The challenge in defining a reliable critical chloride threshold for reinforced concrete service life modelling

In order to support the RC design life modelling related to chloride-induced corrosion, a solid knowledge and understanding of the critical chloride threshold, Clth, is needed. The working party 3 of TG 8.9, dealing with deterioration mechanism related to corrosion, was rearranged in 2022 to provide a guide to the designers to properly select this parameter. The final aim of the working group is to prepare a state-of-art report with several objectives, among which the provision of a Clth definition and the current status on Clth values for carbon steel bars for use in modelling for design life. This paper gives an overview of the works of the group and outline the contents of the state-of-art report.