The effect of simultaneous incorporation of four different corrosion inhibiting admixtures and fly ash or ground granulated blast-furnace slag (ggbfs) in concrete mixture on the corrosion of its embedded steel bar was investigated by ac impedance spectroscopy and Tafel plot. The amounts of fly ash and ggbfs replacing portland cement were 20% and 40% by weight, respectively. Concrete specimens were exposed to alternating cycles of immersion in seawater and drying in air after 7 days'' aging to accelerate the corrosion of the embedded steel bars. Electrochemical properties such as concrete resistance, film resistance, Tafel constants and the corrosion current density for each mixture were measured with time. The average corrosion current densities were estimated and compared with the visual inspection results. The incorporation of corrosion inhibiting admixtures generally improved the corrosion resistance of the embedded steel but with some exceptions. In terms of binder effect, 40% ggbfs blended concrete outperformed 20% fly ash blended concrete and ordinary portland concrete for most cases. Under the test conditions in this study, the performance of the corrosion inhibitors showed a dependence on the type of concrete binder: an inhibitor containing nitrite showed a good performance in ordinary portland concrete and while that containing a modified amino alcohol did in the fly ash or ggbfs blended concrete.