• Title/Summary/Keyword: High-Strength Mass Concrete

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Possibility of Using Landfill Coal Ash as CLSM Material for Emergency Restoration of Ground and Road Joint Parts (지반 및 도로 공동부의 긴급복구용 CLSM 재료로 매립 석탄저회 활용 가능성)

  • Jin-Man Kim;Sang-Chul Shin;Kyoung-Nam Min;Ha-Seog Kim
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.1
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    • pp.55-61
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    • 2023
  • This study aims to develop CLSM fill material for emergency restoration using landfill coal ash. As a result of examining physical properties such as particle size distribution and fines content of landfill coal ash, bottom ash, fly ash, and general soil were mixed, and SP was found to have a density of 2.03 and a residual particle pass rate of 7.8 %. CLSM materials that secure fluidity in unit quantities without using chemical admixtures such as glidants and water reducing agents have a high risk of material separation due to bleeding. As a result of this experiment, it was found that the bleeding ratio did not satisfy the standard in the case of the specimen with a large amount of fly ash and a lot of addition of mixing water. As a result of the compressive strength test, the strength development of 0.5 MPa or more for 4 hours was found to be satisfactory for the specimens using hemihydrate gypsum with a unit binder amount of 200 or more, and the remaining gypsum showed poor strength development. Although it is judged that landfill coal ash can be used as a CLSM material, it is necessary to identify and apply the physical and chemical characteristics of coal ash buried in the ash treatment plant of each power generation company.

An Analytical Study on the Buckling of Orthotropic Plates and Local Buckling of Compression Members (직교이방성 판의 좌굴 및 압축재의 국부좌굴에 대한 해석적 연구)

  • Choi, Jin-Woo;Lee, Kang-Yeon;Park, Jung-Hwan;Yoon, Soon-Jong
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.3 no.1
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    • pp.21-28
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    • 2012
  • In this paper, we present the analytical study results pertaining to the buckling of the orthotropic plates and local buckling of structural compression members composed of orthotropic plate components. Fiber reinforced polymeric plastic (FRP) materials, have many advantages over conventional structural materials such as steel and concrete. The advantages of the FRP materials are high specific strength and stiffness, high corrosion resistance, right weight, etc. Among the various manufacturing methods, pultrusion process is one of the best choices for the mass production of structural plastic members. Since the major reinforcing fibers are placed along the axial direction of the member, this material is usually considered as an orthotropic (tranversely isotropic, more specifically) material. However, pultruded fiber reinforced plastic structural members have low modulus of elasticity and are composed of orthotropic thin plate components the members are prone to buckle. Therefore, stability is an important issue in the design of the pultruded FRP structural members. In this paper, the buckling of orthotropic plates and the local buckling of pultruded FRP structural members are investigated by following the previous research results and the local buckling strength of the member produced in the domestic manufacturer is found.