This study presents a theoretical analysis of the effectiveness of the use of variatropic concretes in multi-layer panel structures of buildings in terms of heat transfer. Theoretical analysis was performed with the aid of the modern numerical modeling software package ELCUT 6.6 and the computer algebra system Maple, which helped improve the reliability of the calculations. The results of this study of the thermophysical parameters of multi-layer panels using variatropic concrete showed that an increase in the degree of variatropy contributes to a rise in the temperature on the inner surface of the panel from 17.94 °C (traditional panel) to 18.87 °C (the most variatropic panel, Scheme 4), which improves indoor comfort conditions and reduces the risk of condensation. Additionally, it is possible to reduce the thickness of the insulation layer without compromising thermal efficiency. The high thermal inertia (D > 7) of variatropic panels ensures the accumulation and retention of heat, which has a positive effect on energy consumption during the heating season. The moisture regime of the studied structures meets regulatory criteria for preventing moisture accumulation, thereby increasing panel durability and eliminating conditions for mold formation or structural degradation. The air permeability performance of the panels also complies with the standards, while the dense outer concrete layers provide additional protection against air infiltration, stabilizing both thermal and moisture balance. The calculated thermal resistance of variatropic panels (Schemes 3 and 4) exceeded the standard requirement (3.20 m²·°C/W) by 1.2 and 1.74 times, respectively. Thus, it was established that the application of the variatropic principle in panel design ensures a more rational distribution of temperature fields, which results in reduced heat losses and improved thermal stability of exterior enclosures. This approach develops new design solutions focused on improving the energy efficiency of buildings and reducing material costs, which is consistent with current trends in Functionally Graded Design (FGD).

This article analyzes the causes of the collapse of a high-rise chimney in Petropavlovsk. A study of the factors of long-term (over 60 years) operation of a high-altitude (H=150 m) chimney was carried out. The analysis of the constructive solution of the pipe was carried out, and the study of the operating conditions was performed. To theoretically assess the technical condition and stress-strain state factors (SSS) of the collapsed chimney, automated verification calculations were carried out based on the actual parameters and characteristics obtained during the last technical inspection. An automated verification calculation of SSS factors determining the bearing capacity of an object (its strength, rigidity, reliability, and durability) has been performed. Theoretically, the physical wear of the object has also been carried out. Based on the study of the available technical documentation and conducting a continuous, detailed instrumental examination of the facility, the expert organization established the significant causes that led to the pipe accident.

Technobius is a peer-reviewed open-access journal that publishes original research articles of experimental and technical nature in the field of construction and building materials

The replacement of clay by coal ash in fired brick is limited by the resulting strength loss. This study examines whether a calcined manganese ore can color a brick body containing ash-slag waste (ASW) without reducing its strength. Four mixes of a medium-plasticity clay with 0 or 20 wt.% ASW (Pavlodar thermal power plant TPP-1) and 0 or 7 wt.% Bogach manganese ore calcined at 1200 °C were fired at 950 °C and characterized by X-ray fluorescence, X-ray diffraction with Rietveld refinement, image-based CIELAB colorimetry and physico-mechanical tests. In the ASW-containing body, the ore raised the mean compressive strength from 9.89 ± 1.33 to 12.41 ± 3.46 MPa (three specimens per mix, p = 0.34) without significant changes in water absorption and density; by mean strength, this body corresponds to grade M100 (GOST 530-2012), class f_b ≥ 10 MPa (EN 771-1) and grade NW (ASTM C62-17). Hausmannite (Mn₃O₄) introduced with the ore persisted as a crystalline phase after firing in both ore-containing mixes (about 2% of the crystalline fraction); the mechanism of the strength change was not established. The ore lowered the lightness L* of the ASW-containing body from 67.3 to 43.3 (ΔE₀₀ = 22.9) at an essentially constant hue angle (57–60°); the fired body is dark brown.