Alkali-activated fly ash binder

In alkali-activated fly ash binders a fly ash is eombined with an alkali metal eompound, preferably sodium silieate, which will secure a high alka-linity (pH=13-14) of the liquid phase. The alkaline activator may be blended with the ash prior to mixing with water, or— preferably—dissolved in the mixing water before mixing with the ash. 

The binder may be suitable for applications in which high chemical corrosion, including acid attack, is likely. It has also been suggested that alkali-activated fly ash binders should be used for fixation of hazardous waste, including radioactive wastes (Brough ei a/., 1995 Roy efo/., 1995). 

Other fast-setting cements not mentioned so far include alkali-activated slag cement (see section 8.5), alkali-activated fly ash binder (see section 9.1), geopolymeric cement (see section 15.7.1), zinc phosphate cement (see section 12.4), magnesium oxychloride and oxysulfate cement (see section 15.1), and alkali silicate binder(see section 15.3). 

A. Femandez-Jimenez and A. Palomo, Composition and microstructure of alkali activated fly ash binder Effect of activator Cem. Conor. Res., 35,1984-1992(2005)... 

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