Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
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Effect of Nano-sized Calcium-silicate-hydrate (C-S-H) Crystals on Cement Hydration

나노 크기 칼슘-실리케이트-하이드레이트(C-S-H) 결정이 시멘트 수화에 미치는 영향 분석

  • Gyeong-Tae Kim (Dept. of Civil & Environmental Engineering, Gachon University) ;
  • Su-Ji Woo (Dept. of Civil & Environmental Engineering, Gachon University) ;
  • Sung-Won Yoo (Dept. of Civil & Environmental Engineering, Gachon University) ;
  • Young-Cheol Choi (Dept. of Civil & Environmental Engineering, Gachon University)
  • 김경태 (가천대학교 토목환경공학과) ;
  • 우수지 (가천대학교 토목환경공학과 ) ;
  • 유성원 (가천대학교 토목환경공학과) ;
  • 최영철 (가천대학교 토목환경공학과)
  • Received : 2023.05.15
  • Accepted : 2023.05.16
  • Published : 2023.06.30
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Abstract

In this study, nano-sized C-S-H crystals were synthesized using the liquid phase reaction method and their properties were investigated. The synthesized C-S-H crystals were added to the cement composite in suspension form to determine their effect on the hydration properties of the cement. The amount of chemical admixture was varied to obtain nano-sized C-S-H crystals with optimal agglomerated morphology, and SEM photographs were analyzed. A cleaning process was added to remove harmful substances other than the synthesiz ed C-S-H crystals. It was found that the concentration of harmful substances was reduced in the case of C-S-H crystals subjected to the cleaning process. The synthesized C-S-H suspensions were prepared with and without the cleaning process, and cement composites were prepared with the cement weight content as the main variable. The effect of C-S-H crystals on the initial hydration properties of the cement was confirmed by microhydration heat analysis. In addition, mortar specimens were prepared to measure the compressive strength over time. The test results showed that the nano-sized C-S-H crystals act as nucleation sites in the cement paste to promote the early hydration of the cement and increase the early compressive strength.

본 연구에서는 액상반응법을 이용하여 나노 크기의 C-S-H 결정을 합성하고 그 특성을 조사하였다. 합성한 C-S-H 결정을 현탁액 형태로 시멘트 복합체에 첨가하여 시멘트의 수화특성에 미치는 영향을 확인하였다. 최적 응집 형태의 나노 크기 C-S-H 결정을 도출하기 위해 화학혼화제의 양을 변수로 제조하였으며, SEM 사진 분석을 하였다. 합성된 C-S-H 결정외 유해물질을 제거하기 위해 세척 과정을 추가하였다. 세척과정을 거친 C-S-H 결정의 경우 유해물질의 농도가 낮아짐을 확인하였다. 합성된 C-S-H 현탁액은 세척 과정 유무에 따라 제조하였으며, 시멘트 중량대비 함유량을 주요 변수로 하여 시멘트 복합체를 제조하였다. 미소수화열 분석을 통해 C-S-H 결정이 시멘트의 초기 수화특성에 미치는 영향을 확인하였다. 또한, 모르타르 시험체를 제작하여 시간에 따른 압축강도를 측정하였다. 실험결과 나노 크기의 C-S-H 결정이 시멘트 페이스트 내에서 핵 생성처 역할을 하여 시멘트의 초기 수화를 촉진시키며, 초기 압축강도 또한 증가하는 것을 확인하였다.

Keywords

Acknowledgement

본 연구는 정부(과학기술정보통신부)의 재원으로 한국연구재단(2020R1A2C2008926)의 지원에 의해 수행되었습니다.

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