• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.613-617
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• 1998

This study deals with the effect on adhesive strength properties of fiber sheet layer and maintenance position of coccrete structure reinforced using epoxy resin carbon and aramit fiber sheet. Properties of epoxy resin adhesive strength of the concrete bridge slab, tunnel and wall etc. reinforced using fiber sheet under many different environment change according to condition of concrete substrate, temperature, moisture, curing, cleaning, and chemical effects and so on. The purpose of this study is that it makes the estimation value of adhesive strength of concrete substrate and fiber sheet reinforcing layer penetrated epoxy resin under high temperature(9$0^{\circ}C$), chemical attack and condition of curing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.126-127
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• 2018

Rebar work is important in terms of cost and process of reinforced concrete construction along with formwork and concrete construction, and the quality of reinforced concrete construction has a great influence on the safety and durability of the structure. Therefore it is important to thoroughly inspect the steel reinforcement after casting the concrete because it is difficult to confirm the actual condition of the reinforcement. The purpose of this study is to develop an augmented reality system to visualize the records of bar placing work, which is increasingly utilized in the construction field. In order to improve maintenance of reinforced concrete, this study suggests a plan to effectively manage the drawing information including the structural drawing, the placing drawing, and the photographed image at the construction and inspection stage, and develop a system that utilizes augmented reality technology that can display the state of the inside of a concrete structure by superimposing it on actual environment.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.17-27
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• 2006

To estimate the retained strength of reinforced concrete structure after fire is very difficult because the complex behavior of structure is hard to understand during course of a fire. However, the damages which is caused by fire of the traffic facility infrastructure are enormous. Therefore the security against fire is important element that must not be overlooked. For this reason, an exact estimate method of the fire endurance is highly demanded. In this study, the validity of the nonlinear finite element method approach for the fire endurance of reinforced concrete structure is verified. The results of fire endurance estimate of underground road way by nonlinear finite element method approach are compared with those by ACI 216R-89.

• Journal of Korean Society of Steel Construction
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• v.22 no.5
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• pp.455-463
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• 2010

This paper describes the experimental study on the mechanical characteristics of a steel plate-reinforced concrete joint. As an alternative reinforced concrete structure, the SC modular construction method is widely used and studied in the field ofindustrial facility field. However, the structure characteristics of RC and SC joint are not yet studied completely. In this paper, the beam-type construction joint of RC and SC walls was made to simulate the application of SC module to the large RC structure. Also, an out-of-plane loading was applied to the test specimen in order to evaluate flexural strength and structural properties of the beam-type RC-SC joint.

• KIEAE Journal
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• v.8 no.5
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• pp.61-68
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• 2008

For the recycling of the resources and the preservation of the environment, this study's purpose is to measure flexural behavior of the reinforced concrete beams with the major variables like concrete strength, replacement ratio of the recycled aggregate and the waste foundry sand and the tension reinforcement ratio and to present the data of the recycled aggregate used for the structure design. The experiment on the flexural behavior resulted in the followings. The ultimate strength of recycled R/C beam was manipulated proportionate to the tension reinforcement ratio, however the strength instantly decreased after passing the ultimate load due to the destroyed concrete of the compression side. The deflection at the maximum load varied from the tension reinforcement ratio by 5.5 times. The test specimen with the tension reinforcement ratio less than $0.5{\rho}b$ showed constant curve without change in the load from the yield to the ultimate load in contrast to the distinctive plastic region where the displacement was rising. Although the strain of main tension steel with the reinforcement ratio indicate different, the design of recycled concrete member can be applied for current design code for reinforced concrete structure as the ratio of tension reinforcement district the under the reinforcement ration in a balanced strain condition.

• Computers and Concrete
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• v.16 no.4
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• pp.531-544
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• 2015

The objective of this study was to examine the effect of repair mortar on the dynamic properties such as natural frequencies, mode shape and damping ratios of two story single span scale reinforced concrete building. To this end, two story single span scale reinforced concrete building having dimensions of 150 cm (width), 150 cm (length) and 135 cm (height) was constructed. Workmanship defects such as separation of material, faulty vibration application and bad gradation of the structure were properly evaluated. Dynamic properties of damaged structure were experimentally determined using Operational Modal Analysis (OMA). Detected defects in the structure were fixed by plastering with repair mortar. Dynamic properties of repaired structure were reevaluated by using the OMA method. Finite element software called Abaqus was used to numerically determine dynamic properties of the structure. Structure modeled as solid was subjected to Linear Perturbation Frequency Method. The changes in dynamic properties of structure after the repair process were comparatively studied by evaluating experimental and numerical results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.21-25
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• 2004

The column for Steel Framed Reinforced Concrete Structure (SFRCS) and the column for Reinforced Concrete Structure (RCS) could be the most common building structure. The increasing of the need for massive space hasaffected the size of building components for supporting the massive structure. However, the changing of components size makes inefficient space of building. Hence, to meet the need for acquiring efficient space comparing the budget and cost the new structure method, Concrete Filled Tube Steel (CFT), was developed. CFT is the structure for which steel tube instead of other materials such as wood for holding concrete is used. The most benefit of this one is to help in reducing the size of the building components and local buckling because of tube steel holding concrete. For this reason, this research will examine the probability of applying CFT on construction sites by using the concrete (800kgf/$\textrm{cm}^2$) especially for CFT through the data from the real size mock-up.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.458-461
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• 2004

The column for Steel Framed Reinforced Concrete Structure (SFRCS) and the column for Reinforced Concrete Structure (RCS) could be the most common building structure. The increasing of the need for massive space hasaffected the size of building components for supporting the massive structure. However, the changing of components size makes inefficient space of building. Hence. to meet the need for acquiring efficient space comparing the budget and cost the new structure method, Concrete Filled Tube Steel (CFT), was developed. CFT is the structure for which steel tube instead of other materials such as wood for holding concrete is used. The most benefit of this one is to help in reducing the size of the building components and local buckling because of tube steel holding concrete. For this reason, this research will examine the probability of applying CFT on construction sites by using the concrete $(800kg/cm^2)$ especially for CFT through the data from the real size mock-up.

• Computational Structural Engineering : An International Journal
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• v.2 no.1
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• pp.25-32
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• 2002

Natural draught cooling towers often develop visible crack structures as consequences of progressive damage processes over their life-time. The aim of this paper is a numerical demonstration of the progressive damage process of cooling towers, representatively for the reinforced concrete structures, in order to improve the durability and extend the life-time of structures subjected to such damage processes. For the analyses, the applied material model for reinforced concrete will be briefly introduced. An existing natural draught cooling tower with a pronounced crack structure, in which this crack structure indicates the typical damage pattern of large cooling towers will be numerically simulated. The change of dynamical behavior of the structure with regard to natural frequencies, reflecting the global damage process due to the degrading stiffness of the structure in dependence of the load type and intensity, will be presented and discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.691-696
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• 2000

Shear strengthening method by steel plates and fiber reinforced polymer lamination has recently been favorably selected due to its efficiencies of duration and performance. Shear failure being brittle and difficult to predict, reinforced concrete structures must have sufficient capacity to absorb the energy for shear failure and to support temporarily the overload which may result due to the loss of shear capacity to the structure. These respects being considered, this research has carried out with the purpose of the experimental verification of the shear strengthening effect and ductility evaluation.