Reinforcement Corrosion in New Zealand Concrete

Abstract

Corroding reinforcement is the most common form of deterioration in reinforced concrete structures in New Zealand. The first part of the paper describes the causes, extent and severity of rebar corrosion in New Zealand concretes as revealed by the systematic inspection of several hundred structures since the early 1980s. The second part of the paper discusses local approaches to inspection, maintenance and repair of affected structures. The third part describes research currently being carried out by the authors to reduce the risk of future rebar corrosion in new construction and in concrete repairs. These research programs include investigations of the effectiveness of coatings for reinforcement, different methods of cleaning contaminated steel, and different cement/binder combinations in preventing further corrosion.