Incorporates the October 2025 and June 2026 Errata This test method covers the determination of the electrical resistivity of water-saturated concrete to provide a rapid indication of its resistance to the penetration of chloride ions. This test method is applicable to types of concrete where correlations have been established between this test procedure and long-term chloride diffusion procedures such as those described in ASTM C1556. Examples of such correlations are discussed in the reference shown in Hamilton et al. (2007). This standard was formerly designated as provisional standard TP 95.