Lesovik R.V.

Doctor of Engineering Sciences(Advanced Doctor), Professor, Belgorod State Technological University named after V.G. Shukhov, Russia

Experimental studies of the processes of structure formation of composite mixtures with technogenic mechanoactivated silica component

https://doi.org/10.58224/2618-7183-2023-6-2-5-18
Abstract
The paper considers the issues of utilization of technogenic fibrous material – waste of basalt production. The chemical composition of the technogenic fibrous material was studied, it was found that it consists of 44% SiO2. The initial basalt rock, which undergoes changes during high-temperature processing in the process of obtaining basalt fiber, was studied using IR spectroscopy. The grinding of the crowns was carried out for 30 minutes, allowing to reach a specific surface area of 800 m2 / kg. Further grinding does not lead to an increase in the specific surface area, which is associated with the phenomenon of secondary aggregation of fine particles. Research on REM has shown that the “cold shots” before grinding are mostly rounded or oval in shape. The compositions were formed and the strength characteristics of the samples for the 3rd and 28th day were determined. The maximum strength gain of 59 MPa was established at the age of 28 days in samples with the addition of 5% ground “cold shots” . When introducing cold shots in an amount of 10% (composition 5) of the cement mass, an intensive strength gain is noted in the early stages of hardening (7 days) with a strength of 38 MPa, slightly higher than the strength of the control composition. The introduction of 15% ground “cold shots” gives a strength value slightly lower (32 MPa) than the values of the control composition (37 MPa) at all stages of hardening.
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Development of Alkali-activated Binders based on Technogenic Fibrous Materials

https://doi.org/10.58224/2618-7183-2023-6-1-60-73
Abstract
The paper discusses the development of alkali-activated binders based on technogenic fibrous materials. An approach to the secondary use of technogenic fibrous materials as a filler of composite binders is offered. The properties of mineral wool waste have been established. The microstructure of finely ground fibrous particles has been studied. Compositions of alkali-activated binders were de-veloped, when grinding basalt insulation production waste to a specific surface of 300-330 m2 /kg, followed by the formation of a binder according to the first method with rod tamping sealing and, ac-cording to the second, by pressing a raw binder mixture at a pressure of 10 MPa. The developed com-positions of alkali–activated binder by pressing with a compressive strength of 22.8 MPa, and when compacted with subsequent rod tamping – 11.8 MPa.
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DEVELOPMENT OF RADIATION-PROOF CONCRETE COMPOSITIONS

https://doi.org/10.34031/2618-7183-2020-3-5-24-33
Abstract
The article considers the possibility of using composite binders and magnetite as components of concrete with radiation-proof properties. The use of the developed concrete is possible not only when it is necessary to build nuclear power plants, but also to create bunkers or anti-radiation shelters. A special feature of con-cretes used for the protection and design of nuclear reactor cranes is their properties, which they must have. These properties include: low thermal conductivity, increased density, high temperature resistance, reduced values of the coefficient of thermal expansion, shrinkage and creep. Technogenic raw materials for the production of very heavy concrete are studied, the main physical and mechanical characteristics, the requirements that need to be considered in the selection of raw mix composition for protective concrete are analyzed. The paper presents a comparison of physical and mechanical characteristics, the advantages and disadvantages of introducing a binder of various types: cement, cement with a superlasticizer and a binder of low water consumption. It was found that the use of a low-water-consumption binder increases the physical and mechanical characteristics while reducing the consumption of cement in the raw material mix compared to traditional heavy concrete with cement.
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