• Magazine of the Korea Concrete Institute
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• v.7 no.3
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• pp.139-148
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• 1995

The test results from three one fourth scale models using high strength Reinforced Concrete $f_x=704\;kg/cm^2,\;f_y=5.830\;kg/cm^2$ are presented. Such specimens are considered to represent the critical 3 storics of 60-story tall building of a structural wall system in area of high seismicity respectively. They are tested under inplane vertical and horizontal loading. The main varlable is the level of axial stress. The amounts of vertical and horizontal reinforcement are identical for the three walls testcd. The cross-section of all walls is barbell shape. The aspectratio($h_w/I_w$) of test specimen is 1.8. The aim of the study is to investigate the effects of levels of applied axial stresses on the inelastic behavior of high-strength R /C tall walls. Experimental results of high strength R /C tall walls subjected to axial load and simulated sels rnic loading show that it is possible to insure a ductlle dominant performance by promotmg flex ural yielding of vertical reinforcement and that axial stresses within $O.21f_x$ causes an increase in horizontal load-carrying capacity, initial secant st~ffness characteristics, but an decrease in displacement ductility. energy dissipation index and work damage index of high strength K /C tall walls

• Explosives and Blasting
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• v.25 no.1
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• pp.53-65
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• 2007

When doing a blasting demolition on RC structures made of scale models, scale model members considering both a proper scale factor and mechanical characteristics of materials have to be similar to prototype RC members to analyze the collapse behavior of RC structures. In this study. a similitude law considering the density of prototype materials is calculated. Both mix of concrete and arrangement of reinforcement have been described referring to Concrete Standard Specification as well as Design Standard of Concrete Structure. The scale factor on scaled concrete models considering maximum size of coarse aggregate is about one-fifth of a cross section of prototype concrete members. A scale factor on staled steel bar models is about one-fifth of a nominal diameter of prototype steel bar. According to the mechanical test results of scale models, it can be concluded that the modified similitude law may be similar to compressive strength of prototype concrete and yield strength of prototype steel bar.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.129-132
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• 2008

Coupled shear wall system is the primary seismic load resisting system of buildings. The coupling beam of these buildings must exhibit excellent ductility and energy dissipation capacity. To achieve better ductility and energy dissipation, the steel coupling beam embedded in the reinforced concrete walls is proposed. Performance of the steel coupling beam is mainly effected by embedment length. ACI equation and BS equation were examined with 23 previous test results. The statistical study uses the values of mean value, standard deviation, correlation coefficient, normal distribution curve, and error analysis. Through the analytical program, the evaluation of the 2 equations was established.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.69-84
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• 2002

In this papers, an analytical model which can simulate the post-cracking behavior and tension stiffening effect in a reinforced concrete(RC) tension member is proposed. Unlike the classical approaches using the bond stress-slip relationship or the assumed bond stress distribution, the tension stiffening effect at post-cracking stage is quantified on the basis of polynomial strain distribution functions of steel and concrete, and its contribution is implemented into the reinforcing steel. The introduced model can be effectively used in constructing the stress-strain curve of concrete at post-cracking stage, and the loads carried by concrete and reinforcing steel along the member axis can be directly evaluated on the basis of the introduced model. In advance, the prediction of cracking loads and elongations of reinforced steel using the introduced model shows good agreement with results from the previous analytical studies and experimental data.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.17-18
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• 2009

This research defined slip function using cracking behavior, bond characteristics and numerical analysis of cracking stabilized reinforced concrete member, and proposed a bond stres-slip model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.261-263
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• 2013

해양환경에서의 아연코팅철근 콘크리트 보의 휨 성능 및 균열 특성 실험을 수행하였다. 또한, 보에서 발생하는 균열 및 파괴양상을 파악하였다. 그 결과, 해양환경에서의 콘크리트 부재의 피복두께를 기존 설계기준보다 작게 적용시켜도 부재에 발생하는 염해에 대한 내구성을 확보할 수 있으며, 아연코팅 철근의 적용은 일반철근 콘크리트 보다 내구성 측면에서 유리하다고 판단된다.

• Journal of the Korea Concrete Institute
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• v.13 no.3
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• pp.251-260
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• 2001

It is required to evaluate the axial strain of reinforced concrete beams in order to predict the ductility of reinforced concrete beams subjected to reversed cyclic loading. A model was proposed to determine the axial strains In reinforced concrete beams by analysing the behavior of reinforced concrete sections and comparing with published test results. The proposed axial strain model inclusively reflected four kinds of paths : Path 1-steel bar in an elastic stage or a unloading region; Path 2-after flexural yielding; Path 3-a slip region; and Path 4-a reversing loading region. The equations to predict the axial strains of each path were proposed. The proposed equations took into account the effects of the loading program. Comparison of axial strains between experimental results and the results from proposed equations showed to be in a good agreement with experimental results.

• Magazine of the Korea Concrete Institute
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• v.3 no.1
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• pp.87-94
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• 1991

Many different damage models have been prolxlsed for concrete in the past. Most of these are not well suited to predict the residual strength of damaged RC members. This paper reviews some basic facts alxlut concrete damage and uses these to systematically model damage as a low-cycle fatigue phenomenon. Instead of the number of load cycles to failure the energy dissipation capacity of a member is taken as the main variable, which depends on many different factors. The model is capable of simulating reasonably well the strength and stiffness degradation of I{C members subjected to strong cyclic loads.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.69-78
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• 1991

This paper concentrates on the analysis of deflection of the reinforced concrete flexural members under monotonic loading. Concrete is treated as an orthotropic nonlinear material. The concept of equivalent strain and crack strain are used to establish independent stress-strain relationships in the directions of orthotropy. Steel is modeled as an elstoplastic material, and von Mises failure criterion is applied. The finite element computer program for the nonlinear analysis of the deflection of RC flexural members under monotonic loading is developed. The accuracy and reliability of the numerical procedure is demonstrated by the FEM analysis and experiments of the under reinforced concrete beams over the entire loading range up to failure.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.73-76
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• 2008

According to the survey of earthquake disaster, low-rise reinforced concrete building larger by the extent of damage and because of the underlying distribution of reinforced concrete structures more, it is very likely to be disasters. The purpose of this study is to discuss how strength and stiffness of each system in low-rise reinforced concrete buildings consisted of extremely brittle, shear and flexural failure lateral-load resisting systems have influence on seismic capacities of the overall system. Generally, if shear failure members including extremely brittle failure members are failed during an earthquake, the lateral-load resisting seismic capacities of RC buildings are lower rapidly, and if the seismic capacities of shear failure members were higher than that of flexural failure members, failures of shear failure members have influence on failures of the overall system. The result of this paper will provide pseudo-dynamic test of carried out to estimate the possibility of proposals.