/methodology/approach

The corrosion behavior of reinforcing bars in concrete was studied by simulating the 4×4 wire‐beam electrode array. Different inhibitors, such as NaNO₂, NaNO₂ + Na₂CO₃ and NaNO₂ + aniline, were added to reinforced concrete. By measuring the open‐circuit potential of an iron wire, the impact of different inhibitors on the corrosion of rebar in the concretes was studied after immersion in 3 percent NaCl solution.

Findings

Best protection was achieved by adding NaNO₂ and aniline as inhibitors jointly to the concrete, as this combination maintained the open‐circuit potential within the passivation range at all times, so ensuring the integrity of the passive membrane.

Originality/value

By addition of this combination of the inhibitors, the compactibility of the cement concrete structure can be increased, thereby protecting the reinforcing bar against the external corrosive media. It is a technical approach that can deliver long‐term protection of the steel, with the best practical and economic advantage.

Citation

Liubin, S., Daowu, Y., Sanjun, P., Yuchun, L. and Cong, L. (2011), "Electrochemical study of inhibitors to improve the anti‐corrosion performance of reinforced bar in the concrete", Anti-Corrosion Methods and Materials, Vol. 58 No. 1, pp. 22-25. https://doi.org/10.1108/00035591111097666