Corrosion development of post-tensioned (PT) tendons has been attributed to void spaces in the PT duct due to bleed water accumulation or improper grouting procedures. New grout material for PT systems allow for minimal bleed water separation to mitigate corrosion formation. However there is interest in gauging the extent to which corrosion may develop for repaired PT systems in which void spaces were regrouted with dissimilar grouting materials. This study aims to determine the extent to which corrosion macrocell of strand in dissimilar grout materials can form.