Correlating the development of chloride profiles and microstructural changes in marine concrete up to ten years

After ten years of marine exposure, chloride and calcium profiles and petrographic data were obtained from the tidal and submerged zones of six concrete panels differing in binder composition. Moisture and portlandite profiles were also determined on the submerged concrete. The data enables us to improve our understanding of the impact of sea water exposure and can also be used for service life modeling. The depth of the maximum chloride content and the depth of the microstructurally changed zone were comparable. Both depths progressed over time and reached a depth of as much as 10 mm after ten years of exposure. When using these and other field data for testing of chloride ingress prediction models, we recommend excluding datapoints from the microstructurally changed zone, i.e., the outermost datapoints including the maximum chloride content, unless reactive transport models are used. [Display omitted] •A peaking behavior was observed in both tidal and submerged marine exposure.•Leaching explains the chloride peaking behavior in submerged exposure.•The chloride peak shifts towards higher concentrations and depths over time.•Gradual development of microstructural zonation in marine exposed concrete.•The chloride peak almost coincides with the depth of the so-called opaline zone.