Miroslava Hajdúchová

Possibilities of Using Plasticizers in Alkali-Activated Systems

The study deals with the preparation process and properties of alkali-activated blast furnace slag with different addition of lignosulphonate plasticizer. The goal of this study is to evaluate the suitability of plasticizer and find the convenient dose of this admixture, which improve the workability and mechanical properties of alkali-activated slag. The stability of plasticizing admixture in alkali environment was studied by infrared spectroscopy (FTIR).

The Role of Temperature on Hydration of Binary System of Metakaolin/Portland Cement

The role of temperature of metakaolin/Portland cement binary system was studied by isothermal calorimetry. Sample with 50 % of metakaolin replacement were monitored at 30 °C, 40 °C, 50 °C and 60 °C. Structural and chemical characterization of hardened pastes was obtained by scanning electron and Raman microscopy. Paper deals with kinetics of main exothermal reactions during early hydration of the system. Activation energies were calculated for processes related to each exothermic peak. The nature of hydration products at different temperatures was revealed by microstructural studies.