期刊
CEMENT AND CONCRETE RESEARCH
卷 53, 期 -, 页码 127-144出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.cemconres.2013.06.007
关键词
Alkali activated cements (D); Granulated blast-furnace slag (D); Fly ash (D); Carbonation (C); NMR spectroscopy
资金
- Australian Research Council, through a Linkage Project co-sponsored by Zeobond Pty Ltd
- Particulate Fluids Processing Centre
Binders formed through alkali-activation of slags and fly ashes, including 'fly ash geopolymers', provide appealing properties as binders for low-emissions concrete production. However, the changes in pH and pore solution chemistry induced during accelerated carbonation testing provide unrealistically low predictions of in-service carbonation resistance. The aluminosilicate gel remaining in an alkali-activated slag system after accelerated carbonation is highly polymerised, consistent with a decalcification mechanism, while fly ash-based binders mainly carbonate through precipitation of alkali salts (bicarbonates at elevated CO2 concentrations, or carbonates under natural exposure) from the pore solution, with little change in the binder gel identifiable by nuclear magnetic resonance spectroscopy. In activated fly ash/slag blends, two distinct gels (C-A-S-H and N-A-S-H) are formed; under accelerated carbonation, the N-A-S-H gel behaves comparably to fly ash-based systems, while the C-A-S-H gel is decalcified similarly to alkali-activated slag. This provides new scope for durability optimisation, and for developing appropriate testing methodologies. (C) 2013 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据