Activarea chimică a cenušilor volante

The manifestation of the pozzolanic character of fly ashes can be improved by mechanical and/or chemical activation. The paper presents the positive effect of NaOH, single or together with CaSO 4 ·2H 2 O on the Ca(OH) 2 linking of a fly ash from Mintia thermal station, grinded up to a specific surface area of 5530 cm 2 /g Blaine. The addition of small amounts of NaOH to the fly ash-lime-gypsum system determines the acceleration of the reaction processes with water, accompanied by the formation of hydrated compounds - calcium silicates and calcium aluminate hydrates and favours the formation of resistance hardening structures.