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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 (Department of Architectural Engineering, Seoul National University of Science and Technology) ;
  • Seo, Seung-Hoon (Department of Design and Engineering, Seoul National University of Science and Technology)
  • Received : 2018.08.29
  • Accepted : 2018.12.21
  • Published : 2019.02.20

Abstract

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.

현대에 가장 널리 쓰이는 건축 재료인 콘크리트는 기술의 지속적인 발전에 따라 고강도화 뿐만 아니라 인성 및 연성의 증가, 경량화와 같은 구조적 성능의 향상이 되었다. 또한 인간의 삶의 질이 향상됨에 따라 감성을 충족시킬 수 있는 것에 대한 수요의 급증으로 건축용 외장패널 그리고 건축의 경계를 넘어 인테리어 소품으로까지 다양하게 쓰이는 추세이다. 국내에서는 플라스틱 봉을 삽입하여 빛과 콘크리트의 결합으로 사용자의 감성을 자극하는 빛 감성친화형콘크리트(LEFC)를 개발하였으나, 높은 단위중량으로 인한 현장에서의 시공성 한계를 보여주었다. 이에 본 연구에서는 LEFC에 기포제를 적용하여 단위중량을 감소시켜 경량화를 달성하고 휨 성능 향상을 위해 두 가지 유기섬유(Nylon Fiber, Polyvinyl Alcohol)를 혼입하여 비교분석하였다. 마지막으로 플라스틱 봉 삽입으로 인한 콘크리트 비표면적 손실 및 봉과의 부착력 감소로 인한 휨 강도 변화를 봉의 직경(5mm, 10mm)과 간격(10mm, 15mm, 20mm)에 따른 변수를 적용한 예측 모델을 제안하고자 한다.

Keywords

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Figure 1. Detailed images of materials

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Figure 2. Production process of LEFC concrete

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Figure 3. Completed LEFC block

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Figure 4. LEFC blocks with varying diameters and spacing

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Figure 5. Slump test result

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Figure 6. Unit volume weight test result

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Figure 7. Compressive strength test result

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Figure 8. Flexural behavior characteristics

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Figure 9. Flexural strength test result

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Figure 10. Toughness (0∼P150) (Foam_Nylon)

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Figure 11. Toughness (0~P150) (Foam_PVA)

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Figure 12. Cross sections of flexural test specimens

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Figure 13. Parameter definition

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Figure 14. Trend line by parameter

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Figure 15. Prediction model

Table 1. Properties of foaming agent

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Table 2. Properties of fibers

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Table 3. Mix design

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Table 4. Parameter data

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Table 5. Flexural strength analysis

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