Cathodic Protection for Parking Structures

Cathodic protection systems for chloride-contaminated reinforced concrete structures have been installed and evaluated since the early 1970s. Until recently, most of these systems have been installed on bridge structures. Since cathodic protection has been recognized as the only method which can stop corroding steel in chloride-contaminated concrete, a variety of cathodic protection components have been developed for use on these structures. Although it is mostly recommended for rehabilitation efforts where chlorides are already present, it has also been used where chloride contamination is anticipated in the future. Research and implementation of cathodic protection systems has been extensively carried out by the Federal Highway Administration. Through this work, cathodic protection system guidelines for bridges are being developed. Guidelines for cathodic protection systems on reinforced concrete parking structure are needed. Unlike bridge structures, parking structures have more complex steel reinforcement schedules, more stringent structural limitations, and are built with a larger variety of differing designs. In addition, the average parking structure typically has far more concrete surface area than the average bridge structure. Structural limitations, design variations, and size of the parking structure require thorough corrosion evaluations to determine the cathodic protection system requirements. To provide the most economical and cost-effective long-term repair, more than one cathodic protection system design and/or material can be applicable to a single structure. This paper discusses design considerations and guidelines for selection of cathodic protection systems and components for parking structures.