Electrochemical Protection of Reinforced Concrete Structures

Reinforced concrete is ubiquitous in infrastructure but vulnerable to steel corrosion induced by chloride ingress and carbonation. Electrochemical protection offers a proactive approach to arresting or preventing reinforcement corrosion by controlling the electrochemical environment at the steel–concrete interface. Techniques include cathodic protection, in which the steel is polarised to inhibit anodic dissolution, and electrochemical chloride extraction, which uses an external electric field to migrate deleterious chloride ions away from the reinforcement. Impressed current cathodic protection (ICCP) systems employ an external power source to deliver controlled current densities, whereas sacrificial anodes rely on galvanic coupling. Recent innovations focus on dual-functional anode materials such as carbon fibre-reinforced polymers (CFRPs) that combine structural strengthening with anode performance. Advances in understanding interfacial chemistry have refined design criteria for current density, electrode configuration and system durability. Electrochemical protection not only extends service life and reduces maintenance costs, but also contributes to sustainability by mitigating the environmental impact of premature demolition and repair. Global deployment ranges from coastal bridges and parking structures to underground tunnels, underscoring the technique’s adaptability to diverse climates and exposure conditions.

Research from Nature Portfolio

Recent studies have provided mechanistic insight into cathodic protection in porous media akin to concrete pore solution. In-situ and ex-situ analyses reveal that cathodic polarisation induces local alkalinisation and deoxygenation at the steel–electrolyte interface, which promotes the formation of iron-oxide films despite simultaneous reduction reactions. These films afford additional barrier properties, while altered interfacial chemistry modifies both anodic and cathodic kinetics. By integrating concentration and activation polarisation theories, researchers propose a unified model that accounts for spatio-temporal changes under varied polarisation regimes. This improved mechanistic understanding underpins more accurate predictions of current requirements and informs the development of environmentally benign and cost-effective corrosion protection strategies for steel-based infrastructures.

Electrochemical Protection of Reinforced Concrete Structures publication trend

The graph below shows the total number of articles in electrochemical protection of reinforced concrete structures across all publications each year (not limited to Nature Index journals).

Technical terms

Cathodic protection: An electrochemical method that polarises reinforcing steel to a potential at which anodic dissolution is inhibited, preventing corrosion.

Impressed current cathodic protection (ICCP): A system that uses an external power supply to deliver controlled current density to the reinforcement via an inert anode.

Electrochemical chloride extraction (ECE): A technique that applies an electric field to migrate chloride ions away from steel reinforcement towards an external electrolyte.

Polarisation: The shift in electrode potential induced by the flow of current, affecting the rates of anodic and cathodic reactions.

Carbon fibre-reinforced polymer (CFRP): A composite material combining high-strength carbon fibres and polymer resin, used for structural strengthening and as a dual-functional ICCP anode.

References

1. Cathodic protection mechanism of iron and steel in porous media. Communications Materials (2024).
2. Electrical and Mechanical Performance of Carbon Fiber-Reinforced Polymer Used as the Impressed Current Anode Material. Materials (2014).
3. Dual Function Behavior of Carbon Fiber-Reinforced Polymer in Simulated Pore Solution. Materials (2016).
4. Sustainable Assessment of Concrete Repairs through Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA). Infrastructures (2022).
5. Impressed current cathodic protection of chloride-contaminated RC structures with cracking: A numerical study. Journal of Building Engineering (2021).
6. Anodic and Mechanical Behavior of Carbon Fiber Reinforced Polymer as a Dual-Functional Material in Chloride-Contaminated Concrete. Materials (2020).