Influence of Calcium Silicate Hydrate Seed on Compressive Strength of CaO-SiO2-H2O Autoclaved System and Its Mechanism Analysis

被引：0
作者：
Zhang H. [1 ,2 ]
Wei J. [1 ,2 ]
Zhao Z. [1 ,2 ]
Yu Q. [1 ,2 ]
Li F. [1 ,2 ]
机构：
[1] School of Materials Science and Engineering, South China University of Technology, Guangzhou
[2] Low Carbon Technology Engineering Research Center for Building Materials of Guangdong Province, Guangzhou
来源：
Li, Fangxian (msfxli@scut.edu.cn) | 1600年 / Cailiao Daobaoshe/ Materials Review卷 / 31期
关键词：
Autoclaved silicate products; Calcium silicate hydrate; Degree of hydration; Fly ash; Seed crystals;
D O I：
10.11896/j.issn.1005-023X.2017.014.026
中图分类号：
学科分类号：
摘要：
The effect of calcium silicate hydrate seed on the CaO-SiO2-H2O hydrothermal reaction was studied. Calcium silicate hydrate seed were prepared by hydrothermal synthesis with lime and nano silica under different thermal conditions. Chemical analysis method was used for the determination of reactive degree of fly ash. The effect of calcium silicate hydrate seed on types and morphology of hydration products was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). The distribution of pore size was investigated by mercury intrusion porosimetry (MIP). The results indicated that the compression strength of CaO-SiO2-H2O autoclaved system increased most obviously when mixed with calcium silicate hydrate and synthesized under the 150℃ with calcium silica ratio of 1.0. Calcium silicate hydrate seed promoted dissolution of SiO2PPP from fly ash and decomposition of hydrogarnet, and accelerated the generation of hydration products (mainly C-S-H(B) and tobermorite). Meamwhile, the pore structure was refined and the distribution of the pore size was more uniform with the addition of calcium silicate hydrate. The addition of calcium silicate hydrate caused the number of pores below 50 nm increase and the number of pores above 200 nm decrease, compared with the reference sample. © 2017, Materials Review Magazine. All right reserved.
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页码：122 / 126and137
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共 16 条
  • [1] Alexanderson, Relations of structure and mechanical properties of autoclaved aerated concrete, Cem Concr Compos, 4, 9, (1979)
  • [2] Sun B., Li G., Jia C., The relationship between the hydrates and the strength and shrinkage of autoclaved aerated concrete, J Chin Ceram Soc, 11, 1, (1983)
  • [3] Rios C.A., Williams C.D., Fullen M.A., Hydrothermal synthesis of hydrogarnet and tobermorite at 175℃from kaolinite and metakaolinite in the CaO-Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub>-H<sub>2</sub>O system: A comparative study, Appl Clay Sci, 43, 2, (2009)
  • [4] Mitasuda T., Taylor H.F.W., Influence of aluminium on the conversion of calcium silicate hydrate gels into 11 Å tobermorite at 90℃ and 120℃, Cem Concr Res, 5, 3, (1975)
  • [5] Al-Wakeel E.L., El-Korashy S.A., Reaction mechanism of hydrothermally treated CaO-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub> and CaO-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-CaSO<sub>4</sub> systems, J Mater Sci, 31, 7, (1996)
  • [6] Hong S.Y., Glasser F.P., Phase relations in the CaO-SiO<sub>2</sub>-H<sub>2</sub>O system to 200℃ at saturated steam pressure, Cem Concr Res, 34, (2004)
  • [7] Isu N., Et al., Influence of quartz particle size on the chemical and mechanical properties of autoclaved aerated concrete(I) tobermorite formation, Cem Concr Res, 25, 2, (1995)
  • [8] Al-Wakeel, El-Korashy S.A., El-Hemaly S.A., Promotion effect of C-S-H phase nuclei on building calcium silicate hydrate phase, Cem Concr Compos, 21, 3, (1999)
  • [9] Wang Z., Yang Y., Li J., Preparation of C-S-H-phase nuclei and its effects on compressive sthrenth of cement, Mater Sci Technol, 15, 6, (2007)
  • [10] Yao B., Et al., New hardening accelerator affecting concrete properties, Concrete, 9, (2005)
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