Reinforced concrete marine bridges are susceptible to corrosion. In conventional repairs, a structurally damaged element is often restored with repair patches. Due to the presence of low-level chlorides in the remaining concrete, incipient anodes can develop and lead to the halo effect which is the main reason of short-lived repair. Ultra-high-performance concrete (UHPC) has been promoted as a durable construction material that can provide a barrier to corrosion due to its low permeability, ideally resulting in a durable repair solution with no need for other corrosion control systems. Other material conditions afforded by UHPC such as concrete resistivity, internal moisture availability and oxygen availability will influence the level of galvanic coupling between steel in the dissimilar UHPC repair material and the existing concrete with vestigial low-level chloride concentrations. In this study, the extent of macrocell development between the dissimilar concrete materials was examined to identify possible benefits and challenges of utilizing UHPC as a repair material for reinforced concrete marine bridges.