Marine Exposure of Concrete Under Selected South African Conditions

Results from a research program are presented where concrete specimens were initially characterized at 28 days before being exposed to four marine environments in South Africa. The concrete was tested using a newly developed chloride conductivity test which determined the chloride resistance of concrete using an accelerated technique. Chloride contents were measured after 24 months of exposure and the diffusion coefficients were related to the initial characterization values. Results indicated that the severity of exposure has a major influence on the relative rate of chloride ingress into the concrete. The chloride conductivity test was found to be a useful indicator of chloride resistance but the results are specific to the type of concrete being tested.