The effect of ground limestone on the properties of a composite gypsum binder using thermally activated clay as a pozzolan component
Problem statement. The purpose of this work was to study the influence of methods of preliminary preparation of thermally activated clay, which is a pozzolan component in the preparation of water-resistant composite gypsum binders, as well as the effect of mechanochemical activation in the joint grinding of thermally activated clay with the addition of a plasticizer on the pozzolanic activity and the change in the required number of pozzolanic component in the composition of composite gypsum binders. Results. It is established that the required amount of thermally activated clay in the composition of gypsum-cement-pozzolan composition at its grinding to specific surfaces of 200-500 m2/kg together with the addition of the Melflux 2651 F plasticizer decreases by 20-25 % compared with the use of thermally activated clay ground without the introduction of a plasticizer. The optimal amount of Melflux 2651 F plasticizer introduced during grinding with thermally activated clay was established. Conclusions. The significance of the results for the construction industry lies in the fact that the application of the technology of production of composite gypsum binders thermoactivating grinding clay to a dispersion with the introduction of additives of a plasticizer due to the effect of mechanical activation allows to reduce the consumption of pozzolanic component in the composition of the binder or the energy consumption for grinding.