The alkali activation of fly ash (AAFA) is a chemical process in which the ash is mixed with an alkaline activator and cured at a mild temperature to generate compact solids. Both the curing conditions (temperature, time, relative humidity, etc.) and the nature and concentration of the alkali activator play a key role in the development of AAFA micro- and nanostructure, and consequently the properties of these materials. In the present study, fly ash was activated with a 15% water-glass (Na2SiO3) + 85% 10-M NaOH solution at 85 °C for 12 h, 7 and 30 days. Two curing methods were used, in which the variable was the relative humidity (RH).

This research project was funded under Spanish Ministry of Science and Innovation project BIA2010-17530. M. Criado participated in this study under a Post-graduate Studies Council grant (ref. JAE-Doc2007) co-financed by the European Social Fund.

Peer reviewed