Improved Tafel-Based Potentiostatic Approach for Corrosion Rate Monitoring of Reinforcing Steel

[EN] Potential step voltammetry (PSV) was introduced in earlier works as an advantageous alternative to traditional methods for measuring corrosion rate in reinforced concrete. The present study aims to improve PSV to maximize its applicability in corrosion rate monitoring, that is, beyond the narrowly-defined steel¿concrete systems in which was initially validated. It was therefore identified necessary to address the most suitable PSV pulse amplitudes to accurately obtain the Tafel lines and, therefore, corrosion rate in steel-mortar systems with well-differentiated ohmic drop. PSV findings were compared to reference methods, i.e. Tafel intersection and linear polarization resistance. As a novelty, we propose a procedure to improve the reliability of the PSV-determined Tafel lines, which is based on three protocols (P1, P2 and P3). P1 consists of a specific pulse sequence to accurately characterize the morphology of the polarization curve without disturbing the system. P2 consists of two short pulses for determining the ohmic drop compensation factor. Finally, P3 consists of a simple calculation procedure to accurately adjust the PSV pulse amplitudes (V) to the steel¿concrete system assessed, thus obviating the need for preset values and, therefore, ensuring accurate corrosion rate results. The procedure proposed is intended to improve PSV with a view to its consolidation as a reliable tool for the unsupervised monitoring of real structures. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the pre-doctoral scholarship granted to Jose Enrique Ramon Zamora by the Spanish Ministry of Science and Innovation (Grant Number FPU13/00911). We would also like to acknowledge financial support from the Spanish Ministry of Science and Innovation through the national programs of oriented research, development and innovation to societal challenges (Project Numbers BIA2016-78460-C33-R, PID2020-119744RB-C21 and PID2020-119744RB-C22). To the Universitat Politecnica de Valencia for the financial support in the project "Ayudas a Primeros Proyectos de Investigacion (PAID-0618)"-SP20180245. Ramón, JE.; Martínez, I.; Gandía-Romero, JM.; Soto Camino, J. (2022). Improved Tafel-Based Potentiostatic Approach for Corrosion Rate Monitoring of Reinforcing Steel. Journal of Nondestructive Evaluation. 41:1-25. https://doi.org/10.1007/s10921-022-00903-z Papavinasam, S.: Electrochemical polarization techniques for corrosion mo