• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.121-124
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• 2006

This study focuses on the flexural behavior of RC beam with externally bonding FRP reinforcement. FRP-plate strengthening system is mainly installed with an anchor-bolt. But the installation with it has several disadvantage as a complicated work, a high labor costs. To complement these disadvantage, the test is performed about improved FRP-plate strengthening system.

• 한국구조물진단유지관리공학회 논문집
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• 제12권6호
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• pp.225-232
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• 2008

본 논문에서는 FRP 보강재의 부착방식에 따른 RC보의 휨보강 성능평가에 대하여 연구하였다. 기존의 FRP 휨보강공법은 보강재의 형태에 따라 크게 FRP 쉬트 보강공법과 FRP 플레이트 보강공법으로 분류될 수 있으며, 각 공법은 에폭시의 양생기간동안 쉬트의 들뜸이 발생하지 않도록 주의해야하거나, 앵커설치 등 시공이 복잡하며, 인력이 많이 소요되는 단점이 있다. 이러한 문제점을 개선하기 위하여 본 논문에서는 Velcro형 고정재를 사용하여 FRP 플레이트를 임시 고정하는 보강공법을 제안하였고, 이에 대한 휨보강 성능평가 실험을 실시하였다. 실험은 FRP보강재의 부착방식을 변수로 하여 총 4개 실험체에 대하여 수행하였다. 실험결과 벨크로형 FRP판 보강공법은 타 공법에 비하여 우수한 시공성을 가짐과 동시에 휨내력이나 연성도 면에서도 우수한 보강성능을 확보하고 있는 것으로 나타났다.

• International Journal of Concrete Structures and Materials
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• 제7권1호
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• pp.17-33
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• 2013

The most recent report by ACI Committee 440 on externally bonded fiber reinforced polymer (FRP) strengthening systems states that systems designed to mechanically anchor FRP should be studied in detail and substantiated by physical testing. To select and design an appropriate anchorage system for use in an FRP strengthening system, it is important that findings from previous research studies be known. This paper presents a comprehensive literature review of the performance of different mechanical anchorage systems used in FRP strengthening applications. Each anchorage system is discussed in terms of its purpose and performance. Advantages and disadvantages of each system are discussed, and areas in need of future research are explored.

• International Journal of Concrete Structures and Materials
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• 제7권1호
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• pp.3-16
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• 2013

Strengthening concrete structures using FRP composites is a commonly considered technology in many practical situations. The success of the strengthening intervention largely depends on adequate bond between FRP sheets and the concrete substrate. In recent years, techniques to anchor FRP sheets in applications where sheets must develop strength in a short length have been proposed. One of these techniques includes use of FRP anchors embedded into the concrete substrate and forming part of the composite strengthening system. This paper presents the results of studies conducted recently at the University of Massachusetts Amherst to advance the understanding on the behavior of FRP anchored systems.

• Composites Research
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• 제18권4호
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• pp.66-74
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• 2005

This paper reports new repair and strengthening mathod using improved material. This mathod have two type according to covering thickness of reinforcement. One type is near surface mounted FRP rod. Anther type is overay. Fiber Reinforced Plastic (FRP) materials has become very popular in recent years. FRP material used to rehabilitate many types of structures with superior characteristics such as high strength and stiffness and corrosion resistance. This strengthening mathod were used FRP rod which have better bond and shear strangth than current FRP rod. Development of FRP rod due to 3-D winding system. In addition, Ductile hybrid FRP has a certain plastic deformation and an elongation greater than 3% at maximum load is usually required for steel reinforcement in concrete structures. Moerover this mathod can be effective repair of base concrete by sprayed polymer mortar.

• Ocean Systems Engineering
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• 제8권1호
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• pp.21-32
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• 2018

Due to the escalation in hydrocarbon consumption, the offshore industry is now looking for advanced technology to be employed for deep sea exploration. Riser system is an integral part of floating structure used for such oil and gas extraction from deep water offering a system of drill twines and production tubing to spread the exploration well towards the ocean bed. Thus, the marine risers need to be precisely employed. The incorporation of the strengthening material, fiber reinforced polymer (FRP) for deep and ultra-deep water riser has drawn extensive curiosity in offshore engineering as it might offer potential weight savings and improved durability. The design for FRP strengthening involves the local design for critical loads along with the global analysis under all possible nonlinearities and imposed loadings such as platform motion, gravity, buoyancy, wave force, hydrostatic pressure, current etc. for computing and evaluating critical situations. Finite element package, ABAQUS/AQUA is the competent tool to analyze the static and dynamic responses under the offshore hydrodynamic loads. The necessities in design and operating conditions are studied. The study includes describing the methodology, procedure of analysis and the local design of composite riser. The responses and fatigue damage characteristics of the risers are explored for the effects of FRP strengthening. A detail assessment on the technical expansion of strengthening riser has been outlined comprising the inquiry on its behavior. The enquiry exemplifies the strengthening of riser as very potential idea and suitable in marine structures to explore oil and gas in deep sea.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.17-20
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• 2004

FRP strengthening system that bonds FRP sheet or laminate underneath structure has been used popularly thesedays. The failure of this bonding system occurs mainly at the interface of bonded surface abruptly. So it is difficult to expect the failure and FRP can't show its full material capacity that makes it uneconomically. By that reason, KICT proposed a system to install FRP aminate to structure for strengthening not by bondging but by unbonding. It is to install both ends of FRP laminate by anchoring underneath structure without bonding. Then, the failure is not an interfacial problem any more, it is governed by mechanical anchoring. This paper includes an experimental study about anchoring system for prestressing CFRP laminate.

• 콘크리트학회지
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• 제12권6호
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• pp.63-69
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• 2000

• 복합신소재구조학회 논문집
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• 제3권2호
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• pp.11-18
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• 2012

This study proposes flexural failure design criteria of continuous slabs enhanced by a hybrid system of fiber reinforced polymer (FRP) and ultra high performance concrete (UHPC). The proposed hybrid retrofit system is designed to be placed at the top surface of the slabs for flexural strengthening of the sections in both positive and negative moment zones. The enhancing mechanisms of the proposed system for both positive and negative moment regions are presented. The neutral axis of the enhanced sections in positive moment zone at flexural failure is enforced to be in UHPC overlay for preventing the compression in FRP. From this condition, a relationship between design parameters of FRP and UHPC is established. Although the capacity of the proposed retrofit system to enhance flexural strength and ductility is confirmed through experiments of one-way RC slabs having two continuous spans, the retrofitted slabs failed in shear. To prevent this shear failure, a design criteria of flexural failure is proposed.

• Computers and Concrete
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• 제2권5호
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• pp.389-409
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• 2005

The Finite Element Analysis (FEA) is evidently a powerful tool for the analysis of structural concrete having nonlinearity and brittle failure properties. However, the result of FEA of structural concrete is sensitive to two modeling factors: the shear transfer coefficient (STC) for an open concrete crack and force convergence tolerance value (CONVTOL). Very limited work has been done to find the optimal FE Modeling (FEM) methodologies for structural concrete members strengthened with externally bonded FRP sheets. A total of 22 experimental deep beams with or without FRP flexure or/and shear strengthening systems are analyzed by nonlinear FEA using ANAYS program. For each experimental beams, an FE model with a total of 16 cases of modeling factor combinations are developed and analyzed to find the optimal FEM methodology. Two elements the SHELL63 and SOLID46 representing the material properties of FRP laminate are investigated and compared. The results of this research suggest that the optimal combination of modeling factor is STC of 0.25 and CONVTOL of 0.2. A SOLID 46 element representing the FRP strengthening system leads to better results than a SHELL 63 element does.