Understanding the resistance of concretes to ingress of chloride ions is critical towards developing service life models for concrete infrastructure. Several laboratory tests are in use that provides indicators of chloride transport in concretes. In this paper, the chloride ion transport resistance of alkali silicate powder and liquid activated slag systems is explored, with a focus on linking the microstructural changes as a result of activator parameter changes to the chloride ion transport behavior. The better chloride ion transport resistance of alkali activated slag concretes, measured using commonly employed transport tests, as compared to typical ordinary Portland cement concretes is brought out. Along with the charge passed during the NSSM test over the 24 hours, the ionic transference numbers are used to determine the total chloride concentrations in the specimens. This easy means of determining chloride concentration lends itself for use in service life models. Electrical conductivity is used to extract the pore connectivity factor, which is linearly related to the RCP and NSSM values of conventional concretes. The changes in material microstructure, induced as a result of electromigration is evaluated through the use of electrical circuit models in conjunction with electrical impedance spectroscopic observations.