Comparison of Two Methods for the Assessment of Chloride Ion Penetration in Concrete: A Field Study

The currently accepted method for assessing the resistance of concrete to penetration of chloride ions is ASTM C1202, commonly known as the “Rapid Chloride Permeability (RCP) Test.” The test is time-consuming, laborious, has rather high variability, and, is to a degree, user sensitive, making it problematic for inclusion in a performance-based specification. A potential alternative to the RCP test is the “Surface Resistivity (SR) Test”, a method which is dramatically easier, faster, and has less variability than the RCP test. The research reported herein was directed toward determining a correlation between RCP and SR test measurements for Tennessee bridge deck concrete, based on cylinders collected from concrete bridge decks being constructed across the state, and evaluating the appropriateness of the SR test as an alternative to the RCP test for inclusion in a performance-based specification. Results of the testing showed a clear correlation between the two methods and identified potential limits for possible inclusion in a performance-based specification.