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Title |
Corrosion Characteristics in Prestressing Tendon System with Eccentricity and Cracks
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Authors |
권성준(Seung-Jun Kwon) ; 고경택(Kyung-Taek Koh) ; 류금성(Gum-Sung Ryu) ; 류화성(Hwa-Sung Ryu) |
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DOI |
https://doi.org/10.4334/JKCI.2018.30.5.481 |
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Keywords |
PS 텐던 ; 부식 ; 그라우트 ; 블리딩 ; 균열 ps tendon ; corrosion ; ICM (Impressed Current Method) ; grout ; bleeding ; crack |
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Abstract |
PS (Prestresssing) tendon in a PSC (Pre-Stressed Concrete) structure is always subjected to high tensile stress and it causes corrosion-related problems. Particularly, insufficient compaction of grout and de-icing agent from upper girder can accelerate tendon corrosion, and this propagates to tendon break and critical safety problem in PSC structures. In the work, PS tendon systems are prepared and corrosion acceleration is performed using ICM (Impressed Current Method) for 4 days considering 2 types of grout (A-type which is conventionally used and B-type which has a reduced w/c ratio and silica fume addition). For 2 grout types, corrosion amounts are evaluated considering various conditions like bleeding area, cracks, and tendon eccentricity. In the case of tendon eccentricity, both grout systems show similar increasing corrosion, however B-type grout system shows much reduced corrosion in the crack and bleeding conditions. It is also evaluated that a careful maintenance is strongly required in the bleeding and cracked grout area since corrosion amount increase to 3.25~5.14 times in the vulnerable grout area of bleeding and cracks in the corrosive conditions.
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