Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
권호 표지
DOI QR코드

DOI QR Code

The Strength Properties Activated Granulated Ground Blast Furnace Slag with Aluminum Potassium Sulfate and Sodium Hydroxide

칼륨명반과 수산화나트륨으로 활성화된 고로슬래그 미분말의 강도 특성

  • Kim, Taw-Wan (Research Institute of Industrial Technology (RIIT), Pusan National University) ;
  • Hahm, Hyung-Gil (Dept. of Civil and Environmental Engineering, Major in Civil Engineering, Pusan National University)
  • 김태완 (부산대학교 생산기술연구소) ;
  • 함형길 (부산대학교 일반대학원 사회환경시스템공학과 토목공학전공)
  • Received : 2014.07.08
  • Accepted : 2014.12.09
  • Published : 2015.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the effects of sodium hydroxide (NaOH) and aluminum potassium sulfate ($AlK(SO_4)_2{\cdot}12H_2O$) dosage on strength properties were investigated. For evaluating the property related to the dosage of alkali activator, sodium hydroxide (NaOH) of 4% (N1 series) and 8% (N2 series) was added to 1~5% (K1~K5) dosage of aluminum potassium sulfate ($AlK(SO_4)_2{\cdot}12H_2O$) and 1% (C1) and 2% (C2) dosage of calcium oxide (CaO). W/B ratio was 0.5 and binder/ fine aggregate ratio was 0.5, respectively. Test result clearly showed that the compressive strength development of alkali-activated slag cement (AASC) mortars were significantly dependent on the dosage of NaOH and $AlK(SO_4)_2{\cdot}12H_2O$. The result of XRD analysis indicated that the main hydration product of $NaOH+AlK (SO_4)_2{\cdot}12H_2O$ activated slag was ettringite and CSH. But at early ages, ettringite and sulfate coated the surface of unhydrated slag grains and inhibited the hydration reaction of slag in high dosage of $NaOH+AlK(SO_4)_2{\cdot}12H_2O$. The $SO_4{^{-2}}$ ions from $AlK(SO_4)_2{\cdot}12H_2O$ reacts with CaO in blast furnace slag or added CaO to form gypsum ($CaSO_4{\cdot}2H_2O$), which reacts with CaO and $Al_2O_3$ to from ettringite in $NaOH+AlK(SO_4)_2{\cdot}12H_2O$ activated slag cement system. Therefore, blast furnace slag can be activated by $NaOH+AlK(SO_4)_2{\cdot}12H_2O$.

본 연구는 수산화나트륨(NaOH)과 칼륨명반($AlK(SO_4)_2{\cdot}12H_2O$)의 농도에 따른 강도특성에 관한 연구이다. 활성화제의 농도에 따른 강도 특성연구를 위해 4%(N1 series)와 8%(N2 series) 농도의 NaOH에 대해 1~5%(K1~K5) 농도의 칼륨명반과 1%(C1)과 2%(C2) 농도의 산화칼슘(CaO)을 고려하였다. 물-결합재 비(W/B)는 0.5, 결합재/잔골재의 비는 0.5로 하였다. 실험결과 알칼리 활성화 슬래그 시멘트(AASC)의 강도는 NaOH와 $AlK(SO_4)_2{\cdot}12H_2O$의 농도에 영향을 받았다. XRD 분석결과 NaOH와 $AlK(SO_4)_2{\cdot}12H_2O$에 의해 활성화된 슬래그의 주요 반응생성물질은 ettringite와 CSH로 나타났다. 그러나 초기재령에서 ettringite와 황산염은 미수화된 고로슬래그 미분말의 표면에 침착하거나 고로슬래그 미분말의 수화반응을 방해하였다. $AlK(SO_4)_2{\cdot}12H_2O$에서 용출된 $SO_4{^{-2}}$ 이온은 고로슬래그 미분말에 포함된 CaO와 첨가된 CaO와 반응하여 석고(gypsum, $CaSO_4{\cdot}2H_2O$)를 생성하고, 다시 CaO와 $Al_2O_3$와 반응하여 ettringite를 생성한다. 따라서 $NaOH+AlK(SO_4)_2{\cdot}12H_2O$는 고로슬래그 미분말의 활성화를 통한 강도향상에 효과가 있음을 알 수 있었다.

Keywords

References

  1. Kim, G. W., Kim, B. J., Yang, K. H., and Song, J. K., "Strength Development of Blended Sodium Alkali-Activated Ground Granulated Blast-Furnace Slag(GGBS) Mortar", Journal of the Korea Concrete Institute, Vol. 24, No. 2, 2012, pp. 134-145.
  2. Kim, J. H., Lee, J. K., Bae, S. C., and Hyung, W. G., "Properties of Alkali-Activated Cement Mortar by Curing Method", Journal of the Korea Concrete Institute, Vol. 26, No. 2, 2014. pp. 117-124. https://doi.org/10.4334/JKCI.2014.26.2.117
  3. Yang, K. H. and Sin, J. I., "Compressive Strength and Shrinkage of Slag-Based Alkali-Activated Mortar with Gypsum", Journal of the Korea Institute of Building Construction, Vol. 8, No. 1, 2008, pp. 57-62. https://doi.org/10.5345/JKIC.2008.8.1.057
  4. Escalante-Garcia, J. I., Fuentes, F. A., Gorokhovsky, A., Fraire-Luna, P. E., and Mendoza-Suarez, G., "Hydration Products and Reactivity of Blast-Furnace Slag Activated by Various Alkalis", Journal of American Ceramic Society, Vol. 86, No. 12, 2003, pp. 2148-2153. https://doi.org/10.1111/j.1151-2916.2003.tb03623.x
  5. Rashad, A. M., Bai, Y., Basheer, P. A. M., Milestone, N. B., and Collier, N. C., "Hydration and properties of sodium sulfate activated slag", Cement & Concrete Composites, Vol. 37, 2013, pp. 20-29. https://doi.org/10.1016/j.cemconcomp.2012.12.010
  6. Rashad, A. M., Bai, Y., Basheer, P. A. M., Collier, N. C., and Milestone, N. B., "Chemical and mechanical stability of sodium sulfate activated slag after exposure to elevated temperature", Cement and Concrete Research, Vol. 42, 2012, pp. 333-343. https://doi.org/10.1016/j.cemconres.2011.10.007
  7. Song, C. T., "Hydration of Granulated Blast Furnace Slag in the Presence of $CaSO_4$", Journal of the Korea Ceramic Society, Vol. 17, No. 4, 1980, pp. 208-212.
  8. Kim, H. S., Jo, Y. D., Ahn, J. W., Kimura, K., and Han, C., "Activation Property of Blast Furnace Slag by Calcined Alumite", Journal of Korean Inst. of Resources Recycling, Vol. 15, No. 4, 2006, pp. 27-35.
  9. Wu, X., Jiang, W., and Roy, D. M., "Early activation and properties of slag cement", Cement and Concrete Research, Vol. 20, 1990, pp. 961-974. https://doi.org/10.1016/0008-8846(90)90060-B