Electrochemical studies of steel rebar corrosion in clay: Application to a raw earth concrete

Abstract

Reinforcement feasibility of a new ecological earth concrete was examined. Steel rebar corrosion, when in contact with three different types of clayey soil, was investigated using electrochemical methods, potentiodynamic voltammetry and impedance spectroscopy (EIS).Results have shown that the voltammetry method overestimates the corrosion rate while EIS supplies the most reliable results. Corrosion rate decreased and a steady state was reached after four months of contact. The type of clay does not have a significant influence on the corrosion rate of the steel rebar, and the average value of 3 was considered acceptable for the lifetime of the structure.

Improving the Anticorrosion and Self-Healing Properties of the Epoxy Coating Using the Mn–Zn2SiO4/PDA Composite

“…Figure 5 presents the EIS plots obtained from the experimental results. In Figure 5a 1 −e 1 , the Nyquist plots are shown for the Blank coating and four different Zn 2 SiO 4 -based coatings, the semicircular arcs reflect the restricted charge transfer reaction, 56,57 and the diameter of the semicircle is positively correlated with the impedance of the electrochemical interface. 58,59 A larger diameter indicates a higher impedance, suggesting a better inhibition of current flow at the interface and improved corrosion resistance.…”

Degradation Mechanisms and Residual Mechanical Properties of Reinforcing Steel Bars Exposed to Natural and Artificial Corrosion – Review & Analysis

“…Half-cell reactions are commonly used to identify reactions that occur at the anode and cathode. The anodic reaction leading to metal dissolution or loss, however the cathodic reaction outcomes the dissolved oxygen decreases and the creation of hydroxyl ions (Eid et al 2020). Possible anodic reactions for steel embedded in concrete are represented by equations Eq.1-4 below, which depend on pH level of the interstitial electrolyte, the occurrence of aggressive anions, as well as the availability of a suitable electrochemical potential at the rebar surface of aggressive anions, and the availability of a proper electrochemical potential at the rebar surface: 3𝐹𝑒 + 4𝐻 2 𝑂 → 𝐹𝑒 3 𝑂 4 + 8𝐻 + + 8𝑒 −…”

Electrochemical corrosion behaviour of four low-carbon steels in saline soil

“…Physical properties refer to the protective lm that inhibits corrosion, while electrochemical properties refer to the redox properties of these iron oxides, which can accelerate corrosion. 30,[37][38][39][40] It has been conrmed that iron oxides in corrosion products participate in cathodic reactions. Moreover, their ability to promote corrosion in the early stage of the reaction is stronger than their ability to act as a protective barrier and inhibit corrosion.…”