The rheological properties of fresh plaster mortars, with varied contents of porous fillers and polymer admixtures, have been studied. The quantities of fine limestone and expanded perlite, and dosages of methyl hydroxy ethyl cellulose and ethylene vinyl acetate were varied in the experiment. Effective viscosity (at a shear rate from 0.045 to 5.705 s⁻¹) and the thixotropy of the mixes were determined with rotational viscometer for 18 compositions (according to the design of the experiment). Each of the 18 viscosity curves were described with the Ostwald–de-Waele equation. The Experimental–Statistical models describing the dependencies of the parameters of the rheological model and of mix thixotropy on the composition factors were built on the obtained data. ES-models have allowed the individual and synergetic effects of mix components on the rheological characteristics to be evaluated. The expanded perlite powder can increase the viscosity by two times, probably due to its pozzolanic effect increasing the content of the CSH phase during cement hydration. The thixotropy can be increased by the quantity of limestone. The computational experiments with ES-models have made it possible for the information set, without a noticeable interrelation between rheological characteristics, to be stratified into subsets, in which such interrelations differ significantly.

The influence of the components of plaster mortars on their properties is considered in a lot of studies at a qualitative level without searching for optimal compositions of these multicomponent composite materials. The purpose of this study was to obtain the experimental–statistical models based on the results of the designed experiment, allowing the influence of light fillers and polymer admixtures on the properties of the mortars to be evaluated and analysed; the compositions complying with specified requirements and compromised optimally by a number of properties should be found. The quantities of fine limestone and perlite as well as of the hydroxyethyl methyl cellulose and dispersible polymer were varied in the experiment. The effective viscosity and thixotropy of the mix, compression, tensile, adhesive strength, frost resistance, and density of hardened mortars were determined for 18 compositions according to the experiment design. The obtained models have allowed the individual and synergetic effects of mix components to be evaluated. The fine perlite has turned out to have the greatest positive effect on the properties. This porous filler increases the strength while decreasing the density of the mortars. It is shown how the composition complying with specified requirements—and the best based on several properties—has been found.

The relevance of the initiated research is determined by a few dominating challenges of modern art and pedagogical education. In particular, these are the interaction between the participants in the educational process, given the spread of the pandemic; insufficient development of ways to form the professional competence in students of art and pedagogical specialties; the inertia of art and pedagogical education and, as a consequence, the slow introduction of innovations in higher education; the insufficient reflection of the principles of poly-arts education in art and pedagogical studies. The nature of poly-arts competence in specialists of art and pedagogical direction specialists has been redefined and adjusted. This competence is interpreted as an integral professional quality of personality. The methodical conditions of its formation have been outlined, embracing the updating of the educational process, use of interactive technologies and methods of personality-oriented learning, the introduction of integration of different levels, etc. Neuropedagogical prerequisites of formation of poly-artistic competence for students of art and pedagogical directions are defined. We have also identified interrelated and complementary aspects of poly-artistic competence (cognitive, reflexive, methodological and procedural), as well as directions of their development. Prospects for further research lie with the development of the methodological formation of poly-artistic competence for students in art and pedagogical specialties and the subsequent testing of its effectiveness in an actual educational process.