• Title/Summary/Keyword: ductility improvement

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Prediction Model of Flexural Properties of LEFC using Foaming Agent (기포제 적용 빛 감성 친화형 콘크리트의 휨 특성 예측 모델)

  • Kim, Byoung-Il;Seo, Seung-Hoon
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.1
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    • pp.9-18
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    • 2019
  • Concrete, which is the most widely used building material in modern times, has been improved not only in strength but also in structural performance such as increase in toughness and ductility, weight reduction, and improvement in quality of human life. Due to the surge in demand for the building, there is a tendency to be used variously from architectural panel and architecture to interior accessories. In Korea, a light-transmitting concrete, LEFC(Light Emotion Friendly Concrete), that insert plastic rods to stimulate emotional sensation through the combination of light and concrete has developed. In previous research, it was confirmed that the use of a synthetic foam agent rather than an animal foam agent did not cause a fogging phenomenon. In this study, lightweight by applying foaming agent to LEFC and two types of fiber (Nylon Fiber, Polyvinyl Alcohol) were compared to achieve to investigate the fiber to be applied in future. An equation that can predict the loss and adhesion reduction of the concrete section according to the diameter of the rod (5mm, 10mm) and the interval (10mm, 15mm, 20mm) was proposed.

An Experimental Study on Seismic Performance of Two-story Reinforced Concrete Frames Retrofitted with Internal Steel Frame and Wall Type Friction Damper (내부 철골끼움골조 및 벽체형 마찰댐퍼(WFD)로 보강된 2층 철근콘크리트골조 내진성능에 대한 실험적 연구)

  • Yoo, Chang-Gi;Choi, Chang-Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.6
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    • pp.64-72
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    • 2022
  • In this study, in order to confirm the seismic performance of reinforced concrete frames retrofitted with Wall Friction Damper(WFD), the test was conducted by setting two-story Reinforced concrete frames (reference specimen, OMF-N and specimen retrofitted with internal H-shaped steel frame and WFD, OMF-ALL(H)) as main variables. The WFD Seismic Retrofit Method is a mixture of strength improvement and energy dissipation methods. To prevent the pre-destruction of existing structure by friction force before sufficient energy dissipation of WFD, the internal H-shaped steel frame and chemical anchor that penetrates the side of the beam were used to install WFD. According to the test results, the OMF-N specimen showed an brittle failure pattern caused by the shear force of the R/C column after the maximum strength was expressed. The OMF-ALL(H) specimen showed that the reduction of pinching effect and the failure of the RC column occurred. Also, the maximum strength, cumulative energy dissipation and ductility of OMF-ALL(H) increased 3.01 times, 7.2 times and 1.72 times for OMF-N. As a results, test results revealed that the WFD Seismic Retrofit Method installed on Reinforced concrete structure improves the seismic performance and the strengthening effect is valid.