| Abstract | This paper presents condition assessment guidelines developed for galvanized reinforcing steel in concrete structures that are equivalent to ASTM C876 guidelines for carbon reinforcing steel by using half-cell potential (HCP) technique. The study consists of a comprehensive experimental program, corrosion performance analysis, statistical analysis and modeling, as well as a field survey for validation. A spectrum of corrosive environments were simulated for the galvanized steel bar in concrete samples under combinations of chlorides, concrete grades, relative humidity, and temperature, representing a wide range of field conditions. Corrosion potential and corrosion rate measurements were conducted over a two years of time in order to obtain their correlation from a large amount of corrosion data. A set of guidelines (HCP-Gal) were developed from the methodologies of cumulative probability. They can be used for galvanized steel that are equivalent to the ASTM C876 guidelines for carbon steel but offer 5 categories of corrosion probability. The condition assessment was conducted on a concrete highway bridge for validation. The guidelines HCP-Gal were used to identify two columns that had the overall respective best and worst corrosion conditions, as well as the condition ranking among the surveyed 5 columns. They were validated by both visual examination and chloride analysis. Furthermore, an advanced Model-HCP-Gal was developed that determines the corrosion probability from a continuous function of corrosion potential, based on a probabilistic methodology. |
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