• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.6
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• pp.667-674
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• 2015

In this paper, shear behavior of concrete wide beam reinforced with plates with openings was evaluated. For this evaluation, evelen specimens were manufactured. One specimen was non-shear reinforced, five specimens were reinforced with steel plates and the other five specimens were reinforced GFRP plates. Shear strengths measured through experiments were compared with ones calculated from the equation provided by ACI 318. Longitudinal spacing of shear reinforcement, transverse spacing of shear reinforcement and shear reinforcement material were considered as variables. Test results showed that the shear strength increased as the transverse and longitudinal spacing of shear reinforcement became narrow. Also, regardless of material type of shear reinforcement, the shear capacity was similar when the amount of shear reinforcement was the same.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.3
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• pp.267-274
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• 2015

In this paper, an experimental evaluation of shear strength of wide beam is presented. By the experiment in paper, shear strength depending on parameter of shear reinforcement by GFRP plate on wide beam is investigated. Specimens are 7 of reinforced by GFRP plate with openings. The shear reinforcement is manufactured into plate shape with openings to ensure perfect integration with concrete. The test was performed on 7 specimens. The parameters are including number of shear reinforcement by GFRP plates and center-to-center spacing between vertical strip. We analysed the crack, failure mode, strain, shear strength of specimens. A calculation of the shear strength of reinforced wide beam with GFRP plate based on ACI 318-11. The result of the experiment shows that the GFRP plate is works successfully as shear reinforcement in the wide beam.

• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.37-48
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• 2018

Cyclic loading tests for shear dominant hybrid steel link beams with circular web openings were performed to evaluate the seismic performance. Four half-scaled specimens with bolted connections were tested. The test parameter is a diameter of the web opening, i.e., shear strength ratio ($V_{pw}/V_p$) of the link beam and presence of top-seat angles. Using test results, adequate design shear strength of link beam was finally suggested. Test results showed that when the shear capacity is less than half of the plastic shear strength, seismic performance was improved due to mitigation of pinching under reversed cyclic inelastic deformations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.3
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• pp.269-275
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• 2016

In this paper, shear performance of concrete wide beams was evaluated through shear failure tests. The specimens were designed to have two continuous spans with a column at the center of the wide beam. Also the specimens were reinforced with plates with openings as shear reinforcements. For the test, total eight specimens, including five specimens were reinforced with steel plates and the other three specimens were reinforced with GFRP plates were manufactured. And the shear strengths obtained from the tests were compared with ones from the equation provided by ACI 318. Support width of wide beam, support section of wide beam and shear reinforcement material were considered as variables. The results showed that the support width was proportional to the increase of shear strength. Also, regardless of material type of shear reinforcement, the shear reinforcing effect was similar when the amount of shear reinforcement was the same.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.51-58
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• 2022

Flat plate slab is cost-efficient structural system widely used in high rise building, apartment and parking garages. But flat plate-column connections are so weak against punching shear failure that it may cause collapse of overall structure. In this study, spiral type shear reinforcement which increases the shear strength and ductility of the plate-column connection and has good workability was proposed. And experimental test was performed to verify the punching shear capacity of spiral type shear reinforcement. The current code does not accurately estimate the punching shear strength of slab-column connection with shear reinforcement because slab is so slender that punching failure may occurred before shear reinforcement reached yield stress. Therefore modified equation of ACI code for punching shear strength was proposed base on finite element analysis using LUSAS program, and data analysis from CEB-FIP database.

• Journal of Korean Society of Steel Construction
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• v.20 no.5
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• pp.665-673
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• 2008

The composite structures of steel and reinforced concrete, which have been widely used in large-scale concrete structures, werestudied to investigate the cause of unexpected cracks and to verify the composite actions between the two materials. Vertical stiffeners between flanges, studs and dowel bars, stirrups, and concrete strength were chosen as experimental variables in afour-point loading test. The results showed that the vertical stiffener prevented not only the local web buckling, but also bond failures between steel and concrete. It increased the flexural resistance (fracture loads) due to the composite action of two materials, compared withthose of any experimental variable. However, the composite behavior of steel reinforced concrete beam was not affected seriously by additional studs, dowel bars, stirrups, and concrete strength.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.3
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• pp.23-34
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• 2000

반복하중을 지지하는 4개의 2/3 크리 접합부 실험을 통하여 콘크리트 기둥 및 강재 보로 구성된 골조에 대한 외부 모멘트 접합부의 이력거동을 조사하였다. 주요 실험 변수는 접합부에 배치된 후프근의 수, 콘크리트만의 전단강도 발현응ㄹ 유도한 접합부 상세, 강재 보 플랜지 상, 하부에 스터드 형태의 전단키를 사용한 상세 등이다. 실험 시 관측된 균열양상, 파괴형상 및 다양한 계측결과에 근거하여 접합부 상세에 따른 각 시험체의 거동이 자세히 기술되었으며, 항복 후 보유강도, 강성저하 정도 및 에너지 소산능력 등이 분석되었다. 실험결과에 의하면, 이들 중 패널 및 인접 기둥 영역에 각각 2개의 후프근을 갖는 시험체 (CF3) 가 가장 우수한 이력응답을 나타냈으며, 이러한 형태의 접합부 상헤는 우리나와 같은 약진 지역에 적합할 것으로 판단되었다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.81-88
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• 2022

In the NRC (New paradigm Reinforced Concrete) beam, steel forms, main angles used as main reinforcements, and shear angles used as basic shear reinforcements are welded and assembled in the form of vierendeel truss structures in a steel factory. After the NRC truss frame is installed at the site, additional main reinforcement and shear reinforcement are distributed. In this study, the shear performance evaluation of the NRC beam was conducted through shear tests in accordance with the type of shear reinforcement of the NRC beam (shear angle, inclined shear reinforcing bar, and U-type cover bar). As a result of the test, the initial stiffness was similar before the initial cracking of each specimen, and all specimens were shear fractured.The shear reinforcements of the specimens exhibited a yielding behavior at the time of the maximum sheat force, and the shear strengths of the specimens increased as the amount of reinforcement of the shear reinforcement increased. These results show that NRC shear reinforcements exhibit shear performance corresponding to their shear strength contribution. As a result of calculating the nominal shear strengths according to KDS 14 20 22, the experimental shear strengths of the NRC beam specimens with shear reinforcement was 37~146% larger than the nominal shear strengths, so It was evaluated as a safety side.

• Journal of Korean Society of Steel Construction
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• v.11 no.2 s.39
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• pp.167-179
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• 1999

The thin web panels of plate girders often need to be reinforced with transverse stiffeners to increase the shear strength. Since early 1960s, extensive researches have been conducted on the ultimate shear strength of plate girder webs with transverse stiffeners. These results have been first adopted into AASHTO(1970) and British Standard(1983) Specifications for the determination of the ultimate shear strength of transversely stiffened web panels. Although the main purposes of reinforcing web panels with longitudinal stiffeners are to increase the buckling strength and to control the lateral deflections due to bending, it has been reported that the longitudinal stiffeners increase the shear strength. However lack of studies has kept the effects of the longitudinal stiffeners on the ultimate shear strength from the design of plate girder web panels. In the present study an experimental investigation is carried out in order to assess the increment of the ultimate shear strength of shear web panels due to the longitudinal stiffeners and the results are compared with the existing failure theories.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.405-416
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• 2006

In composite girders with steel embedded in concrete as preflex beams, horseshoe connectors and bar connectors are commonly used to achieve composite action. Considering the requirements on the concrete cover in the thin concrete part surrounding a steel member, it has limitations with respect to the use of stud shear connectors, and significant bond and friction resistance can be generated. High horizontal shear strength between the casing concrete and the steel section is needed to introduce prestress to the concrete section in the form of preflex beams.In this paper, experiments on the evaluation of the static strength of horseshoe connectors and bar connectors were conducted and the effects of bonds were also considered. Based on the test results, current design codes were estimated and more general design guidelines that consider the design concept of Eurocode were proposed for the connectors. A strength evaluation according to failure and compared with the test results.