영신컨설턴트 (02) 529 8803 ystcha@naver.com 2021 5
콘크리트 포장 도로에서 온도 변화로 콘크리트는 팽창과 수축한다. 팽창과 수축에 대비하여 줄눈을 두고 두 콘크리트 사이에 철근 (dowel bar)을 넣어 하중을 전달한다. 철근의 위치가 잘 못된 경우 콘크리트에 균열이 발생한다.
콘크리트 포장 줄눈에 dowel bar 설치
dowel bar 하중 전달
dowel bar 위치 중요
Concrete slabs contract and expand due to temperature fluctuations. Contraction joints serve to absorb these movements. Dowel bars are embedded in concrete pavements to transfer the load across the joints.
The proper alignment of dowel bars is critical to ensure the long-term performance of the joint. Misaligned bars can lock up the joints and prevent them from opening and closing freely.
If bars are not centered adequately under the joint saw cut, they may not be effective in providing load transfer, which can cause uncontrolled crack formation and may reduce the life time of concrete pavement significantly
ASTM E3013/E3013M-17 Standard Test Method for Evaluating Concrete Pavement Dowel Bar Alignment Using Magnetic Pulse Induction
잘못된 철근 위치
탐지기 화면
측정 사양
측정 결과
Dowel bar depth 150 ± 40 mm (4.3 to 7.5 in.)
Horizontal and vertical misalignment less than +40 mm (1.6 in.)
Lateral shift (side shift) less than +80 mm (+3.2 in.)
평가 방법
Weighting Factors Used to Determine Joint Score
Joint Score s < 5 indicates very low risk of joint locking
Joint Score 5 < s < 10 indicates low risk of joint locking
Joint Score 10 < s < 15 indicates moderate risk of joint locking
Joint Score 15 < s indicates high risk of joint locking