The aim of this work is to compare the influence of addition of waste aluminosilicate catalyst on the initial periods of hydration
of different cements, i.e. calcium aluminate cements of different composition and Portland cement, basing on the calorimetric
studies. Cement pastes containing up to 25 mass% of additive were studied, where the water/(cement+additive) ratio was 0.5.
An attempt was undertaken to explain the mechanism of action of introduced aluminosilicate in the system of hydrating cement,
particularly in the case of calcium aluminate cement pastes.
It was found that the presence of fine-grained additive caused in all studied cases the increase of the amount of released
heat in the first period after the addition of water. In the case of aluminate cements with aluminosilicate addition, a significant
reduction of induction time and faster precipitation of hydration products were observed compared to the reference sample
(without additive). In the experimental conditions, the additive caused the acceleration of aluminate cements hydration, and
the mechanism of its action is probably complex and can encompass: nucleative action of small grains and formation of new