All bridges are inevitably undergoing deterioration over time. Therefore, it is necessary to predict the maintenance control and to properly manage the maintenance control cost by deriving the appropriate repair and reinforcement timing. The deterioration of bridges appears to vary according to the years of use of bridges and the exposed environment. In this study, the correlation between the deterioration factor of the winter season and the damage rate of the bridge deck was derived from 1117 total bridge data collected through the GPR(Ground Penetration Radar) system.

교량 바닥판은 대형 차량 및 제설제와 같은 다양한 환경 요인으로 인해 급속히 악화되는 부재이다. 한국에 건설된 교량의 수명이 길 어짐에 따라 교량 바닥판의 교체 수요가 증가 할 것으로 예상된다. 다른 국가에서는 프리 캐스트 바닥판을 이용한 급속 교량 건설 기술이 열화 된 교량 바닥판의 교체 수요 대응을 위해 적극적으로 사용되고 있다. 본 연구에서는 국내 교량 바닥판의 상태평가 데이터를 수집 및 분석하여 교량 바닥판 열화 모델을 제안 하였다. 또한 교량 규모의 관점에서 열화된 교량 바닥판의 미래 대체 수요를 예측하였다.

Bridge decks are rapidly deteriorated by various environmental effects such as heavy vehicle and deicing salt, etc. For bridge owners in Korea, therefore, it is important to understand the defect characteristics and causes of deterioration of bridge decks as well as to predict the future need for bridge deck replacement based on proper deterioration models. Finding a solution to the problem, in this research, the site investigation for 76 domestic old bridges were undertaken and deterioration models of bridge decks were proposed by analysing service year-condition index relationships of more than 500 bridges.

This study established key factors causing deck slab deterioration based on GPR database of 747 highway bridges, and predicted deck slab damage rates with respect to bridge service life. To minimize the influence of bridge service life on deck slab deterioration, the deck slab damage rate database was corrected based on a linear regression model of bridge service life vs. deck slab damage rate. The corrected deck slab damage rates were analyzed to determine correlation considering the number of snowy days, the amount of snowfalls, the number of freeze-thaw days, average winter temperature, altitude, the amount of deicing chemicals and equivalent traffic volume, and then both the number of freeze-thaw days and the amount of deicing chemicals were determined to be key factors causing deck slab deterioration. The complex deterioration considering both key factors was represented deck slab damage rate charts, and the average deck slab life was derived. The results of this study will be used as a guideline for highway bridge maintenance to identify the progress of deck slab deterioration for a given bridge and predict the time required deck slab rehabilitation.

본 연구에서는 콘크리트 교량 바닥판의 열화를 비파괴시험인 지표투과레이더(GPR)를 이용하여 평가하는 방법을 개발하였다. 콘크리트 교량 바닥판의 유전 상수를 계산하기 위하여 비접촉식 GPR 안테나를 이용하여 2층 구조체에 적용할 수 있는 확장형 공통중간점 방법을 개발하였다. 콘크리트 교량 바닥판의 열화 깊이와 열화 상태는 콘크리트 교량 바닥판의 유전 상수와 표면대비 평균 유전상수비를 이용하여 평가하였다. 제안된 방법을 검증하기 위하여 GPR 현장 시험을 공용수명이 오래된 콘크리트 교량에서 실시하였다. 시험 결과 새로 제안된 방법을 이용하여 추정된 두께와 열화 깊이가 어느 정도 신뢰성을 가지는 것으로 나타났다.