This work demonstrates a non-destructive method for using half-cell potential to monitor corrosion of reinforcing steel in reinforced concrete structures. Many commonly used techniques can only predict the presence of corrosion, but the half-cell potential monitors the level of corrosion over time. Four large reinforced concrete slabs were cast to simulate conditions on bridge deck and other large reinforced concrete structures. The slabs were ponded with saline solution to accelerate corrosion. Results show that the half-cell potential can be used to accurately monitor corrosion within large reinforced concrete specimens.