• Title/Summary/Keyword: 볼트접합부

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An Experimental Study on the Evaluation of EMP Shielding Performance of Concrete Applied with ATMSM Using Zn-Al Alloy Wire (Zn-Al 합금 선재를 이용한 금속용사 공법 적용 콘크리트의 전자파 차폐 성능 평가에 관한 실험적 연구)

  • Choi, Hyun-Jun;Park, Jin-Ho;Min, Tae-Beom;Jang, Hyun-O;Lee, Han-Seung
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.3
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    • pp.209-217
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    • 2019
  • EMP (Electromagnetic Pulse) usually means High Power Electromagnetic Wave (HPEM). In the case of the shielding plate against the EMP, there is a possibility of deterioration of the electromagnetic wave shielding performance due to the skill of the constructor, bad construction, deformation of the shielding plate at the connection portion (joint portion). The inefficient use of space due to the separation distance is also pointed out as a problem. Therefore, this study aims to derive the optimum electromagnetic shielding condition by applying ATMSM to concrete as a part of securing electromagnetic wave shielding performance with reflection loss against concrete wall. Experimental parameters included concrete wall thickness and application of Zn-Al ATMSM. For the concrete wall, the wall thickness was 100 to 300mm, which is generally applied, and experimental parameters were set for the application of Zn-Al metal spraying method to evaluate electromagnetic shielding performance. Experimental results showed that as the thickness increases, the electromagnetic shielding performance increases due to the increase of absorption loss. In addition, after the application of Zn-Al ATMSM, the average shielding performance increased by 56.68 dB on average, which is considered to be increased by the reflection loss of the ATMSM. In addition, it is considered that the shielding performance will be better than that when the conductive mixed material and the ATMSM are simultaneously applied.

Analysis about Flexural Strength of Steel Plate-Concrete Composite Beam using Folded Steel Plate (Cap) as Shear Connector (절곡 강판(Cap)을 전단연결재로 사용한 강판-콘크리트 합성보의 휨강도 분석)

  • Cho, Tae-Gu;Choi, Byong-Jeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.481-492
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    • 2018
  • The steel-plate concrete composite beam is composed of a steel plate, concrete and shear connector to combine two inhomogeneous materials. In general, the steel plate is assembled by welding an existing composite beam. In this study, the SPC beam was composed of folding steel plates and concrete, without a headed stud. The folding steel plate was assembled by a high strength bolt instead of welding. To improve the workability in a field construction, a hat-shaped cap was attached to the junction with a slab. Monotonic load testing under two points was conducted under displacement control mode to analyze the flexural strength of the SPC beam using a cap as the shear connector. Five specimens with shear connector types, protrusion length, and different thickness of steel plates were constructed and tested. The experimental results were analyzed through the relationship between the shear strength ratio and flexural strength in KBC 2009. The test results showed a shear strength ratio of more than 40 %. In the case of using a cap-like specimen as the shear connector, the flexural strength was 70% of the value calculated as a fully composite beam. In addition, the cap showed a smaller shear strength than the stud, but the cap served as a shear connection. When the thickness of the steel plate was taken as a variable, the steel plate exhibited a bending strength of approximately 70% compared to a fully formed steel plate, and exhibited similar deformation performance. Local buckling occurred due to incomplete composite behavior, but local buckling occurred at a 5% higher strength for a relatively thick steel plate. The buckling width also decreased by 15%.