현장코어시료에 의한 항만콘크리트구조물의 내구특성 평가

Abstract

The corrosion of steel by the damage of passivity layer around steel bars is a major source of durability problems in concrete structures. As chloride ion penetration is a major cause of destruction of passivity layer, the evaluation of concentration profile of chloride ion is the essential factor for the service-life estimation of concrete structure. To estimate chloride ion penetration characteristics, this paper investigated the depth of critical chloride concentration and the concentration profile of chloride ion on the basis of in-situ core specimens. The core specimens are obtained at air-zone, splash zone, and tidal zone in Wando, Masan, Incheon, Gwangyang and Donghae harbors. Colorimetric method measured the chloride ion penetration depth, and ASTM C 114 and RCT test proposed by Germann Instruments evaluated the concentration profile of chloride ion. Based on experimental data, the influence of harbor location and vertical exposure condition on chloride ion penetration is evaluated. The analysis of experimental data showed that the surface chloride ion concentration increased with age of structure and the average of test results of surface chloride ion was 13.1 kg/m3. Also, the chloride ion diffusion coefficient decreased with age. Surface chloride ion concentration and chloride ion diffusion coefficient were not influenced by vertical exposure condition.