Shodmonov Anarkul
Study of the Properties of Basalt Fiber Concrete
DJizzakh Polytechnic Institute
Abstract. The technology of dispersed concrete reinforcement with fiber is becoming more and more popular. Its relevance is primarily due to the fact that due to this it is possible to significantly increase the physical and mechanical properties of concrete structures. Fiber for concrete is the so-called «dispersed reinforcement»; its fibers adhere to concrete and reinforce it throughout the entire volume, thereby increasing the strength characteristics of the structure. The resulting composite material is called fiber concrete. Basalt has a similar structure to cement stone and has a natural natural roughness, which contributes to high adhesion of the fibers to the concrete matrix. In this article, the composition and properties of a concrete mixture prepared on the basis of basalt fiber are studied and analyzed according to the results of a research work carried out on the topic «Selection and study of the composition of fiber concrete based on waste and basalt fiber in the production of basalt reinforcement».
Keywords: basalt, basalt fiber, basalt fiber, basalt fiber concrete.
Alena Sadovskaya, Sergei Leonovich, Alena Polonina, Nelli Budrevich
Method for Quality Control of Steel Fiber Concrete by the Stress Intensity Coefficient at Normal Separation
Belarusian National Technical University
Abstract. There are no particular obstacles for crack propagation in high-strength concrete. However, in dispersed-reinforced concrete, obstacles in the form of fibers make it difficult for the crack to spread. It is clear that under the action of the load, the development of a crack is inevitable, but additional energy is expended on overcoming each obstacle in the form of a fiber, so the process of cracking can gradually fade. Thus, the fibers in the concrete are crack inhibitors. Crack resistance is a local physicomechanical property of a solid that characterizes the ability to resist the propagation of cracks in it. Fiber concrete is a building material for which a distinctive feature is the improvement of crack resistance characteristics. The determination of the stress intensity factor makes it possible to correctly assess the resistance of the material during the formation and development of cracks. The stress intensity factor is one of the most important indicators of the crack resistance of a material such as fiber-reinforced concrete. For this reason, the methods and methods for determining this indicator should most fully disclose all the features of work under load and the quality of fiber-reinforced concrete. To determine the stress intensity factor in the laboratory, you can use the technique of S. N. Leonovich, O. V. Popov, K. A. Piradov. The essence of the method consists in determining the maximum loads destroying control specimens in compression and calculating the critical values of the stress intensity. For the authors, the task was to find a way to determine the stress intensity factor in already existing fiber-reinforced concrete structures. This article describes a method for determining the critical stress intensity factor of steel fiber concrete in a structure with normal separation. On the surface of the structure, a stress concentration zone is carried out, which is loaded through an anchor installed in a hole drilled in a fiber-reinforced concrete hole before the microvolume is pulled out. According to the obtained data, the critical stress intensity coefficient is determined. In addition to the breaking force, geometric measurements of the truncated cone of destruction of the steel-fiber concrete structure are made. According to the established relationship between them, the critical stress intensity coefficient KIC of steel fiber concrete is determined at normal separation.
Keywords: steel fiber concrete, critical intensity coefficient, crack resistance, fracture toughness, direct separation.
Dilorom Kadyrova, Abdulaziz Saydullayev
Strength and Deformative Properties of Concretes Based on Local Raw Materials and Industrial Waste
Тashkent Institute of Architecture and Civil Engineering
Abstract. This article examines the problem of using dune sands and waste in the production of nonmetallic industry for the production of concrete and reinforced concrete products. The use of sand dunes as a fine aggregate is most appropriate together with an enlarging additive, as which waste from the industry of non-metallic materials, in particular porphyritic rock, is recommended. The proposals of researchers on the use of fine sands in concrete and methods for selecting the composition of concrete are discussed. The share of deposits in Central Asia containing fine-grained and dune sand is indicated. The problematic nature of the use of building sand for use in the construction industry has been determined. The strength, deformability indicators, frost resistance, corrosion resistance of concrete based on the integrated use of sand dunes, crushing screenings and porphyry crushed stone were studied. The basics of the selection of sand dunes and porphyrite crushing screenings located on the territory of the Republic of Karakalpakstan for research purposes are given.
Keywords: porphyrites, dune sands, enlarger, size modulus, granulometry.
Stanislav Orlov
Research of Methods and Means of Reducing Energy Consumption During Gas Purification by Cyclones
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article discusses the issues of electricization of dust in cyclones, as the most characteristic representatives of dry inertial dust collectors. Due to the division of dust particles according to fractions, a pronounced two zones with multi-dimensional charges are formed in cyclone. According to the cyclone axis, a zone (dusty thrombus) is formed with a negative charge, while the inner surface of the outer wall of the cyclone is formed a zone with a positive charge. Studies have shown that the electric capacity of the dusty thrombus can reach large velyrics, commensurate with the globe with a container. However, despite the larger capacity, and accordingly the charge of the dusty thrombus, due to the low curvature, the tension of the electric field created by electrification rarely reaches critical quantities to create a corona discharge. It is necessary to conduct research to find methods for the concentration of the electric field, which will make it possible to more fully use the energy spent on swirling the vortex flow, and, accordingly, to reduce energy consumption when cleaning gases by cyclones.
Keywords: cyclone, dust, electrification, electric container, electric charge, electric field strength, dusty thrombus.
Nickolay Sholukh, Ekaterina Satsura, Anastasia Ivanova
Arrangement of Sensory Spaces in the Structure of Social and Rehabilitation Institutions for Persons with Physical Disabilities: Experimental Design and Construction
Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the functional-technological and architectural-planning aspects of the arrangement of special sensory spaces and their individual elements in the structure of some types of social and rehabilitation institutions for persons with physical disabilities. The authors have shown that sensory spaces with appropriate functional content and planning solutions can have a very significant psychotherapeutic, corrective-restorative, stimulating and other types of positive impact in relation to certain contingents of persons with physical disabilities – especially in relation to persons with lost or significantly impaired functions of the leading sensory analyzers (vision, hearing). The potential possibilities of using sensory spaces and their individual elements for these purposes are demonstrated by examples of models of sensory rooms proposed by the authors for use in children’s rehabilitation institutions with departments of alternative forms of therapy, as well as examples of experimental design solutions of specialized centers for social assistance and industrial and labor rehabilitation of disabled people developed within the framework of the renovation program of some inoperative industrial enterprises in the cities of the Donetsk region. Based on the results of the performed analytical studies, as well as the experience of experimental design and construction, a conclusion is made about the possibility and expediency of more active use of the considered types of spaces in improving the living conditions and rehabilitation of persons with severe sensory disorders.
Keywords: persons with physical impairments, pronounced impairments in the sensory sphere, secondary and tertiary deviations in development, productionrelated disability, sensory spaces and their constituent elements, compensatory and correctiverestorative functions, informing, stimulating and developing types of influences, associative characteristics and synthesized images, special architectural planning and engineering techniques and means, social and rehabilitation institutions, experimental design, social and economic efficiency.
Tuygun Shakirov, Nilufar Muminova
Development of Properties of Binders with the Help of Mineral and Chemical Additives
Тashkent Institute of Architecture and Civil Engineering
Abstract. The article presents the results of research work on the development of properties of binders with complex-mineral and at the same time chemical additives and the optimal compositions are determined. The use of local industrial waste as a secondary raw material in the production of new and modern types of building materials, namely fine mineral additives, ensuring the formation of a dense and durable structure of the concrete mixture, which achieves properties such as strength, frost resistance, without adversely affecting the cement hydration process, on the properties of a binder is one of the most important and relevant research areas at present [1–12]. Today, along with water, filler and binder, additives have become an indispensable component of the concrete mix. Among the many types of chemical additives, plasticizers occupy a separate place, especially the most effective of them – super plasticizers [1–12]. With regard to local construction practice, it should be noted that the use of super plasticizer in monolithic building technology is very low in the country. This can be explained by the fact that, firstly, in Uzbekistan, few chemical additives are produced for target concrete, including super plasticizers, and secondly, it is also a very urgent issue to conduct comparative studies of commercially available super plasticizers and develop recommendations for their practical use.
Keywords: сomplex additives, industrial waste, secondary materials, fly ash, copper-smelting industry waste, chemical additives, strength, durability, сomplex additives, industrial waste, secondary materials, fly-ash, copper-smelting industry waste, chemical additives, strength, durability.