Construction Materials

The reasons for decline in GDP and investment in the Russian economy are analyzed. It is shown that the fiscal policy tightening against the background of the high key rate of the Central Bank leads to higher costs and lower profitability. One of the consequences of such a policy may be excessive consolidation of building materials production having further affect to the pricing policy. Transition to the completion stage of previously started facilities is leading to a faster decline in demand for key building materials. In the housing construction structure, there is a steady downtrend in the share of apartment building, as well as a speculative prices increase in the primary housing market, which are almost twice as high as prices in the secondary market. These factors combination contributes to a rapid decline in building materials demand and production: in January 2026 the decline in some types of construction materials production was more than 30%. According to the Ministry of Economic Development of Russia forecasts, the decrease in investments to fixed assets in 2026 will range from 0.5% to 1.3%. And this means a further drop in the building materials output. Some improvement in the situation against the background of the conflict between Iran and the United States is situational and short-term with unpredictable consequences.

Precast concrete production technologies history from bench technology to pallet circulation line is considered: comparison of solutions, analysis of strengths and weaknesses, impact of digital transformation, development forecast and key requirements for plants wanting to move to a new efficiency level. The redevelopments of the reinforced concrete products full production cycle on a pallet circulation line are given: pallet cleaning; application of separation compound; tooling and magnetic sides installation; reinforcement; concrete laying and molding; vibration compaction; heat treatment; demoulding.

A problem of quality control and assessment at precast concrete plants is relevant, since the quality management effectiveness is quite poor because of following: lack of qualified employees and regulations for nonconforming products management (corrective actions), etc. The paper considers organization of the quality control system based on a graphical interface for reinforced concrete products. A special feature of the system is traceability of all technological chain stages from launching into production to shipment to a buyer in the 1C system: 1C: Production Management in real time and high-quality items production process management. The elaborated quality control system makes it possible identification of an employee committed nonconformity, the nonconformity type/amount, its dynamics over time, etc., as well as efficient working hours usage.

Industrial construction development and magnification involves increasing labor productivity on the construction site, reducing building construction time and their cost on account of fully assembled construction technologies usage. It is known that in the 1950s and 1960s, the massive fully assembled buildings construction assumed a number of limitations, such as the uniformity of architectural solutions, small apartment areas, low performance, etc. Currently special attention is paid not only to production indicators, but also to comfortable people living conditions. Comparative analysis of the traditional technologies for the fully assembled construction and one of the modern modular buildings construction methods according to architectural, structural, technical and economic indicators is presented. On the base of results obtained a generalized gradation of characteristics of the buildings erected with various technologies for fully assembled construction was compiled. According to it, in comparison with traditional methods of fully assembled construction it is possible to reduce the construction time by 3–6 months, the cost of construction and installation work by 10–15% and increase the facility under construction operational characteristics.

In the context of the global transition to the circular economy principles, arbolite as a composite material with a high content of secondary organic resources is of particular importance. However, the arbolite widespread usage is hindered by the insufficient study of non-stationary heat and mass transfer processes during the raw blocks drying, which leads to structural defects formation and product quality decrease. The purpose of this work is to develop a mathematical model of moisture transfer in arbolite products for three drying schemes: on the permeable, impermeable, and partially permeable base. Based on the nonlinear diffusion equation for capillary-porous media, an analytical solution of the non-stationary mass conductivity problem was obtained for an uneven initial moisture distribution and second-kind boundary conditions using the Fourier and Kirpichev dimensionless criteria. The microprocess method allowed for the consideration of the mass flows temporal non-stationarity at the computational domain boundaries with an approximation error of no more than 3–5%. The modeling showed that drying on the impermeable base forms the asymmetric moisture profile with a maximum in the bottom zone, increasing the shrinkage defects risk, while the partially permeable flooring scheme reduces the drying time by 25–30% with maintaining structural homogeneity. The proposed model provides a basis for optimizing thermal treatment modes and developing a digital twin for the production of arbolite products.

Currently, saponite is widely applied in various industries. However, at present this mineral usage conditions are related to a polymineral system with saponite content level of up to 60-65%. Thus, saponite-containing material (SCM) extracted from a recycled water suspension at kimberlite ores enrichment is one of by-products of mining. But to achieve the necessary properties in terms of designed products (including ceramic products), preliminary physico-chemical treatment of SCM is almost always required. Natural saponite contains a significant amount of bound water, which removal at elevated temperatures leads to the mineral basal interlayer compression, the material shrinkage and the microcracks formation. Based on it, the work purpose was to evaluate prospects of using the intercalation with electrolyte solutions as a method of saponite-containing material modification, to minimize fire shrinkage.