The effect of temperature and duration of curing on the strength of fly ash based geopolymer mortar

The optimum temperature and duration of curing is essential in geopolymerization reaction to achieve higher strength. As such, fly ash based geopolymer mortars were prepared by varying the curing temperature of 80, 100 and 120 degrees C, for the duration of 4, 6 and 20 hours. The fly ash was activated by sodium silicate and sodium hydroxide solution. The dosage of activator was 55% and the ratio between sodium silicate and alkaline activator was 1 : 2. The results show that the highest compressive strength was obtained at the temperature and duration of curing of 120 degrees C and 20 hours. (C) 2014 The Authors. Published by Elsevier Ltd.