Сергей Сахно | Kryvyi Rih National University (original) (raw)

Papers by Сергей Сахно

IOP Conference Series: Earth and Environmental Science, Sep 30, 2023

IOP Conference Series: Earth and Environmental Science, Jun 1, 2022

This paper represents a preface to the Proceedings of the 3rd International Conference on Sustain... more This paper represents a preface to the Proceedings of the 3rd International Conference on Sustainable Futures: Environmental, Technological, Social, and Economic Matters (ICSF 2022) held at the Kryvyi Rih, Ukraine, 24–27 May 2022. Background information and the organizational structure of the meeting, program committee, and acknowledgments of the contributions of the many people who made the conference a success are presented.

Social Science Research Network, May 21, 2020

Sustainable development of construction materials is directly related to research on the processe... more Sustainable development of construction materials is directly related to research on the processes of hydration of binders. Builders need better types of cement, with lower cost and energy consumption in production. The development of spin chemistry methods allows us to consider the processes of hydration and structure formation of binders from the spin state of the elements involved in chemical reactions. Magnetic interactions have a significant effect on the spin dynamics and the control of the spin multiplicity of radical pairs. The practical implementation of magnetic effects on a binder can be carried out in various ways. However, a long-term impact can be achieved only by introducing ferromagnetic substances into the binders. In the paper presented the results of a study of the influence of the characteristics of finely dispersed powdered ferromagnetic additives on the strength characteristics of cement. Ferromagnetic additives regulate the behavior of the reactants during rotation during the hydration of the binders due to magnetic interactions and control the reactivity of the chemical reaction. A comparative analysis revealed that it is most expedient to use as powdery ferromagnetic additives are the waste from mining and processing enterprises of the Krivorozhsky field. The work investigated the magnetic and dispersed characteristics of 12 different dust. The experiments showed that the origin of dust and the method of their capture are determined their magnetic characteristics. Preparation of samples with the dust and determination of the strength characteristics of cement were carried out by standard methods. The results obtained made it possible to reveal the laws of the effect of the dispersed and magnetic properties of various dust on the degree of activation of binders.

IOP conference series, Jun 1, 2022

Cement production is a significant source of carbon dioxide emissions. One of the ways to reduce ... more Cement production is a significant source of carbon dioxide emissions. One of the ways to reduce emissions is to reduce the proportion of clinker in cement by introducing active mineral additives into its composition, particularly granulated blast-furnace slag. One of the ways to increase the activity of such cement is the effect of magnetic fields on the spin multiplicity of the substances involved in the hardening reaction. In this case, the maximum effect is ensured by introducing a magnetized finely dispersed ferromagnetic substance into the cement composition. The activation effect depends on the additive’s adding method to the cement’s composition, the components ratio in the cement, and the cement hardening mode. This work aims to identify the influence of the adding method of the additive, the slag and additive proportion in cement, and the steam curing temperature on the activity effect of the binder. Three groups of studies were carried out to determine the strength characteristics of laboratory samples hardened both in natural conditions and during steaming. In the first group, cement samples have tested containing 40% slag obtained by joint grinding and joint mixing of the additive with cement for 0.5, 1, 2, 4 and 8 minutes. In the second group, samples have tested with the additive amount varied from 0 to 2.5%, and slag amount from 0 to 80%. Finally, cement samples were tested in the third group containing 50% slag and from 0 to 2.5% additive. The samples were steam cured at temperatures ranging from 50 to 90° C and tested one day, 28 and 90 days after steam curing. As a result of the research, it has revealed that to obtain the maximum effect, the additive must be introduced into the cement composition by joint grinding. The factors influencing the activity have been determined. At the same time, the time of joint grinding should ensure uniform mixing of the components and the formation of new surfaces of cement grains in the presence of magnetic fields. Too long joint grinding leads to the loss of the magnetic properties of the addition. It was found that the activation effect from the additive addition increases with an increase in the proportion of slag. In cement without slag, an increase in the additive content leads to a drop in strength. It was revealed that the introduction of magnetized ferromagnetic dust additives into the composition of the SPC makes it possible to reduce the steam curing temperature of products by 20-25° C. Studies have shown that using a finely dispersed ferromagnetic substance as an activating additive can save energy resources and reduce emissions.

The subject of the study. The work investigated the deformative, strength, and cost parameters of... more The subject of the study. The work investigated the deformative, strength, and cost parameters of concrete beams with various reinforcement types. The nature of the behavior under a load of beams reinforced with steel reinforcement and beams with basalt reinforcement of multiple diameters has been studied. A research methodology is the studying of finite element models of the reinforced concrete beam. The Drucker-Prager model was used to simulate concrete behavior. For steel reinforcement, a bilinear isotropic hardening model, a linear orthotropic model was used for composite reinforcement. The goal is to reveal the advantages and disadvantages of using basalt composite reinforcement in reinforced concrete. Conclusion of the study. The paper considers the behavior of four models of reinforced beams. In the first model, a control one, steel reinforcement, is used. In the second, the composite reinforcement diameter is equal to the diameter of the steel one. In the third model, the diameters of the composite reinforcement are taken from the conditions of its similar bearing capacity with the steel one. The fourth model's composite reinforcement diameters have been taken from the requirements of its equal deformation with the steel one. The paper presents a method for calculating the corresponding diameters of reinforcement. The model in which the diameters of the composite reinforcement are taken from the conditions of its equal deformation with the steel reinforcement has the beam's best operation. In this case, the deformations and stresses in concrete practically do not differ from the corresponding stresses in the model with steel reinforcement. However, the utilization factor of the bearing capacity of the reinforcement in this model is deficient, and the cost of reinforcing elements is almost three times the cost of steel rods. The model in which the diameters of composite reinforcement are taken based on its equal bearing capacity with steel reduces the cost of reinforcement almost three times. However, such a beam's deformation and strength properties are significantly worse than in the control sample. The model with composite reinforcement diameters equal to the steel reinforcement diameters has no advantages over the model with steel reinforcement.

The subject of the studyinvestigation of dust formation processes in the zone of cement flour tra... more The subject of the studyinvestigation of dust formation processes in the zone of cement flour transfer from one conveyor to another. Research methodology-the study of the behavior of particles of different dispersion during loading from one conveyor to another using the Discrete Element Method. The goal-determination of places of localization of dust emission and the behavior of dust in these places to improve dust collection processes. Conclusion of the study. The proposed method made it possible to identify the features of the interaction of particles of different dispersion both among themselves and with the surrounding space. The method designated areas where the most significant dust emission occurs and to which special attention should be paid when developing dust cleaning measures. The research results apply to various sectors of the mining and processing industries.

Social Science Research Network, 2018

The subject of the study is the application of the combined method of vibration analysis for the ... more The subject of the study is the application of the combined method of vibration analysis for the study of dynamic phenomena in the elements of the overhead traveling crane structure that affect both the durability and reliability of structural elements and the health and efficiency of maintenance personnel. Research methodology - simulation of cargo lifting dynamics using Matlab Simulink and SolidWorks software, using combined calculations in which the system response generated from the solved system of differential equations in Matlab Simulink was used to excite the crane support structure during the FEM simulation in SolidWorks. The goal is to identify the vulnerabilities in the construction of overhead traveling cranes, by examining the dynamic phenomena in the structure and the effect of vibration on the safety of the crane's operation, on health, and the capacity of the operating personnel. Conclusion of the study. The proposed method allows more accurately and less costly to predict the response of the crane structure to various dynamic effects, particularly lifting and lowering the load. The presented models of FEM and rigid masses can become the basis for studies based on an integrated approach that integrates the dynamic model with the CE model. The influence of the action of various vibration frequencies on the machinist's body of the overhead traveling crane is analyzed.

E3S web of conferences, 2021

One of the essential tasks for a sustainable future is to reduce harmful emissions into the atmos... more One of the essential tasks for a sustainable future is to reduce harmful emissions into the atmosphere significantly. Cement production is the world's largest industrial carbon pollutant, accounting for 8 % of global emissions. More than 2.2 gigatons of carbon dioxide are emitted into the atmosphere every year. Therefore, reducing the energy intensity of products and reducing the number of harmful emissions in cement production is becoming critical. One strategy to reduce cement production emissions is to reduce the most energy-consuming component in cement-clinker. In this case, various activation methods are used for maintaining the same level of cement activity. One of these methods is the impact on the hardening binder with magnetic fields. The paper presented a study of hydration processes of blast-furnace cement activated by a magnetized ferromagnetic additive. The work established that the introduction of pre-magnetized ferromagnetic dust into blast-furnace cement composition has an activating effect on binder hydration. It shows that activation occurs both in the initial and long periods of hardening. The nature of the mutual influence of the components of the hydration system alite-lime-slag in a modified binder was revealed. The investigation determined that the ferromagnetic additive, intensifying the process of slag hardening, increases the proportion of hydrated slag by 1.5-2 times. It was revealed that the formation of the ettringite framework in the modified binder's gel is completed within one day. It is shown that in the subsequent periods, hydration of aluminates occurs mainly due to the formation of tricalcium aluminate hexahydrate (C3AH6), which excludes destructive processes in the late periods of binder hardening. It has been established that under the action of a ferromagnetic additive, the degree of crystallization of hydro silicates in the modified binder increases.

Mining Journal of Kryvyi Rih National University, 2020

E3S web of conferences, 2020

SSRN Electronic Journal, 2018

In connection with the growing need for saving natural resources used in aggregates for concrete,... more In connection with the growing need for saving natural resources used in aggregates for concrete, the importance of lightweight structural aggregates obtained from production waste is continuously increasing. Lightweight structural concretes on porous aggregates can significantly reduce own weight of structures, make it possible to manufacture larger structures, reduce transport costs, and improve the thermal insulation and acoustic properties of enclosing structures. The use of waste from the mining and metallurgical industry to produce construction materials significantly reduces environmental pollution. The article is devoted to studying the possibility of using wastes from the mining and processing industry of enterprises of the Kryvyi Rih iron ore basin to produce lightweight porous aggregate. The paper presents the results of studies of the effect of the charge's granulometric composition, the quantitative content of the raw mix components, and the temperature of heat trea...

MatSciRN: Concrete (Topic), 2020

The subject of the study the possibility of applying the finite element method to determine the b... more The subject of the study the possibility of applying the finite element method to determine the bearing capacity of a damaged reinforced concrete structure and the subsequent selection of its reinforcement parameters with composite materials. Research methodology – the studying of finite element models of the serviceable destroyed and restored structure and determination of design parameters of the structure before destruction, after the destruction, and after its strengthening. The goal – identification of the possibility of further operation of the damaged structure using the finite element method, finding the most dangerous places in the construction, selection of parameters for its amplification. Conclusion of the study – The proposed research method made it possible to more accurately and at a lower cost, identify the most dangerous areas in the damaged structure, and verify the effectiveness of the applied method of its ...

E3S Web of Conferences, 2021

This is an introductory text to a collection of papers from the ICSF 2021: Second International C... more This is an introductory text to a collection of papers from the ICSF 2021: Second International Conference on Sustainable Futures: Environmental, Technological, Social, and Economic Matters, which held at Kryvyi Rih National University, Kryvyi Rih, Ukraine, on May 19-21, 2021. It consists of an introduction, conference topics review, and some observations about the event and its future.

Proceedings of The International Conference on Sustainable Futures: Environmental, Technological,... more Proceedings of The International Conference on Sustainable Futures: Environmental, Technological, Social and Economic Matters (ICSF 2020)