Interaction of combined chloride and sulfate ingression in concrete

Jonathon Backus, Daniel McPolin, Adrian Long, Niall Holmes

    Research output: Contribution to conferencePaperpeer-review


    Chloride is the most severe form of deterioration experienced by concrete and one of the principal sources of chlorides is sea water. However, the presence of sulfates in seawater will influence the movement of chloride ions and vice versa. This interaction is not well understood and current codes of practice provide no guidelines for such dual exposure.
    An investigation to monitor combined effect of the ingress of chlorides and sulfates during a realistic 12 month wetting and drying exposure regime to simulate conditions in which multiple mode transport mechanisms are active was conducted on a variety of binders (PC, PFA and GGBS). Penetration was evaluated using water and acid soluble chloride profiles and sulfate profiles.
    It was found that the nature of the exposure provided multiple modes of transport within the concrete, thus creating a complex pattern of distribution of ions. The presence of sulfates decreased the penetration of chlorides in the PC system at all ages relative to a chloride only control. The matrices containing PFA and GGBS also showed an initial decrease in chloride penetration. However, after six months the presence of sulfates then increased chloride penetration.
    Original languageEnglish
    Publication statusPublished - 02 Sep 2013
    Event33rd Cement and Concrete Science Conference - Portsmouth, United Kingdom
    Duration: 02 Sep 201303 Sep 2013


    Conference33rd Cement and Concrete Science Conference
    Country/TerritoryUnited Kingdom


    Dive into the research topics of 'Interaction of combined chloride and sulfate ingression in concrete'. Together they form a unique fingerprint.

    Cite this