Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)
- Volume 4 Issue 1
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- Pages.45-55
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- 2002
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- 2233-8292(pISSN)
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- 2287-4747(eISSN)
Application of New Type Accelerator for High Quality Shotcrete
고품질 숏크리트 개발을 위한 새로운 급결제 적용
- Published : 2002.03.01
Abstract
From the early 1980's, the New Austrian Tunnelling Method (NATM) has been developed as one of the standard tunnelling methods in Korea. Approximately 10 years ago, wet-mix shotcrete with sodium silicate (waterglass) accelerator was introduced and widely used to tunnel lining and underground support. However, this accelerator had some disadvantages due to the decrease of long-term strength compared to plain concrete (without accelerator) and low quality of the hardened shotcrete. In order to compensate for these disadvantages, recently developed alkali-free accelerator has been successfully demonstrated in numerous projects and applications as a new material to make tunnels more durable and safer. An experimental investigation was carried out in order to verify the strength behavior of wet-mix Steel Fiber Reinforced Shotcrete (SFRS) with alkali-free accelerator. Compressive strength, flexural strength, and flexural toughness were measured by testing specimens extracted from the shotcrete panels. From the results, wet-mix SFRS with alkali-free accelerator exhibited excellent strength improvement compared to the conventional shotcrete accelerator.