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Pore and Efflorescence Characteristics of Alkali Activated Slag-Red Mud Cement Mortar depending on Red Mud Content

레드머드 대체율에 따른 알칼리활성화 슬래그-레드머드 시멘트 모르타르의 기공 및 백화특성

  • Kang, Suk-Pyo (Department of Architecture, Woosuk University) ;
  • Kang, Hye-Ju (Department of Construction Engineering, Woosuk University)
  • Received : 2017.03.02
  • Accepted : 2017.04.13
  • Published : 2017.06.20

Abstract

Red mud is an inorganic by-product obtained from the mineral processing of alumina from Bauxite ores. A highly alkali inorganic waste product with a pH level over 11, red mud in its original state negatively impacts the ecosystem, so appropriate treatment is necessary. The development of alkali activated slag-red mud cement can be a representative study aimed at recycling the strong alkali of the red mud as a construction material. However, Alkali-activated binders that use sodium activators have been reported to be more vulnerable to efflorescence. Therefore, in this study, the compressive strength, pore characteristics, water absorption, elution characteristics, and efflorescence properties of alkali-activated slag cement mortar were assessed according to their red mud substitution ratio.

본 연구에서는 레드머드 대체율에 따른 알칼리활성화 슬래그-레드머드 시멘트 모르타르의 압축강도, 기공특성, 흡수율, 용출특성 및 백화 특성을 검토하여 알칼리활성화 슬래그 시멘트에 나트륨계 자극제인 레드머드를 사용함으로서 발생될 수 있는 백화특성을 확인하였다. 알칼리활성화 슬래그-레드머드 시멘트에서 레드머드 대체율이 높아질수록 10~100nm 직경의 기공은 증가하였으며 백화면적이 증가하는 것으로 나타났다. 알칼리활성화 슬래그-레드머드 시멘트의 백화물질은 $Na_2SO_4$가 가장 많이 생성되며 다음으로 $Na_2CO_3$로 백화의 발생원인은 레드머드에서 공급되는 Na+인 것으로 판단된다.

Keywords

References

  1. Pacheco-torcal, Fernando, Labrincha, Joao, Leonelli, C. Handbook of Alkali-activated cements, Mortars and Concretes. USA: Elsevier Science Ltd; 2014. Chapter 9, Analysing the relation between pore structure and permeability of alkali-activated concrete binders; p.243-57.
  2. Moon KJ. Properties of non-sintered cement and concrete recycled with industrial waste. Ph.D thesis. Korea: Chonbuk National University; 2004. 319 p.
  3. Kim TW, Hahm HG. The strength properties activated granulated ground blast furnace slag with aluminum potassium sulfate and sodium hydroxide. Journal of the Korea Concrete Institute. 2015 12;27(2):95-102. https://doi.org/10.4334/JKCI.2015.27.2.095
  4. Pontikes Y, Angelopoulos GN. Bauxite residue in cement and cementitious applications : Current status and a possible way forward, Resources. Conservation and Recycling. 2013 1;73:53-63. https://doi.org/10.1016/j.resconrec.2013.01.005
  5. Daniel VR, Joao AL, Marcio RM. Potential use of natural red mud as pozzolan for portland cement. Materials Research. 2011 11;14(1):60-6. https://doi.org/10.1590/S1516-14392011005000001
  6. Pan Z, Cheng L, Lu Y, Yang N. Hydration products of alkali-activated slag-red mud cementitious material. Cement and Concrete Research. 2002;32(3):357-62. https://doi.org/10.1016/S0008-8846(01)00683-4
  7. Pan Z, Li D, Yu J, Yang N. Properties and microstructure of the hardened alkali-activated red mud-slag cementitious material. Cement and Concrete Research. 2003 2;33(9):1437-41. https://doi.org/10.1016/S0008-8846(03)00093-0
  8. Kang SP, Kwon SJ. Effects of red mud and alkali-activated slag cement on efflorescence in cement mortar. Construction and Building Materials. 2017 12;133:459–67. https://doi.org/10.1016/j.conbuildmat.2016.12.123
  9. Kang SP, Kang HJ. Durability of alkali-activated slag-red mud cement mortar using polymer. Journal of the Architectural Institute of Korea Structure & Construction. 2017 1;33(1):81-8. https://doi.org/10.5659/JAIK_SC.2017.33.1.81