A Theoretical and Practical Review of Half Cell Potential Measurements for Assessing Reinforcement Corrosion

Early identification of degradation of infrastructure materials can provide significant economic benefits to the management and maintenance of a structure. For reinforced concrete structures, there is a significant delay between corrosion initiation and visible evidence of deterioration. The recommended maintenance approach can vary for structures with only localised versus widespread deterioration. Half-cell potential measurements are commonly used as a non-destructive technique to assess the likelihood of reinforcement corrosion within a concrete structure. The results of this technique are dependent on a range of factors – including construction and environmental factors – and skilled interpretation is required. One common standard to interpret half-cell potential measurements is ASTM C876, however there is other published experimental research that offer alternative criteria.

In this paper, the theoretical basis of the technique, along with a practical method for taking measurements in the field, is described. Limitations and sources of error are identified. A review of the published literature is undertaken to identify theoretical and experimental data that can be used as criteria when assessing half-cell potential measurements. Finally, the authors present data from additional investigative works for a pre-stressed reinforced concrete structure, and contrast the practical results with the outcomes of the
literature review.