Technological properties of cement systems with complex modifiers based on polycarboxylate superplasticizer and sedimentary rocks.

An effective prescription solution for improving the technological and physico-mechanical characteristics of cement systems is the use of complexes of organic and mineral modifiers combined into groups according to the principles of additivity. The purpose of this study was to establish the influence regularities of polycarboxylate superplasticizer and mineral additives based on sedimentary rocks of various compositions (calcined polymineral clay, carbonate rocks (dolomite and chalk), thermally activated mixture of clay and chalk) on the technological properties of cement systems with the identification of the most effective modifiers. The experimental data obtained show the dependence of the plasticizing and water-reducing ability of Melflux 5581 F polycarboxylate superplasticizer on the mineral additive used in the formulation of cement systems. The highest and lowest technological efficiency values of surfactant was recorded in cement-mineral suspensions with additives of dolomite and thermally activated mixture 'polymineral clay + chalk', respectively. It was found that with the adopted water-solid ratio (0.18-0.225 rel. units) the greatest growth in the mini-cone spread diameter of modified cement paste is achieved with an increase the surfactant dosage from 0 to 0.5-1% of the solid phase weight. While a further increase in the superplasticizer content from 1 to 1.5% does not lead to a significant increase in the technological indicator. [ABSTRACT FROM AUTHOR]