Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
권호 표지
DOI QR코드

DOI QR Code

The Feasibility Study for Utilization of Blended Cement as a Activator of Bottom Ash from Circulating Fluidized Bed Combuster Boiler

순환유동층 보일러 바텀애시의 혼합시멘트 자극제 활용을 위한 타당성 연구

  • Received : 2020.06.10
  • Accepted : 2020.09.09
  • Published : 2020.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

Blended cement with fly ash and bottom ash from Circulating Fluidized Bed Combustor boiler(CFBC) burned at a low temperature, can be high heat of hydration and abnormal setting caused by higher volumn contents of Fe2O3, free-CaO, SO3. In this study, the ground CFBC bottom ash powder mixed with blast furnace slag was used as substitute activator of gypsum and recycled iron slag was produced from mix and pulverized by ball mill to increase the recycling rate. The effect on compressive strength of cements with the mixture of original and hydrated bottom ash mixtures with BFS with small water, respectively, was analyzed, and it was found that the hydrated bottom ash activator was more effective in initial strength development. To improve the initial strength of blended cement, an activator mixed with a blast furnace slag and bottom ash mixing ratio of 5:95 and 10:90, respectively, the slag cement by about 6%, and it was analyzed to develop an initial strength similar to gypsum as a conventional activator.

순환유동층 보일러는 낮은 온도에서 연소되기 때문에 플라이 애시와 바텀애시내에 Fe2O3, free-CaO, SO3 등의 함유량이 높아 시멘트 수화반응시 고온과 이상응결 등이 발생하고, 입자가 크기 때문에 콘크리트에서의 활용도가 제한적이다. 본 연구에서는 고로슬래그와 바텀애시를 혼합 분쇄하여 미분말을 석고대체제 자극제로 활용하고, 볼밀로 혼합분쇄시 폐철은 분리함으로서 재활용율을 높이고자 하였다. 원상태와 소량의 수분으로 기수화시킨 바텀애시를 슬래그와 혼합분쇄하여 자극제로서 시멘트강도에 미치는 영향을 분석하였으며, 기수화된 바텀애시를 사용한 경우 초기강도에 효과적인 것으로 나타났다. 혼합시멘트의 초기강도 향상을 위한 고로슬래그와 바텀애시 혼합비를 5:95와 10:90으로 혼합한 자극제를 혼합시멘트에 6% 정도 첨가하였으며, 석고와 유사한 초기 강도를 발현하는 것으로 분석되었다.

Keywords

References

  1. Chi, M., Huang, R. (2014). Effect of circulating fluidized bed combustion ash on the properties of roller compacted concrete, Cement and Concrete Composites, 45, 148-56. https://doi.org/10.1016/j.cemconcomp.2013.10.001
  2. Havlica, J., Brandstetr, J., Odler, I. (1998). Possibilities of utilizing solid residues from pressured fluidized bed coal combustion (PFBC) for the production of blended cements, Cement and Concrete Research, 28, 299-307. https://doi.org/10.1016/S0008-8846(97)00258-5
  3. Jeong, J.Y., Jang, S.Y., Choi, Y.C., Jung, S.H., Kim, S.I. (2015). Effects of replacement ratio and fineness of GGBFS on the hydration and pozzolanic reaction of high-strength high-volume GGBFS blended cement pastes, Journal of the Korea Concrete Institute, 27(2), 115-125 [in Korean]. https://doi.org/10.4334/JKCI.2015.27.2.115
  4. Kang, Y.H., Jung, S.H. (2017). Material properties of circulating fluidized bed combustion fly ash and utilization of non-sintered cement field, Magazine of RCR, 12(2), 26-32 [in Korean]. https://doi.org/10.14190/MRCR.2017.12.2.026
  5. Kang, Y.H., Lim, G.H., Kim, S.J., Choi, Y.C. (2018). Feasibility study on the use of CFBC ash as non-sintered binder, Journal of the Korea Institute for Structural Maintenance and Inspection, 22(5), 119-126 [in Korean]. https://doi.org/10.11112/JKSMI.2018.22.5.119
  6. Lee, G.H., Lee, S.H., Jo, U.J., Kim, G.S. (2015). Properties of modified slag binder using circulating fluidized bed combustion fly ash as activator, Proceeding of Korea Concrete Institute, 501-502 [in Korean].
  7. Park, J., Oh, H. (2018). A study on the pozzolan reactivity and mechanical characteristic of blended portland cements using CFBC fly ash, Journal of the Korean Recycled Construction Resources Institute, 6(3), 207-213 [in Korean]. https://doi.org/10.14190/JRCR.2018.6.3.207
  8. Park, J., Oh, H., Jung, G.S., Kang, C.H. (2020). Application on the CFBC fly ash as a stimulant to improve the early strength of hydration portland cement, Journal of the Korean Recycled Construction Resources Institute, 8(1), 8-16 [in Korean]. https://doi.org/10.14190/JRCR.2020.8.1.8
  9. Park, J.T., Oh, H.S. (2009). Experimental study on the material characteristics of slag cement with various phosphogypsum materials, Journal of the Korea Concrete Institute, 21(6), 729-735 [in Korean]. https://doi.org/10.4334/JKCI.2009.21.6.729
  10. Sheng, G., Li, Q., Zhai, J., Li, F. (2007). Self-cementitious properties of fly ashes from CFBC boilers co-firing coal and high-sulphur petroleum coke, Cement and Concrete Research, 37, 871-876. https://doi.org/10.1016/j.cemconres.2007.03.013
  11. Sim, J.S., Lee, K.G., Kim, Y.T., Kang, S.K. (2012). Hydration characteristics of coal-fly ash containing high CaO compound, Journal of the Korean Ceramic Society, 49(2), 185-190 [in Korean]. https://doi.org/10.4191/kcers.2012.49.2.185
  12. Wang, B., Song, Y.M. (2013). Methods for the control of volume stability of sulfur-rich CFBC ash cementitious system, Magazine of Concrete Research, 65(1), 1-5. https://doi.org/10.1680/macr.11.00191
  13. Xia, Y., Yan, Y., Hu, Z. (2013). Utilization of circulating fluidized bed fly ash in preparing non-autoclaved aerated concrete production, Construction and Building Materials, 47, 1461-1467. https://doi.org/10.1016/j.conbuildmat.2013.06.033