Reactivity of different size fractions of Tata power flyash in geopolymerization reaction

Geopolymerization of different size fractions of flyash was studied at 27ºC, 45 ºC, 60 ºC by Isothermal conduction calorimeter and observed that the finest fraction (<32µm) showed highest reactivity. Variation of reactivity with different size fractions was observed. It was also obser-ved that (dq/dt)max depends on calcium content present in the sample and also on surface area of that sample. Comp-ressive strength of different size fractions of cast samples (flyash and 6M NaOH), of which one batch was heat treated in muffle furnace at 60ºC and the other was left open to atmosphere, were studied. The best compressive strength was observed in finest fraction (<32µm). Further microstructural studies were carried out to explain the findings.