Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
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Self-Healing Properties in Cracking of Blast Furnace Slag Cement Paste

고로 슬래그 시멘트 페이스트 균열에서의 자기치유 특성

  • Lee, Seung-Heun (Dep. of Materials Engineering, Kunsan National University) ;
  • Kang, Kook-Hee (Dep. of Materials Engineering, Kunsan National University) ;
  • Lim, Young-Jin (Dep. of Materials Engineering, Kunsan National University) ;
  • Lee, Se-Jin (Dep. of Materials Engineering, Kunsan National University) ;
  • Park, Byeong-Seon (Korea Conformity Laboratories)
  • 이승헌 (군산대학교 신소재공학과) ;
  • 강국희 (군산대학교 신소재공학과 대학원) ;
  • 임영진 (군산대학교 신소재공학과 대학원) ;
  • 이세진 (군산대학교 신소재공학과 대학원) ;
  • 박병선 (한국건설생활환경시험연구원)
  • Received : 2019.01.03
  • Accepted : 2019.02.07
  • Published : 2019.03.30
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Abstract

This study investigated the self-healing properties of blast furnace slag cement paste sample with $Na_2SO_4$ as a blast furnace slag activator after conducting the permeability test. Self-healing properties were examined by crack filling ratio and quantification of self-healing products. The degree of self-healing was evaluated by the crack filling ratio, and the crack filling ratio was analyzed by panoramic analysis using BSE-DIP for objectivity. The average crack filling ratio showed a tendency of decreasing from the upper part of the specimen to the lower part as the average of the top part was 18%, the middle part was 7% and the bottom part was 5% on average. The maximum crack filling ratio was 44% and the minimum crack filling ratio was 3%. The residual self-healing product after the permeability test contained a large amount of Ca element and Al element derived from the blast furnace slag, and the Si element was mainly present near the crack surface. The most abundant minerals in self-healing products were about 68% C-A-H. $CaCO_3$ was about 13% and C-A-S-H was about 8%. Three minerals accounted for 90% of self-healing products. C-A-H was mainly present at a part slightly distant from the crack surface and showed an angular or acicular shape. The C-A-S-H was generated on the surface naturally connected to the existing specimen, and the $CaCO_3$ was generally observed on the surface of the specimen or the inside of the crack.

본 연구는 투수시험 실시 후 고로 슬래그 자극제로 $Na_2SO_4$를 첨가한 고로 슬래그 시멘트 페이스트 시편의 자기치유 특성으로서 충진율과 자기치유 생성물을 고찰하였다. 실시한 시편에 대해 충진율과 자기치유 생성물을 분석하였다. 자기치유 정도는 충진율로 평가하였으며 충진율은 객관성을 갖기 위해 BSE-DIP를 이용한 파노라마 분석법으로 실시하였다. 평균 충진율은 Top 부분은 평균 18%, Middle 부분은 평균 7%, Bottom 부분은 평균 5%로 시편의 윗부분에서 아래 부분으로 갈수록 충진율은 감소되는 경향을 나타냈다. 또한 구간별 최대 충진율은 44%이었고 최소 충진율은 3%이었다. 투수시험 후 잔존하는 자기치유생성물은 기본적으로 Ca 원소와 고로 슬래그에서 유래된 Al 원소를 다량 함유하고 있었으며 Si 원소는 균열 표면으로부터 가깝게 위치한 곳에 주로 존재하였다. 자기치유 생성물 중에서 가장 많이 존재하는 광물은 C-A-H로 68% 정도 존재하였다. $CaCO_3$는 13%, C-A-S-H는 8% 순으로 3가지 물질이 자기치유 생성물의 90% 정도를 차지하고 있었다. C-A-H는 주로 균열 표면에서 약간 떨어진 부분에서 존재하였으며 각진 형태 이거나 침상 형태의 형상을 나타냈다. C-A-S-H는 기존의 시편과 자연스럽게 이어지게 표면을 타고 생성되었으며 $CaCO_3$는 시편의 표면이나 균열의 내부 등 위치에 상관없이 전반적으로 보였다.

Keywords

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Fig. 1. Sample preparation process for BSE test

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Fig. 2. Images derived from a portion of the crack using image tool

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Fig. 3. BSE images for top, middle and bottom

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Fig. 4. Total image and self-healing product(sky blue) image of top, middle and bottom

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Fig. 5. Crack filling ratio of top, middle and bottom

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Fig. 6. SEM-EDS analysis for each part of the crack

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Fig. 7. Element analysis of self-healing product by SEM-EDS overlaying

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Fig. 8. Molar ratios of self-healing product

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Fig. 9. Type and amount of self-healing product of top, middle and bottom

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Fig. 10. Type and amount of self-healing product in crack

Table 1. Chemical composition of raw materials(Mass %)

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References

  1. Ahn, T.H., Kishi, T. (2010). Crack self-healing behavior of cementitious composites incorporating various mineral admixtures, Journal of Advanced Concrete Technology, 8(2), 171-186. https://doi.org/10.3151/jact.8.171
  2. Chen, J., Liu, X., Ye, G. (2016). Quantification the filling of microcracks due to autogenous self-healing in cement paste, International RILEM Conference on Materials, International RILEM Conference on Materials, 22-24.
  3. Huang, H., Ye, G., Damidot, D. (2013). Characterization and quantification of self-healing behaviors of microcracks due to further hydration in cement paste, Cement and Concrete Research, 52, 71-81. https://doi.org/10.1016/j.cemconres.2013.05.003
  4. Hong, G.T., Choi, S.C. (2017). Rapid self-sealing of cracks in cementitious materials incorporating superabsorbent polymers, Construction and Building Materials, 143, 366-375. https://doi.org/10.1016/j.conbuildmat.2017.03.133
  5. Huang, H., Ye, G., Damiot, D. (2014). Effect of blast furnace slag on self-healing of microcracks in cementitious materials, Cement and Concrete Research. 60, 68-82. https://doi.org/10.1016/j.cemconres.2014.03.010
  6. Joseph, C., Gardner D., Jefferson, T., Isaacs, B., Lark, B. (2010). Self-healing cementitious materials: a review of recent work, Proceedings of the ICE - Construction Materials, 164(1), 29-41. https://doi.org/10.1680/coma.900051
  7. Jiang, Z., Li, W., Yuan, Z. (2015). Influence of mineral additives and environmental conditions on the self-healing capabilities of cementitious materials, Cement and Concrete Composites, 57, 116-127. https://doi.org/10.1016/j.cemconcomp.2014.11.014
  8. Kapeluszna, E., Kotowica, L., Rozycka, A., Golek, L. (2017). Incorporation of Al in C-A-S-H gels with various Ca/Si and Al/Si ratio: Microstructural and structural characteristics with DTA/TG, XRD, FTIR and TEM analysis, Construction Building Materials, 155, 643-653. https://doi.org/10.1016/j.conbuildmat.2017.08.091
  9. Mehta, P.K., Monteiro, P.J.M. (2006). Concrete-Third Edition, McGraw-Hill, 121-198.
  10. Nijland, T.J., Larbi, J.A., van Hees, R.P.J., Lubelli, B., de Rooij, M.R. (2007). "Self-healing phenomena in concretes and masonry mortars: a microscopic study," Proceedings of the First International Conference on self Healing Materials, Noordwijk aan zee, the Netherlands April, 1-9.
  11. Neville, A.M. (2012). Properties of Concrete: Fourth and Final Edition, McGraw-Hill, 91-102.
  12. Wang, S.D., Scrivener, K.L. (1995). Hydration products of alkali activated slag cement, Cement and Conrete Research, 25, 561-571. https://doi.org/10.1016/0008-8846(95)00045-E