강교량은 표면에 도장을 실시함으로써 물리적 외부환경으로부터 시설물을 보호하고 노후화 및 열화방지, 미적기능 향상시키고 있다. 하지만 대기환경에 노출된 강교량은 강우, 온도, 습도 등의 기후조건과 비산염분, 동결방지제 등의 환경조건에 의해 부식 손상이 발생하며, 일정주기에 따라 재도장을 실시하고 있다. 최근에 강교량의 재도장시 적용되는 도장계에 대한 실제 교량의 노화조사 데이터가 적어 표면처리방법에 따른 도장수명 예측이 곤란하여 적절한 도장계의 선정이 용이하지 않다. 중방식 및 내후성 중박식 도장으로 적용되는 우례탄계, 불소수지계, 세라믹계, 폴리실록산계를 대상으로 표면처리 방법에 따른 도장노화 거동을 평가하였다.

Painting system are widely used to prevent corrosion damage The coating method on various corrosion preventive method was usually adopted for the functional ability and excellent appearance. In this study, to evaluate the deterioration curve of coating system for steel bridge, the combined cyclic corrosion test was conducted base on ISO 20340. The deterioration areas were measured depending on corrosion cycle. The deteriorations of newly-built coating were compared with those of re-coating.

In this study, Impedence of bridge paint coating was measured using EIS(Electrochemical Impedance Spectroscopy) to evaluate durability of paint coating depeding on coating thickness. Thus, paint coating specimens with different paint thickness were used. From impedence mesearment, the durability of paint coating was compared.

The lifetime of painting is shorter than the lifetime of the bridge. Thus, ongoing maintenance for the lifetime of the bridge is needed. In addition, determination of the repainting period in order to maintenance costs predict is very important. In previous studies were calculated repainting period using survey of experts and some field data. In this study, the properties of the repainting period were analyzed using repainting data of bridge maintenance system.

Investigated were relationships between deteriorated coating surface conditions of laboratory test panels determined by image processing software and coating impedance data collected with Electrochemical Impedance Spectroscopy (EIS). This study demonstrates that estimation of log(Rpo)at a certain deterioration stage is feasible via field image processing alone without running in-situ EIS measurements and going through time consuming EIS fitting analysis.

To promote applicability of steel bridge coating diagnosing system developed and used by Korea Expressway Corporation, problems found in deterioration degree evaluation standard for steel bridge coatings were revised in this study. Suitability of revised evaluation standard was confirmed by field survey.