Predicting chloride testing outcome of different cementitious systems

The American Concrete Institute (ACI) specifies allowable admixed chloride limit (C_limit) values to minimize the corrosion risk of steel reinforcement in concrete. The chloride concentration of concrete for new construction must not exceed this C_limit value. While most ACI documents require the ASTM C1218 (watersoluble) test standard to measure chlorides, some documents allow the ASTM C1152 (acid-soluble) test standard. ACI documents that require ASTM C1218 report the same C_limit value for different cementitious systems. Different cementitious systems, with similar chloride concentrations, could have different ASTM C1218 test outcomes due to differences in chloride binding capacities. This paper develops models to predict ASTM C1218 test outcomes. These models can assist in choosing appropriate concrete mixtures that can meet ACI C_limit values. This paper also reports models to predict the ratio of ASTM C1218 and ASTM C1152 test outcomes to better correlate C_limit values in ACI 222R, which allows both test methods.