The polycarboxylate type superplasticizers are substances with dispersing and fluidizing effect on cement pastes, allowing a very important reduction of the water/cement ratio, with favorable influences on mechanical strengths that the binding materials are developing. Depending on their nature, cement nature and dosage, the polycarboxylate superplasticizers cause certain changes in the kinetics of hydration processes and hydrates formation.

This paper brings information regarding the influence of polycarboxylate type superplasticizers on hydration processes and on the hardening structure formation for binding systems containing cements with different mineralogical compositions, synthesized in laboratory. The considered superplasticizer additive was CHRYSO Fluid Premia 180 type, used as a solution, containing the active substance in the proportion of 21.5 % ± 1.0%.Their dosage was in proportion of 0.3 % and 0.9%, related to the cement (these values were chosen based on literature data).

The influence of this additive on cements hydration processes was investigated by X-ray diffraction analysis on the binding pastes, after hardening till 28 days.

Information regarding the influence of the polycarboxylate additive on the binding properties were assessed by mechanical strength measurements on micro samples prepared from plastic mortars without/with addition of 0.9 % superplasticizer, after hardening periods of time 2-28 days. The proportion of 0.9% superplasticizers was selected considering the results obtained on the cement pastes prepared from an ordinary Portland cement CEM I 52.5 R with the same superplasticizer additive, varying the proportion between 0.3% and 1.3%.