Half cell corrosion potential is a non-destructive testing method majorly performed to evaluate the probability of steel corrosion in reinforced concrete.
Corrosion of steel reinforcement inside concrete can pose serious safety concerns, as it directly deteriorates the strength, weakens the concrete structure, reducing its service life.
When steel corrodes, the corrosion products often occupy more volume than the steel, hence the steel bars naturally expands. This expansion creates internal tensile stresses in concrete that leads to cracking, delamination, and eventual strength loss.
Half cell corrosion potential provides an effective and reliable way to assess the probability of corrosion activity of the steel reinforcement without damaging the concrete structure.
The key parameter that is measured in this test is the electrical potential difference between the reference electrode, commonly a copper/copper sulfate electrode, and the steel reinforcement.
The measured value is then compared with the chart provided by standards like ASTM C876 to determine the probability of corrosion activity.
Another reason half cell corrosion potential testing is important is due to its applications in long-term monitoring.
Since corrosion is a time-dependent process, half cell corrosion tests performed at defined time points allow engineers to track the progression of corrosion potential across months or years.
Many agencies perform Half cell corrosion potential testing in routine infrastructure inspection programs for bridges, tunnels, and marine structures.
Results of hall cell corrosion potential tests can also be directly compared with others for a comprehensive durability assessment.
When used with other tools, it is possible to identify not only areas of active corrosion but also the underlying causes such as chloride contamination, carbonation, or moisture.
Ultimately, the importance of half-cell corrosion potential testing lies in its ability to provide fast, cost-effective, and reliable information about the electrochemical condition of embedded steel.
