Properties of Modified Belite Cement with the Content of Clinker Minerals

클링커 광물 함량 변화시 Modified belite Cement의 특성

  • 최연묵 (한양대학교 세라믹공정연구센터) ;
  • 이양수 (동양중앙연구소) ;
  • 김남호 (동양중앙연구소) ;
  • 최상홀 (한양대학교 세라믹공정연구센터)
  • Published : 1998.05.01

Abstract

Raw mateials such as limestone quartzite bauxite and anhydrite were used in the production of mod-ified beloite cement. Two kinds of clinker were synthesized with relatively higher content of $C_2S$ than that of $C_4A_3{\={S}}$ Concerning $C_2S$ the main mineral component borax ($Na_2O\;2B_2O_3\;10H_2O$) was added to stimu-late hydraulic reactivity and this would be possible by stabilizing ${\alpha}'-C_2S$ at room temperature. We had in-tended to compare burning and hydraulic characteristics of clinkers with one another by varying the amount of borax addition and to study the appropriate amount of anhydrite addition needed in the strengthening of cement during hydration. It was concluded that the effective amount of borax addition ne-eded for stabilization of ${\alpha}'-C_2S$ was 5 wt% in 60wt% $C_2S$ inclusive clinker and adding anhydrite in the ra-tio of 1.3 of $SO_3/Al_3O_3$ was appropriate in the production of cement by this clinker. Only ettringite was seen to contribute to the strength without additives but C-S-H was found to form along with ettringite with the addition of borax in the initial stage of hydration.

천연 원료인 석회석, 규석, bauxite, 무수석고를 이용하여 belite계 시멘트의 한 종류인 고기능성의 modified belite cement를 제조하고자 $C_4A_3{\={S}}$에 비해 $C_2S$의 함량이 상대적으로 많은 두가지 클링커를 합성하였다. 주광물 $C_2S$는, 고온형의 ${\alpha}'-C_2S$를 상온까지 안정화시켜서 수화시 활성을 높이기 위해 붕사($Na_2O\;2B_2O_3{\cdot}10H_2O$)를 첨가하였다. 붕사의 첨가량을 변화시켜 각 클링커의 소성과 수화특성을 비교하고, 이들을 시멘트로 제조할 때 무수석고의 함량을 변화시켜 강도 증진에 기여하는 적정 석고 혼합량을 구하고자 하였다. 그 결과, $C_2S$의 함량을 60 wt.%로 목적할 때, ${\alpha}'-C_2S$로 안정화시키기 위한 붕사의 첨가량은 5 wt.%가 효과적이었으며, 시멘트 제조시 $SO_3/Al_3O_3$ 비가 1.3이 되도록 무수석고를 첨가한는 것이 적절하였다. 붕사가 없는 경우 수화 초기에 ettringite만이 강도에 기여하는 반면 봉사를 첨가하면 수화 초기에 ettringite와 함게 C-S-H 수화물이 생성되었음을 알 수 있었다.

Keywords

References

  1. Cem.Conc.Res. v.16 no.3 Influence of Alkalies on the Composition of Belite-rich Cement Clinkers and the Technological Properties of the Resulting Cement A.Gies;D.Knofel;M.Bujan
  2. J.Am.Ceram.Soc. v.60 no.3-4 Preparation of Very Reactive Ca2SiO₄Powder D.M.Roy;S.O.Oyefesobi
  3. Cem.Conc.Res. v.1 no.1 Belite in Portland Cement L.Hjorth;K.-G.Lauren
  4. Cem.Conc.Res. v.24 no.4 Studies on the Formation Kinetics Calcium Sulphoaluminate M.MAli;S.Gopal;S.K.Handoo
  5. J.Kor.Ceram.Soc. v.27 no.2 Synthesis and Hydration of Modified Belite Cement Clinker C.B.Kim;K.S.Han;S.H.Choi
  6. 8th Inter.Cong.Chem.Cem. v.2 Conditions of the Existence of Hydraulically Active Belite Cement J.Stark;A.Muller;R.Sydel
  7. 8th Inter.Cong.Chem.Cem v.1 Special Cement W.Kurdowski;C.M.George;F.P.Sorientino
  8. 6th Inter.Cong Chem.Cem. The Mechanism of Clinker Formation Process and Ways of Modification Y.M.Butt;V.V.Timashev
  9. The Chemistry of Portland Cement R.H.Bogue
  10. Cement Chemistry H.F.W.Taylor
  11. Cem.Conc.Res. v.23 no.6 Phase Compatibility in the System CaO-SiO₂-Al₂O₃-Fe₂O₃-SO₁Referred to Sulphoaluminate Belite Cement Clinker S.Sahu;J.Majling