• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.796-803
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• 2002

T-shaped walls have different strength, stiffness and ductility in the two opposite directions parallel to the web when subjected to horizontal in-plane loads. When the flange is in tension, the extent that the flange reinforcement contributes to the flexural strength will be subjected to shear-lag effect. Because of this shear-lag effect, the flange may not participate fully in the action with the web, and the effective flange width is needed for predicting the actual strength and stiffness of structures. The objective of this paper is to evaluate the effective flange width and actual strength of the T-shaped wall with Korean code specified detailing of the wall web. Three specimens were tested with cyclic lateral loading applied at top of the wall. A constant axial load of approximately 0.1f$\_$ck/$.$A$\_$g/ is maintained during the testing. Test results show that the effective flange width increases with increasing drift level, such that the entire overhanging flange of h/3 is effective at the maximum strength level. Therefore, the use of PCI or KBC(Korean Building Code) value of h/10 is unconservative with respect to detailing at the wall web boundary.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.571-581
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• 2014

In the present study, hollow precast concrete wall (PC Double Wall) for staircase construction was developed. Comparing the conventional walls, the PC Double Wall can be reduced the lift weight using hollow core and improves the integrity between the PC members. The cross-section and re-bar details of the PC Double Wall were developed considering precast concrete manufacturing, constructability, and the structural safety. Particularly, a form system was developed to manufacture thin and hollow core PC wall efficiently. A mock-up test for a staircase using the PC Double wall was performed to verify the constructability and integrity of the PC walls. The test result verified that joint deformation and cracking did not occur as showing good constructability.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.2
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• pp.93-100
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• 2021

In Korea, one of the most used structural systems for residential apartment buildings is the combination of the reinforced concrete (RC) wall and rahmen structures in the upper and lower floors, respectively. To alleviate the significant difference between the stiffnesses of these two structural systems, large transfer girders are generally required in the transition zone of the structure, which then results in the use of large amounts of construction materials and low economic feasibility. This paper proposes a new RC boundary-beam-wall system that can minimize the disadvantages of the RC transfer girder system. The structural performance of the proposed system subjected to axial loading was evaluated via rigorous three-dimensional nonlinear finite element analysis. Four parameters, namely the ratio of lower wall to upper wall lengths, distance between stirrups, main bar slope ratio, and slab length, were considered in the finite element analysis, and their effects on the maximum axial load were analyzed and discussed.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.661-668
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• 2015

Coupled shear walls are effective lateral force resisting system in which coupling beams link individual walls. For improving the energy dissipation capacity of coupling beams, diagonal reinforcement details were developed. However, it is difficult to construct diagonal reinforced coupling beams due to the congestion of reinforcement in the beam. For resolving the problem, this study developed precast coupling beams with bundled diagonal reinforcement. To reduce the reinforcement congestion, bundled diagonal reinforcement were placed in the coupling beam. To evaluate the cyclic performance of coupling beams with bundled diagonal reinforcement, experimental test were conducted. For this purpose, two slender specimens with an aspect ratio of 3.5 were made and tested. It was observed that the cyclic performance of the coupling beam with bundled diagonal reinforcement was similar with that of the coupling beam with normal diagonal reinforcement placed according to design code to ACI 318-11.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.437-440
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• 1999

A numerical study is preformed to investigate behavioral characteristics of T-shaped RC wall that is frequently used for the wall-slab structure system. This study provides design methods to address shear lag and to prevent early failure due to cracking and crushing.

• Magazine of the Korea Concrete Institute
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• v.14 no.5
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• pp.27-30
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• 2002

ACS(Automatic Climbing System) 거푸집은 당 현장에서 코어 월 철근 콘크리트 공사시 사용되는 대형 거푸집으로써 상대 플로우 잭에 의해 자동으로 1개 층씩 상승되는 시스템으로 안전난간 및 안전발판을 설치하여 추락, 낙하재해에 대비하였으며 외부에 천막을 설치하여 비산먼지, 소음 등을 방지할 수 있도록 설치/운영 중이다. (그림 1)은 ACS 거푸집의 구성을 나타내었다.(중략)

• Computational Structural Engineering
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• v.30 no.3
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• pp.16-23
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• 2017

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.193-196
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• 2008

This paper presents an experimental study to investigate enhanced performance of the masonry walls strengthened in shear and ductility using honeycomb steel mesh. The performance of masonry walls strengthened with steel mesh will compare with unreinforced masonry walls to show the performance of reinforced masonry walls. According to the experiment, it is expected that this system is effective to enhance the shear strength and ductility of the masonry walls.

• Journal of the Korea Institute of Building Construction
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• v.23 no.2
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• pp.209-220
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• 2023

Ensuring accuracy within tolerance is crucial for a marking robot; however, rebar displacement frequently occurs during the structural work process, necessitating corrections to layout lines or rebar locations. To guarantee precision and automation, the marking robot must be capable of measuring rebar error and determining appropriate adjustments for marking lines and rebar placement. Consequently, this study proposes a method for measuring rebar location error using a LiDAR sensor and implementing a layout assessment process based on the measurement results. The rebar recognition experiment using the LiDAR sensor yielded an average error of 5mm, demonstrating a reliable level of accuracy for wall rebars. Additionally, this research proposed a process that enables the robot to evaluate rebar and marking corrections based on the error range. The findings of this study can contribute to the automated operation of marking robots while accounting for construction errors, potentially leading to improvements in structural quality.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.451-458
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• 2015

The infill-wall strengthening method has been widely used for the seismic performance enhancement of the conventional reinforced concrete (RC) frame structures with non-seismic detail, which is one of the promising techniques to secure the high resisting capacity against lateral forces induced by earthquake. During the application of the infill-wall strengthening method, however, it often restricts the use of the structure. In addition, it is difficult to cast the connection part between the wall and the frame, and also difficult to ensure the shear resistance performances along the connection. In this study, an advanced strengthening method using the externally-anchored precast wall-panel (EPCW) was proposed to overcome the disadvantages of the conventional infill-wall strengthening method. The one-third scaled four RC frame specimens were fabricated, and the cyclic loading tests were conducted to verify the EPCW strengthening method. The test results showed that the strength, lateral stiffness, energy dissipation capacity of the RC frame structures strengthened by the proposed EPCW method were significantly improved compared to the control test specimen.