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Keywords: portlandtsement

BINDER COMPOSITIONS BASED ON PORTLAND CEMENT AND VOLCANIC ASH

https://doi.org/10.58224/2618-7183-2022-5-4-30-38
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 30-38 p.
Abstract
Today, preference is given to composite binders. The use of dispersed mineral fillers makes it possible to realize the potential of binders to a large extent, which leads to an increase in the physico-mechanical, operational and technical properties of composite binders, as well as building materials based on them, and reduces the consumption of expensive binders. The creation of highly effective composite binders is based on the management of their production technology at all stages: the selection of raw materials, the development of optimal compositions, the use of mechanical activation of raw materials, the modification of composite binders with functional chemical additives, and some other methods. The use of volcanic ash in the world is quite diverse, it is used not only as additives for building materials, but also it has found its application in medicine. Many countries are beginning to use volcanic ash as a building material. The article presents the results of obtaining binder compositions of optimal composition based on Portland cement and volcanic ash. Experimental studies of the granulometric composition have been carried out, the results of tests of binder compositions of the compositions: cement – volcanic ash, prepared in a vibratory mill, have been presented. The results of physical and mechanical tests of binder compositions with different content of volcanic ash, activated for 10 and 20 minutes in a vibratory mill, have been obtained. Research work has been carried out to study the microstructure of volcanic ash.
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INCREASING IN IMPACT VISCOSITY OF FIBER-ASH-CONCRETE

https://doi.org/10.34031/2618-7183-2020-3-6-5-16
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 5-16 p.
Abstract
The trend in building materials science is to replace the different proportions of Portland cement in the binder. Therefore, the paper proposes the principles of controlling the static and dynamic strength of fiber-reinforced concrete, consisting in the complex effect of the hydro-removed ash and slag mix and basalt fiber on the processes of structure formation of the cement composite. A four-stage purification system for the hydro-removed ash and slag mixture has been developed, including disintegration, flotation and two-stage magnetic separation. It was found that the density of the fresh mix from the dose behaves naturally, and the density of solid samples at low doses slightly decreases. High early strength of the developed composites is noted, in particular, for specimens with ASM, one and a half increase in compressive strength is traced in comparison with non-additive specimens. Combinations of "fiber + ASM" with a quadrupling of strength have a significant effect on bending strength. Successful approximations of the compressive strength and bending strength on the ASM dose for different ages (1, 7, 28 days) are traced with the regular behavior of the coefficients in the power dependences. Revealed a multiple increase in the impact strength of the developed compositions. The use of the results will lead to the possibility of designing high-strength concretes, including for special structures.
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EFFECT OF WOLLASTONITE ON THE MECHANICAL CHARACTERISTICS OF CONCRETE

https://doi.org/10.34031/2618-7183-2020-3-5-34-42
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 34-42 p.
Abstract
Improvement of the physical and mechanical properties of cement composites should be accompanied by the disposal of industrial waste of various generation. Therefore, the paper proposes the principles of con-trolling the strength properties of concrete, which consist in the complex effect of wollastonite obtained from boron production waste on the processes of structure formation of the cement matrix. When this introduced in an amount of 2-8 wt. % wollastonite has a dual function as a mineral filler and a reinforcing fiber. It has been proven that in the presence of wollastonite, the concrete mix becomes lighter without reducing its physical and mechanical properties. It was revealed that the early strength for all the developed compositions with the addition of wollastonite increases due to the acceleration of hydration processes. Calcium silicate, which is wollastonite CaSiO3, has a close chemical composition with cement clinker, especially with Ca2SiO4 belite and Ca3SiO5 alite. This leads to the formation of a chemically homogeneous and, as a result, hardened microstructure. Elongated wollastonite fibers with good adhesion to the cement stone provide effective micro-reinforcement of the concrete composite. Using the results will lead to the possibility of designing high-strength concretes, including for special structures.
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OPTIMIZATION OF RAW MIX COMPOSITION OF SEREBRYANSKY CEMENT PLANT

https://doi.org/10.34031/2618-7183-2018-1-4-13-20
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 13-20 p.
Abstract
Now a top trend of technical development in the cement industry of Russia, is optimization of all technological repartitions of production. Obtaining the quality portlandtsement is multiple-factor process. It is influenced not only by the physical and chemical transformations of raw materials occurring during the firing of cement clinker, but also what will be the composition of the raw mixture and whether this mixture is prepared qualitatively. Work consists in a research and selection of an optimum compounding of raw mix, with the purpose to receive cement with high rates of quality. This direction will allow: first, to expand a source of raw materials, to process raw materials which go to dumps because in it is mute a large amount of quartz and impurity connections contains; secondly, to make small reconstruction of the line of preparation of raw mix. At the moment, the plant works on mixed mixtures of aluminosilicate raw materials, i.e. two types of aluminosilicate raw materials which are previously mixed in certain ratios therefore it affects on the accuracy of dispensing of components are used. Accuracy of dispensing of modern batchers, a component ± (1 … 2) %, is often insufficient. In this regard, the new option of optimum composition of mix is offered and investigated. This option of a "clean" mixing of components, will allow to improve process of mixing of initial raw materials, to operate process of drawing up proportions of mixes in a supply line of materials. And also it will allow to eliminate long-term deviations, guaranteeing the solution of problems at the earliest stage of their emergence. Receiving a qualitative ready-made product, reduction of costs for energy resources and cost efficiency of the proposed solution is result of this work.
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