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Retrofitting of district heating systems is a comprehensive process which covers all stages of district heating (DH) systems: production, distribution and consumption. This study quantitatively shows the effect of retrofitting measures and represents strengths and weaknesses of different development scenarios. Improvements in production units show improvements in fuel use efficiency and thus indirectly reduce CO2 emissions due to unburned fuel. For this purpose, validated district planning tools have been used. Tool uses mathematical model for calculation and evaluation of all three main components of the DH system. For the quantitative evaluation, nine efficiency and balance indicators were used. For each indicator, recommended boundary values were proposed. In total, six simulation scenarios were simulated, and the last scenario have shown significant reduction in CO2 emissions by 40% (from 3376 to 2000 t CO2 compared to the actual state), while share of biomass has reached 47%.
Aleksandrs Zajacs; Anatolijs Borodinecs; Nikolai Vatin. Environmental Impact of District Heating System Retrofitting. Atmosphere 2021, 12, 1110 .
AMA StyleAleksandrs Zajacs, Anatolijs Borodinecs, Nikolai Vatin. Environmental Impact of District Heating System Retrofitting. Atmosphere. 2021; 12 (9):1110.
Chicago/Turabian StyleAleksandrs Zajacs; Anatolijs Borodinecs; Nikolai Vatin. 2021. "Environmental Impact of District Heating System Retrofitting." Atmosphere 12, no. 9: 1110.
A cement paste or mortar is composed of a mineral skeleton with micron to millimeter-sized grains, surrounded by water filaments. The cohesion or shear resistance in the cement paste and mortar is caused by capillary forces of action. In the case of mortar mixes, there is friction between the particles. Therefore, the mortar mixture shows both friction between particles and cohesion, while the paste shows only cohesion, and the friction between particles is negligible. The property of the cement paste is greatly influenced by the rheological characteristics like cohesion and internal angle friction. It is also interesting that when studying the rheology of fresh concrete, the rheological behavior of cement paste and mortar has direct applicability. In this paper, the rheological characteristics of cement paste and mortar with and without mineral admixtures, that is, fly ash and ground granulated blast-furnace slag (GGBS), were studied. A cement mortar mix with a cement-to-sand ratio of 1:3 was investigated, including fly ash replacement from 10% to 40%, and GGBS from 10% to 70% of the weight of the cement. A suitable blend of fly ash, GGBS, and ordinary Portland cement (OPC) was also selected to determine rheological parameters. For mortar mixtures, the flow table was conducted for workability studies. The flexural and split tensile strength tests were conducted on various mortar mixtures for different curing times. The results indicate that in the presence of a mineral mixture of fly ash and GGBS, the rheological behavior of paste and mortar is similar. Compared with OPC-GGBS-based mixtures, both cement with fly ash and ternary mixtures show less shear resistance or impact resistance. The rheological behavior of the mortar also matches the rheological behavior in the flow table test. Therefore, it is easy to use the vane shear test equipment to conduct cohesion studies to understand the properties of cement paste and mortar using mineral admixtures. The strength results show that the long-term strength of GGBS-based mixtures and ternary mixed mixtures is better than that of fly-ash-based mixtures. For all mixtures, the strength characteristics are greatest at a w/b ratio of 0.6.
V. Arularasi; P. Thamilselvi; Siva Avudaiappan; Erick I. Saavedra Flores; Mugahed Amran; Roman Fediuk; Nikolai Vatin; Maria Karelina. Rheological Behavior and Strength Characteristics of Cement Paste and Mortar with Fly Ash and GGBS Admixtures. Sustainability 2021, 13, 9600 .
AMA StyleV. Arularasi, P. Thamilselvi, Siva Avudaiappan, Erick I. Saavedra Flores, Mugahed Amran, Roman Fediuk, Nikolai Vatin, Maria Karelina. Rheological Behavior and Strength Characteristics of Cement Paste and Mortar with Fly Ash and GGBS Admixtures. Sustainability. 2021; 13 (17):9600.
Chicago/Turabian StyleV. Arularasi; P. Thamilselvi; Siva Avudaiappan; Erick I. Saavedra Flores; Mugahed Amran; Roman Fediuk; Nikolai Vatin; Maria Karelina. 2021. "Rheological Behavior and Strength Characteristics of Cement Paste and Mortar with Fly Ash and GGBS Admixtures." Sustainability 13, no. 17: 9600.
A person spends most of his life in rooms built from various building materials; therefore, the optimization of the human environment is an important and complex task that requires interdisciplinary approaches. Within the framework of the new theory of geomimetics in the building science of materials, the concepts of technogenic metasomatism, the affinity of microstructures, and the possibilities of creating composites that respond to operational loads and can self-heal defects have been created. The article aims to introduce the basic principles of the science of geomimetics in terms of the design and synthesis of building materials. The study’s novelty lies in the concept of technogenic metasomatism and the affinity of microstructures developed by the authors. Novel technologies have been proposed to produce a wide range of composite binders (including waterproof and frost-resistant gypsum binders) using novel forms of source materials with high free internal energy. The affinity microstructures for anisotropic materials have been formulated, which involves the design of multilayered composites and the repair of compounds at three levels (nano-, micro-, macro-). The proposed theory of technogenic metasomatism in the building science of materials represents an evolutionary stage for composites that are categorized by their adaptation to evolving circumstances in the operation of buildings and structures. Materials for three-dimensional additive technologies in construction are proposed, and examples of these can be found in nature. Different ways of applying our concept for the design of building materials in future works are proposed.
Valery Lesovik; Roman Fediuk; Mugahed Amran; Nikolai Vatin; Roman Timokhin. Self-Healing Construction Materials: The Geomimetic Approach. Sustainability 2021, 13, 9033 .
AMA StyleValery Lesovik, Roman Fediuk, Mugahed Amran, Nikolai Vatin, Roman Timokhin. Self-Healing Construction Materials: The Geomimetic Approach. Sustainability. 2021; 13 (16):9033.
Chicago/Turabian StyleValery Lesovik; Roman Fediuk; Mugahed Amran; Nikolai Vatin; Roman Timokhin. 2021. "Self-Healing Construction Materials: The Geomimetic Approach." Sustainability 13, no. 16: 9033.
Development of sustainable concrete as an alternative to conventional concrete helps in reducing carbon dioxide footprint associated with the use of cement and disposal of waste materials in landfill. One way to achieve that is the use of fly ash (FA) as an alternative to ordinary Portland cement (OPC) because FA is a pozzolanic material and has a high amount of alumina and silica content. Because of its excellent mechanical properties, several studies have been conducted to investigate the use of alkali-activated FA-based concrete as an alternative to conventional concrete. FA, as an industrial by-product, occupies land, thereby causing environmental pollution and health problems. FA-based concrete has numerous advantages, such as it has early strength gaining, it uses low natural resources, and it can be configurated into different structural elements. This study initially presents a review of the classifications, sources, chemical composition, curing regimes and clean production of FA. Then, physical, fresh, and mechanical properties of FA-based concretes are studied. This review helps in better understanding of the behavior of FA-based concrete as a sustainable and eco-friendly material used in construction and building industries.
Mugahed Amran; Roman Fediuk; Gunasekaran Murali; Siva Avudaiappan; Togay Ozbakkaloglu; Nikolai Vatin; Maria Karelina; Sergey Klyuev; Aliakbar Gholampour. Fly Ash-Based Eco-Efficient Concretes: A Comprehensive Review of the Short-Term Properties. Materials 2021, 14, 4264 .
AMA StyleMugahed Amran, Roman Fediuk, Gunasekaran Murali, Siva Avudaiappan, Togay Ozbakkaloglu, Nikolai Vatin, Maria Karelina, Sergey Klyuev, Aliakbar Gholampour. Fly Ash-Based Eco-Efficient Concretes: A Comprehensive Review of the Short-Term Properties. Materials. 2021; 14 (15):4264.
Chicago/Turabian StyleMugahed Amran; Roman Fediuk; Gunasekaran Murali; Siva Avudaiappan; Togay Ozbakkaloglu; Nikolai Vatin; Maria Karelina; Sergey Klyuev; Aliakbar Gholampour. 2021. "Fly Ash-Based Eco-Efficient Concretes: A Comprehensive Review of the Short-Term Properties." Materials 14, no. 15: 4264.
Geopolymer materials have been gaining ground in the civil construction sector not only for having superior physical properties when compared to conventional cement, but also for being less harmful to the environment, since the synthesis of the geopolymer does not release toxic gases or require high energy costs. On the other hand, geopolymer materials like cementitious matrices have low flexural strength and have fragile breakage. To overcome these deficiencies, the insertion of fibers in geopolymeric matrices has been evaluated as a solution. Although most research on this practice focuses on the use of synthetic fibers, the use of natural fibers has been growing and brings as an advantage the possibility of producing an even more ecological material, satisfying the need to create eco-friendly materials that exists today in society. Thus, this paper aimed to, through the evaluation of research available in the literature, understand the behavior of fibers in geopolymer matrices, identify similarities and differences between the performance of geopolymer composites reinforced with natural and synthetic fibers and, understanding that it is possible, point out ways to optimize the performance of these composites.
Afonso de Azevedo; Ariana Cruz; Markssuel Marvila; Leandro de Oliveira; Sergio Monteiro; Carlos Vieira; Roman Fediuk; Roman Timokhin; Nikolai Vatin; Marina Daironas. Natural Fibers as an Alternative to Synthetic Fibers in Reinforcement of Geopolymer Matrices: A Comparative Review. Polymers 2021, 13, 2493 .
AMA StyleAfonso de Azevedo, Ariana Cruz, Markssuel Marvila, Leandro de Oliveira, Sergio Monteiro, Carlos Vieira, Roman Fediuk, Roman Timokhin, Nikolai Vatin, Marina Daironas. Natural Fibers as an Alternative to Synthetic Fibers in Reinforcement of Geopolymer Matrices: A Comparative Review. Polymers. 2021; 13 (15):2493.
Chicago/Turabian StyleAfonso de Azevedo; Ariana Cruz; Markssuel Marvila; Leandro de Oliveira; Sergio Monteiro; Carlos Vieira; Roman Fediuk; Roman Timokhin; Nikolai Vatin; Marina Daironas. 2021. "Natural Fibers as an Alternative to Synthetic Fibers in Reinforcement of Geopolymer Matrices: A Comparative Review." Polymers 13, no. 15: 2493.
The stress values at the crack tip in bending reinforced concrete beams are considered. The stress state is analytically determined with an initial and propagating crack. Equations of the equilibrium of a part of the beam cut along the crack line are compiled. These equations are reduced to a system of two nonlinear algebraic equations using the plane-sections hypothesis. The equations determine the stress zone’s height and the nominal stress at the crack tip for a beam with an initial crack and the crack length. The rest of the stress state parameters are expressed regarding the zone stress height and the nominal stress or crack length. The same equation system determines the external moment starting from which the crack length increases. The analytical method for determining the stress intensity factor (SIF) with an initial and growing crack in bent reinforced concrete beams is proposed. The method is based on the assumption that the size of the stress concentration zone at the crack tip is determined by the equality of the nominal and local stresses at the end of this zone. The method determines the value of the external moment starting from which the crack length increases. The stress zone’s size is determined by the coincidence of the local stress with the nominal stress. The same problem is solved in a three-dimensional formulation by the FE method, considering the stress field’s peculiarities at the crack tip. The calculation results coincide with the analytical solutions.
Zhmagul Nuguzhinov; Zhetpisbay Bakirov; Nikolai Vatin; Madi Bakirov; Irina Kurokhtina; Daniyar Tokanov; Omirkhan Khabidolda. Stress Intensity Factor of Reinforced Concrete Beams in Bending. Buildings 2021, 11, 287 .
AMA StyleZhmagul Nuguzhinov, Zhetpisbay Bakirov, Nikolai Vatin, Madi Bakirov, Irina Kurokhtina, Daniyar Tokanov, Omirkhan Khabidolda. Stress Intensity Factor of Reinforced Concrete Beams in Bending. Buildings. 2021; 11 (7):287.
Chicago/Turabian StyleZhmagul Nuguzhinov; Zhetpisbay Bakirov; Nikolai Vatin; Madi Bakirov; Irina Kurokhtina; Daniyar Tokanov; Omirkhan Khabidolda. 2021. "Stress Intensity Factor of Reinforced Concrete Beams in Bending." Buildings 11, no. 7: 287.
Geopolymer composites have been around only for 40 years. Nowadays, they are used in buildings and infrastructures of various kinds. A geopolymer’s main benefit is that it is a green material that is partially made by utilizing waste products. The carbon footprint from geopolymer matrix manufacturing is at least two times less than Portland cement manufacturing. Due to the nature of the geopolymer manufacturing process, there is a high risk of shrinkage that could develop unwanted micro-cracks that could reduce strength and create higher creep strains. Because of this concern, a common strategy to reduce long-term strains of the material, such as shrinkage and creep, is to add fiber reinforcement that would constrain crack development in the material. This article aims to determine how various kinds and amounts of different fiber reinforcement affect fly ash-based geopolymer composites’ creep strains in compression. Specimen mixes were produced with 1% steel fibers, 1% polypropylene fibers, 5% polypropylene fibers, and without fibers (plain geopolymer). For creep and shrinkage testing, cylindrical specimens Ø46 × 190 mm were used. The highest creep resistance was observed in 5% polypropylene fiber specimens, followed by 1% polypropylene fiber, plain, and 1% steel fiber specimens. The highest compressive strength was observed in 1% polypropylene fiber specimens, followed by plain specimens, 1% steel fiber specimens, and 5% polypropylene fiber-reinforced specimens. The only fiber-reinforced geopolymer mix with improved long-term properties was observed with 1% polypropylene fiber inclusion, whereas other fiber-introduced mixes showed significant decreases in long-term properties. The geopolymer composite mix with 1% polypropylene fiber reinforcement showed a reduction in creep strains of 31% compared to the plain geopolymer composite.
Rihards Gailitis; Andina Sprince; Tomass Kozlovskis; Liga Radina; Leonids Pakrastins; Nikolai Vatin. Long-Term Properties of Different Fiber Reinforcement Effect on Fly Ash-Based Geopolymer Composite. Crystals 2021, 11, 760 .
AMA StyleRihards Gailitis, Andina Sprince, Tomass Kozlovskis, Liga Radina, Leonids Pakrastins, Nikolai Vatin. Long-Term Properties of Different Fiber Reinforcement Effect on Fly Ash-Based Geopolymer Composite. Crystals. 2021; 11 (7):760.
Chicago/Turabian StyleRihards Gailitis; Andina Sprince; Tomass Kozlovskis; Liga Radina; Leonids Pakrastins; Nikolai Vatin. 2021. "Long-Term Properties of Different Fiber Reinforcement Effect on Fly Ash-Based Geopolymer Composite." Crystals 11, no. 7: 760.
The research object of this work is an orthotropic viscoelastic plate with an arbitrarily varying thickness. The plate was subjected to dynamic periodic load. Within the Kirchhoff–Love hypothesis framework, a mathematical model was built in a geometrically nonlinear formulation, taking into account the tangential forces of inertia. The Bubnov–Galerkin method, based on a polynomial approximation of the deflection and displacement, was used. The problem was reduced to solving systems of nonlinear integrodifferential equations. The solution of the system was obtained for an arbitrarily varying thickness of the plate. With a weakly singular Koltunov–Rzhanitsyn kernel with variable coefficients, the resulting system was solved by a numerical method based on quadrature formulas. The computational algorithm was developed and implemented in the Delphi algorithmic language. The plate’s dynamic stability was investigated depending on the plate’s geometric parameters and viscoelastic and inhomogeneous material properties. It was found that the results of the viscoelastic problem obtained using the exponential relaxation kernel almost coincide with the results of the elastic problem. Using the Koltunov–Rzhanitsyn kernel, the differences between elastic and viscoelastic problems are significant and amount to more than 40%. The proposed method can be used for various viscoelastic thin-walled structures such as plates, panels, and shells of variable thickness.
Rustamkhan Abdikarimov; Marco Amabili; Nikolai Vatin; Dadakhan Khodzhaev. Dynamic Stability of Orthotropic Viscoelastic Rectangular Plate of an Arbitrarily Varying Thickness. Applied Sciences 2021, 11, 6029 .
AMA StyleRustamkhan Abdikarimov, Marco Amabili, Nikolai Vatin, Dadakhan Khodzhaev. Dynamic Stability of Orthotropic Viscoelastic Rectangular Plate of an Arbitrarily Varying Thickness. Applied Sciences. 2021; 11 (13):6029.
Chicago/Turabian StyleRustamkhan Abdikarimov; Marco Amabili; Nikolai Vatin; Dadakhan Khodzhaev. 2021. "Dynamic Stability of Orthotropic Viscoelastic Rectangular Plate of an Arbitrarily Varying Thickness." Applied Sciences 11, no. 13: 6029.
The urbanization process contributes to the growth of solid waste generation and causes an increase in environmental impacts and failures in the management of solid waste. The number of dumps is a concern due to the limited implementation and safe disposal of this waste. The interest in sustainable techniques has been growing in relation to waste management, which is largely absorbed by the civil construction sector. This work aimed to review plastic waste, especially polyethylene terephthalate (PET), that can be incorporated with construction materials, such as concrete, mortars, asphalt mixtures, and paving. The use of life-cycle assessment (LCA) is related, as a tool that allows the sustainability of products and processes to be enhanced in the long term. After analyzing the recent literature, it was identified that studies related to plastic wastes in construction materials concentrate sustainability around the alternative destination of waste. Since the plastic waste from different production chains are obtained, it was possible to affirm the need for a broader assessment, such as the LCA, providing greater quantification of data making the alternative processes and products more sustainable. The study contributes to enhance sustainability in alternative building materials through LCA.
Tulane da Silva; Afonso de Azevedo; Daiane Cecchin; Markssuel Marvila; Mugahed Amran; Roman Fediuk; Nikolai Vatin; Maria Karelina; Sergey Klyuev; Maciej Szelag. Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives. Materials 2021, 14, 3549 .
AMA StyleTulane da Silva, Afonso de Azevedo, Daiane Cecchin, Markssuel Marvila, Mugahed Amran, Roman Fediuk, Nikolai Vatin, Maria Karelina, Sergey Klyuev, Maciej Szelag. Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives. Materials. 2021; 14 (13):3549.
Chicago/Turabian StyleTulane da Silva; Afonso de Azevedo; Daiane Cecchin; Markssuel Marvila; Mugahed Amran; Roman Fediuk; Nikolai Vatin; Maria Karelina; Sergey Klyuev; Maciej Szelag. 2021. "Application of Plastic Wastes in Construction Materials: A Review Using the Concept of Life-Cycle Assessment in the Context of Recent Research for Future Perspectives." Materials 14, no. 13: 3549.
The use of expanded clay aggregate (ECA) for developing lightweight concrete results in strength-reduction properties. However, the ECA-based concrete strength properties can be improved by adding steel fibre (SF), glass fibre mesh (GFM) and multi-walled nano-carbon tubes (MWCNT). The combined effect of MWCNT, GFM, SF and ECA-based concrete and its strength properties is still unexplored. It is worth drawing a logical conclusion concerning the impact on the strength of concrete by incorporating the materials mentioned above. Two-stage expanded clay aggregate fibrous concrete (TECAFC) is a new concrete type and an emerging research area in material engineering. The casting method of TECAFC includes the two essential phases as follows. First, ECA and fibres are filled into the empty cylindrical mould to develop a natural skeleton. Second, the grout comprising cement, sand and MWCNT, are injected into the developed skeleton to fill voids. In this research, eight mixtures were prepared with 0.1 and 0.2% of MWCNT, 2.5% dosage of SF and three different layers of GFM inserted between the two layers of concrete. These eight mixtures were divided into two series of three mixtures each, in addition to two reference mixtures that include no SF or GFM. The first series of mixtures was comprised of 0.1% of MWCNT and 2.5% of SF and one, two and three layers of GFM insertion. The second series was the same as the first series and the dosage of MWCNT was taken as 0.2%. All cylindrical specimens were tested under drop mass impact as per the suggestions made by the ACI Committee 544. The test results showed that incorporating steel fibres and GFM improved the cracking and failure impact resistance by more than 270 and 1100%, respectively, and increased the impact ductility index by more than 220%, significantly contributing to steel fibres.
Gunasekaran Murali; Sallal Abid; Mugahed Amran; Roman Fediuk; Nikolai Vatin; Maria Karelina. Combined Effect of Multi-Walled Carbon Nanotubes, Steel Fibre and Glass Fibre Mesh on Novel Two-Stage Expanded Clay Aggregate Concrete against Impact Loading. Crystals 2021, 11, 720 .
AMA StyleGunasekaran Murali, Sallal Abid, Mugahed Amran, Roman Fediuk, Nikolai Vatin, Maria Karelina. Combined Effect of Multi-Walled Carbon Nanotubes, Steel Fibre and Glass Fibre Mesh on Novel Two-Stage Expanded Clay Aggregate Concrete against Impact Loading. Crystals. 2021; 11 (7):720.
Chicago/Turabian StyleGunasekaran Murali; Sallal Abid; Mugahed Amran; Roman Fediuk; Nikolai Vatin; Maria Karelina. 2021. "Combined Effect of Multi-Walled Carbon Nanotubes, Steel Fibre and Glass Fibre Mesh on Novel Two-Stage Expanded Clay Aggregate Concrete against Impact Loading." Crystals 11, no. 7: 720.
Structural health monitoring (SHM) provides an opportunity to assess and predict changes in the technical condition of structures during the operation of a building. Structural damage, as well as several operational and environmental conditions, causes changes in modal parameters. Temperature is the most popular environmental condition which is used for research. However, to the authors’ knowledge, this is the first investigation that highlights the effect of groundwater level change on the natural frequencies of the buildings and the impact of possible damage detection features. Groundwater level change can influence structural health monitoring measurements and cause faulty structural damage identification using vibration-based methods. This paper aims to analyse the impact of the groundwater level changes on the modal parameters of mid-rise reinforced concrete buildings. The modal parameters of mid-rise reinforced concrete buildings are determined using finite element (FE) models. Three different FE models of structural system types of nine-storey reinforced concrete (RC) buildings with shallow foundations are used to determine the impact of groundwater level fluctuation on the values of the buildings’ natural frequencies. Changes in the groundwater level have an impact on the natural frequencies of the mid-rise reinforced concrete buildings. This research proposes a new environmental condition that has to be considered to identify the structural damage using the vibration-based method. It is found that groundwater level rise causes a decrease in the natural frequency value. In this research, it is established that the influence of the groundwater level on the natural frequencies of the buildings can change abruptly, and there is a non-linear correlation between groundwater level change and natural frequencies of the buildings. The natural frequencies of the buildings can change under varying environmental conditions as well as in the case of structural damage. To identify structural damage in the long-term structural health monitoring measurements, it is recommended to select features which are sensitive to structural damage but are not affected by groundwater level change. Data normalisation and elimination using linear correlation methods can be used for short-term SHM under varying seasonal groundwater level change.
Lasma Ratnika; Liga Gaile; Nikolai Vatin. Impact of Groundwater Level Change on Natural Frequencies of RC Buildings. Buildings 2021, 11, 265 .
AMA StyleLasma Ratnika, Liga Gaile, Nikolai Vatin. Impact of Groundwater Level Change on Natural Frequencies of RC Buildings. Buildings. 2021; 11 (7):265.
Chicago/Turabian StyleLasma Ratnika; Liga Gaile; Nikolai Vatin. 2021. "Impact of Groundwater Level Change on Natural Frequencies of RC Buildings." Buildings 11, no. 7: 265.
Currently, a number of disadvantages hampers the use of recycled concrete aggregates (RCA). The current review proves that concretes made with complete replacement of natural aggregate with RCA allow the production of high-quality concrete. One of the possibilities for improving concrete properties with RCA is the use of extended curing and pozzolanic materials with varying cement ratios. The potential use of RCA concretes is in the production of high-value materials that increase environmental and financial benefits. RCA have strong potential in the development of a new generation of concrete and stimulate economic activity in many countries in addition to optimizing natural resources. Economic benefits include minimal travel costs; cheaper sources of concrete than newly mined aggregates; reduction of the landfill area required for the placement of concrete waste; the use of RCA minimizes the need for gravel extraction, etc. The proposed strategy could be to sequentially separate demolition waste such as roof finishes, waterproof materials, interior and exterior materials, etc. Closing life cycles is the main approach used for efficient structures for the recycling and reuse of construction and demolition waste in the production and recovery of materials, especially when recycling and reusing materials. In the life cycle, the recycling of recovered materials allows them to be used for new construction purposes, avoiding the use of natural concrete aggregates. Government, design institutes, construction departments and project managers should be involved in the creation and use of RCA. In demolition and construction, the main players are the project owners. Their obligations, expectations and responsibilities must be properly aligned. For the past 20 years, recycled concrete aggregate from demolition and construction waste has been considered as an alternative to pure concrete in structural concrete to minimize the environmental impact of construction waste and demolition waste and the conversion of natural aggregate resources. It is now recognized that the use of RCA for the generations of concrete is a promising and very attractive technology for reducing the environmental impact of the construction sector and conserving natural resources. In the market, the selling price is not an obstacle for market applications of RCA, as there are scenarios in which their cost is lower than the cost of products made from conventional building materials. This is more of an acceptance factor in the market for recycled concrete aggregates. In this sector, the lack of identification, accreditation and uniform quality certification systems and their narrow application cause some marketing problems. With proper RCA preparation, concrete with standard physical and mechanical properties and performance characteristics can be obtained.
Natt Makul; Roman Fediuk; Mugahed Amran; Abdullah Zeyad; Sergey Klyuev; Irina Chulkova; Togay Ozbakkaloglu; Nikolai Vatin; Maria Karelina; Afonso Azevedo. Design Strategy for Recycled Aggregate Concrete: A Review of Status and Future Perspectives. Crystals 2021, 11, 695 .
AMA StyleNatt Makul, Roman Fediuk, Mugahed Amran, Abdullah Zeyad, Sergey Klyuev, Irina Chulkova, Togay Ozbakkaloglu, Nikolai Vatin, Maria Karelina, Afonso Azevedo. Design Strategy for Recycled Aggregate Concrete: A Review of Status and Future Perspectives. Crystals. 2021; 11 (6):695.
Chicago/Turabian StyleNatt Makul; Roman Fediuk; Mugahed Amran; Abdullah Zeyad; Sergey Klyuev; Irina Chulkova; Togay Ozbakkaloglu; Nikolai Vatin; Maria Karelina; Afonso Azevedo. 2021. "Design Strategy for Recycled Aggregate Concrete: A Review of Status and Future Perspectives." Crystals 11, no. 6: 695.
In this research, a phase formation in CaO–SiO2–Al2O3–H2O binding system under hydrothermal conditions was studied. The novelty of this article lies in the quantitative full-profile X-ray diffraction (XRD) analysis used to determine kinetics of mineral formation in the binder system “lime–granite mineral modifier (GMM)”. The formation of a polymineral system is described in detail, as well as quantitative relationships between mineral composition of newly formed phases and the binding mixture ratios were determined. Phenomenological model of mineral formation in a “lime–GMM” system under hydrothermal conditions was proposed. The results obtained allow the demonstration of this binding system as a binder that is characterized by superposition of hydration and geopolymerization. The properties (strength, density, water absorption, porosity) of compressed autoclave-hardened materials with the addition of a granite modifier introduced instead of part of the sand as an aggregate have been studied. The maximum increase in strength (more than 50%) is observed at a modifier content of 15%. This is due to the formation of a rational composition of neoplasms, the compaction of the structure of the pressed products and the optimization of their pore space, which is confirmed by the data of X-ray diffraction analysis, scanning electron microscopy and the method of gas adsorption.
Viktoriya Nelubova; Valeria Strokova; Roman Fediuk; Mugahed Amran; Nikolai Vatin; Yuriy Vasilev. Effect of an Aluminosilicate Disperse Additive on Behaviors of Autoclave Silicate Materials. Buildings 2021, 11, 239 .
AMA StyleViktoriya Nelubova, Valeria Strokova, Roman Fediuk, Mugahed Amran, Nikolai Vatin, Yuriy Vasilev. Effect of an Aluminosilicate Disperse Additive on Behaviors of Autoclave Silicate Materials. Buildings. 2021; 11 (6):239.
Chicago/Turabian StyleViktoriya Nelubova; Valeria Strokova; Roman Fediuk; Mugahed Amran; Nikolai Vatin; Yuriy Vasilev. 2021. "Effect of an Aluminosilicate Disperse Additive on Behaviors of Autoclave Silicate Materials." Buildings 11, no. 6: 239.
The global sustainable construction aimed to minimize the ecological impacts of constructed facilities’ lifetime. In construction, concretes are the major materials utilized in South East Asia. Thus, it makes environmental and economic sense to utilize recycled materials in the production of new concretes for diverse uses. This review indicated that the practical implementations of the recycled aggregate concretes (RAC) in the area is greatly lacking, even though there are reasonable studies on RAC, particularly because of lack awareness and economic viability of such uses at the present period. This research aims to establish an interdisciplinary consortium with researchers, policy makers, practitioners, and social scientists in Southeast Asia to investigate the development of sustainable, durable, cost-effective, green concrete by utilizing recycled aggregates. Concentrating on waste resource recovery, this research presents an integrated modeling method. The approaches track and forecast a variety of values across technical, economic, social, and environmental areas linking these to the material flow and therefore integrating and building upon one-dimensional models like life cycle assessments (LCAs) and material flow analyses (MFAs). Additionally, the analysis of this study supported the recycling of cement for general use in construction, emphasizing the feasibility, reliability, and longevity of a project at the same time. However, the analysis also demonstrated that although there is fair progress on recycled concrete, there is still a severe lack of appropriate development in particular because of the lack of economic sustainability and knowledge of such applications at present. Raw material conservations were recorded; carbon dioxide costs and footprint were also reduced. Considering the RAC economic, technical, and environmental parameters, frameworks were applied for sustainable selections with target compressive strengths as the major goal.
Natt Makul; Roman Fediuk; Mugahed Amran; Abdullah Zeyad; Afonso de Azevedo; Sergey Klyuev; Nikolai Vatin; Maria Karelina. Capacity to Develop Recycled Aggregate Concrete in South East Asia. Buildings 2021, 11, 234 .
AMA StyleNatt Makul, Roman Fediuk, Mugahed Amran, Abdullah Zeyad, Afonso de Azevedo, Sergey Klyuev, Nikolai Vatin, Maria Karelina. Capacity to Develop Recycled Aggregate Concrete in South East Asia. Buildings. 2021; 11 (6):234.
Chicago/Turabian StyleNatt Makul; Roman Fediuk; Mugahed Amran; Abdullah Zeyad; Afonso de Azevedo; Sergey Klyuev; Nikolai Vatin; Maria Karelina. 2021. "Capacity to Develop Recycled Aggregate Concrete in South East Asia." Buildings 11, no. 6: 234.
Residential consumption dominates the energy expenditure of heating and cooling systems, especially in tropical climates where building envelopes play an important role in energy efficiency. The thermal properties of concrete that are commonly employed as the building envelope material affect directly human comfort in a building. In addressing both the concrete thermal performance and industrial waste issues, this paper experimentally studies the concrete compressive strength and thermal properties used later for comparative energy analysis for human comfort. Four design mixes and a conventional concrete as control specimen are considered utilizing industrial wastes; palm oil fly ash (POFA), lightweight expanded clay aggregate (LECA), oil palm shell (OPS), and quarry dust, as constituents. These mixes are cast for cube compressive strength (to ensure the achievement of structural concrete requirement) and small-scaled wall tests. The measurement of surface temperatures of scaled wall tests is conducted in a polystyrene box to determine the concrete time lag and decrement factor. It is found that the density of concrete governs the compressive strength and that air pockets in the concrete matrix play an essential role as far as the thermal properties are concerned. From the energy analysis, structural lightweight concrete may save approximately 50% of the residential energy consumption.
Yeong Lee; Nicholas Chua; Mugahed Amran; Yee Yong Lee; Ahmad Hong Kueh; Roman Fediuk; Nikolai Vatin; Yuriy Vasilev. Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving. Crystals 2021, 11, 461 .
AMA StyleYeong Lee, Nicholas Chua, Mugahed Amran, Yee Yong Lee, Ahmad Hong Kueh, Roman Fediuk, Nikolai Vatin, Yuriy Vasilev. Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving. Crystals. 2021; 11 (5):461.
Chicago/Turabian StyleYeong Lee; Nicholas Chua; Mugahed Amran; Yee Yong Lee; Ahmad Hong Kueh; Roman Fediuk; Nikolai Vatin; Yuriy Vasilev. 2021. "Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving." Crystals 11, no. 5: 461.
Reconstruction of buildings and structures is becoming one of the main directions in the field of construction, and the design and production of works during reconstruction are significantly different from the ones of new buildings and structures. After carrying out a number of studies on the inspection of the technical condition of buildings in order to determine the effect of defects on the bearing capacity, the criteria for assessing the state of floor slab structures were identified. Conclusions on the state and further work of elements of reinforced concrete structures are considered. The authors achieve the aim of reinforcing flexural elements of reinforced concrete structures with fiber-reinforced mortar, which is especially important for floor elements with increased operational requirements. A technique for constructing a reinforcement layer using fiber-reinforced mortar from coarse basalt fiber has been developed. The parameters of basalt fiber in the reinforcement layer are substantiated. A method for solving problems of the operation of multilayer coatings under the influence of operational loads is used, in which the model prerequisites for describing the operation of layers are simplified, where the bearing layers are represented by classical Kirchhoff-Love plates. When solving problems, the maximum possible number of design features of flexural members is taken into account, in combination with appropriate experimental studies, the method allows us to consider all the variety of structures for reinforcing coatings and meet the needs of their practical application.
Dmitry Kurlapov; Sergey Klyuev; Yury Biryukov; Nikolai Vatin; Dmitry Biryukov; Roman Fediuk; Yuriy Vasilev. Reinforcement of Flexural Members with Basalt Fiber Mortar. Fibers 2021, 9, 26 .
AMA StyleDmitry Kurlapov, Sergey Klyuev, Yury Biryukov, Nikolai Vatin, Dmitry Biryukov, Roman Fediuk, Yuriy Vasilev. Reinforcement of Flexural Members with Basalt Fiber Mortar. Fibers. 2021; 9 (4):26.
Chicago/Turabian StyleDmitry Kurlapov; Sergey Klyuev; Yury Biryukov; Nikolai Vatin; Dmitry Biryukov; Roman Fediuk; Yuriy Vasilev. 2021. "Reinforcement of Flexural Members with Basalt Fiber Mortar." Fibers 9, no. 4: 26.
Lime plaster mixes are becoming more and more popular in the world’s building materials market every year. Therefore, the issue of increasing the efficiency of lime finishing coatings is relevant. The paper aim is the modification of lime binders with specially synthesized calcium silicate hydrates (CSHs). To obtain the CSH filler, liquid sodium glass was used with a silicate module of 1.53–2.9 and a density of 1130–1663 kg/m3. Using differential thermal analysis (DTA), X-ray diffraction (XRD) patterns, synthesized calcium silicate hydrates, as well as dry plaster mixes, and finishing coatings based on using them were studied. The regularities of the filler synthesis were established depending on the temperature, density, and silicate modulus of liquid glass, the amount of the precipitant additive, the rate of its introduction, and the drying mode. As a result of processing the obtained experimental data, a mathematical model was obtained for the composition “lime + CSH”. The phase composition of the filler was revealed, which is characterized by the presence of calcium silicate hydrates of the tobermorite group, a solid solution CSH (B) in the form of a weakly crystallized gel, a solid solution of C–S–H (II), hydrohalites, and calcites. It was found that the use of the fillers into the lime compositions, obtained with the rapid introduction of CaCl2 additive into water glass during the synthesis of the filler, promotes the acceleration of the plastic strength gain of lime compositions. It was revealed that the lime composites with the CSH filler are characterized by reduced shrinkage deformations up to 45%. The introduction of the CSH filler into the lime compositions increases the water resistance of the lime finishing layer by 36%. A technological scheme for the production of the lime dry plaster mixes has been developed; it can be introduced at existing factories of building materials without significant re-equipment of production.
Valentina Loganina; Kristina Sergeeva; Roman Fediuk; Valery Uvarov; Nikolai Vatin; Yuriy Vasilev; Mugahed Amran; Maciej Szelag. Increase the Performances of Lime Finishing Mixes Due to Modification with Calcium Silicate Hydrates. Crystals 2021, 11, 399 .
AMA StyleValentina Loganina, Kristina Sergeeva, Roman Fediuk, Valery Uvarov, Nikolai Vatin, Yuriy Vasilev, Mugahed Amran, Maciej Szelag. Increase the Performances of Lime Finishing Mixes Due to Modification with Calcium Silicate Hydrates. Crystals. 2021; 11 (4):399.
Chicago/Turabian StyleValentina Loganina; Kristina Sergeeva; Roman Fediuk; Valery Uvarov; Nikolai Vatin; Yuriy Vasilev; Mugahed Amran; Maciej Szelag. 2021. "Increase the Performances of Lime Finishing Mixes Due to Modification with Calcium Silicate Hydrates." Crystals 11, no. 4: 399.
It is necessary to solve the ecological problems of regions where there is large-tonnage storage of various finely dispersed materials, including technogenic ones. This article presents the results of an investigation into the possible use of substandard dispersed quartz sands to obtain effective granular aggregates, with the purpose of putting them to use in mortars and concrete. The study used standard and original experimental research methods related to the analysis and preparation of raw materials, technological tests, and the study of the properties of finished composites. Investigations were carried out to obtain composite binders in the component composition of which the use of different ratios of Portland cement and substandard quartz sands prepared in a vortex jet mill was envisaged. It was found that the obtained composite binders had high physical and mechanical characteristics, which was due to the high specific surface area and hydration activity. On the basis of composite binders and finely dispersed quartz sands (fineness from ≤0.16 mm to 1 mm), the granulation of mixtures of 36 types of component compositions was performed. The developed compositions of granular aggregates (GAs) showed the possibility of obtaining them with sufficiently high strength values in cement stone. The studies carried out make it possible to recommend finely dispersed substandard and technogenic materials for the production of GAs, which would ensure the economy of binding materials as well as contribute to the reuse of large-tonnage waste of ferrous and nonferrous metallurgy and the chemical and mining industries.
Valery Lesovik; Liliya Zagorodnyuk; Vladislav Ryzhikh; Ruslan Lesovik; Roman Fediuk; Nikolai Vatin; Maria Karelina. Granular Aggregates Based on Finely Dispersed Substandard Raw Materials. Crystals 2021, 11, 369 .
AMA StyleValery Lesovik, Liliya Zagorodnyuk, Vladislav Ryzhikh, Ruslan Lesovik, Roman Fediuk, Nikolai Vatin, Maria Karelina. Granular Aggregates Based on Finely Dispersed Substandard Raw Materials. Crystals. 2021; 11 (4):369.
Chicago/Turabian StyleValery Lesovik; Liliya Zagorodnyuk; Vladislav Ryzhikh; Ruslan Lesovik; Roman Fediuk; Nikolai Vatin; Maria Karelina. 2021. "Granular Aggregates Based on Finely Dispersed Substandard Raw Materials." Crystals 11, no. 4: 369.
Compositions and technology for obtaining a photocatalytic composite material (PCM) by deposition of titanium dioxide particles synthesized by the sol–gel method on a silica support of various types (microsilica, gaize and diatomite) have been developed. The properties (chemical and mineral composition, dispersion, specific surface area, porosity, ζ-potential, acid–base properties, and microstructure) of microsilica, gaize and diatomite were studied to assess the effectiveness of using a photocatalytic agent as a carrier. In terms of specific viscosity (ηsp = 45), the concentration of the precursor (tetrabutoxytitanium—TBT) is set at 22 vol. % in a solvent (ethanol), at which it is possible to obtain the maximum amount of dissolved film oligomer without the formation of an aggregate-like precipitate. Modification of the reaction mixture (precursor: ethanol = 1:3) by replacing part of the solvent with a Span-60 surfactant/TBT = 1–1.1 made it possible to obtain polydisperse titanium dioxide particles with peak sizes of 43 nm and 690 nm according to laser granulometry data. Taking into account the interaction of titanium complexes with the surface of a silica support, a phenomenological model of the processes of structure formation of a photocatalytic composite material is proposed. By the value of the decomposition of rhodamine B, the photocatalytic activity of the developed composite materials was determined: PCM based on diatomite—86%; PCM based on microsilica—85%; PCM based on gaize—57%.
Valeria Strokova; Ekaterina Gubareva; Yulia Ogurtsova; Roman Fediuk; Piqi Zhao; Nikolai Vatin; Yuriy Vasilev. Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials. Nanomaterials 2021, 11, 866 .
AMA StyleValeria Strokova, Ekaterina Gubareva, Yulia Ogurtsova, Roman Fediuk, Piqi Zhao, Nikolai Vatin, Yuriy Vasilev. Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials. Nanomaterials. 2021; 11 (4):866.
Chicago/Turabian StyleValeria Strokova; Ekaterina Gubareva; Yulia Ogurtsova; Roman Fediuk; Piqi Zhao; Nikolai Vatin; Yuriy Vasilev. 2021. "Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials." Nanomaterials 11, no. 4: 866.
The article considers the nonlinear vibrations of orthotropic viscoelastic rectangular plates with a concentrated mass. In the calculations, the mass is considered rigidly fixed and concentrated at points. The classical Kirchhoff-Love theory is used to derive the equations describing the stress-strain state of the plates. When composing the equations for the equilibrium of the plate, the effect of a concentrated mass is taken into account using the Dirac delta function. With the Bubnov-Galerkin method, the problem is reduced to solving a system of ordinary nonlinear integro-differential equations of Volterra type with a Koltunov-Rzhanitsyn singular kernel. To solve the resulting system, a numerical method based on the use of quadrature formulas is applied. The amplitude-frequency response of vibrations was investigated for various values of geometrical and physical-mechanical parameters of the plate. The calculation of nonlinear vibrations of orthotropic viscoelastic rectangular plates with concentrated masses showed that an increase in the concentrated mass leads to a more intense decrease in the vibration amplitude as compared to the elastic plate.
Nikolai Vatin; Rustamkhan Abdikarimov; Dadakhan Khodzhaev. Nonlinear Vibrations of Orthotropic Viscoelastic Plates with a Concentrated Mass. Lecture Notes in Civil Engineering 2021, 132 -139.
AMA StyleNikolai Vatin, Rustamkhan Abdikarimov, Dadakhan Khodzhaev. Nonlinear Vibrations of Orthotropic Viscoelastic Plates with a Concentrated Mass. Lecture Notes in Civil Engineering. 2021; ():132-139.
Chicago/Turabian StyleNikolai Vatin; Rustamkhan Abdikarimov; Dadakhan Khodzhaev. 2021. "Nonlinear Vibrations of Orthotropic Viscoelastic Plates with a Concentrated Mass." Lecture Notes in Civil Engineering , no. : 132-139.