• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.875-878
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• 2008

This paper summarizes on the state-of-the-art research on the reinforced concrete (RC) walls for evaluating and predicting the performance of RC walls analytically and experimentally. A brief discussion of the research trends is presented to propose the further research direction of RC walls. In the paper, 102 papers published on the ACI, Engineering Structure, KCI journal, and AIK journal are collected and reviewed.

• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.1001-1009
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• 2002

The objective of this study is to determine the range of confinement (or the transverse reinforcement of the reinforced concrete structural walls with the T-shaped cross section subjected to cyclic lateral loads. The range of confinement for transverse reinforcement is related to the location of neutral axis and determined by the magnitude and distribution of compressive strain. The compressive strain depends on the ratio of wall cross sectional area to the floor-plan area, the aspect ratio, configuration, the axial load, and the reinforcement ratios. By affection of flange, the neutral axis appears different depending on positive and negative forces and because of this reason, when web and flange are subjected to compressive stress, the range of confinement for the transverse reinforcement of T-shaped walls would shows different result. Therefore this experimental research focused on the structural characteristics of T-shaped walls and suggested the neutral axis depth through comparing the results of this study with sectional analysis.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.569-579
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• 2011

Reinforced concrete walls subjected to cyclic loading show complicated inelastic behaviors varying with aspect ratio, re-bar detail, and loading condition. In the present study, a macro model for nonlinear analysis of reinforced concrete walls was developed. For exact prediction of inelastic flexure-compression and shear behaviors, the macro model of the wall was idealized with longitudinal and diagonal uniaxial elements. The uniaxial elements consist of concrete and re-bars. Simplified cyclic models for concrete and re-bars under uniaxial loading was used. For verification, the proposed model was applied to slender, lowrise, and coupled walls subjected to cyclic loading. The results showed that the proposed method predicted the nonlinear behaviors of the walls with reasonable precision.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.591-602
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• 2015

In this paper, cyclic loading test was performed to evaluate the seismic performance of the steel coupling beam and RC shear wall. The test parameter was reinforcement detail of the shear wall. For the shear wall which was designed in accordance with the current design codes, a premature bearing failure occurred at the face of the wall. On the other hand, the bearing failure of walls was prevented due to the new type of reinforcement details. Test results indicated that the vertical reinforcements were more affected to the shear strength of the coupled shear wall than the horizontal reinforcement. Based on the failure mode, concrete stress distribution above and below flanges of the embedded steel beam was proposed. Assuming proposed concrete stress distribution, load resistance was predicted and it was agree well with test data.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.3-4
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• 2010

Strength of PC walls with diagonal reinforcements can be obtained by using the section analysis. Deformation of the diagonal reinforcements is related to that of flexural reinforcement and makes the another tensile strength on the PC wall. Another tensile strength due to diagonal reinforcements is assumed to be 1/3 point of the distance between the flexural reinforcements.

• Magazine of the Korea Concrete Institute
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• v.4 no.2
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• pp.127-137
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• 1992

원자력발전소의 콘크리트 격납용기구조물등과 같이 안전성이 높게 요구되는 구조물들은 예기치 않은 혹은 부주의한 사고로 인하여 발생하는 비산물체에 의한 충격에 충분히 저항할 수 있도록 설계되어야 한다. 이러한 물체에 의한 충격은 벽면의 국부적인 피해와 벽 전체의 전반휨응답으로 나타나며, 이에 저항하기 위해서는 벽체의 관통이나 스캐빙(scabbing)이 일어나지 않도록 벽두께를 결정하여야 하고 또한, 파괴가 일어나지 않도록 벽체를 설계하여야 한다. 본 논문에서는 지금까지 연구된 충격현상에 대한 이론 및 실험결과를 토대로 하여 벽면의 국부효가 발생시 이와 동시에 진행되는 탄성효과 및 전반거동효과를 고려하여 관입깊이를 계산할 수 있는 이론을 유도하였으며, 기존의 실험결과를 이용하여 이론적인 결점을 보완한 반이론식을 제안하였다. 또한, 본 논문에서는 실험결과와 기존식성충격과 소성충격을 구분짓는 스폴링속도에 대한 개념을 제시하였다. 본 논문은 충격을 받는 철근콘크리트 구조물의 벽체설계에 유용한 토대를 제공할 것으로 사료된다.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.601-612
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• 2013

In the construction of nuclear power plants using massive walls, the use of high-strength re-bars for shear design is necessary to enhance the constructability and economy. In this study, low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars were tested under cyclic loading to investigate the shear capacity and deformation capacity. The test parameters were the grade of horizontal re-bars (550 MPa, 420 MPa), strength of concrete compressive strength (46 MPa, 70 MPa), horizontal/vertical reinforcement ratio, use of lateral confinement hoops, shape of cross section, and failure modes (shear failure before or after flexural yielding). The test results were compared with those of walls with grade 420 MPa bars and predicted strength by current design codes. The results showed that the shear strength of the walls with 550 MPa bars was comparable to that of the walls with 420 MPa bars though the safe margin slightly decreased. ACI 349 provides underestimated shear strength for the walls with 550 MPa bars. In case of the wall with flexural yielding, a large deformation capacity was achieved. This result indicates that the ACI 349 provisions can be safely applied to seismic design of the low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.113-124
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• 1998

Numerical study using nonlinear finite element analysis is done for investigating behavior of isolated reinforced concrete walls subject to combined in-plane and out-of-plane bending moments and axial force. A method for estimating the ultimate strength of wall is developed, based on the analytical results. For the nonlinear finite element analysis, a computer program addressing material and geometric nonlinearities is developed. An existing unified method combining plasticity theory and damage model is used for material model of reinforced concrete. By numerical studies, the internal force distribution in the cross section is idealized, and a new method for estimating the ultimate strength of wall is developed. According to the proposed method, variation of the interaction curve of in-plane bending moment and axial force depends on the range of the permissible axial force per unit length that is determined by the given amount of out-of-plane bending moment. As the out-of-plane bending moment increases, the interaction curve shrinks, which indicates a decrease in the ultimate strength. The proposed method is compared with an existing method using the general assumption that strain shall be directly proportional to the distance from the neutral axis. Compared with the proposed method, the existing method overestimates the ultimate strength for walls subject to low out-of-plane bending moments, and it underestimates the ultimate strength for walls subject to high out-of-plane bending moments.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.131-137
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• 2010

12 trial-scale wall panels are tested and evaluated to investigate the ultimate load capacity of axially loaded concrete walls with various opening configurations. The experimental tests have been undertaken to obtain data for the modification of existing equations. A new design equation has been generated using the precise test data and it incorporates the unique length factors. This new design equation for concrete walls with openings is then compared with existing code formulae.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.5
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• pp.161-168
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• 2010

Practicing engineers and researchers need computational tools that estimate accurately the cyclic response of RC walls, and in particular, force and deformation capacities and their materials strains. So this paper describes a nonlinear truss modeling approach for reinforced concrete walls, or in general, for plane stress reinforced concrete elements subjected to cyclic reversals. Nonlinear vertical, horizontal, and diagonal truss elements are used to represent concrete and steel reinforcement. The wall having aspect ratio of 1.2 was chosen to be compared with the experimental results. Here, four types of main diagonal member models and three types of diagonal members models were applied to find out more accurate results of analysis.