Case studies of hybrid and galvanic systems on bridge structures

Abstract

Corrosion of steel in bridge structures is a growing issue worldwide. Case studies of galvanic and hybrid systems show the diverse range of challenges and corrosion hazards that are faced during the design of these systems. Data from these case studies show the effectiveness of this approach. Hybrid systems have been utilised in controlling corrosion during refurbishment work on bridges for over a decade. Galvanic systems have been around much longer. By utilising these systems individually or together there is great flexibility in design. This allows intensive concrete restoration from a hybrid system alongside the maintenance of repairs in lower risk areas from galvanic anodes. This paper presents case studies covering hybrid and galvanic systems applied to bridge structures. Included is a prestressed concrete bridge in a tidal environment, we believe to be the first of its kind fitted with a hybrid system. Tidal considerations and flooding are key challenges in corrosion mitigation. Data shows the systems are particularly effective in these transitory environments reacting rapidly to increased risk.