Increasing the energy efficiency of panel houses of mass development in the territory of the Republic of Khakassia is an urgent problem, since typical panel buildings make up the majority of the housing stock of the Republic. The purpose of the study is to find the most effective design solution that minimizes heat loss through the enclosing structures. The paper presents a thermal imaging survey of a panel residential building located on the territory of the region, identifies the main areas of heat loss. The analysis of calculations of structural coupling units performed by the finite element method in the Elcut Professional software package is carried out. The most effective version of the wall construction to reduce heat loss has been proposed.

Keywords: energy efficiency, heat loss, exfiltration, infiltration, building inspection, thermal imaging inspection, enclosing structures, panel five-story houses

Hydrolysis lignin is a waste product of hydrolysis production (wood that has undergone thermochemical treatment). Lignin is of particular interest in the production of building materials, since it is unique in its chemical composition and physical properties. At the same time, the use of lignin at the present time will reduce the technogenic load on the environment, since the dumps of this waste occupy large areas, harming the ecology of cities. The purpose of this work is to study the possibility of obtaining effective ceramic products based on production waste for external enclosing structures. The article presents the results of determining the optimal percentage of the content of the burnout additive in the production of porous ceramics. The work shows the dependence of the change in physical and mechanical properties on the content and composition of the additive. It is shown that the best indicators are characterized by compositions with a 1: 1 content of lignin and sawdust in addition. The authors investigated shrinkage deformations during ceramics firing and drying. It is shown that when using the hydrolysis lignin of the Ust-Abakan plant, there is no loosening of the samples during sintering.

Keywords: waste, recycling, hydrolysis lignin, ceramic products, sawdust, porosity, shrinkage, density, water absorption

According to regulatory requirements, the Khakassia Republic is characterized by high seismicity, and therefore reliability and safety requirements are imposed on buildings and structures in accordance with SP 14.13330.2014 “Construction in seismic regions”. It is necessary to significantly reduce or eliminate the likelihood of an emergency, to ensure the necessary margin of safety and durability of buildings. It is possible to achieve such a multifaceted effect, including through the introduction of construction technologies using fiber-reinforced concrete. The experience of Russian and foreign researchers shows that the use of fiber-reinforced concrete in various structures makes it possible to achieve higher tensile strength, no shrinkage and resistance to cracking, as well as high impact strength and plasticity. In this regard, the study of the possibility of using fiber-reinforced concrete in the conditions of the Khakassia Republic is relevant. The purpose of this work is to study structures using fiber-reinforced concrete based on basalt fiber, which has increased strength, as well as to analyze the stress-strain state of models of various structures. The article presents the results of determining the optimal percentage of concrete reinforcement with basalt fiber based on the study of the kinetics of changes in strength in compression and bending. The paper presents the dependences of changes in strength and shrinkage deformations on the percentage of reinforcement. It is shown that concretes with 2% fiber content are characterized by the best performance. It is noted that an increase in the percentage of fiber reinforcement does not always lead to an increase in strength due to the uneven distribution of fiber throughout the volume. The authors investigated the stress-strain state of bending elements (slabs, beams) based on fiber-reinforced concrete. It is shown that when using basalt fiber, there is a decrease in the percentage of reinforcement with working reinforcement of reinforced concrete elements to 26–57 %.

Keywords: Fiber concrete, basalt fiber, percentage of reinforcement, bending element, shrinkage, deformation, stress-strain state, compressive strength, flexural strength, steel economy