• Title/Summary/Keyword: permanent shotcrete linings

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Development of High Performance Shotcrete for Permanent Shotcrete Tunnel Linings (III) (Field Test of Wet-mixed Shotcrete with Powder Types Cement Mineral Accelerator) (Permanent Shotcrete Tunnel Linings 구축을 위한 고성능 숏크리트 개발(III)(시멘트 광물계 분말형 급결제를 사용한 습식숏크리트 현장시험시공))

  • 박해균;이명섭;김재권;김용하
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.609-617
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    • 2003

  • The use of Shotcrete(Sprayed concrete) for the support of underground excavations was pioneered by the Civil engineering industry. Permanent shotcrete tunnel linings such as Single-shell, NMT(Norwegian Method of Tunnelling) have been constructed in many countries for reducing construction time and lowering construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of Permanent Shotcrete Linings, high performance shotcrete having high strength, high durability, better pumpability has to be developed in advance. This paper presents the ideas and the first field test results of wet-mixed Steel Fiber Reinforced Shotcrete(SFRS) with powder types cement mineral accelerator. From the results, wet-mix SFRS with powdered accelerator exhibited good early strength improvement and less rebound ratio compared to the ordinary accelerator.

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Development of High Performance Shotcrete for Permanent Shotcrete Tunnel Linings II(II： Application of high-early strength cement in sump water condition) (Permanent Shotcrete Tunnel Linings 구축을 위한 고성능 숏크리트 개발 II (II： 용수부에서의 조강시멘트 적용))

  • 박해균;이명섭;김재권;안병제
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.695-702
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    • 2002

  • Shotcrete (or Sprayed concrete) has been used as an important support material in New Austrian Tunnelling Method (NATM). Since the mid of 1990, permanent shotcrete tunnel linings such as Single-shell, NMT (Norwegian Method of Tunnelling) has been constructed in many countries for reducing the construction time and lowing construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of permanent shotcrcte linings, high performance shotcrete providing high strength, high durability, better pumpability has to be developed in advance as an integral component. This paper presents the Ideas and first experimental attempts to increase early strength and bond strength of wet-mixed Steel Fiber Reinforced Shotcrete(SFRS) in sump water condition. In order to increase early strength, a new approach using high-early strength cement with liquid alkali-free accelerator has been investigated From the results, wet-mix SFRS with high-early strength cement and alkali-free accelerator exhibited excellent early strength improvement compared to the ordinary portland content and good bond strength even under sump water condition.

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Development of high performance shotcrete for permanent shotcrete tunnel linings (Application of high-early strength cement with alkali-free accelerator in spring water condition) (영구 숏크리트 터널 라이닝 구축을 위한 고성능 숏크리트 개발 (용수부에서의 조강시멘트와 alkali-free급결제 적용 검토))

  • Park, Hae Geun;Lee, Myeong Sub;Kim, Jea Kwon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.5 no.1
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    • pp.23-31
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    • 2003

  • Since the mid of 1990, permanent shotcrete tunnel linings such as Single-shell and NMT have been constructed in many countries for reducing the construction time and lowing construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of permanent shotcrete linings, high performance shotcrete having high strength, high durability and better pumpability has to be developed in advance as an integral component. This paper presents the idea and first experimental attempts to increase early strength and bond strength of wet-mixed Steel Fiber Reinforced Shotcrete (SFRS) in spring water condition. In order to increase early behavior of SFRS, a new approach using high-early strength cement with alkali-free liquid accelerator has been investigated. From the test results, wet-mix SFRS with high-early strength cement and alkali-free accelerator exhibited excellent early compressive strength improvement compared to the ordinary portland cement and good bond strength even under spring water condition.

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Development of High Performance Shotcrete for Permanent Shotcrete Tunnel Linings(II) (Construction of Wet-Mixed Shotcrete with Powder Types Cement Mineral Accelerator) (영구 숏크리트 터널 라이닝 구축을 위한 고성능 숏크리트 개발（II） - 시멘트 광물계 분말형 급결제를 사용한 습식 숏크리트 시공 -)