The durability of reinforced concrete structures is one of the most hotly debated topics in modern civil engineering. While concrete itself boasts exceptional durability, the steel reinforcement inside remains vulnerable to chloride penetration, carbonation, and moisture. Corrosion monitoring enables early detection, while cathodic protection addresses the electrochemical cause of reinforcement corrosion itself.
Conventional concrete patching, commonly used on bridges, in parking garages, and in industrial buildings, may not provide a permanent solution and can lead to a recurring cycle of repairs, deterioration, and further repairs.
Platform ACTIVECONTROL Systems takes corrosion management a step further by combining protection, monitoring, precise automation, and digital documentation into a single modular platform. It thus provides building owners, structural engineers, and designers with a 21st-century tool for managing corrosion and supporting the long-term durability of structures.
Why Local Repairs Involving Demolition and Patching May Not Solve the Problem
When chlorides or carbonation destroy the passive layer on the surface of steel reinforcement, corrosion can begin long before visible cracks and concrete spalling appear.
In conventional repair, the damaged concrete is removed, the reinforcement is cleaned, and the concrete cover is restored. This procedure remains necessary in areas where the concrete has already lost its cohesion or integrity. However, localized repair alone may not always resolve corrosion processes in the surrounding chloride-contaminated concrete.
A highly alkaline repair compound can restore the passivation of the reinforcement in the repaired area, while the adjacent reinforcement remains exposed to a more aggressive environment. The resulting “anode effect” at the interface, also known as the “halo effect,” can shift corrosion activity toward the edges of the repaired area. This can lead to a recurring cycle of local repairs, operational restrictions, and rising costs over the structure’s life cycle for the owner.
Cathodic protection (CP) interrupts this cycle by applying a controlled electric current that polarizes the reinforcement and reduces the anodic corrosion reaction to a non-critical level. Unlike a one-time intervention, cathodic protection is a controlled protection system: its effectiveness must be measured, documented, and adjusted during operation.
A standards-based engineering method
Impressed-current cathodic protection (ICCP) is a well-established engineering method that can be used for both existing and new concrete structures.
The ISO 12696:2022 standard specifies requirements for the performance of cathodic protection of steel embedded in cement-based concrete and requires an adequate monitoring system to demonstrate compliance with the specified protection criteria.
Monitoring is therefore not merely an optional add-on to the system. Reliable reference electrodes, current and voltage measurements, controlled interruption of the protective current, and traceable records are essential for demonstrating the effectiveness of the protection. ACTIVECONTROL Systems products are designed specifically around this measurement and control loop.
In Western Europe, North America, and the Middle East, impressed-current cathodic protection is not considered a novelty. It is a standard and strictly regulated engineering method with decades of experience in long-term operation. Systems installed in the 1980s and 1990s continue to actively protect structures to this day, proving that a service life of 50 years or more is easily achievable.
Companies such as the German Catódica GmbHhave built up an extensive portfolio of projects that demonstrates the potential applications of ICCP in various types of structures.
The Electrochemical Principle of Operation of Impressed Current Cathodic Protection (ICCP) in Reinforced Concrete Structures
Where is the economic benefit most significant over the life cycle:
- Parking Structures: Ceiling and floor structures, ramps, columns, and wall bases are repeatedly exposed to de-icing and road salt. ICCP can reduce the need for repeated large-scale concrete removal while allowing for phased rehabilitation.
- Bridges and tunnels: Remote, distributed monitoring supports critical infrastructure in locations where access is difficult and downtime is costly.
- Marine, industrial, and underground structures: Deep foundations, underground walls, and other inaccessible elements can benefit from protective systems that can be installed early on and whose operation can subsequently be monitored remotely.
- New Construction: Installing anodes, reference electrodes, and cabling before concrete is poured makes it possible to establish a planned long-term corrosion control system from the outset, without having to wait for visible signs of degradation to appear.
Costs, Complexity, and Downtime: A Comparison of ICCP with Conventional Repair
For owners and designers, the choice between conventional concrete repair, impressed-current cathodic protection (ICCP), or a combined approach is not merely a matter of comparing initial costs.
The appropriate solution depends, for example, on the extent of delamination, the distribution of chlorides, the condition and electrical continuity of the reinforcement, the accessibility of the structure, the required service life, and also on the operations that must be maintained during the project.
ICCP does not eliminate the need to repair damaged or deteriorated concrete. However, it may allow chloride-contaminated concrete that is still mechanically sound to remain in place, provided that this approach is supported by a system design and subsequent verification of its performance.
1. Scope of Construction Work, Phasing, and Downtime Period
Conventional remediation may require extensive concrete removal in cases where it is necessary to remove chloride-contaminated material around the reinforcing bars.
Removing concrete using high-pressure water jets, cutting, or mechanical demolition can cause noise, generate wastewater, dust, and construction debris, and may require temporary load or traffic restrictions on the structure.
Temporary shoring may also be necessary in cases where a reduction in the cross-sectional area of the reinforcement or the gradual removal of concrete affects the structure’s load-bearing capacity. The actual extent of the impact always depends on the specific structure and the scope of the repair work.
However, even the ICCP project does not mean implementation without preparatory construction work. It requires an inspection of the structure’s condition, localized repairs of defects, verification of the electrical continuity of the reinforcement, installation of anodes, reference electrodes, and cabling, commissioning of the system, and verification of its functionality.
Depending on the chosen anode system, it is possible, for example, to create grooves for titanium strip anodes, apply a conductive surface coating, or drill holes for discrete anodes.
Work can often be divided into individual zones so that part of the facility can remain in operation during construction. However, any reduction in the closure period is always specific to a given project and must be based on the chosen method of execution, the accessibility of the structure, and the phasing plan. It cannot be expressed as a single universal percentage.
Practical Applications of Titanium Strip Anodes on Concrete Surfaces
2. Life-Cycle Costs and Maintenance Requirements
Compared to a limited local repair, ICCP generally requires a more extensive specialized design, measurement and control technology, and professional system commissioning.
At the same time, there are long-term requirements related to the system’s power supply, regular inspections, verification of the monitoring components’ functionality, data analysis, and the possible replacement of selected parts. These costs must be transparently included in the economic assessment. The system is not maintenance-free.
If the structure is extensively contaminated, access is difficult, or operational restrictions are very costly, leaving the mechanically sound concrete in place and limiting repeated large-scale removal may lead to a more cost-effective outcome over the entire life cycle.
The assessment should include future repairs, access to the structure and traffic management, renewal of membrane systems, inspections, energy consumption, monitoring, component replacements, waste generation, lost operating revenue, and extension of the structure’s service life.
Conventional remediation may still be the best solution for isolated, localized contamination. However, in cases of extensive contamination, ICCP may be a more attractive option despite the higher initial investment.
3. Waterproofing and cathodic protection serve different purposes
Waterproofing and cathodic protection are not interchangeable.
A traffic-resistant membrane or other surface protection system limits the penetration of water and chlorides and can simultaneously protect the structure against abrasion, chemical exposure, and leaks.
ICCP acts directly on the reinforcement and controls the electrochemical corrosion process. It does not make concrete or steel “immune” to chlorides, nor does it prevent damage caused by freeze-thaw cycles, cracking, joint leaks, or surface wear.
When active cathodic protection is used, the surface protection design can be optimized in some cases, since completely preventing chloride penetration is no longer the sole mechanism for protecting the reinforcement against corrosion.
However, a membrane, coating, abrasion-resistant layer, or localized waterproofing may still be necessary for the structural integrity of the structure, the protection of the spaces below it, the treatment of joints and drainage, the appearance, or the protection of the concrete itself.
The specific layer configuration must be designed with consideration for exposure conditions, traffic loads, crack propagation, and the maintenance plan for the structure in question.
The technical benefit, therefore, does not lie in the principle of “no removal and no waterproofing,” but in targeted intervention: removing damaged concrete, leaving mechanically sound concrete where technically justified, electrochemically controlling reinforcement corrosion, and designing surface protection in accordance with the remaining requirements for the structure’s durability and serviceability.
ACTIVECONTROL Systems: A Single Modular Platform from Sensors to Protection
Traditional ICCP installations often separated rectifiers, sensors, manual measurements, and reporting into different workflows. ACTIVECONTROL combines these functions.
The system’s architecture allows it to scale from standalone monitoring to a multi-zone protection system serving several sections of a single structure or multiple structures.
- Integrated Multi-Parameter Measurement: The platform can combine measurements of electrical potential and voltage, current, coupon current, impedance, anode current, temperature, humidity, and other project-specific parameters. This provides the designer or administrator with a broader picture than that provided by a single potential measurement and allows them to monitor correlations with changes in the surrounding environment.
- Adaptive multi-channel power management: Individual protection zones can be powered and regulated independently in constant-current or constant-voltage mode. The system can thus respond to differences in the concrete’s electrical resistivity, moisture content, exposure conditions, and the geometry of individual zones, rather than treating the entire structure as a single homogeneous electrical load.
- Precise current interruption and depolarization measurement: Semiconductor switching enables fast and reproducible interruption of individual outputs. This supports precise potential measurement immediately after the protective current is turned off (“Instant-Off”) and subsequent depolarization, while simultaneously eliminating the mechanical wear typical of conventional relays.
- Local autonomy with remote monitoring: The local control unit can continue to provide basic protective functions even in the event of a communication failure. The connected platform also enables remote configuration, data logging, alarms, and report generation. It is therefore not merely a cloud-based dashboard, but a distributed control system capable of local autonomous operation.
- Modular and Scalable Architecture: Sensors, protective current sources, control units, and power or data modules can be added or removed as needed for the design. This modular principle supports phased projects, future system expansion, and easier replacement of individual components.
- Shared data and power infrastructure: Hybrid cabling can transmit both Ethernet-based communication and low-voltage power. This reduces the need for separate cable runs and simplifies future system expansion. The architecture, for which a patent application is pending, includes configurations up to 48 V and 10 A, as well as shielded data pairs suitable for Ethernet or Gigabit communication.
- Easy maintenance and self-diagnostics: Switchable input impedance for sensor inputs, reference electrode function checks, local displays, mobile configuration tools, and app-based access are designed to increase transparency during system commissioning, functional verification, and subsequent maintenance.
- Data Ready for Digital Twins and AI Tools: Time-stamped measurements can be used to create digital representations of the structure, analyze trends, and perform predictive maintenance. Optional machine learning features can identify recurring patterns or recommend adjustments to settings within predefined safety limits.
Protection Without Excessive Polarization
A higher protective current does not automatically mean better protection.
Excessive polarization can increase the risk of undesirable side effects, and special attention is required for structures containing prestressed steel.
ACTIVECONTROL Systems therefore focuses on controlled output, measurable threshold values, and individual settings for each zone. The system is designed to help designers and operators maintain specified protection criteria without relying solely on occasional manual corrections.
Modular hardware components of the ACTIVECONTROL platform installed in live operation
A practical “monitoring first” strategy
Not every structure needs a complete ICCP system from day one.
Permanent reference electrodes and sensors for monitoring corrosion can be installed during construction or renovation and connected to the same digital platform.
This provides the owner with baseline data, the ability to monitor long-term trends, and alerts regarding changes in the structure’s condition even before more extensive visible damage becomes apparent.
Thanks to its modular architecture, monitoring alone can serve as the first step in a broader security strategy.
If subsequent measurements indicate a need for active intervention, protective current source modules and additional protective zones can be added without having to remove or replace the original monitoring infrastructure.
The APORTAL cloud platform for remote monitoring and automatic evaluation of security criteria
Engineering Collaboration Across Germany and the Czech Republic
CATÓDICA combines expertise in corrosion engineering and project implementation from Germany with ACTIVECONTROL Systems electronics, which are designed and manufactured in the Czech Republic by egmenergo (EGMedical, s.r.o.).
This collaboration combines the practical implementation of cathodic protection, embedded electronics, software, and long-term data management—fields that are often separate in conventional projects.
Conclusion: Make corrosion behavior measurable and controllable
The key question is no longer whether corrosion will affect a reinforced concrete structure, but how soon it will be detected and how effectively it can be managed.
Cathodic protection is a well-established electrochemical method. Smart sensors and automation make it easier to verify its effectiveness, adapt the system to current conditions, and document its operation.
ACTIVECONTROL Systems products transform corrosion management into an integrated engineering process: measuring the condition of the structure, managing each protective zone, maintaining a traceable data history, and scaling the system to meet changing requirements.
For owners and engineers who are responsible for a structure throughout its entire life cycle, this represents a practical shift from repeated reactive interventions to proactive prevention.
Reinforcement corrosion does not have to be an inevitable fate for reinforced concrete structures. Thanks to their widespread use in Western countries, technologies such as ACTIVECONTROL Systems are transforming cathodic protection from a highly specialized field into a highly reliable, standardized, and cost-effective engineering tool.
For licensed engineers, designing modern structures and planning their rehabilitation primarily involves thinking in terms of the entire life cycle. Intelligent cathodic protection—whether in the form of an active ICCP system or intelligent monitoring—is one way to ensure a truly long service life for reinforced concrete structures.
