The article discusses the use of simplex methods of experiment planning to determine the optimal composition of composite building materials. Composite building materials are multicomponent systems, so their properties depend on a large number of factors that are diverse in nature and influence. The use of orthogonal plans is not able to adequately describe experimental data with a wide range of varying factors. Therefore, the article proposes to use simplex-lattice Scheffe's plans. A complete third-order model was developed to determine the optimal composition of the filled cement composite, and a regression equation was written. The adequacy of the equation was confirmed at the control points of the plan using the Student's criterion. The proposed planning method can be used to optimize the composition of multicomponent systems.

Keywords: multicomponent system, optimization methods, composite building material, experiment planning, simplex plans, Scheffe's polynomial, regression equation

The article discusses the possibility of using the ANSYS WORKBENCH software package to calculate the uneven settlement of building foundations. The heterogeneity of the physical and mechanical properties of the soil, the difference in the thickness of the bearing layer and other factors lead to uneven development of settlement. This causes the appearance of cracks in the supporting structures, and in the worst case, the destruction of part of the building or the building as a whole. Methods for calculating settlements are very complex, but using the capabilities of modern computers and computer simulation programs makes it possible to obtain a simple and accurate solution to such problems. To evaluate the deformations of the foundation on heterogeneous soils the ANSYS software package was be used. The proposed method can be used to quantify the uneven settlement of the foundations of real buildings and structures.

Keywords: ANSYS WORKBENCH, foundation, uneven settlement, skew, computer modeling, deformation, finite element method

The article considers the possibility of using the ANSYS WORKBENCH software complex for calculating beams on an elastic base. The mechanical properties of the soil base are very complex, therefore, when calculating structures on an elastic foundation, mathematical difficulties arise. Thus, the task of improving calculation methods becomes extremely urgent. The use of computer modeling programs and the possibilities of modern computers allows you to get a more accurate solution to such problems. From using the ANSYS software package and the finite element method modeling of beam deformations on an elastic Winkler foundation was performed. The proposed method can be used to calculate the settlement of building and structures foundations

Keywords: ANSYS WORKBENCH, elastic foundation, beam, computer modelling, deformation, finite element method, Winkler hypothesis

The article is devoted to the relationship between the strength of cement composites and the fractal dimension of their structure. In solid state physics, fractal algorithms can accurately describe and predict their properties and can be used in modeling the structure of composite building materials. Determination of the material fractal dimension according to its structure image at the macrolevel allows to understand its microstructure, and its properties as the result. Using the methods of experiment mathematical planning, the study was carried out and the relationship between the strength of the cement composite and its fractal dimension was established. It has been found out that the lower the fractal dimension, the higher the strength of cement composites. However, there is an area on the function graph that shows the increase in strength at sufficiently large values of the fractal dimension. Presumably, this is due to a change in the parameters of material differential porosity. For example, such as the average pore size index, the coefficient of pores uniformity in size, and the coefficient of microporosity. Such circumstance arouses interest and conditions for further research.

Keywords: fractal dimension, microstructure, strength, cement composite, composite building material, experiment planning, three-component system, regression equation, regression coefficient