One of the techniques frequently used to measure corrosion in concrete in both laboratory and field evaluations is the galvanostatic pulse technique. This technique provides an alternative evaluation, which has substantial advantages with respect to the most commonly used techniques due to it is linear polarization resistance and control over the applied current, thus minimizing noise problems in the measurement of small polarization potentials. These advantages impart the galvanostatic pulse technique with robustness and reliability in calculating the resistance polarization and other variables. In this work, galvanostatic pulse measurements were applied to concrete of steel slag and alkali-activated fly ash subjected to accelerated carbonation processes by exposing the specimens in a carbonation chamber with 3% carbon dioxide at 65% relative humidity for different times, with full carbonation of concrete to determine the resistance between the reinforcement and a handheld electrode system at the concrete surface due to the entry of carbon dioxide.