• Journal of the Korea Construction Safety Engineering Association
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• s.31
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• pp.60-72
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• 2005

• International Journal of Concrete Structures and Materials
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• v.6 no.3
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• pp.199-207
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• 2012

Concrete is an economical construction material and for that reason it is widely used in buildings and infrastructures. The use of deicing salts, expansion joint failure, and freeze-thaw cycles have led to concrete bridge girders experiencing corrosion of steel reinforcement and becoming unsafe for driving. The goal of this research is to assess the effectiveness of current and possible repair techniques for the end region of damaged prestressed concrete girders. To do this, three American Association of State Highway and Transportation prestressed concrete girders were tested to failure, repaired, and retested. Three different repair materials were tested including carbon fiber, glass fiber, and surface mounted rods. Each different repair material was also tested with and without injected epoxy. Comparisons were then made to determine if injecting epoxy had a positive effect on stiffness and strength recovery as well as which repair type regained the largest percentage of original strength.

• Composites Research
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• v.18 no.4
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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.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.145-148
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• 2006

Near surface mounted (NSM) is a recent strengthening technique based on bonding fiber reinforced polymer (CFRP) bars (rods and laminate strips), the use of NSM FRP bars is Emerging as a promising technology for increasing flexural strength of deficient concrete. In order for this technique to perform effectively, the structural behaviour of RC element strengthened with NSM FRP bars to be fully characterized. Totally, 10 beams were tested using symmetrical two-point loads test. The parameters examined under the beam test were a diffrent type of strengthening length.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.549-554
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• 2003

In order to overcome the brittle failure of strengthening with FRP-rebars inherent to their brittle properties, two approaches have been attempted. One is to improve the properties like ductile Hybrid FRP Rods, and the other is to develop a ductile strengthening with partially unbonded FRP rebars. Experiments on real size specimen were performed to evaluate the performance of NSM (Near Surface Mounted Strengthening) and SIM (Section Increment Methods) with FRP rebars. This paper discusses the results of the tests on 8 slab specimen in terms of flexural resistance, ductility, and fatigue. They show that NSM or S1M with FRP rebars are very effective measures to strengthen existing RC structures. Above all, strengthening with partially unbonded ductile Hybrid FRP Rods shows sufficient ductility similar to that of properly designed RC structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.99-102
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• 2005

This paper presents test results on strengthening details of reinforced concrete beams strengthened with near-surface mounted(NSM) CFRP rod and strip. A total of 8 specimens have been tested. The specimens can be classified into the same strengthening area group and the different spacing group. For the same strengthening area group, experimental results revealed that specimens strengthened with NSM CFRP strips improved the flexural capacity of RC beams. For the different spacing group, the flexural capacity of RC beams was almost the same, but it was different in case of NSM CFRP rods.