Effect of sodium sulfate on the alkali activation of fly ash

被引：81
作者：
Criado, M. [1 ]
Fernandez Jimenez, A. [2 ]
Palomo, A. [2 ]
机构：
[1] CSIC, Ctr Natl Met Res, Madrid 28045, Spain
[2] CSIC, Eduardo Torroja Inst, Madrid 28033, Spain
来源：
CEMENT & CONCRETE COMPOSITES | 2010年 / 32卷 / 08期
关键词：
Fly ash; Alkaline activation; Sulfate; N-A-S-H gel; Zeolites; Mechanical strength; QUANTITATIVE-DETERMINATION; SIO2/NA2O RATIO; PART II; ZEOLITES; PROMOTER; CRYSTALLIZATION; REACTIVITY; METAKAOLIN; HYDRATION; MIXTURES;
D O I：
10.1016/j.cemconcomp.2010.05.002
中图分类号：
TU [建筑科学];
学科分类号：
0813 ;
摘要：
This paper discusses the effect of the presence of a small amount of SO(4)(2-) (a 16 group oxyanion) on the nature and chemical composition of the resulting N-A-S-H gel and zeolites (main reaction products from the alkaline activation of fly ashes). To this end, fly ash was activated with different alkaline solutions containing 2.5% by weight of sodium sulfate. The paste was cured in an oven at 85 degrees C for different periods of time. The presence of sulfate was observed to lengthen the time needed for certain percentages of N-A-S-H gel to precipitate, while shortening the time needed for a given percentage of zeolites to precipitate. This, in turn, had an adverse effect on the mechanical strength of the material. (c) 2010 Elsevier Ltd. All rights reserved.
引用
收藏
页码：589 / 594
页数：6
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