Browsing by Author "Chernil'nik, Andrei"

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Citation - WoS: 50
Citation - Scopus: 55
Normal-Weight Concrete With Improved Stress-Strain Characteristics Reinforced With Dispersed Coconut Fibers
(MDPI, 2022) Shcherban, Evgenii M.; Stel'makh, Sergey A.; Beskopylny, Alexey N.; Mailyan, Levon R.; Meskhi, Besarion; Shilov, Alexandr A.; Chernil'nik, Andrei; Aksoylu, Ceyhun
According to the sustainable development concept, it is necessary to solve the issue of replacing fiber from synthetic materials with natural, environmentally friendly, and cheap-to-manufacture renewable resources and agricultural waste. Concrete is the primary material for which fibers are intended. Therefore, the use of vegetable waste in concrete is an essential and urgent task. Coconut fiber has attracted attention in this matter, which is a by-product of the processing of coconuts and makes it relevant. This work aims to investigate the experimental base for the strength properties of dispersed fiber-reinforced concrete with coconut fibers, as well as the influence of the fiber percentage on the mechanical, physical, and deformation characteristics. The samples were made of concrete with a compressive strength at 28 days from 40 to 50 MPa. The main mechanical characteristics such as strength in compression (cubic and prismatic) and tension (axial and bending), as well as the material's compressive and tensile strains, were investigated. The percentage of reinforcement with coconut fibers was taken in the range of 0% to 2.5% with an increment of 0.25 wt.%. Tests were carried out 28 days after the manufacture. The microstructure of the resulting compositions was investigating using the electron microscopy method. The most rational percentage of coconut fibers was obtained at 1.75%. The increase in mechanical indicators was 24% and 26% for compression and axial compression, respectively, and 42% and 43% for tensile bending and axial tension, respectively. The ultimate strains in compression were raised by 46% and in tension by 51%. The elastic modulus was increased by 16%.
Citation - WoS: 4
Citation - Scopus: 3
Performance Assessment of a Novel Green Concrete Using Coffee Grounds Biochar Waste
(Mdpi, 2024) Beskopylny, Alexey N.; Stel'makh, Sergey A.; Shcherban', Evgenii M.; Ananova, Oxana; Chernil'nik, Andrei; El'shaeva, Diana; Pogrebnyak, Anastasia
An actual scientific problem in current concrete science is poor knowledge of the problem of modifying concrete with plant waste. At the same time, plant waste benefits from other types of waste because it is a recycled raw material. A promising technological approach to modifying concrete with plant waste is the introduction of components based on the processing of coffee production waste into concrete. This study aims to investigate the use of biochar additives from spent coffee grounds (biochar spent coffee grounds-BSCG) in the technology of cement composites and to identify rational formulations. A biochar-modifying additive was produced from waste coffee grounds by heat treatment of these wastes and additional mechanical grinding after pyrolysis. The phase composition of the manufactured BSCG additive was determined, which is characterized by the presence of phases such as quartz, cristobalite, and amorphous carbon. The results showed that the use of BSCG increases the water demand for cement pastes and reduces the cone slump of concrete mixtures. Rational dosages of BSCG have been determined to improve the properties of cement pastes and concrete. As a result of the tests, it was determined that the ideal situation is for the BSCG ratio to be at a maximum of 8% in the concrete and not to exceed this rate. For cement pastes, the most effective BSCG content was 3% for concrete (3%-4%). The compressive and flexural strengths of the cement pastes were 6.06% and 6.32%, respectively. Concrete's compressive strength increased by 5.85%, and water absorption decreased by 6.58%. The obtained results prove the feasibility of using BSCG in cement composite technology to reduce cement consumption and solve the environmental problem of recycling plant waste.
Citation - WoS: 2
Citation - Scopus: 2
Porosity Analysis and Thermal Conductivity Prediction of Non-Autoclaved Aerated Concrete Using Convolutional Neural Network and Numerical Modeling
(MDPI, 2025) Beskopylny, Alexey N.; Shcherban', Evgenii M.; Stel'makh, Sergey A.; Elshaeva, Diana; Chernil'nik, Andrei; Razveeva, Irina; Ozkilic, Yasin Onuralp
Currently, the visual study of the structure of building materials and products is gradually supplemented by intelligent algorithms based on computer vision technologies. These algorithms are powerful tools for the visual diagnostic analysis of materials and are of great importance in analyzing the quality of production processes and predicting their mechanical properties. This paper considers the process of analyzing the visual structure of non-autoclaved aerated concrete products, namely their porosity, using the YOLOv11 convolutional neural network, with a subsequent prediction of one of the most important properties-thermal conductivity. The object of this study is a database of images of aerated concrete samples obtained under laboratory conditions and under the same photography conditions, supplemented by using the author's augmentation algorithm (up to 100 photographs). The results of the porosity analysis, obtained in the form of a log-normal distribution of pore sizes, show that the developed computer vision model has a high accuracy of analyzing the porous structure of the material under study: Precision = 0.86 and Recall = 0.88 for detection; precision = 0.86 and recall = 0.91 for segmentation. The Hellinger and Kolmogorov-Smirnov statistical criteria, for determining the belonging of the real distribution and the one obtained using the intelligent algorithm to the same general population show high significance. Subsequent modeling of the material using the ANSYS 2024 R2 Material Designer module, taking into account the stochastic nature of the pore size, allowed us to predict the main characteristics-thermal conductivity and density. Comparison of the predicted results with real data showed an error less than 7%.
Citation - WoS: 2
Citation - Scopus: 2
Properties and Structure of Functional Concrete Mixtures Modified With River Shell Powder
(C Ej Publishing Group, 2024) Stel'makh, Sergey A.; Shcherban, Evgenii M.; Beskopylny, Alexey N.; Hiep, Nguyen Quang; Song, Yamin; Elshaeva, Diana; Chernil'nik, Andrei; Aksoylu, Ceyhun
The recycling of the aquaculture waste into clam powder reduces solid emissions and natural resources, which is important for Portland cement production. This study determines the feasibility of using recycled river shell waste as a partial replacement for cement in concrete technology. The study used normative methods and optical microscopy; the properties of cement mixtures, such as normal consistency, setting time (ST), compressive and flexural strength, were studied. Research findings have shown that the inclusion of river shell powder (RSP) in cement mixtures can reduce water demand and a decrease in setting time with increasing RSP content. It was also found that the strength of the cement mixture can be maintained with an RSP content of up to 10%. The following properties of the concrete were determined: workability, compressive strength (CS), and water absorption. Using RSP as a partial replacement for cement has been proven to elevate the slump of the fresh concrete cone. CS is maintained at a level comparable to the control composition, with an RSP content of no more than 8%, and water-absorbing is reduced by 7.31%. This study created new compositions, and the links between the ingredients, properties, and structure of cement composites modified with river shell powder were investigated. Additionally, the properties of the structure-formation process of these modified composites were studied.