Mailyan D.R.

Doctor of Engineering Sciences (Advanced Doctor), Professor of the Department of Reinforced Concrete and Stone Structures, Chief Researcher of the De-partment of Scientific Research, Don State Technical University

PM2.5 and PM10 fine dust pollution of construction waste transloading at dwelling zone

https://doi.org/10.58224/2618-7183-2026-9-4-1
Аннотация
In many cities, the problem of dust pollution from construction waste caused by fine dust particles PM2,5 and PM10 is particularly acute. In the context of the rapidly developing construction industry in cities, issues of environmental safety of the urban air environment are becoming critically important for many states. The main source of urban waste in the context of growing urbanization has become construction waste, which accounts for more than 80% of the total urban waste in the Russian Federation. These areas of accumulation of construction debris not only take up space but also contribute to the deterioration of the urban environment due to dust that rises into the air during transportation and storage of waste. The purpose of this study is to determine the degree of impact of dust emissions of PM2.5 and PM10 particles on the air environment in the dwelling zone, to obtain empirically parameterized «distance–concentration» relationship for PM10 and PM2.5 particles during the loading of solid waste into an open container, and to present the results both in absolute units and in a standardized form using the concentration excess index I. Dust pollution monitoring was carried out at an active construction site located in a dense residential area in St. Petersburg, Russia. Concentration measurements were carried out during periods of dumping garbage into a container and transportation outside the construction site. The PM10 concentration decreased from 30.6 mg/m3 at the dust source to 1.2 mg/m3 at a distance of 50 m. The MPC limits of PM10 concentration (0.06 mg/m3) were determined at a distance of 37.5 m from the dust source. The PM2.5 concentration at a distance of 0-50 m remained below the MPC limits (0.035 mg/m3). From a practical point of view, the data obtained make it possible to organize an effective multi-level dust management system and can be integrated into summary calculations of emissions and an inventory of sources of pollutants.
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Experimental analysis of a new high-tech method of strengthening reinforced concrete structures based on the use of metal and CFRP materials

https://doi.org/10.58224/2618-7183-2025-8-6-9
Аннотация
This paper presents a large-scale experimental analysis of a new high-tech method for strengthening reinforced concrete columns using metal and CFRP materials. The research is justified by evaluating existing traditional and modern methods of strengthening reinforced concrete compressed elements, identifying their main drawbacks, and taking these into account, a new strengthening method was developed. To study the large-scale effect of the new high-tech metal and composite-based strengthening method, two groups of a total of 46 reinforced concrete column samples with different flexibilities were designed and tested for central and eccentric compression until failure. The main test parameters included column flexibility, load application eccentricity, internal and external metal reinforcement, spacing, and cross-sectional area of composite strengthening. The study investigated the influence of the above-mentioned variable factors on the failure pattern, ultimate strength, peak stress, and deformation characteristics of columns strengthened with carbon fiber composite materials (CFRP). The results showed that reinforced concrete columns strengthened with CFRP, having the same dimensions and tested under the same load application eccentricities, demonstrated different increases in ultimate strength compared to unstrengthened columns. Peak stress increased with an increase in the cross-sectional area of metal reinforcement and decreased with an increase in the distance between composite stirrups. Ultimate axial strains of strengthened samples increased with a decrease in the distance between composite stirrups. The difference in the cross-sectional area of composite strengthening did not have a significant impact on the load-bearing capacity and ultimate strains of reinforced concrete strengthened structures.
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