Multi-Laboratory Validation Study of Critical Chloride Threshold Test Method

The critical chloride threshold, Ccrit, is a value of a reinforced concrete system and the critical parameter that is used to define the initiation of reinforcement corrosion and is used for service life predictions. The published Ccrit data in the literature shows signif-icant variability due to the lack of a standardized laboratory test that can consistently be used by the industry and researchers. This paper reports data from a multi-laboratory validation study of a novel Ccrit test method, developed based on a framework estab-lished by ACI Committee 222. The study was conducted using the same set of materials in three different laboratories, and its repeat-ability and reproducibility were evaluated. Results indicated that the mean Ccrit values were not statistically significantly different. Exhibiting good repeatability and reproducibility, this test method should be further evaluated to be implemented as a standard labo-ratory Ccrit test method.

Automated summary

This paper presents a new method for testing the critical chloride threshold in reinforced concrete and evaluates its repeatability and reproducibility through a multi-laboratory validation study.