Radiative cooling is an innovative and highly promising passive cooling technology that allows surfaces to dissipate heat via infrared radiation directly into the cold outer space. Unlike traditional cooling methods that require an external energy source, radiative cooling operates autonomously, offering a sustainable and energy-efficient alternative for temperature control. This natural process has attracted considerable attention in recent years due to its potential to mitigate the growing energy demands associated with air conditioning and refrigeration, which contribute significantly to global energy consumption and environmental degradation.
Keywords: radiation cooling, temperature, atmospheric window, air conditioning, energy efficiency, passive cooling, calcium carbonate, barium sulfide, boron nitride, titanium dioxide
A study was conducted on the development of filler compositions based on heat-treated phosphogypsum for the production of paints and varnishes with luminescent ability. In the course of the study, it was revealed that the reduced phosphogypsum, which exhibits the properties of an ultraviolet pigment, can be used to produce paints and varnishes based on colorless varnish XB-784. When using a colorless varnish and synthesized ultraviolet pigment, paint and varnish materials can be obtained that form almost transparent coatings and have a luminescent ability. The introduction of unreconstructed phosphogypsum as a filler increases the covering capacity of paint coatings. Non-reduced heat-treated phosphogypsum as a filler does not give a luminescent glow under the influence of UV irradiation, however, it increases the hiding power of the material and enhances the luminescent ability of the UV pigment.
Keywords: filler compositions, colorless varnish, ultraviolet pigments, phosphogypsum, waste recycling
This research presents the methods and conclusions obtained from modeling a composite wall panel with a wooden frame and polystyrene concrete core in the Lira-SAPR program, used in the construction of low-rise buildings for residential and commercial purposes. The findings were compared with the results of panel tests at the research laboratory of the Pacific State University (hereinafter TOGU).
Keywords: linear calculation, panel construction, low-rise construction, LIRA-SAPR, modeling
В статье представляется совершенствование технологии гидроизоляции с помощью инъектирования. Специально для этих технологий разработана полимерцементная композиция для инъекционной гидроизоляции. The article presents the improvement of waterproofing technology by injection. A polymer cement composition for injection waterproofing has been developed specifically for these technologies.
Keywords: technology, production, injection waterproofing, injection method, repair and restoration work, polymer cement composition
The physical and mechanical properties, as well as structural and rheological indices of blended compositions based on viscous oil road bitumen and three specific grades of butadiene-styrene thermoplastic elastomers (KRATON 0243, KRATON 0246, KRATON 1192) of different composition and structure are investigated. The structure and properties of initial butadiene-styrene thermoplastic elastomers are considered. The influence of the polymer modifier topology on the properties of the final blended bitumen-polymer compositions has been shown. It is established that the change of polymer composition affects the whole complex of technical, technological and operational indicators of polymer-bitumen binders. Thus, the presence of 75% diblock structures in KRATON 0243 and 55% diblock structures in KRATON 0246 significantly affect both penetration and ductility of bitumen-polymer mixtures at 0 deg. С.
Keywords: butadiene-styrene thermoplastic elastomers of various topologies, viscous petroleum road bitumen
Vulcanization is a technological process that transforms plastic rubber into rubber. As a result of vulcanization, the shape of the product is fixed, and the material becomes more durable, hard and elastic. The purpose of the article is to determine the effect of octyl phenol-formaldehyde resin on the vulcanization parameters and to identify its optimal amount for the development of vibration-absorbing materials based on butyl rubber. The effect of a vulcanizing agent (octyl phenol formaldehyde resin) on the properties of the rubber compound during vulcanization was established. As a result of the study, the kinetics of vulcanization and the effect of various components on the properties of the rubber compound, such as elongation at break, conditional tensile strength and specific damping ability, were studied. This study is conducted in order to find the optimal rubber for placement in a seismic damper used in buildings and structures.
Keywords: vulcanizing group, vibration absorbing material, butyl rubber, rubber compound, vulcanization, octyl phenol formaldehyde resin, seismic damper
The article deals with the results of research on the influence of the dosage and composition of the complex mineral additive containing chemical water treatment sludge with gaize, burnt rock or fly ash. The result of investigation is the equation for the change in shrinkage deformations over the time for mortars containing a complex mineral additive in comparison with a standard mixture without additives. There is evaluating of the influence of changes in the mortar moisture on the amount of shrinkage deformation. On the base of the research, we astablished the dependences of shrinkage deformations on the moisture content of the mortar, according to the composition and dosage of the complex mineral additive. The study revaels the influence of a complex mineral additive on shrinkage deformations. The equation has been obtained that describes the change in shrinkage deformations depending on the relative humidity and it has been shown that the tested mortars with a rational composition and dosage of a complex mineral additive with an average air humidity of the driest month in Rostov-on-Don of 47% will not exceed 0.55 mm/m . Shrinkage deformation with the ratio of the complex additive with fly ash or burnt rock 20-30% are 0.42-0.79 relative to the additive-free standard.
Keywords: dry construction mixture, shrinkage, mineral additive, mortar, chemical water treatment sludge, burnt rock, fly ash
The article is devoted to the study of the main methods of ice crossings and their reinforcement. Key concepts related to this type of transportation are considered, including the definition of an ice crossing, its role in the transportation infrastructure, and the conditions necessary for its construction. Special attention is paid to the preparatory work carried out in summer and the main work carried out in winter. The methods of ice crossing reinforcement are described in detail, including thermal reinforcement, use of logs, snow reinforcement and use of geosynthetic materials. The advantages and disadvantages of each method are discussed, as well as factors influencing the choice of a particular reinforcement method.
Keywords: ice crossing, reinforcement
A device has been developed that allows measuring the edge angle of wetting of flat surfaces with liquid. The device is characterized by simplicity of implementation, low cost, allows you to simplify the measurement process and eliminate errors associated with the individual characteristics of the observer. As an example, by determining the wetting edge angle, the hydrophilicity (hydrophobicity) of surfaces – fluoroplast, steel and steel with a separation coating based on the composition of Penta-100 when they are wetted with water. The dependence of the wetting edge angle of the initial composition of Penta-100 in the liquid state on the viability of the solution has been studied. The correlation of the marginal wetting angle of the Penta-100 solution with the porosity of the formed coating with the surface is shown. The proposed device can be used in educational and industrial laboratories for rapid assessment of the condition of various surfaces.
Keywords: surface, wetting edge angle, water, coating
The article discusses the use of simplex methods of experiment planning to determine the optimal composition of composite building materials. Composite building materials are multicomponent systems, so their properties depend on a large number of factors that are diverse in nature and influence. The use of orthogonal plans is not able to adequately describe experimental data with a wide range of varying factors. Therefore, the article proposes to use simplex-lattice Scheffe's plans. A complete third-order model was developed to determine the optimal composition of the filled cement composite, and a regression equation was written. The adequacy of the equation was confirmed at the control points of the plan using the Student's criterion. The proposed planning method can be used to optimize the composition of multicomponent systems.
Keywords: multicomponent system, optimization methods, composite building material, experiment planning, simplex plans, Scheffe's polynomial, regression equation
This paper presents the results of experimental studies on the development of a chemical additive for concrete and mortar mixtures to establish a modifying effect. A chemical additive was developed - a multifunctional cleaning agent - “LOC”, in order to establish its modifying effect for concrete composites. The results of the experimental studies confirm the effectiveness of the chemical additive under study as a modifier. Composite material samples modified with the developed product show higher technical characteristics: the obtained BC samples correspond to the concrete grade for workability - P3, when the standard sample has a grade - P2, the compressive strength of the control BC samples, with a chemical additive - ""LOC"" in an amount of 1%, increases by 28%, the established optimal dose of the additive being developed - Ministry of Emergency Situations - “LOC” for Bx and mortar mixtures is 1%, which guarantees its economic efficiency.
Keywords: concrete composite, modification, surfactants, cleaning agent – “LOC”, anionic and nonionic surfactants, modifier, development, chemical additive, plasticity, strength, water absorption
The review describers an eco-friendly strategy based on aqueous system. Easy biodegradability and an eco-friendly nature make paper a very good packaging material for food as well as non-food items. The review contained many abstracts of an international patent's documentations.
Keywords: principles of biodegradable hydrophobic materials' creations, review of an international patents
The article examines the application of the method of mathematical planning of an optimal experiment in determining the strength characteristics of reinforced soils. For the analysis, a multicomponent soil system was studied, consisting of unsalted and saline soils reinforced with bitumen with cement additives and surfactants. During the planning of the experiment, factors affecting the strength characteristics and their levels, as well as the intervals of variation of factors, were determined. As a result of solving the problem, mathematical models of adhesion and angle of internal friction of reinforced soils were obtained. Based on the obtained regression equations, the main conclusions were drawn.
Keywords: stabilized soils, complex soil strengthening, experiment planning, complete factor experiment, mathematical model, regression equation
To implement effective adhesion of reinforcement to concrete, a large number of different types of periodic reinforcement profiles have recently been developed, the control of geometric parameters of which presents serious difficulties and allows for a high probability of measurement error. The urgency of the problem is due to the need to improve methods for measuring the geometric dimensions of reinforcement with a complex periodic profile in order to increase the accuracy of results along the entire length of the rod, the ability to measure the angles of inclination of axes, protrusions and dents, identify places of geometric stress concentrators to ensure the necessary quality of the finished product, reliable adhesion of reinforcement to concrete, increase the durability of reinforced concrete structures and products. The paper proposes a new method for measuring geometric parameters based on removing replicas from the surface of the reinforcement in different sections along the length of the rod. The analysis of prints presented in an expanded, flat form is carried out using counting and measuring devices, which significantly improves the accuracy and comparability of measurements, including angular dimensions. The use of modern optical devices and software for them helps to reduce the time for determining and visualizing geometric parameters, and improve measurement accuracy, which is measured in microns. The analysis of the obtained results showed an increase in the accuracy of measurements by removing replicas of geometric parameters of samples by 10-16.5% compared with traditional control methods. The developed method simplifies the measurement process, allows the use of alternative measuring instruments, a combination of calculation and instrument measurement methods.
Keywords: reinforced concrete products, profiles of reinforcing bars, methods of controlling geometric parameters, method of removing replicas, improving accuracy, reliability and comparability of measurements
The paper investigates the possibility of obtaining a luminescent material by heat treatment of phosphogypsum at a temperature of 800 degrees Celsius. It is shown that it is not enough to achieve the result of heating the system to a given temperature, the luminosity of the samples is practically absent.For phosphogypsum subjected to heat treatment at a temperature of 800 degrees Celsius for 60 minutes, it was found that images obtained in the presence of 50-150% moles of citric acid showed the most pronounced luminosity. The luminosity of samples with starch in the amount of 50-75 mol% was worse (by about 50%). The use of coal as a reducing agent under given conditions led to the formation of samples with the lowest luminosity. An extreme change in the dependence of luminosity on the amount of the introduced reducing agent with maxima of 25-75% (mol.) was revealed. It is suggested that the luminescent ability of the reduced phosphogypsum is associated with the formation of the composite material calcium sulfate/sulfide.
Keywords: heat treatment mode, luminescent material, phosphogypsum recycling, reducing
The study of the influence of the number of layers of glass composite pipe on dynamic loading, including operation in seismically active areas, is conditioned by compliance with the requirements of the latest documents in the field of construction standard control. Mechanical characteristics of glass composite pipe depend on elastic and strength properties of glass fibre, silica sand and binder, their ratio and bonding strength between layers. The key parameter of glass composite pipe compliance with the given requirements is ring stiffness. The strength of the composite material is determined using the rule of mixtures. The properties of the glass composite pipe using the rule of mixtures are determined. The influence of the number of layers of glass composite pipe on its elastic-strength properties is considered. The experiment with uniaxial compression of the pipe link is simulated in Midas GTS NX software package. The maximum load at which the sample reaches 5% deformation was determined. According to the results of the study, it was obtained that the best elastic-strength and operational properties have three-layer composite structure.
Keywords: glass composite pipe, layer scheme, earthquake resistance, continuous winding method, elastic-strength properties
The work is devoted to an urgent problem - the development of automated process control systems for the production of bricks with improved characteristics. The purpose of the article is to define and systematize the tasks of automation of brick production control systems, to develop both an algorithm for managing brick production and a generalized structure of automated control systems for brick production, and the tasks of the work are: optimization of control automation levels that determine the generalized structure of automated control systems for brick production, determination of information collection subsystems corresponding to the stages of brick production, and development of their structures, the choice of basic measurement tools for information collection subsystems. The results of the work are: systematization of requirements for modern automated process control systems, development of an algorithm for controlling technological processes and a generalized structural scheme of automated process control systems for brick production, development of information collection subsystems for the developed automated process control system, development of the structure of a local automated process control system in brick production - brick drying. The developed technical solutions can be recommended for control automation in various industries.
Keywords: brick production, technological process, drying, firing, control algorithm, automated control system, structural scheme, information collection subsystem, single-channel circuit, multi-channel circuit, measuring circuit, four-arm bridge circuit
The aim of the present work is to investigate the residual strength behavior of concrete reinforced with straight fibergalss fiber at levels of 0.8%, 1.2% and 1.6% and compare to hooked end steel fibers reinforced concrete same concentation. The laboratory tests were determined according to SP 297.1325800.2017 and reviewed literature. Test sampels was 100x100x400 with cut 17 mm in low beam in center. The residual strength behavior of Fiberglass reinforced concrete (FGRC) appeared to be comparable to SFRC, where the increase of fibers volume ratio cause the increase in prepeak and post-peak parameters of concrete. Nevertheless, the type of fibers influences much this dependency. Сoncrete mix composition was selected on the basis of compressive strength of control samples 37.5MPa. Tests were carried out to determine the crack resistance of fibre concrete on fibreglass fibre. Fibre F1 tested in this work showed a high result of extreme values of residual strength 36.3% higher than anchor fibre and 50% higher than corrugated fibre, this may be due to a more stable bond with the concrete matrix. The work resulted in concrete with crack resistance classes from Bft3= 2,5b to 6с. This study is a practical basis for the theoretical study of the effect of fibreglass fibre on the physical and mechanical characteristics of concrete.
Keywords: fiberglass fiber, FGRC, CMOD, pullout strength, analise, composite, residual strength
The work deals with the results of research on the influence of complex mineral additive: chemical water treatment sludge with burnt rock or fly ash or gaize. The rational content of chemical water treatment sludge in the complex additive was determined to be 50%. The relationship between compressive strength, flexural strength and W/C ratio, bettwen the flexural strength, E-modulus and the compressive strength were obtained. Complex mineral additive into fine grain concrete does not lead to a decrease in flexural strength and does not increase the E-modulus of fine grain concrete. The average range of the E-modulus of fine grain concrete with complex mineral additive practically coincide with those in Russian National Standart 56378 - 2015. The use of chemical water treatment sludge for fine grain concrete at amount of 20% of complex additive of a rateable composition instead of part of the cement provided to increasing of compressive strength at an equal W/C ratio relatively to the non-additive standard by 7 - 20%, and the flexural strength by 12 - 22% .
Keywords: miniral additive, tensile strength, modulus of elasticity, gaize, fly ash, burnt rock, chemical water treatment sludge
In conditions of high cost of construction materials, machinery, equipment and services it is necessary to consider the possibilities of increasing economic and energy efficiency of erected buildings. One of the options for solving this issue is the use of energy efficient products in construction. The article will consider one of the innovative thermal insulation materials - PIR boards.
Keywords: construction, thermal insulation, thermal insulation material, polyisocyanurate foam, frame-monolithic construction, wall panels, reinforced concrete, thermal calculation
Engineering preparation of the territory for the construction and development of a residential complex is a difficult task. In the development area, fluctuations in the groundwater level are possible due to natural processes - flooding of the territory or during operation due to man-made processes. The work presents the results of the survey and assesses the impact of future construction on the hydrological situation of the built-up areas. Materials from engineering-geological surveys of the composition of soils in the lake water area and the building area were studied in order to determine the possibility of using alluvial soil from the lake for engineering preparation of the territory.
Keywords: engineering and geological surveys, urban development, alluvial soil, engineering preparation of the territory
The results of a study of the influence of shrinkage deformations on the basic physical and mechanical properties of concrete are presented depending on various production and technological factors. The research methodology took into account the choice of the period of aging concrete in a dry, hot climate to study the influence of physical processes in concrete on its physical and mechanical properties. The influence of shrinkage deformations on the strength characteristics of concrete was studied. an increase in the intensity of mass transfer processes between concrete and the environment leads to an increase in destructive shrinkage deformations, mainly plastic shrinkage of concrete, which lead to changes in the structure and physical and mechanical properties of mature concrete. The consistency of the concrete mixture also influences the amount of strength reduction. with a greater value of plastic shrinkage of concrete, its compressive and tensile strength in bending decreases. the destructive effect of plastic shrinkage on concrete caused depends on a number of technological factors (consistency of the concrete mixture, w/c, temperature and humidity hardening conditions, etc.).
Keywords: curing period, mass transfer processes, plastic shrinkage, concrete structure, concrete strength, reconstruction, buildings and structures
The article examines the application of properties of polyethyleneimine (PEI) and polyacrylic acid (PAK) polycomplex composition for soil strengthening. During the studies, the ratio of PEI and PAA (by dry weight) was established, at which the reagents most fully enter the complexation reaction. The polycomplex composition of the optimal composition was used to strengthen the soils of some varieties. When studying the properties of hardened soils, dependencies were obtained: the ultimate strength of the hardened soil on the relative humidity and the thickness of the layer of hardened soil on the consumption of complexing reagents. The paper concluded that the use of polycomplexes for soil strengthening is promising.
Keywords: polycomplex composition, soil strengthening, polyethyleneimine, polyacrylic acid, impregnation method, dedusting, optimal humidity
A technological scheme for the production of biostable materials based on monoethanol-modified (N→B)-trihydroxyborate (MEATHB) stems of Sosnovsky's borer and polyurethane binder has been developed. This technological scheme differs from the traditional one in that it includes the process of plant raw material modification to ensure its biostability. The paper presents the results of determining the thermophysical properties of the obtained thermal insulation boards, as well as the results of assessing their biostability. The obtained results correspond to the current requirements for thermal insulation materials. The paper analyzes the main stages and processes necessary to create a high-quality and environmentally friendly product. The main types of plant raw materials used in the production of thermal insulation materials are considered, as well as the features of technological processes associated with its processing and formation. In addition, the advantages of using plant materials in the production of thermal insulation materials from the point of view of ecology are presented.
Keywords: technological scheme, biostable composites, Sosnovsky's borer, modification, biostability, monoethanolamino(N→B)-trihydroxyborate, heat-insulating material
In the article there was considered a possibility of off-grade materials utilization for making fine concrete with a multicomponent complex additive applied. Use of fine sands as raw material for fine concretes is actual for many regions in Russia because of deficiency of sands of necessary fineness modulus. There was considered the issue of utilization of fine sand and stale cement for reducing cost (loss), widening materials’ assortment for low-rise building, and energy- and resource-saving. To achieve the assigned purpose a multicomponent complex additive was applied. The research was carried out in full correspondence with the adopted design of the fractional factorial experiment. The acquired results were subject to a preliminary analysis and processing, and consequently dependences of strength properties upon varying factors were obtained. The obtained dependences made it possible to select optimal ingredients’ proportion of the complex modifying additive in order to increase strength properties of fine concrete based on off-grade materials. It was established that the use of optimal consumption of the complex additive components allows increase strength properties by 25-30% in comparison with the reference composition.
Keywords: fine concrete, fine sand, stale cement, complex additive, fractional factorial experiment, strength