The effect of silica availability on the mechanism of geopolymerisation

被引:216
作者
Hajimohammadi, Ailar [1 ]
Provis, John L. [1 ]
van Deventer, Jannie S. J. [1 ,2 ]
机构
[1] Univ Melbourne, Dept Chem & Biomol Engn, Melbourne, Vic 3010, Australia
[2] Zeobond Pty Ltd, Somerton, Vic 3062, Australia
基金
澳大利亚研究理事会;
关键词
Alkali activated cement; Kinetics; Reaction; Nucleation; Characterization; FLY-ASH; GEL FORMATION; SODIUM ALUMINATE; FTIR; MICROSTRUCTURE; MICROANALYSIS; TECHNOLOGY; ACTIVATION; MICROSCOPY; CHEMISTRY;
D O I
10.1016/j.cemconres.2011.02.001
中图分类号
TU [建筑科学];
学科分类号
0813 ;
摘要
The effect of silica availability on geopolymer binder formation is investigated in the geothermal silica-sodium aluminate-water system, using sodium silicate solution as an additional, highly available silica source. Time-resolved and spatially-resolved FTIR data are combined to provide a mechanistic understanding of the role of silica availability in controlling geopolymer nucleation and gel growth behaviour. A higher degree of alumina contribution to geopolymer gels and newly formed crystal phases is observed in systems with higher silica availability. Gel nucleation is observed to take place in the region immediately surrounding the solid silica source particles when no dissolved silica is initially supplied. Conversely, mixes which initially contain dissolved silica show nucleation in bulk regions, and involving more of the Al which is rapidly released from the sodium aluminate precursor. These differences in nucleation lead to a more chemically heterogeneous binder in the case where silica is released more gradually. (C) 2011 Elsevier Ltd. All rights reserved.
引用
收藏
页码:210 / 216
页数:7
相关论文
共 41 条
[1]  
BARRER RM, 1972, J CHEM SOC DA, V22, P2534
[2]   Geopolymer synthesis using silica fume and sodium aluminate [J].
Brew, D. R. M. ;
MacKenzie, K. J. D. .
JOURNAL OF MATERIALS SCIENCE, 2007, 42 (11) :3990-3993
[3]   Alkali activation of fly ash:: Effect of the SiO2/Na2O ratio Part I:: FTIR study [J].
Criado, M. ;
Fernandez-Jimenez, A. ;
Palomo, A. .
MICROPOROUS AND MESOPOROUS MATERIALS, 2007, 106 (1-3) :180-191
[4]  
Davidovits J., 2008, GEOPOLYMER CHEM APPL
[5]   Kinetics of geopolymerization:: Role of Al2O3 and SiO2 [J].
De Silva, P. ;
Sagoe-Crenstil, K. ;
Sirivivatnanon, V. .
CEMENT AND CONCRETE RESEARCH, 2007, 37 (04) :512-518
[6]   Geopolymer technology:: the current state of the art [J].
Duxson, P. ;
Fernandez-Jimenez, A. ;
Provis, J. L. ;
Lukey, G. C. ;
Palomo, A. ;
van Deventer, J. S. J. .
JOURNAL OF MATERIALS SCIENCE, 2007, 42 (09) :2917-2933
[7]   Understanding the relationship between geopolymer composition, microstructure and mechanical properties [J].
Duxson, P ;
Provis, JL ;
Lukey, GC ;
Mallicoat, SW ;
Kriven, WM ;
van Deventer, JSJ .
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 2005, 269 (1-3) :47-58
[8]   The role of inorganic polymer technology in the development of 'green concrete' [J].
Duxson, Peter ;
Provis, John L. ;
Lukey, Grant C. ;
Van Deventer, Jannie S. J. .
CEMENT AND CONCRETE RESEARCH, 2007, 37 (12) :1590-1597
[9]   Designing Precursors for Geopolymer Cements [J].
Duxson, Peter ;
Provis, John L. .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 2008, 91 (12) :3864-3869
[10]   An ultra-low hydrolysis sol-gel route for titanosilicate xerogels and their characterization [J].
Fernandez, Toney ;
Jose, Gijo ;
Mathew, Siby ;
Rejikumar, P. R. ;
Unnikrishnan, N., V .
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, 2007, 41 (02) :163-168