Nanotechnologies in Construction: A Scientific Internet-Journal @nanobuild-en
Статьи журнала - Nanotechnologies in Construction: A Scientific Internet-Journal
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The electronic edition «Nanotechnologies in construction: A Scientific Internet-Journal»
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Статья научная
Introduction. A primary geotechnical challenge pertains to the stabilization of unstable soils due to their inadequate deformation, physical, mechanical, and filtration characteristics, which, in turn, can result in abnormal settlements, the destabilization of the soil mass under external loads, or even its own weight. The advent of chemical technologies on a global scale, along with their development within the Russian Federation, has precipitated the utilization of advanced equipment in conjunction with novel, innovative technologies. This confluence has given rise to novel methodologies and the fabrication of new materials, which have been instrumental in addressing a myriad of geotechnical challenges. The predominant methods of soil stabilization with mineral compounds (predominantly based on Portland cement) possess clear advantages; however, they do not always permit work to be conducted in soils with high water saturation, under conditions of high filtration, or in soils with low deformation indices. Consequently, issues pertaining to cementation stabilization periodically emerge. These issues manifest, for instance, in water-saturated rock soils under high hydrostatic pressures, in various fractured soils complicated by the presence of karst depressions, and in silty and organomineral soils with structural instability. Materials and methods. The employment of innovative polymer materials, such as polyurethane-based materials, facilitates the injection of mixtures with optimized strength gain, thereby addressing the issue of soil reinforcement within this process or enhancing the criteria for constraining the propagation of injection mixtures for subsequent cement grouting. Results and conclusion. Laboratory tests and analysis of a number of completed projects allow us to consider this technology effective and practical in complex engineering and geological conditions and beyond design-basis parameters for underground construction projects. This research was carried out using the facilities of the Head Regional Shared Research Facilities of the Moscow State University of Civil Engineering, with support from the Ministry of Science and Higher Education of the Russian Federation (Agreement No. 075- 15-2025-549)
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The formation of the sol-gel nanostructures of road bitumen by selecting chemical group composition
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The studies of paving bitumen chemical composition and physicochemical properties produced by compounding deeply oxidized bitumen, tar and vacuum gas-oil of different hydrocarbon composition are carried out. The bitumen is marked to have the optimal complex of properties if the best chemical group composition of three main elements bitumen binding agents – oils, resins and asphaltenes - is formed. That provides the best structure of bitumen oildisperse system. The object of the research is the selection of compounded paving bitumen chemical group composition that provides the formation of bitumen nanodisperse system as «sol-gel» which quality metrics match the requirements of the new State Standard 33133-2014 «Petroleum paving viscous bitumen». The analysis of the research results makes it possible to determine the optimal chemical group composition of compounded bitumen that meets standard requirements by physicochemical properties. It has been determined that the higher the bitumen dispersion is, the more plastic properties it has. In addition, the bitumen ability to thermal-oxidative processes of deterioration decreases. The value range of bitumen dispersion and the most optimal values of asphaltenes ratio to the amount of oils and resins for bitumen grade BND 100/130 and for bitumen grade BND 70/100 were found. This amount of oils and resins for referred bitumen grades provide production of nanostructured bitumen as «sol-gel». It is shown that when processing tar of different chemical composition the optimal chemical group composition of finished product can be formed by compounding. That rises probability that the end product will fit to the new State Standard 33133-2014. The represented results of the research can be used in fabrication as the modern laboratories of the oil-refining enterprises can determine quite efficiently the chemical composition of oil products used in compounding processes in bitumen binding agents production.
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The influence of nano-additives in the synthesis of eco-friendly polyester plasticizers
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Plasticized polymer materials are widely used in all spheres of human life. The most common plasticizers are aromatic compounds-esters of o-phthalic acid. However, their use was limited in accordance with the EU Directive REACH (2009) due to possible toxicity, which contributed to the development of new non-toxic alternatives, which include polyester plasticizers. Polyester plasticizers are classified as special purpose plasticizers. Due to the wide variety of starting materials and the ability to vary the size of the molecule, a wide range of plasticizers can be synthesized. These are mainly polyesters of polyatomic alcohols esterified with dibasic acids and modified with monocarboxylic acid or aliphatic alcohol. Polyesters-based plasticizers contribute to the production of PVC compositions with improved properties such as low volatility, resistance to extraction, excellent flexibility, wear resistance, UV resistance and heat resistance. Also, such plasticizers exhibit an excellent non-sweating property of plastics. This paper describes a method for preparing a polyester compound propylene glycol adipate modified with cyclohexanecarboxylic acid, proposed as a plasticizer of polyvinyl chloride. Conditions of its production with maximum output are given. Physical and chemical properties of the resulting compound were studied. The formulation of PVC-composition on the basis of the received polyester plasticizer is offered. The results of tests of PVC plastic according to state standard 5960-72 are presented. It is shown that the use of propylene adipate modified with cyclohexanecarboxylic acid provides a plasticizing efficiency as high as DOP, while having a reduced migration. This fact allows us to use the developed polyester plasticizer as a non-toxic alternative to industrial PVC plasticizers. It has been found that the use of calcium adipate nano quantities in the production of propylene glycol adipate increases the yield of the desired ester and improves the physical and mechanical properties of PVC plastic.
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Introduction. Drilling and reconstruction of oil and gas wells are key stages in the development of hydrocarbon fields. One of the most significant technological elements that greatly influences the efficiency of the process is the drilling fluid (DF). It performs many functions, including cooling and lubrication of rock-cutting and special tools, bottomhole cleaning from drilled rock, maintaining well wall stability and many others. In recent years, special attention has been paid to the use of nanomaterials in the DF drilling fluid composition. Nanoscale additives can significantly improve technological properties of water-based muds, increase their efficiency and reduce drilling costs. Methods and Materials. The influence of additives on general technological parameters of Clay-Free Drilling Mud (CFDM) was evaluated. Special attention was paid to revealing the influence of the developed experimental additives on the friction coefficient and antifriction properties of (CFDM), which were determined using modified friction machine AI5018. Results and discussion. This study focuses on the investigation of the impact of nano-additives on the technical properties of water-based mud (WBs) and their effectiveness for drilling and well reconstruction. In the course of the work, comprehensive laboratory studies have been carried out to evaluate the effect of nano-additives of different nature, such as nano-graphite and nano-carbon materials, on the lubricating properties of water-based mud (WBs), which helps to reduce the wear of drilling equipment, increase the mechanical speed of drilling and, as a consequence, reduce the time and financial costs of well construction and re-construction. Conclusion. The introduction of nano-additives allowed significantly in improving the technological properties of drilling fluid DF. The obtained results can be used to improve the compositions of solutions based on the use of nanomaterials, which will increase the efficiency and reliability of well drilling processes.
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The inventions in nanotechnologies as practical solutions. Part I
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A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials result in increased efficiency of construction, housing sector and adjacent fields of economy. The invention «A method of introduction of single-shell and/or double-shell and/or multi-shell carbon nanotubes in adhesive additive composition for asphalt coating and application of single-shell and/or double-shell and/or multi-shell carbon nanotubes as a part of adhesive additive composition» refers to construction, in particular, to the materials used in road, airdrome and civil construction. Concentration (content) of single-shell and/or double-shell and/or multi-shell carbon nanotubes varies from 0,01% to 15% of volume of asphalt covering. The invention «A method to produce nanocomposite material» based on aluminium refers to powder metallurgy, in particular to production of metal and carbon composite materials and articles of them in different shapes and can be used in auto industry, shipbuilding, aircraft engineering and instrument manufacture and other areas. The invention «A method of low temperature application of nanocrystal coating of alpha-oxide aluminium» refers to method of production nanocrystal coating of alpha-oxide aluminium with high rate under low temperature. Coatings of aluminium oxide are characterized by high thermal resistance, chemical inaction, hardness, compression resistance, heat-insulation capacity and is widely used for protection the products exposed to high temperatures and aggressive environments. The specialists can also be interested in the following inventions in the area of nanotechnologies: device and method for production of powder materials based on nano- and microparticles through electric explosion of wire; vacuum machine for application of nanostructured coating made of material with shape memory effect on the detail surface; hierarchically reinforced heteromodular extrudable solid lubricant nanocomposite based on UHMW PE and a method to produce it; hydrogen-accumulating materials and a method to produce them et al.
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The inventions in nanotechnologies as practical solutions. Part II
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A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials result in increased efficiency of construction, housing sector and adjacent fields of economy. For example, invention «Elastic conductive film on the basis of silver nanoparticles», according to experts, is of great interest for science and industry. This new type of electronics potentially can be applied in many fields, such as elastic sensor skin for robot devices, portable electronics for functional clothes, elastic sensors and flexible electronic displays. Elasticity of materials is highly needed in electronic devices that contact the human body or curved surfaces. Elastic conductive film contains many annealed nanoparticles of conductive metal, in particular silver, applied on substrate. Adhesion of silver film is of great quality: when abrasion test was finished, there were no defects or there were slight defects. The specialists can also be interested in the following inventions in the area of nanotechnologies: a method to introduce single-wall and/or two-wall and/or multi-wall carbon nanotubes in composition of adhesive additives for asphalt coating and application of single-wall and/or two-wall and/or multi-wall carbon nanotubes in composition of adhesive additives; welding wire with nanocomposite coating for welding of high-tensile steel; A method to produce nanocomposite material based on aluminium; sewage treatment system with nanomodified natural sorbents et al.
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The inventions in nanotechnologies as practical solutions. Part III
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A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials resulted in increased efficiency of construction, housing sector and adjacent fields of economy. For example, the invention «Construction structural element» refers to the field of construction. The building element is made of a cured mixture containing the following components, wt. %: dispersed foamglass – 60–85; 25–30% alumina solution in phosphoric acid – 13–34; basalt microfiber – 2–6; fulleroid type carbon toroid-like nanoparticles (fractions from 15 to 150 nm) – 0.009–0005. The dispersed foamglass is made in the form of foamed glass beads, on the surface of which a layer of polyparaxilylene 2–5 microns thick is applied. The mixture is cured at a temperature of 160–180оC. The technical result is increased strength, toughness, crack resistance and durability at low density, that is important when building objects, for example, to create internal walls and cellular partitions in rooms. The specialists can also be interested in the following inventions in the area of nanotechnologies: composite reinforcement, a method of manufacturing composite powder material from alumina carbon nanotubes; the method of plasma deposition of nanostructured heat-shielding coating; the method of degassing tungsten nanopowder; method to produce mixtures of highly dispersed heterophase powders based on boron carbide, etc.
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The inventions in nanotechnologies as practical solutions. Part IV
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A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials resulted in increased efficiency of construction, housing sector and adjacent fields of economy. For example, the invention «Carbon ceramic fiber-reinforced composite material and method for its production» refers to a class of carbon-based composite materials of heat-shielding, structural, chemical-resistant purposes, can be used under static and dynamic loads when heated to 2000оC in an oxidizing environment (aerospace engineering, construction facilities for special purposes, high-temperature electrothermal equipment, equipment for nuclear reactors, etc.). The technical result of the invention is the strength of the composite increased up to 40% in terms of flexural strength and twice in terms of compressive strength. The specialists can also be interested in the following inventions in the area of nanotechnologies: building construction elements; a method for synthesizing a composite carbon material with metal nanoparticles with transferring a part of their electron density to a carbon matrix; a method of manufacturing marker of fuel and lubricants; wastewater treatment system with nano-modified natural sorbents; nanocrystal, hydrosol of nanocrystalline cellulose and method for producing it; a method for producing membranes for ultrafiltration of aqueous media; a method of obtaining transparent ceramics of yttrium-aluminum garnet; method and device for atomic emission spectral analysis of nanoobjects, etc.
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The inventions in nanotechnologies as practical solutions. Part V
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A brief review of patents is given. The research performed by scientists, engineers and specialists in the area of nanotechnologies and nanomaterials resulted in increased efficiency of construction, housing sector and adjacent fields of economy. For example, the invention «A method to produce fireproof wood-polymer composites on the basis of secondary polyolefine» can be used in construction, car industry, shipbuilding, machine manufacturing, furniture trade and other industries. The method includes following stages: drying of composite components, mixing and heat forming of them by means of extrusion in extrusion Co- Kneader plant under treatment temperature120оС–150оС and conveyor screw rotation speed 350–450 RPM with further granulation. The obtained fire-resistant wood-polymer composite possesses high performance characteristics. The specialists can also be interested in the following inventions in the area of nanotechnologies: a method to produce strengthened nanocomposite with additional properties, anodic material for lithium-ion battery and a method to produce it, a method to rise breaking strength of composite material by preliminary impregnation of carbon fibers with carbon nanotubes, a method to produce carbon metal-containing nanostructures, a method to produce volume microscale structures from nanoparticles and a device to perform it, antistatic floor coating with carbon nanotubes and other.
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This study presents an investigation of the effects of high temperature on the thermal and microstructural properties of cement mortars modified with nanosilica. In the first stage of the research, the effects of nanosilica (NS) and silica fume (SF) on the hydration and compressive strength of cementitious composites were compared. In the second stage, four different types of cement mortars, containing an optimal dosage of NS, were produced. Two of them contained a normal weight aggregate (quartz or limestone), whilst two contained a heavy weight aggregate (barite or magnetite). Specimens without NS were produced for control purposes. The specimens were exposed to 300, 450, 600 and 800°C, with their post-heating properties – including thermal conductivity, specific heat, solvent absorption and cracking behavior – analyzed. The results show that NS exhibits significantly higher reactivity with cement than SF. NS accelerates the cement hydration process and contributes more significantly to the 28 and 365 day compressive strength of mortar, as compared to SF. The incorporation of NS in a composite substantially decreases the amount of CH in the mixture and leads to the production of additional C–S–H gel phase, which improves microstructure. The study also shows that NS contributes to a decrement in the thermal conductivity and density of mortar, both prior to and after heating. The incorporation of NS has a beneficial effect on decreasing the deterioration rate of mortars after heating, by decreasing absorption rate and the amount of cracks in in them.
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Статья научная
This study presents an investigation of the effects of high temperature on the thermal and microstructural properties of cement mortars modified with nanosilica. In the first stage of the research, the effects of nanosilica (NS) and silica fume (SF) on the hydration and compressive strength of cementitious composites were compared. In the second stage, four different types of cement mortars, containing an optimal dosage of NS, were produced. Two of them contained a normal weight aggregate (quartz or limestone), whilst two contained a heavy weight aggregate (barite or magnetite). Specimens without NS were produced for control purposes. The specimens were exposed to 300, 450, 600 and 800°C, with their post-heating properties – including thermal conductivity, specific heat, solvent absorption and cracking behavior – analyzed. The results show that NS exhibits significantly higher reactivity with cement than SF. NS accelerates the cement hydration process and contributes more significantly to the 28 and 365 day compressive strength of mortar, as compared to SF. The incorporation of NS in a composite substantially decreases the amount of CH in the mixture and leads to the production of additional C–S–H gel phase, which improves microstructure. The study also shows that NS contributes to a decrement in the thermal conductivity and density of mortar, both prior to and after heating. The incorporation of NS has a beneficial effect on decreasing the deterioration rate of mortars after heating, by decreasing absorption rate and the amount of cracks in in them.
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The photocatalytic activity of cement-sand plaster under the influence of natural solar radiation
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Introduction. Concrete and cement composites can be considered as the most demanded and versatile building materials nowadays. Recently, photocatalytic building materials containing nano- and finely dispersed oxides and salts photocatalyst particles, especially titanium dioxide of anatase modification, are becoming widespread. Under the influence of light, the surface of these materials becomes capable of self-cleaning. The materials photocatalytic activity is usually determined in the laboratory conditions by irradiating samples with an artificial source of light with certain wavelength, which does not fully characterize the behavior of the material in real-life conditions. Therefore, the purpose of this study is to evaluate the photocatalytic activity of cement-sand plaster samples under natural solar radiation. Materials and methods of research. In this study, the properties of cement-sand plaster modified with an additive of industrial TiO2 were studied. The additive was introduced into the plaster compositions in amounts of 0.3; 1.0; 1.7; 3.0; 5.0 and 10.0 wt.% during the dry mixing of the components. At the first stage, the effect of the additive on physical and mechanical properties of the samples was investigated. The second part of the research is devoted to the study of the photocatalytic properties of the material. Mineralization of the model pollutant Methylene blue was carried out in real-life conditions under sunlight irradiation, the photocatalytic activity of the samples was evaluated in accordance with the European standard UNI 11259-2016. Results and discussion. As a result of the study, the authors found that the maximal increase in compressive and flexural strength corresponds to the sample with 5.0 wt.% of TiO2, and the maximum degree of Methylene blue decomposition corresponds to the sample with 10.0 wt.% of TiO2. Thus, compressive strength increases by 69% at 2 days age, by 58% at 7 days age, and by 50% at 28 days age compared to the control sample. Flexural strength increases by 10, 13, and 50% at 2, 7, and 28 days age, respectively. The strength of the samples with 10.0 wt.% of TiO2 remains approximately at the level of the control sample. Compositions with TiO2 starting from 3 wt.% demonstrate photocatalytic activity (R), the highest R corresponds to 10 wt.% sample with R value is 40–78%. It is also noticeable that the maximum Methylene blue mineralization (58–78%) is observed after 2 days of sunlight irradiation, after 7 days there is a significant decrease in the degree of pigment decomposition. Conclusion. As a result of the research, the authors concluded that the optimal amount of TiO2 photocatalyst in the cement-sand plaster is 5.0–10.0 wt.% since these samples exhibit maximum strength characteristics combined with a high ability of model contaminant degradation.
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The physical and mechanical properties of concrete with multifunctional additive
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Introduction. It is known that concrete is the main building material, despite the introduction of new technologies. The combination of strength and durability makes this material indispensable for the construction of civil and industrial infrastructure. However, the impact of aggressive external factors on concrete structures, such as an acidic or alkaline environment, temperature fluctuations, and the presence of water at low temperatures, can lead to a significant decrease in their strength characteristics. The introduction of various additives based on organic and inorganic compounds into the composition of concrete allows for the regulation of its performance properties and protect concrete structures from the negative impact of the environment. Therefore, research works aimed at improving physical and mechanical properties and quality of concrete structures are relevant. Methods and materials. The objects of our research were concrete samples, prepared with and without the use of a multifunctional additive called “Betomix-ITH Gel”, which was developed by the researchers of the Institute of Theoretical and Applied Mechanics of the Ural Branch of the Russian Academy of Sciences (ITC UB RAS). The physical and chemical properties of the compared samples were studied in accordance with Russian and interstate regulatory documents in accredited laboratories of the Russian Federation and the Republic of Turkey. Results and discussion. As a result of the research, we have found that the introduction of the multifunctional additive "Betomix-ITH Gel" to the concrete mixture significantly increases the water resistance, frost resistance, and strength of concrete samples, compared to samples without the additive. It has been shown that Betomix-ITH Gel imparts the property of "self-healing" to concrete, with cracks up to 0.5 mm in size, and increases the resistance of steel reinforcement to corrosion. Conclusion. The research has proved experimentally the effectiveness of the Betomix-ITH Gel additive for improving the quality characteristics for concrete of various classes, which allows the use of this additive in concrete mixtures in the construction of reinforced concrete structures located in aggressive conditions.
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The potential of nanotechnology: issues of heat supply and heating of buildings
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The article explores the possibility of using nanotechnology to improve the efficiency of centralized and autonomous heating systems on the way to a new technological model. A logical sequence of the development of heat supply and heating is given, conservative equipment and technologies that are used to supply thermal energy to consumers is marked. In the context of the urgent tasks of heat supply and heating of buildings, the concepts of the use of nanotechnologies that meet the goals of maximum heat transfer intensification are considered. Heat conduction analysis, concentration, size, mass and velocity of nanoparticles assesses are the basis for assessing the possibility to use nanofluids as a coolant for improving heat exchangers and to reduce heat losses in heating systems to maximize efficiency of their work. It is shown that the use of nanostructures affects the saving of coolant flow as the main task of the qualitative and quantitative regulation of the heat supply system. Attention is focused on the application of nano-structured materials in low-temperature fuel cells used decentralized heating systems for heating houses.
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Introduction. In the context of the global fight against climate change, the reduction of CO2 emissions and its utilization is a topical theme. One of the promising directions is the utilization of CO2 in construction, in particular, in concrete production. The present research investigates the effect of carbon dioxide on the formation of nanoscale structure and physical and mechanical properties of concrete mixtures. Methods and Materials. A special unit for mixing cement, sand, water and CO2 under pressure was developed for the research. The obtained concrete specimen were subjected to compressive and flexural strength tests using MATEST E161-03N automatic dual range testing press. The microstructure of the specimen was also analyzed using scanning electron microscope (SEM). Discussion. The experimental results showed that the introduction of CO2 into the concrete mixture promotes the formation of nanoscale structure, which improves its strength properties up to a certain pressure. With further increase in pressure, deterioration of these characteristics is being observed. Additional mixing time and increase in water volume also affect the strength of concrete and its microstructure. Conclusion. The use of CO2 in concrete production can significantly reduce the carbon footprint of construction materials and improve their physical and mechanical properties due to the formation of nanoscale structure. Further research and optimization of mixing parameters are necessary to create stronger and more stable concrete mixtures.
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