Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
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Microstructure of Non-Sintered Inorganic Binder using Phosphogypsum and Waste Lime as Activator

  • Kim, Ji-Hoon (School of Engineering, Muroran Institute of Technology) ;
  • An, Yang-Jin (Technical R& D Center, Construction Materials Doctors Group Inc) ;
  • Mun, Kyung-Ju (Technical R& D Center, Construction Materials Doctors Group Inc) ;
  • Hyung, Won-Gil (School of Architectural Engineering, Yeungnam University)
  • Received : 2018.01.10
  • Accepted : 2018.03.08
  • Published : 2018.06.20
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Abstract

This study is about the development of a non-sintered binder (NSB) which does not require a sintering process by using the industrial by-products Phosphogypsum (PG), Waste Lime (WL) and Granulated Blast Furnace Slag (GBFS). In this report, through SEM analysis of the NSB paste hardening body, micropore analysis of paste using the mercury press-in method and microstructure observation were executed to consider the influence of the formation of the pore structure and the distribution of pore volume on strength, and the following conclusions were reached. 1) Pore structure of NSB paste of early age is influenced by hydrate generation amount by GBFS and activator. 2) Through observing the internal microstructure of NSB binder paste, it was found that the strength expression at early age due to hydration reaction was achieved with a large amount of ettringite serving as the frame with C-S-H gel generated at the same time. It was confirmed that C-S-H gel wrapped around ettringite, and as time passed, the amount generated continually increased, and C-S-H gel tightly filled the pores of hardened paste, forming a dense network-type web structure. 3) For NSB-type cement, the degree of formation of gel pores below $10{\mu}m$ had a greater influence on strength improvement than simple pore reduction by charging capillary pores, and the pore size that had the greatest effect on strength was micropores with diameter below $10{\mu}m$.

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References

  1. Mun KJ, Hyung WK, Lee CW, So SY, Soh YS. Basic properties of non-sintering cement using phosphogypsum and waste lime as activator. Construction and building materials. 2007 Jun;21(6):1342-50. https://doi.org/10.1016/j.conbuildmat.2005.12.022
  2. Bijen J, Niel E. Supersulphated cement from blastfurnace slag and chemical gypsum available in the Netherlands and neighbouring countries. Cement and concrete research. 1981 May;11(3):307-22. https://doi.org/10.1016/0008-8846(81)90104-6
  3. Erdem E, Olmez H. The mechanical properties of supersulphated cement containing phosphogypsum. Cement and concrete research. 1993 Jan;23(1): 115-21. https://doi.org/10.1016/0008-8846(93)90141-U
  4. Uchikawa H. Development of new cement and concrete. Gypsum and Lime. 1990;229: 497-505.
  5. Takemoto K, Uchikawa H. Hydration of pozzolanic cement. Proceedings of the 7th International Congress on the Chemistry of Cement; 1980 Jun 30-Jul 4; Paris, France. Paris(France): Editions Septima; 1980. p. 1-29.
  6. Gruskovnjak A, Lothenbach B, Winnefeld F, Figi R, Ko SC, Adler M, Mader U. Hydration mechanisms of super sulphated slag cement. Cement and concrete research. 2008 Jul;38(7):983-92. https://doi.org/10.1016/j.cemconres.2008.03.004
  7. Peiyu Y, Wenyan Y. The cementitious binder derived with fluorogypsum and low quality of fly ash. Cement and concrete research. 2000 Feb;30(2):275-80. https://doi.org/10.1016/S0008-8846(99)00245-8
  8. Midgley HG, Pettifer K. The microstructure of hydrated super sulphated cement. Cement and concrete research. 1971 Jan;1(1):101-4. https://doi.org/10.1016/0008-8846(71)90086-X
  9. Dan TK, Chatterjee MK. Activation of an indian blast furnace slag by lime and lime-gypsum mixed activator in solution phase. Indian journal of technology. 1985:23(9);337-44.
  10. Bijen J, Niel E. Supersulphated cement: Improved properties, silic. Ind. 1982:47(2);45-53.
  11. Diamond S. Cement paste microstructure-an overview at several levels. Proceedings of a conference on Hydraulic Cement Paste: their structures and properties; 1976 Apr 8-9; University of Sheffield, UK. Wexham springs slough(UK): Cement Concrete Associate; 1976. p. 2-30.