• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.15-16
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• 2009

The purpose of this research is to examine the confinement effect of high-strength transverse reinforcement for concrete cylinders. In this study the behavior of concrete cylinders reinforced with high-strength steel spirals was investigated.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.161-164
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• 2003

This experimental investigation was conducted to examine the seismic performance of reinforced concrete bridge columns. The columns were subjected to a constant axial load and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement ($P_s$ =0.96, 1.44 per cent) and axial load ratio (0.05, 0.1, 0.2 P/$P_o$). Test results show that bridge columns with 50 per cent higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour. For bridge columns with axial load ratio(P/$P_o$) less than 0.2, the ratio of $M_{max}$ over $M_{aci}$, nominal moment capacity predicted by ACI 318-02 provisions, is consistently greater than 1 with approximately a 20 percent margin of safty.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.103-104
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• 2010

There are two conflicting opinions about effect of confinement using High-Strength transverse reinforcement. This paper verifies evaluation of structural behavior of RC columns strengthened with high-strength steel bars by performing an experimental study of 15 large-scale column confined by high-strength transverse reinforcement tests.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.411-416
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• 2000

The behavior of high strength reinforced concrete columns subjected to uniaxal reversal loading and biaxial reversal circle path loading was investigated. Four full scale test specimens were tested. All specimens were adopted cantilever type, in order that the critical region is to locate only at the bottom of column. The parameters studied were transverse reinforcement ratio, uniaxial lateral loading and biaxial lateral loading. The damage features of columns by the biaxial loading are different from those of the uniaxial loading, However, the maximum strength and the draft angle at maximum strength were almost the same under uniaxial and biaxial loading. The transverse reinforcement under biaxial loading was very effective for increasing ductility of specimens.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.446-451
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• 2000

In case of strong earthquake, upper-sheat wall lowe-frame structures show the weak-story failure at lower part. Where we should guarantee sufficient strength, energy dissipation capacity and ductility. In this study, a typical structure was selected for a prototype and four 1:2.5 scaled models, representing the subassemblages including the interior column and the deep beam, were constructed. Experimental parameters include transverse reinforcement ratio and axial force. The non- linear behavior of the subassemblages subjected to the cyclic lateral displac-ement were evaluated through investigation of the ultimate strength, ductility, load-deformation characteristics. From the results of the tests on 4 specimens, it is concluded that the strength increased as the axial force increased and the ductility increased as the transverse reinforcement ratio increased.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.204-209
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• 2003

The purpose of this study is to develop new seismic design concept based on ductility demand for reinforced concrete bridge columns in areas of low to moderate seismicity. In developing the ductility based design approach, relationship between ductility demand and transverse reinforcement demand should be quantitatively developed. To evaluate ductility capacity of reinforced concrete columns, analytical models and a non-linear analysis program, NARCC have been developed. Based on analytical and experimental results, an equation for relationship between curvature ductility and displacement ductility, an equation for designing the transverse confinement reinforcement for ductility demand, and a new seismic design concept of RC bridge columns are presented.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.93-102
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• 2009

Because steel girder bridge has big slenderness ratio, buckling is very important in design. Local buckling of plate girders having two longitudinal stiffeners in different positions under various load conditions is investigated. Various parametric study according to the change of web height, transverse stiffeners and load conditions are examined. These parametric studies are performed by numerical simulation utilizing finite element method. The objective of this study is to present the rational reinforcement location of two longitudinal stiffeners. The results of analysis are compared to that recommended by korean specifications for road bridges(2003).

• Earthquakes and Structures
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• v.8 no.3
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• pp.713-732
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• 2015

The application of the compressive force path method for the design of earthquake-resistant reinforced concrete structural walls with a shear span-to-depth ratio larger than 2.5 has been shown by experiment to lead to a significant reduction of the code specified transverse reinforcement within the critical lengths without compromising the code requirements for structural performance. The present work complements these findings with experimental results obtained from tests on structural walls with a shear span-to-depth ratio smaller than 2.5. The results show that the compressive force path method is capable of safeguarding the code performance requirements without the need of transverse reinforcement confining concrete within the critical lengths. Moreover, it is shown that ductility can be considerably increased by improving the strength of the two bottom edges of the walls through the use of structural steel elements extending to a small distance of the order of 100 mm from the wall base.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.41-44
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• 2004

This experimental investigation was conducted to examine the behaviour of eight one-third scale columns made of high-strength concrete (HSC). The columns were subjected to a constant axial load corresponding to 30 per cent of the column axial load capacity and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement, tie configuration and tie yield strength. Columns with 42 per cent higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour. Relationships between the calculated damage index and the observed damage such as initial crack, spalling of concrete, buckling of longitudinal bar, and crushing of concrete are propose.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.105-108
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• 2006

Current ACI and AIJ guidelines only address the importance of the concrete strength and geometry of the joint. There are no significant attention paid to other variables. In addition, the current design code doesn't predict the ductility of the beam-column assemblies. The former researcher proposed the analytical model to predict the shear strength of the joint panel as well as the ductility of the beam-column assemblies in year 2004. In this study, the experiments to investigate shear behavior of reinforced concrete beam-column joints and to verify proposed model were carried out, based on the experimental results. As the formal researcher proposed, the factor K (K=0.5), the ductility of BJ-failure was predicted reasonably when the transverse reinforcement ratio exceeded 0.0186. However, the proposed equation showed a large discrepancies in the ductility estimating when transverse reinforcement ratio was below 0.0186.