철근부식을 고려한 FRP Hybrid Bar 및 일반 철근을 가진 RC 보의 내력저하 평가
Evaluation of Load Capacity Reduction in RC Beam with Corroded FRP Hybrid Bar and Steel
0
조회
0
다운로드
9
인용
0
참고문헌
키워드
초록
RC(Reinforced Concrete) 부재는 인장영역에서 보강재가 하중을 지지해야 하므로, 철근부식은 내구성 뿐 아니라 안전성에서도 매우 중요하다. 본 연구에서는 최근 개발된 FRP Hybrid Bar와 일반 철근을 매립한 RC 보부재를 제작하였으며, ICM(Impressed Current Method)를 적용하여 철근부식을 촉진시켰다. 기존의 이론식인 Faraday 법칙을 이용하여 부식량을 평가하였으며, 일반설계강도를 가진 콘크리트 보부재에 대하여 휨시험을 수행하였다. 일반 철근에서는 부식량이 4.9∼7.8% 수준으로 평가되었으며 이에 따른 휨 저항능력은 -25.4∼-50.8% 수준으로 감소하였다. FRP Hybrid Bar를 매립한 RC 보에서는 부식과 휨 저항 감소가 평가되지 않았는데, 이는 에폭시 도료로 코팅된 철근의 우수한 내부식성에 기인한다. 촉진 부식실험에서는 FRP Hybrid Bar의 우수한 내부식성 및 부착성능을 확인하였는데, 실용화를 위해서는 장기적인침지를 통한 내구성 평가가 필요하다고 판단된다.
Abstract
Steel corrosion is a very significant problem both to durability and structural safety since reinforcement has to support loads in tensile regionin RC(Reinforced Concrete) member. In the paper, newly invented FRP Hybrid Bar and normal steel are embedded in RC beam member, and ICM(Impressed Current Method) is adopted for corrosion acceleration. Utilizing the previous theory of Faraday's Law, corrosion amount is calculated andflexural tests are performed for RC beam with FRP Hybrid Bar and steel, respectively. Corrosion amount level of 4.9∼7.8% is measured in normalRC member and the related reduction of flexural capacity is measured to be -25.4∼-50.8%, however there are no significant reduction of flexural capacityand corrosion initiation in RC samples with FRP Hybrid Bar due to high resistance of epoxy-coated steel to corrosion initiation. In the acceleratedcorrosion test, excellent performance of anti-corrosion and bonding with concrete are evaluated but durability evaluation through long-term submergedtest is required for actual utilization.
참고문헌 (19)
- "ACI 440. 1R-06, Guide for the Design and Construction of Structural Concrete Reinforce with FRP Bars", ACI Committee 440, ~ (2006)
- Baek, S. H., "Nondestructive Corrosion Detection in RC Through Integrated Heat Induction and IR Thermography", Journal of Nondestructive Evaluation, 31(2), pp.181~190 (2012)
- Bautista, A., "Analysis of the Protective Efficiency of Galvanizing against Corrosion of Reinforcements Embedded in Chloride Contaminated Concrete", Cement and Concrete Research, 26(2), pp.215~224 (1996)
- Broomfield, J. P., "Corrosion of Steel in Concrete: Understanding, Investigation and Repair", pp.1~15 (1997), E&FN
- CEB, "New Approach to Durability Design", ~ (1997)
- 정란, "주근 및 띠철근의 부식에 따른 철근콘크리트 기둥의 구조성능", 대한건축학회논문집 구조계, 20(3), pp.7~14 (2004), 대한건축학회
- Development of Enhancing Life Span Technology for Waterfront Structures using FRP Hybrid Bars, "KICT", ~ (2013)
- 고성현, "스터럽이 없는 GFRP 보강근 콘크리트 보에 대한 실험적 연구", 한국구조물진단유지관리공학회 논문집, 18(2), pp.21~29 (2014), 한국구조물진단유지관리공학회[DOI]
- 권성준, "Prediction of Repairing Time for RC Columns with Crack and Joint under Carbonation based on Probabilistic Approach", International Journal of Concrete Structures and Materials, 5(1), pp.11~18 (2011), 한국콘크리트학회
- Kwon, S. J., "Nondestructive corrosion detection in concrete through integrated heat induction and IR thermography", pp.1~11 (2011), SPIE Proceedings
- 권성준, "열유도 장치와 적외선 열화상을 이용한 철근부식탐지 비파괴 평가기법", 한국구조물진단유지관리공학회 논문집, 16(2), pp.40~48 (2012), 한국구조물진단유지관리공학회
- 이찬식, "천연해수 중 전류밀도 변화에 따라 형성된 환경친화적인 전착 코팅막의 특성 분석", 한국표면공학회지, 37(5), pp.253~262 (2004), 한국표면공학회
- Lee, M. H., "Surface Coating Method of Environment-Friendly Calcareous Deposit formed in Natural Seawater", Fourth International Symposium on Biomimetic Materials Processing, 4, pp.94~ (2004)
- Oh, B. H., "An Experimental Study on Corrosion Resistance of Epoxy Coated Reinforcements", Journal of the Korea Concrete Institute, 4(4), pp.161~170 (1992)
- Park, S. S., "Analysis technique for chloride penetration in cracked concrete using equivalent diffusion and permeation", Construction and Building Materials, 29, pp.183~192 (2012)
- Sakurada, S., "Development of Reinforced Concrete Corrosion Amount Presumption Method by Ultrasonic Method", 17th World Conference on Nondestructive Testing, pp.1~6 (2008)
- Seo, D. W., "Enhancement in Elastic Modulus of GFRP Bars by Material Hybridization", Engineering, 5, pp.685~869 (2013)
- Song, H. W., "Service life prediction of concrete structures under marine environment considering coupled deterioration", Restoration of Buildings and Monuments, 12(4) (2006)
- Song, H. W., "Predicting carbonation in early-aged cracked concrete", Cement and Concrete Research, 26(5), pp.979~989 (2006)