Measuring critical chloride contents in structures and the influence on service life modeling

While knowledge of mechanical properties of a specific structure is considered relevant for structural considerations, there exists currently no generally accepted method to assess the ability of a structure to withstand corrosion. An important parameter in this regard is the critical chloride content (Ccrit ). Due to the lack of a reliable method to determine Ccrit , this value is typically looked up in standards and text books. This paper presents a novel method that allows the determination of Ccrit for individual engineering structures and reduces therefore current uncertainties in condition assessments. This is considered a particular advantage because of 1) the difficulties associated with mimicking real conditions in laboratory specimens, and 2) the lack of knowledge of the relevant parameters for corrosion initiation. First results from a structure are reported and their influence on the assessment of the remaining time to corrosion in existing structures is discussed.