Influence of mechanoactivation of Portland cement on the hydration heat and mechanical properties of binders and mortars based on them

The issues considered in the article are related to determining the effect of mechanical activation in the presence of a superplasticising admixture on the properties of binders and mortars based on them. The activation of cement, in combination with the use of ground quartz sand (S = 250 m²/kg) and the polycarboxylate superplasticising admixture (SP), is relevant for this study. The amount of quartz sand was adjusted in the range from 0 to 40% of the cement weight, and the superplasticiser from 0.15 to 0.5% of the cement weight or the weight of cement + ground sand. The presented data made it possible to evaluate the influence of factors on the fluidity of the binder. Activation, in combination with a reduced water-cement ratio (for cement and cement + ground sand) of the cement paste, helps to increase the intensity of its heating, as well as to increase the maximum temperature. The peak of the exothermic reaction for the mechanically activated binder occurs 3 hours earlier compared to the non-activated mixture. The increase in the strength of the mortar (without ground sand) on mechanically activated cement with the addition of a superplasticising admixture reached 80% compared to the control.