Volcanic materials are widely used in the production of mixed cement. Volcanic tuff, as a mineral additive to Portland cement, is effective in improving the rheological characteristics of the hydraulic binder, has medium pozzolanic activity, improves the properties of the material and can be used in the composition of light plaster mixtures.. The purpose of the studies presented in the article was to form models of such mixtures that allow their properties to be assessed. The experiment was conducted on the basis of methods of mathematical planning, statistical processing of the results and analytical optimization of the obtained regression equations. The experimental studies are based on the matrix of a complete three-factor experiment. The composition of the light plaster mixture included the following components: hydraulic binder, crushed volcanic tuff (as a fine light filler), reinforcing fiber and synthetic additive. Compositions of plaster mixtures based on volcanic tuff have been developed. The optimal values of the main components of the plaster mixture based on volcanic tuff, which is present in the composition of the mixture as a light fine filler and as a component of a hydraulic binder, have been established. An engineering interpretation of the simulation results is given.

Keywords: plaster material, volcanic tuff, pozzolan activity, mathematical modeling, analytical optimization

The composition of the lightweight plaster mix includes the following components: hydraulic binder, crushed volcanic tuff-scoria (as a fine lightweight filler), reinforcing fiber and synthetic additive. The hydraulic binder consists of Portland cement and finely ground volcanic tuff. Plaster mixes based on volcanic tuff are in demand in regions with a warm or sharply continental climate: high temperatures during the day or low at night, including Ethiopia. The purpose of the research presented in the article was: to form material structure models that allow evaluating the material properties and evaluating the solutions obtained during the implementation of an active experiment. As a result of the experiment, optimal values ​​​​of the main components of the plaster mix based on volcanic tuff were established, which is present in the mixture as a light fine filler and as a component of the hydraulic binder. Modeling of the material structure and engineering interpretation of its properties were carried out.

Keywords: plaster material, tuff-scoria, pozzolanic activity, mathematical modeling, analytical optimization