Galyna Kotsay

Dr. Galyna Kotsay

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Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 June 2021 in Materials
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WSWiktor Szewczenko
Wiktor Szewczenko
Galyna KotsayGalyna Kotsay
Galyna Kotsay
This article presents a study of the effect of water glass and its introduction on the hydration of Portland cement and its properties in plastic and solid states. The introduction of sodium water glass into the mixing water extends the setting time of Portland cement by 35%, while introduction into the cement paste reduces it by 24.4%; for potassium water glass, the respective values are 10.8% and 10.8%. The introduction of sodium water glass into the mixing water decreases its consistency by 17.6%; its introduction into the cement paste reduces its consistency by 97%. Based on microcalorimetric studies and using the modelling method, mechanisms of the processes occurring in the cement paste, for various methods of introducing water glass admixtures, and their influence on the properties of cement are proposed. The important implications of the obtained results are that, using various methods for introducing admixtures of water glass, it is possible to regulate the setting of cement slurries within significant limits that are important during their transportation.

10 March 2021 in Materials
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WSWiktor Szewczenko
Wiktor Szewczenko
Galyna KotsayGalyna Kotsay
Galyna Kotsay
The concept of the alkaline activity of powdered materials introduced into cement compositions has been proposed, along with methods for its determination. The possibility of using waste glass as an active additive to Portland cement was evaluated from the standpoint of alkaline activity. Replacing the Portland cement component with glass waste in the form of glass powder at amounts from 1 to 35% made it possible to maintain the cement composition’s alkaline activity at a level that met the standard requirements. The previously unknown effects of mixed alkali in Portland cement in the presence of glass waste are described. Portland cement has a high potassium alkaline activity; however, container glass has a high sodium alkaline activity and a fairly low potassium alkaline activity. When glass waste is introduced into the structure of cement compositions, potassium alkaline activity is reduced.

31 July 2023 in Materials
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Galyna KotsayGalyna Kotsay
Galyna Kotsay
Paweł GrabowskiPaweł Grabowski
Paweł Grabowski
The paper determines the properties of geopolymer pastes based on metakaolin and soda-lime waste glass. The density, alkaline activity, strength and microstructure of the reference geopolymer, as well as geopolymers with a 10%, 30% and 50% soda-lime waste glass content instead of metakaolin, were tested. The experimental results indicate that the properties of the geopolymers with waste glass largely depend on the ratio of the liquid to solid substance. Increasing the content of waste glass causes an increase in the fluidity of the geopolymer paste, which in turn allows the amount of water glass, i.e., an activator during the obtaining of geopolymers, to be reduced. On the basis of the conducted tests, it was found that the strength of geopolymers can be increased by adding up to 50% of soda-lime waste glass instead of metakaolin and by having a lower content of water glass.

25 June 2014 in Chemistry & Chemical Technology
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Journal Article
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VSViktor Shevchenko
Viktor Shevchenko
Galyna KotsayGalyna Kotsay
Galyna Kotsay

15 May 2021 in Chemistry & Chemical Technology
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Galyna KotsayGalyna Kotsay
Galyna Kotsay
ABAleksandra Brzóska
Aleksandra Brzóska
This paper presents the findings of research study on the effect of borosilicate glass wastes on properties of cement paste and mortar. The borosilicate glass contains three times less alkali than soda-lime glass and about 12 % of boron oxide, so pozzolanic activity of borosilicate glass is three times higher compared to soda-lime glass. In order to increase the pozzolanic activity of glass precipitated synthetic silica was used. Mathematical models were used in order to test the effect of synthetic silica on pozzolanic activity of borosilicate glass. Test results indicate that replacement of 1 % of borosilicate glass by synthetic silica increased the pozzolanic activity up to 9.4 mg CaO/g of additive. By adding 5 % of borosilicate glass instead of cement, the standard compressive strength is reduced by about 20 %. However, complex additive of borosilicate glass (2–5 %) and synthetic silica (0.5 %) increased initial compressive strength of cement mortars to 10 %.

17 August 2021 in Materials
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Galyna KotsayGalyna Kotsay
Galyna Kotsay
IMIrmina Masztakowska
Irmina Masztakowska
This paper discusses studies regarding the impact of fine-ground glass additives on the hydration and properties of alumina cement pastes and mortars. Fine-ground glass was added to pastes and mortars instead of high-alumina cement and calcium aluminate cement in quantities of 5% and 10%. The findings are inconclusive as to the impact of glass on the properties of tested alumina cement types. The effect produced via the addition of glass instead of cement depends on the type of alumina cement used. Adding fine-ground glass to high-alumina cement enhances the paste’s density while improving paste and mortar strength. Using the same additive for calcium aluminate cement reduces its density and strength. The addition of glass to high-alumina cement adversely affects its strength at higher temperatures.