'Do Nothing' and Patch Repair (without anodes): Engineered Maintenance Experiences of Marine Concrete Structures

摘要

Reinforced concrete, when suitably designed, constructed and maintained has the ability of exceeding structure design lives by numerous decades. Concrete provides reinforcing steel with excellent corrosion protection due to the highly alkaline (pH ~ 13) environment which results in the spontaneous formation of a tenacious passive iron oxide film protecting it from corrosion. This passive film may be lost or locally compromised if the pH of the concrete pore solution falls because of carbonation or if aggressive ions such as chlorides penetrate in sufficient concentration to the steel reinforcement surface.