The guidelines presented here are limited to SACP on existing atmospherically exposed concrete structures. This standard applies to both conventionally reinforced concrete and prestressed reinforced concrete.
1.3.3 SACP systems require monitoring provisions to determine the performance and to comply with this standard. SACP systems used without monitoring systems or methods to measure their performance do not comply with this standard practice as their performance cannot be verified.
Cathodic protection is a proven technique for controlling corrosion of steel in existing structures for certain applications. However, cathodic protection neither replaces lost steel nor returns corroded reinforcement to its original diameter. Although a reinforced concrete element may appear sound by traditional inspection techniques after a SACP system is installed, it could be experiencing corrosion-related tensile stress near ruptures in localized areas. This may lead to movements, deflection, cracking, delaminations or spalls that can appear several years subsequent to the installation of the SACP system.
Sacrificial anode systems have inherent limited current output characteristics and electrochemical characteristics. Accordingly, sacrificial cathodic protection systems may not always be the best system for all combinations of structure, environment, distress, and design life.