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Beskopylny AN, Shcherban' EM, Stel'makh SA, Shilov AA, Chernil'nik A, El'shaeva D, Chistyakov VA. Analysis of the Current State of Research on Bio-Healing Concrete (Bioconcrete). MATERIALS (BASEL, SWITZERLAND) 2024; 17:4508. [PMID: 39336249 PMCID: PMC11433433 DOI: 10.3390/ma17184508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2024] [Revised: 09/09/2024] [Accepted: 09/11/2024] [Indexed: 09/30/2024]
Abstract
The relatively small tensile strength of concrete makes this material particularly vulnerable to cracking. However, the reality is that it is not always possible and practically useful to conduct studies on high-quality sealing cracks due to their inaccessibility or small opening width. Despite the fact that currently there are many technologies for creating self-healing cement composites, one of the most popular is the technology for creating a biologically active self-healing mechanism for concrete. It is based on the process of carbonate ion production by cellular respiration or urease enzymes by bacteria, which results in the precipitation of calcium carbonate in concrete. This technology is environmentally friendly and promising from a scientific and practical point of view. This research focuses on the technology of creating autonomous self-healing concrete using a biological crack-healing mechanism. The research methodology consisted of four main stages, including an analysis of the already conducted global studies, ecological and economic analysis, the prospects and advantages of further studies, as well as a discussion and the conclusions. A total of 257 works from about 10 global databases were analyzed. An overview of the physical, mechanical and operational properties of bioconcrete and their changes is presented, depending on the type of active bacteria and the method of their introduction into the concrete mixture. An analysis of the influence of the automatic addition of various types of bacteria on various properties of self-healing bioconcrete is carried out, and an assessment of the influence of the method of adding bacteria to concrete on the process of crack healing is also given. A comparative analysis of various techniques for creating self-healing bioconcrete was performed from the point of view of technical progress, scientific potential, the methods of application of this technology, and their resulting advantages, considered as the factor impacting on strength and life cycle. The main conditions for a quantitative assessment of the sustainability and the possibility of the industrial implementation of the technology of self-healing bioconcrete are identified and presented. Various techniques aimed at improving the recovery process of such materials are considered. An assessment of the influence of the strength of cement mortar after adding bacteria to it is also given. Images obtained using electron microscopy methods are analyzed in relation to the life cycle of bacteria in mineral deposits of microbiological origin. Current gaps and future research prospects are discussed.
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Affiliation(s)
- Alexey N Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Evgenii M Shcherban'
- Department of Engineering Geometry and Computer Graphics, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Sergey A Stel'makh
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Alexandr A Shilov
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Andrei Chernil'nik
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Diana El'shaeva
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Vladimir A Chistyakov
- Center for Agrobiotechnology, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
- Laboratory of Mechanics of Multicomponent and Multiphase Media, Peter the Great St. Petersburg Polytechnic University (SPbPU), 195251 St. Peterburg, Russia
- D.I. Ivanovsky Academy of Biology and Biotechnology, Southern Federal University, Stachky 194/1, 344090 Rostov-on-Don, Russia
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Zargari M, Ardeshiri HH, Ghafuri H, Hassanzadeh MM. Fe 3O 4 nanoparticles impregnated eggshell as an efficient biocatalyst for eco-friendly synthesis of 2-amino thiophene derivatives. Heliyon 2024; 10:e29674. [PMID: 38681630 PMCID: PMC11046122 DOI: 10.1016/j.heliyon.2024.e29674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 04/08/2024] [Accepted: 04/12/2024] [Indexed: 05/01/2024] Open
Abstract
In this study, a biodegradable and eco-friendly biocatalyst (eggshell/Fe3O4) was synthesized utilizing eggshell impregnated with Fe3O4 nanoparticles. The characterization of prepared catalyst was carried out by Fourier transform infrared radiation (FT-IR), scanning electron microscopy (SEM), X-ray Diffraction (XRD), energy-dispersive X-ray (EDX), thermal gravimetric analysis-differential thermogravimetry (TGA-DTG), vibrating sample magnometer (VSM), and atomic force microscopy (AFM). The eggshell/Fe3O4 biocatalyst was served in multi-component reactions (MCRs) for the synthesis of 2-amino thiophene derivatives from variety aromatic aldehydes, malononitrile, ethyl acetoacetate, and sulfur (S8). To achieve optimal reaction conditions, a thorough examination was conducted on key factors, such as the solvent type, reaction time and temperature, and the ratio of eggshell to Fe3O4. The findings suggest that high yield product can be obtained at microwave temperature (MW) in EtOH solvent within 10 min. Additionally, the eggshell/Fe3O4 biocatalyst exhibited high catalytic activity, which was sustained over the five cycles, without any significant decline in its performance.
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Affiliation(s)
- Mahsan Zargari
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran, 16846-13114, Iran
| | - Hadi Hassani Ardeshiri
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran, 16846-13114, Iran
| | - Hossein Ghafuri
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran, 16846-13114, Iran
| | - Maryam Mohammad Hassanzadeh
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran, 16846-13114, Iran
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Shcherban’ EM, Stel’makh SA, Beskopylny AN, Mailyan LR, Meskhi B, Elshaeva D, Chernil’nik A, Mailyan AL, Ananova O. Eco-Friendly Sustainable Concrete and Mortar Using Coal Dust Waste. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6604. [PMID: 37834742 PMCID: PMC10574357 DOI: 10.3390/ma16196604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/02/2023] [Accepted: 10/04/2023] [Indexed: 10/15/2023]
Abstract
Finding the solution to the problem of the accumulating waste from the mining and processing industries, as well as reducing their carbon footprint, is among the most important tasks today. Within the construction industry, in the field of the production of building materials such as concrete, these problems may be solved through the use of waste and by saving the binder component. The purpose of this study is to substantiate the feasibility of using waste coal dust (CD) in concrete and cement-sand mortars as a partial replacement for cement. Test samples were made by partially replacing cement with CD in an amount from 0% to 10% in increments of 2% by weight. The following main characteristics were studied: mobility and density of mixtures, as well as density, compressive strength, bending strength and water absorption of concrete and mortars. X-ray diffraction and microscopic analysis methods were used in this work. The introduction of CD to replace part of the cement, up to 10%, did not have a significant effect on the density of concrete and mortar mixtures but reduced their workability. The best values of physical and mechanical characteristics were recorded for concrete and mortar with 4% CD. The increases in the compressive strength of concrete and mortars were 6.6% and 5.7%, and in flexural strength 6.1% and 5.6%, respectively. Water absorption decreased by 9.7% for concrete and by 9.3% for mortar.
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Affiliation(s)
- Evgenii M. Shcherban’
- Department of Engineering Geology, Bases and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia;
| | - Sergey A. Stel’makh
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (L.R.M.); (D.E.); (A.C.)
| | - Alexey N. Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Levon R. Mailyan
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (L.R.M.); (D.E.); (A.C.)
| | - Besarion Meskhi
- Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia;
| | - Diana Elshaeva
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (L.R.M.); (D.E.); (A.C.)
| | - Andrei Chernil’nik
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia; (S.A.S.); (L.R.M.); (D.E.); (A.C.)
| | - Alexander L. Mailyan
- Department of Urban Construction and Economy, Don State Technical University, 344003 Rostov-on-Don, Russia;
| | - Oxana Ananova
- Department of Marketing and Engineering Economics, Faculty of Innovative Business and Management, Don State Technical University, 344003 Rostov-on-Don, Russia;
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Stel'makh SA, Beskopylny AN, Shcherban' EM, Mailyan LR, Meskhi B, Shilov AA, El'shaeva D, Chernil'nik A, Kurilova S. Alteration of Structure and Characteristics of Concrete with Coconut Shell as a Substitution of a Part of Coarse Aggregate. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4422. [PMID: 37374604 DOI: 10.3390/ma16124422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/10/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
One of the most promising ways to solve the problem of reducing the rate of depletion of natural non-renewable components of concrete is their complete or partial replacement with renewable plant counterparts that are industrial and agricultural waste. The research significance of this article lies in the determination at the micro- and macro-levels of the principles of the relationship between the composition, the process of structure formation and the formation of properties of concrete based on coconut shells (CSs), as well as the substantiation at the micro- and macro-levels of the effectiveness of such a solution from the point of view of fundamental and applied materials science. The aim of this study was to solve the problem of substantiating the feasibility of concrete consisting of a mineral cement-sand matrix and aggregate in the form of crushed CS, as well as finding a rational combination of components and studying the structure and characteristics of concrete. Test samples were manufactured with a partial substitution of natural coarse aggregate with CS in an amount from 0% to 30% in increments of 5% by volume. The following main characteristics have been studied: density, compressive strength, bending strength and prism strength. The study used regulatory testing and scanning electron microscopy. The density of concrete decreased to 9.1% with increasing the CS content to 30%. The highest values for the strength characteristics and coefficient of construction quality (CCQ) were recorded for concretes containing 5% CS: compressive strength-38.0 MPa, prism strength-28.9 MPa, bending strength-6.1 MPa and CCQ-0.01731 MPa × m3/kg. The increase in compressive strength was 4.1%, prismatic strength-4.0%, bending strength-3.4% and CCQ-6.1% compared with concrete without CS. Increasing the CS content from 10% to 30% inevitably led to a significant drop in the strength characteristics (up to 42%) compared with concrete without CS. Analysis of the microstructure of concrete containing CS instead of part of the natural coarse aggregate revealed that the cement paste penetrates into the pores of the CS, thereby creating good adhesion of this aggregate to the cement-sand matrix.
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Affiliation(s)
- Sergey A Stel'makh
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Alexey N Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Evgenii M Shcherban'
- Department of Engineering Geology, Bases and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Levon R Mailyan
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Besarion Meskhi
- Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Alexandr A Shilov
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Diana El'shaeva
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Andrei Chernil'nik
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Svetlana Kurilova
- Department of Building Materials, Don State Technical University, 344003 Rostov-on-Don, Russia
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Meskhi B, Beskopylny AN, Stel'makh SA, Shcherban' EM, Mailyan LR, Shilov AA, El'shaeva D, Shilova K, Karalar M, Aksoylu C, Özkılıç YO. Analytical Review of Geopolymer Concrete: Retrospective and Current Issues. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16103792. [PMID: 37241419 DOI: 10.3390/ma16103792] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/04/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023]
Abstract
The concept of sustainable development provides for the search for environmentally friendly alternatives to traditional materials and technologies that would reduce the amount of CO2 emissions into the atmosphere, do not pollute the environment, and reduce energy costs and the cost of production processes. These technologies include the production of geopolymer concretes. The purpose of the study was a detailed in-depth analytical review of studies of the processes of structure formation and properties of geopolymer concretes in retrospect and the current state of the issue. Geopolymer concrete is a suitable, environmentally friendly and sustainable alternative to concrete based on ordinary Portland cement (OPC) with higher strength and deformation properties due to its more stable and denser aluminosilicate spatial microstructure. The properties and durability of geopolymer concretes depend on the composition of the mixture and the proportions of its components. A review of the mechanisms of structure formation, the main directions for the selection of compositions and processes of polymerization of geopolymer concretes has been made. The technologies of combined selection of the composition of geopolymer concrete, production of nanomodified geopolymer concrete, 3D printing of building structures from geopolymer concrete, and monitoring the state of structures using self-sensitive geopolymer concrete are considered. Geopolymer concrete with the optimal ratio of activator and binder has the best properties. Geopolymer concretes with partial replacement of OPC with aluminosilicate binder have a denser and more compact microstructure due to the formation of a large amount of calcium silicate hydrate, which provides improved strength, durability, less shrinkage, porosity and water absorption. An assessment of the potential reduction in greenhouse gas emissions from the production of geopolymer concrete compared to the production of OPC has been made. The potential of using geopolymer concretes in construction practice is assessed in detail.
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Affiliation(s)
- Besarion Meskhi
- Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, Gagarin, 1, 344003 Rostov-on-Don, Russia
| | - Alexey N Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, Gagarin, 1, 344003 Rostov-on-Don, Russia
| | - Sergey A Stel'makh
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Evgenii M Shcherban'
- Department of Engineering Geology, Bases, and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Levon R Mailyan
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Alexandr A Shilov
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Diana El'shaeva
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Karolina Shilova
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Memduh Karalar
- Department of Civil Engineering, Faculty of Engineering, Zonguldak Bulent Ecevit University, Zonguldak 67100, Türkiye
| | - Ceyhun Aksoylu
- Department of Civil Engineering, Faculty of Engineering and Natural Sciences, Konya Technical University, Konya 42075, Türkiye
| | - Yasin Onuralp Özkılıç
- Department of Civil Engineering, Faculty of Engineering, Necmettin Erbakan University, Konya 42000, Türkiye
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Beskopylny AN, Stel’makh SA, Shcherban’ EM, Mailyan LR, Meskhi B, Shilov AA, Chernil’nik A, El’shaeva D. Effect of Walnut-Shell Additive on the Structure and Characteristics of Concrete. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16041752. [PMID: 36837382 PMCID: PMC9968172 DOI: 10.3390/ma16041752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/13/2023] [Accepted: 02/18/2023] [Indexed: 05/14/2023]
Abstract
The partial replacement of the mineral components of concrete with natural renewable analogues in full possession of the performance characteristics of the final material, allows not only the concrete-production process to be made more environmentally friendly and inexpensive, but also to solve an important task for the agricultural industry, which is that associated with waste disposal. The scientific novelty of the work is in the obtaining of new concrete compositions by the partial replacement of coarse aggregate with a natural analogue in the form of a walnut shell, which has the maximum ratio of the strength of the composite to its density, as well as in identifying new dependencies of strength and density and their ratio on the amount of replacement of mineral coarse-aggregate walnut shell. The main goal of this article was to analyze the effect of composition factors on characteristics of concrete with partial replacement of large aggregates with walnut shells and to search for the optimal compound that would make it possible to obtain concrete with a minimum decrease in strength characteristics with a maximum decrease in concrete density. Cubes and prism laboratory samples were made from concrete of normal density with the replacement of coarse aggregate by 5, 10, 15, 20, 25 and 30%, by volume. The main mechanical properties, such as density, strength (compressive, tensile, tensile strength in bending) of the concrete samples were studied. The investigation used standard methods and scanning electron microscopy. An increase into strength characteristics up to 3.5%, as well as the maximum ratio of strength to density of concrete, was observed at a walnut-shell dosage of 5%. Effective partial replacement of coarse aggregate with walnut shells leads to a reduction in the consumption of crushed stone by up to 10% and a decrease in the mass of concrete by up to 6%.
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Affiliation(s)
- Alexey N. Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, Rostov-on-Don 344003, Russia
- Correspondence: ; Tel.: +7-863-273-8454
| | - Sergey A. Stel’makh
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Rostov-on-Don 344003, Russia
| | - Evgenii M. Shcherban’
- Department of Engineering Geology, Bases, and Foundations, Don State Technical University, Rostov-on-Don 344003, Russia
| | - Levon R. Mailyan
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Rostov-on-Don 344003, Russia
| | - Besarion Meskhi
- Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, Rostov-on-Don 344003, Russia
| | - Alexandr A. Shilov
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Rostov-on-Don 344003, Russia
| | - Andrei Chernil’nik
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Rostov-on-Don 344003, Russia
| | - Diana El’shaeva
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Rostov-on-Don 344003, Russia
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Stel’makh SA, Shcherban’ EM, Beskopylny AN, Mailyan LR, Meskhi B, Tashpulatov SS, Chernil’nik A, Shcherban’ N, Tyutina A. Composition, Technological, and Microstructural Aspects of Concrete Modified with Finely Ground Mussel Shell Powder. MATERIALS (BASEL, SWITZERLAND) 2022; 16:ma16010082. [PMID: 36614422 PMCID: PMC9821640 DOI: 10.3390/ma16010082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 05/27/2023]
Abstract
Reducing the negative environmental impact of a widely spread building material such as concrete is possible by decreasing the amount of cement in this composite material, especially when specific waste is included as a substitution for the binder. Another important environmental issue is accumulated aquaculture waste. This work justifies the possibility of achieving modified concrete with improved properties based on sea mussel shell powder (MSP). An improved environmentally friendly concrete was obtained and modified with MSP as a result of experimental studies. The dosage of MSP in the amount of 6% instead of part of the cement turned out to be optimal and most effective. Because of the modification, it was possible to increase the strength properties: the increments were up to 12% for the compressive strength (CS), up to 13% for the axial CS, up to 14% for the tensile strength (TS) in bending, and up to 12% for the axial TS. The ultimate strains under axial compression and tension decreased to 9% and 12%, respectively, and the elastic modulus increased to 15%. SEM analysis showed a more integral microstructure without voids and cracks in this composite with a modifier content of 6% compared with the sample of the ordinary composition. Economic efficiency is expressed in reducing the total cost of new concrete compared to traditional ones by about 17% and the cost of building construction by up to 15% due to a decrease in the percentage of defects.
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Affiliation(s)
- Sergey A. Stel’makh
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Evgenii M. Shcherban’
- Department of Engineering Geology, Bases, and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Alexey N. Beskopylny
- Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Levon R. Mailyan
- Department of Roads, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Besarion Meskhi
- Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia
| | - Salikh Sh. Tashpulatov
- Department of Technological Machines and Mechanics, Tashkent Institute of Textile and Light Industry, Shakhjakhon Str., 5, Tashkent 100100, Uzbekistan
| | - Andrei Chernil’nik
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Natalya Shcherban’
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
| | - Anastasia Tyutina
- Department of Unique Buildings and Constructions Engineering, Don State Technical University, Gagarin Sq. 1, 344003 Rostov-on-Don, Russia
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The Investigation of Compacting Cement Systems for Studying the Fundamental Process of Cement Gel Formation. Gels 2022; 8:gels8090530. [PMID: 36135242 PMCID: PMC9498377 DOI: 10.3390/gels8090530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/02/2022] [Accepted: 08/20/2022] [Indexed: 11/25/2022] Open
Abstract
Fundamental knowledge of the processes of cement gel formation for new generation concretes is a scientific deficit. Studies aimed at the formation of a cement gel for standard vibrated concrete research, and especially for centrifugally compacted concrete, are of interest because the structure of this concrete differs significantly from the structure of standard vibrated concrete. This article aims to study the fundamental dependencies of the theoretical and practical values that occur during compaction using vibration, as well as the centrifugal force of new emerging concrete structures. New theoretical findings about the processes of cement gel formation for three technologies were developed: vibrating, centrifuging, and vibrocentrifuging of concrete; the fundamental difference in gel formation has been determined, the main physical and chemical processes were described, and a significant effect of technology on the gel formation process was established. The influence of indirect characteristics based on the processes of cement gel formation, rheological properties of concrete mixtures, water squeezing processes, and the ratio between the liquid and solid phases in the mixture was evaluated. The process of formation of cement gel for centrifugally compacted cement systems was studied and graphical dependences were constructed, giving answers to the mechanism of interaction according to the principle “composition-rheological characteristics-structure-properties of concrete”. The quantitative aspect of the achieved result is expressed in the increase in the indicators demonstrated by centrifuged and especially vibrocentrifuged samples compared to vibrated ones. Additionally, in terms of strength indicators, vibrocentrifuged samples demonstrated an increase from 22% to 32%, depending on the type of strength, and the rheological characteristics of concrete mixes differed by 80% and 300% in terms of delamination.
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Nanomodified Concrete with Enhanced Characteristics Based on River Snail Shell Powder. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12157839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The utilization of aquaculture waste, such as snail shells, is a severe issue. These shells are common in water-sources and are a by-product of sifting sand for masonry and concrete work. Calcium-rich river shells are of great interest for cement building materials. In this regard, the purpose of this article was to develop a nanomodified concrete with improved characteristics based on the powder of snail shells. Experimental studies have confirmed the effectiveness of the use of river shells in concrete without a decrease in strength characteristics and deterioration of other properties. It has been found that the optimal replacement by the snail shell powder that replaced cement is in the amount of 6%. By the nanomodification of concrete with the powdered shells of river snails, it was possible to achieve an increase in compressive strength up to 12%, axial compressive strength—up to 8%, tensile strength in bending—up to 9%, axial tensile strength—up to 11%, elastic modulus—up to 8%. Concrete nanomodification with snail shell powder in the amount of 6% contributed to a reduction of deformations of up to 7%. The study of the microstructure of concrete samples nanomodified with snail shell powder confirmed the obtained dependences of the cement’s properties on the nanomodifier dosage, as well as the most effective dosage of snail shell powder.
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