Effectiveness of Continuous Corrosion Monitoring for Detecting Critical Zones in Partially Submerged Reinforced Concrete Columns Exposed to Seawater

Sustainability in construction depends not only on reducing the environmental impact of materials, but also on extending the service life of structures through timely maintenance and accurate durability assessment. In reinforced concrete structures exposed to marine environments, chloride-induced corrosion of steel reinforcement is one of the main causes of premature deterioration. Since corrosion often develops in areas that are not directly visible or easily accessible, conventional inspections may detect the problem only after cracking, staining or spalling have appeared, leading to more invasive repairs and greater material consumption.

This study assesses the performance of a continuous corrosion monitoring system developed by the authors for identifying critical deterioration zones in reinforced concrete columns partially submerged in seawater. The system was validated through an experimental programme designed to reproduce the main exposure conditions found in marine structural elements, including submerged, tidal, splash and atmospheric zones along the height of several concrete columns. Corrosion sensors were embedded at representative positions, and the monitoring system was used to continuously track their electrochemical response over time. This approach enabled the corrosion activity associated with each exposure zone to be evaluated and the ability of the system to detect spatial and temporal variations under seawater exposure to be assessed.

The results show that continuous monitoring provides useful information on the evolution of corrosion activity, allowing the most vulnerable areas to be identified before deterioration becomes externally evident. The monitoring records make it possible to distinguish the behaviour of different exposure zones and to detect changes associated with moisture availability, oxygen access and chloride presence. Overall, this work highlights corrosion monitoring as an effective diagnostic tool for reinforced concrete structures exposed to seawater, supporting earlier intervention, more efficient maintenance strategies and improved sustainability through service-life extension.