Deterioration of concrete bridges is a continuing problem facing the NCDOT. Use of deicing salts in the western part of the state and humidity and salty conditions in the eastern part of the state cause premature deterioration of concrete bridge elements. This premature deterioration results in a financial burden on the NCDOT's maintenance budget, negative psychological effects on highway users, increased traffic delays during maintenance and reconstruction, potential safety hazards, and reduced service life of bridges.
A number of corrosion inhibitors claim to delay, slow, stop, or even reverse the corrosion process in existing concrete structures. Such claims have not been fully verified through independent and comprehensive studies, and specifically for the conditions and problems facing the NCDOT.
The proposed study would complement the existing and on-going research by providing realistic accelerated test data to compare the effectiveness of six, surface-applied corrosion inhibitors on concrete specimens with different levels of chloride contamination and subjected to different environmental conditions. The study will establish threshold chloride content, beyond which surface treatments are not useful. Also, the products will be evaluated for any possible detrimental effects on concrete, and any potential application problems. Guidelines and specifications will be developed for surface treatment using corrosion inhibitors, and recommended means to incorporate surface treatments within the state bridge inspection and maintenance program. Means for technology transfer will be recommended, as well as future field applications and validations with continuous monitoring.
