Kolesnikova O.G.

Master of Engineering and Technology, M. Auezov South Kazakhstan University

Coarse-grained soils compaction at the experimental site during the safe construction of the earthen dam

https://doi.org/10.58224/2618-7183-2026-9-5-1
Аннотация
Achieving a high degree of compaction in coarse-grained soils is a critical requirement for ensuring the stability, safety, and long-term performance of earth dams. This study presents the results of comprehensive laboratory and field investigations aimed at identifying the optimal technological parameters for compaction of coarse-grained soils used in hydraulic embankment construction. The influence of grain-size distribution, fine fraction content, and compacted layer thickness on the achieved dry density was systematically investigated. Laboratory experiments were performed using the standard Soyuzdornii compaction apparatus and a vibration compaction device with a cylindrical mold of 300 mm in diameter. Field investigations were conducted at an experimental test site using a 27-ton SANY vibratory roller with compacted layer thicknesses of 50, 70, and 80 cm. The experimental results demonstrated that the highest dry density was achieved for a compacted layer thickness of 50 cm, whereas increasing the layer thickness reduced compaction efficiency due to the limited transmission of vibratory energy throughout the embankment. Furthermore, the proposed grain-size modelling approach was validated by comparing laboratory and field test results, confirming its applicability for reproducing the mechanical behaviour of natural coarse-grained soils under controlled laboratory conditions. The findings provide practical recommendations for selecting rational compaction parameters and can be applied in the design and construction of earth-filled hydraulic structures to improve embankment quality, structural reliability, and long-term operational performance.
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Research on air purification from pulverized large-tonnage tailings of non-ferrous metal ores and the possibility of their use as secondary raw materials

https://doi.org/10.58224/2618-7183-2025-8-6-1
Аннотация
Pulverized waste (large-tonnage tailings) from the enrichment of non-ferrous metal ores pose a significant environmental threat and a health hazard to the personnel of enterprises and the population of nearby territories. In this regard, this study is devoted to solving the problem of dust suppression with the prospect of subsequent complex tailings processing. The effectiveness of a combined method combining fine-dispersed hydraulic spraying and pulsating ventilation for dust deposition from the tailings of the former Kentau Enrichment Plant (Kentau, Kazakhstan) has been experimentally studied. Laboratory tests were carried out on a specialized stand with monitoring of microclimatic parameters. The results showed that the combined method reduces the dust deposition time by approximately 30% compared to traditional irrigation and by more than two times compared to natural precipitation. Optimal process parameters have been established: nozzle diameter of 10 microns, liquid pressure of 5.4 MPa, air flow velocity of 4 m/s, pulsation frequency of 13 Hz. Based on the X-ray phase analysis of the tailings composition (the total content of zinc compounds is ~3.77%, lead ~4.47%), the economic feasibility of their complex processing is substantiated. A two-stage technology is proposed: preliminary, associated extraction of valuable metals (Zn and Pb) followed by the use of a non-metallized residue rich in oxides of silicon, aluminum and calcium in the production of building materials (cement clinker, ceramics). Thus, effective dust suppression is the first step towards the transition from passive waste storage to active recycling within the framework of the principles of circular economy, which will significantly improve the environmental situation in the region.
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Development of a modified bitumen emulsion to enhance the operational properties of asphalt concrete

https://doi.org/10.58224/2618-7183-2025-8-3-1
Аннотация
At present, the primary objective of the road construction industry is to increase the service life of road pavements by implementing innovative technologies that meet modern standards of operational reliability. The key advantages of bitumen emulsions were analyzed, including improved adhesion and cohesion, environmental safety, resistance to water exposure, rapid curing and opening to traffic, applicability under cold conditions, as well as enhanced stability and durability. The research findings confirm the benefits of using bitumen emulsions in road construction, contributing to high-quality and long-lasting pavement performance. Studies were conducted on the modification of petroleum bitumen. The additional incorporation of Kulantau vermiculite into the composition enhances and stabilizes adhesion across a wide range of ambient humidity and temperature conditions. The adhesion process can be regarded as the adsorption of bitumen emulsion on the surface of mineral aggregates. Adsorption occurs through intermolecular interactions, and adhesion is improved by strengthening these interactions, which is achieved by increasing the activity of the bitumen emulsion through the introduction of additives with active functional groups. It was found that incorporating secondary polyethylene and Kulantau vermiculite into asphalt concrete leads to a noticeable decrease in the air void content. This reduction enhances the material’s resistance to moisture and freeze-thaw cycles.
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