• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.73-76
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• 2005

This paper discussed finite element method(FEM) models of the reinforced concrete frame retrofitted with cast-in plate infilled shear wall and analysed under constant axial and monotonic lateral load using ABAQUS. Detailed finite element models are created by studying the monotonic load response of the designed connection of reinforced concrete frame and cast-in plate infilled shear wall. The developed models account for the effect of material inelasticity, concrete cracking, geometric nonlinearity and bond-slip of steel, frame and infilled shear wall. In order to verify the proposed FEM, this study behaved analysis considered a diagonal reinforced steel. The analytical results compared with the experimental results.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.399-404
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• 2002

This paper presents the results cf research on improved flexural performance cf reinforced concrete beams strengthened with bonded carbon fiber reinforced polymer plate. Recently, strengthening technique with CFRP plate were almost carried out by external bonding. But current external bonding technique cf CFRP plates may result in debonding CFRP plate. Therefore, this study proposes a strengthening method that prevents or delays debonding between CFRP plates and concrete and at the same time improves the strength. For this test, there were only 14 test beams manufactured and failure load, deflection, strains and modes cf failure have been examined Test variables included the type cf strengthening, steel ratio and strengthening length, and the effects according to each test variables were analyzed. The experimental results show that the strength and stiffness cf the beam significantly increased between 34.55 and 116.51% and the increase cf the more lead-carrying capacity than the control beams.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.145-148
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• 2005

Recently the construction of high-rise reinforced concrete building is progressively increased as the social demands. It is significantly important factors such as economy, the safety of structure, and the flexibility of internal space. Therefore new structural system is also required to be attained the reduction of story height, the flexibility and efficient use of space. The most suitable structural system is with the economy and flexibility, flat plate slab system in high-rise reinforced concrete building. In this research, it was focused in the improvement of shear performance in the flat plate system using high ductile fiber reinforced mortar. It was evaluated the shear performance in the critical region of slab-column connection. The flat plate system, designed by the high performance and safety, was developed as a new technique in the application of high-rise R/C building.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.775-780
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• 2000

This paper was aimed to investigate the shear strengthening effect of the pre-loaded reinforced concrete beams strengthened by carbon fiber sheet (CFS) & steel plate. Main test parameters were the magnitude of pre-loading at the time of the retrofit, the strengthening methods of carbon fiber sheet and aid ratio. A series of seventeen specimens was tested to evaluate the corresponding effect of each parameters such as maximum load capacity, load-deflection relationship, load-strain relationship and failure mode. As a result, using the steel plate can increase the capacity of not only shear but also bending moment.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.935-940
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• 2002

This paper presents the failure mode on Headed Bars and prediction of tensile capacity, which is governed by concrete cone failure. 17 different plate types, three different concrete strengths and three different welding types of specimens were simulated. Static tensile load was applied Headed Bars were manufactured in different areas, and their shape and thickness are based on ASTM 970-98. Calculation of embedment length in concrete is conducted based on CSA 23.3-94, and static tensile load was applied. Tested pullout capacities were compared to the values determined using current design methods such as ACI-349 and CCD method.

• International Journal of Concrete Structures and Materials
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• v.1 no.1
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• pp.37-43
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• 2007

This paper discusses the failure mode of reinforced concrete beams strengthened with composite materials based on six experimental set-ups to determine the FRP-to-concrete bond strength. Interfacial bond behavior between concrete and CFRP plates was discussed. Shear test were performed with different concrete compressive strengths (21 MPa and 28 MPa) and different bonding length (100 mm, 150 mm, 200 mm, and 250 mm). Shear test results indicate that the effective bond length (the bond length beyond which the ultimate load does not increase) was estimated as $196{\sim}204\;mm$ through linear regression analysis. Failure mode of specimens occurred due to debonding between concrete and CFRP plates. Maximum bond stress is calculated as about $3.0{\sim}3.3\;MPa$ from the relationships between bond stress and slip. Finally, the interfacial bond-slip model between CFRP plates and concrete, which is governed debonding failure, has been estimated from shear tests. Average bond stress was about $1.86{\sim}2.04\;MPa$, the volume of slip between CFRP plate and concrete was about $1.45{\sim}1.72\;mm$, and the fracture energy was found to be about $1.35{\sim}1.71\;N/mm$.

• 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.

• Journal of Korean Association for Spatial Structures
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• v.4 no.3 s.13
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• pp.85-91
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• 2004

Rehabilitations of reinforced concrete(RC) structures using advanced fibre-reinfored plastic(FRP) composites has become very popular in last few years. Typical method of strengthening strategy using FRP composite is bonding the CFRP plate or sheet on the surface of existing concrete structures. Many researches, however, have shown that bonding FRP plate or sheet on the surface of concrete has tendancy to debond prematurely induced by stress concentrations at the end of the plate. In order for overcoming the premature failure, the filling-up method which places FRP-rod into the existing concrete sawing groove has been developed. Through filling-up test results, aims of this research is to investigate the efficiencies of the filling-up method and is to determine the availabilities of traditional flexural theories that has provided all over the world.

• Steel and Composite Structures
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• v.5 no.5
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• pp.375-394
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• 2005

An experimental study was conducted to develop a new base plate anchorage system for concrete filled tubular column under an axial load and a moment. The column was connected to a concrete foundation using ordinary deformed reinforcing bars that are installed at the inside and outside of the column. In order to investigate the moment resisting capacity of the system, horizontal cyclic loads are applied until the ultimate condition is reached with the axial load held constant. To derive a design method for moment resisting capacity, the reinforced concrete section approach was investigated with the assumption of strain compatibility. The results by this approach agreeded well with those of experiments when the bearing pressure of confined concrete and tangent modulus of steel bars are assumed appropriately. Also, it was found that the column interaction curve can be used to predict the yield strength of the base plate system.

• Magazine of the Korea Concrete Institute
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• v.15 no.2
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• pp.102-107
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• 2003