Underwater half-cell corrosion potential bench mark measurements of corroding steel in concrete influenced by a variety of material science and environmental engineering variables

摘要

This paper aims at detailed investigation of the chloride induced corrosion potential in submerged reinforced concrete structures in comparison to various other relative humidity conditions. Corrosion cells with different concrete material compositions under four different environmental engineering conditions (air dry, submerged, 95percent RH and alternate wetting-drying) were used to explore the underwater half-cell corrosion potential in a comparative study with reference to other environmental conditions by taking into account the actual field engineering material variables such as concrete cover depth, relative humidity, water-cement ratio and chloride content. From the experiment results it was verified that the half-cell potential values for reinforced concrete specimens submerged underwater are not the true representative of corrosion rate and need to be re-calibrated in the light of experiment results obtained in this research. For this purpose, detailed bench mark testing has been conducted in this paper involving a variety of material and environmental variables. This will provide basis for the future calibration of underwater half-cell potential values of corroding steel in chloride contaminated concrete in a variety of material and environmental variables for which the previous research data is limited.