The influence of highly dispersed tungsten-containing powders (WC, WO₃, a mixture of WC, TiC) obtained as a result of recycling of carbide products on change in the structural and physico-mechanical properties of cement materials at elevated temperatures has been studied. Powders of tungsten carbide WC, tungsten oxide WO₃, mixtures of tungsten and titanium carbides WC, TiC (average particle size 20–150 nm, agglomerates 300 nm – 1.5 microns) were added to the cement mortar, by partial replacement of the binder, in various concentrations (1–5 wt. %). The effect of additives on the thermal stability of cement samples was assessed by weight loss, residual compressive strength, exposed to temperatures at 300, 600 and 800^оC for 2 hours. The microstructural analysis was performed using scanning electron microscopy (SEM) with an integrated energy dispersion analysis system. It was established that in the entire temperature range under consideration (20–800^оC), the modified samples demonstrate a denser microstructure, have less mass loss and have increased residual compressive strength compared with the control composition. The obtained research results are of considerable value for understanding the mechanisms of influence of highly dispersed tungsten-containing particles on the characteristics of cement materials under high-temperature exposure.

T.V. CHAYKA, Assistant Professor (This email address is being protected from spambots. You need JavaScript enabled to view it.),
V.М. GAVRISH, Candidate of Sciences (Engineering), Docent (This email address is being protected from spambots. You need JavaScript enabled to view it.),
A.Y. OLEYNIK, Graduate Student, Assistant (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Sevastopol State University (33, Universitetskaya Street, Sevastopol, 299053, Russian Federation)

1. Sikora P., Abd Elrahman M., Stephan D. The influence of nanomaterials on the thermal resistance of cement-based composites – a review. Nanomaterials. 2018. Vol. 8. 465. https://doi.org/10.3390/nano8070465
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6. Hafiz Waheed Iqbal, Rao Arsalan Khushnood, Waqas Latif Baloch, Adnan Nawaz, Rana Faisal Tufail. Influence of graphite nano/microplatelets on the residual performance of high strength concrete exposed to elevated temperature. Construction and Building Materials. 2020. 253. 119029. https://doi.org/10.1016/j.conbuildmat.2020.119029
7. Yuzhuo Wang, Zejian Liu, Shuang Qu, Junlin Gong, Xiao Lyu. Fire resistance of reinforced concrete beams: State of the art, analysis and prediction. Construction and Building Materials. 2023. Vol. 409. 134029. https://doi.org/10.1016/j.conbuildmat.2023.134029
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9. Voutetaki M.E., Naoum M.C., Papadopoulos N.A., Chalioris C.E. Cracking diagnosis in fiber-reinforced concrete with synthetic fibers using piezoelectric transducers. Fibers. 2022. Vol. 10. No. 1. https://doi.org/10.3390/fib10010005
10. Tobbala D.E., Rashed A.S., Tayeh B.A. et al. Performance and microstructure analysis of high-strength concrete in corporate with nanoparticles subjected to high temperatures and actual fires. Archives of Civil and Mechanical Engineering. 2022. Vol. 22. 85. https://doi.org/10.1007/s43452-022-00397-6
11. Селеем С.Е. Ахмад, Хоссам С. Халил, Ибрагим А. Шараки, Ахмад М. Эль-Азаб. Свойства высокопрочного бетона с нанокремнеземом после воздействия высокой температуры // Строительные материалы. 2018. № 11. C. 8–14. DOI: https://doi.org/10.31659/0585-430X-2018-765-11-8-14
11. Seleem S.E. Ahmad, Hossam S. Khalil, Ibrahim A. Sharaky, Ahmad M. El-Azab. Performance of residual properties for high strength concrete incorporating nanosilica against temperatures. Stroitel’nye Materialy [Construction Materials]. 2018. No. 11, pp. 8–14. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2018-765-11-8-14
12. Irshidat M R, Al-Nuaimi N, Rabie M. Influence of carbon nanotubes on phase composition, thermal and post-heating behavior of cementitious composites. Molecules. 2021. Vol. 26 (4). 850. https://doi.org/10.3390/molecules26040850
13. Dong Lu, Xianming Shi, Jing Zhong. Interfacial bonding between graphene oxide coated carbon nanotube fiber and cement paste matrix. Cement and Concrete Composites. 2022. Vol. 134. 104802. https://doi.org/10.1016/j.cemconcomp.2022.104802
14. Mohammed A., Al-Saadi N.T.K., Sanjayan. J. Inclusion of graphene oxide in cementitious composites: state-of-the-art review. Australian Journal of Civil Engineering. 2018. Vol. 16 (2), pp. 81–95. DOI: https://doi.org/10.1080/14488353.2018.1450699
15. Lu Dong, Zhong Jing. Carbon-based nanomaterials engineered cement composites: a review. Journal of Infrastructure Preservation and Resilience. 2022. 3. 10. https://doi.org/1186/s43065-021-00045-y
16. Khan M.A., Imam M.K., Irshad K., Ali H.M., Hasan M.A., Islam S. Comparative overview of the performance of cementitious and non-cementitious nanomaterials in mortar at normal and elevated temperatures. Nanomaterials. 2021. 11 (4). 911. https://doi.org/10.3390/nano11040911
17. Agzamov F.A., Grigoryev A.Y. Modification of Portland cement with nanoadditives. Nanotechnologies in Construction. 2022. 14 (4), pp. 319–327. https://doi.org/10.15828/2075-8545-2022-14-4-319-327
18. Ahmed A. Amer, Tarek M. El-Sokkary, Nagwa I. Abdullah. Thermal durability of OPC pastes admixed with nano iron oxide. HBRC Journal. 2015. Vol. 11. Iss. 2, pp. 299–305. https://doi.org/10.1016/j.hbrcj.2014.04.002
19. Ghazanlou S.I., Jalaly M., Sadeghzadeh S. et al. A comparative study on the mechanical, physical and morphological properties of cement-micro/nano Fe₃O₄ composite. Scientific Reports. 2020. Vol. 10. 59. https://www.nature.com/articles/s41598-020-59846-y
20. Aref Sadeghi-Nik, Javad Berenjian, Ali Bahari, Abdul Sattar Safaei, Mehdi Dehestani. Modification of microstructure and mechanical properties of cement by nanoparticles through a sustainable development approach. Construction and Building Materials. 2017. Vol. 155, pp. 880–891. https://doi.org/10.1016/j.conbuildmat.2017.08.107
21. Kanagaraj B., Nammalvar A., Andrushia A.D., Gurupatham B.G.A., Roy K. Influence of nano composites on the impact resistance of concrete at elevated temperatures. Fire. 2023. 6 (4). 135. https://doi.org/10.3390/fire6040135
22. Europäische Patentanmeldung EP 3 138 932 A1 Verfahren und vorrichtung zur gewinnung eines pulvers aus partikeln von wolfram oder wolframverbindungen mit einer partikel grösse im nano-, mikron- oder submikronbereich. Galuga A., Baranov G., Gavrish V., Smirnov S., Losenkov A., Vostrognutov S. Declared 01.09.2015. Published 08.03.2017.
23. Чайка Т.В., Гавриш В.М., Павленко В.И., Черкашина Н.И. Влияние высокодисперсного порошка смеси WC и TiC на свойства композиционных материалов // Нанотехнологии в строительстве. 2023. № 15 (1). С. 14–26. EDN: TSWXBD. https://doi.org/10.15828/2075-8545-2023-15-1-14-26
23. Chaika T.V., Gavrish V.M., Pavlenko V.I., Cherkashina N.I. Influence of high-dispersive powder mixture of WC and TiC on the composite materials properties. Nanotechnologies in construction. 2023. No. 15 (1), pp. 14–26. EDN: TSWXBD. https://doi.org/10.15828/2075-8545-2023-15-1-14-26
24. Чайка Т.В., Гавриш В.М., Черкашина Н.И., Сидельников Р.В., Романюк Д.С. Модификация композиционных материалов высокодисперсными порошками WC и WO₃ // Строительные материалы. 2023. № 10. C. 121–128. https://doi.org/10.31659/0585-430X-2023-818-10-121-128
24. Chayka T.V., Gavrish V.M., Cherkashina N.I., Sidelnikov R.V., Romanyuk D.S. Modification of composite materials with highly dispersed WC and WO₃ powders. Stroitel’nye Materialy [Construction Materials]. 2023. No. 10, pp. 121–128. (In Russian). https://doi.org/10.31659/0585-430X-2023-818-10-121-128
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25. Chayka T.V., Gavrish V.M., Rapatskiy Yu.L., Lypka V.M., Chayka А.К. Effects of highly dispersed WC powder on the properties of cement stone at elevated temperatures. Advanced technologies and materials: Materials of the International Scientific and Practical Conference. Sevastopol. 2022. pp. 437–439. (In Russian).
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Photocatalytically active fine-grained concrete has been developed using a titanosilicate additive, which is a waste product from the production of titanosilicate sorbent. It has been established that the introduction of a titanosilicate additive into the composition of fine-grained concrete ensures the formation of an additional amount of calcium hydrosilicates, mainly low-basic ones, increases the density of the cement stone and reduces structural defects, thereby facilitating the production of higher-strength concrete with improved technical and operational properties. For the developed concrete composition containing 2% (by weight of cement) titanosilicate powder, 1.1 wt. % Glenium 51 superplasticizer, with a W/C of 0.42, an increase in compressive strength by 52% and a decrease in water absorption by 32% were recorded, reducing the depth of wear and weight loss by 35%, increasing frost resistance by 3 grades, compared to the additive-free composition. The surface of fine-grained concrete containing waste titanosilicate sorbent, in the decomposition reaction of methylene blue, exhibits the ability to self-clean under the influence of visible light, and under ultraviolet light it exceeds samples with commercial titanium dioxide.Also, the manifestation of the self-cleaning ability of modified concrete is confirmed by a decrease in the contact angle during irradiation with ultraviolet light.

V.V. TYUKAVKINA, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
A.V. TSYRYATEVA, Engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials named after I.V. Tananaev, FRC, Kola Science Centre of the Russian Academy of Sciences (26a, Akademgorodok micro-district, Apatity, 184209, Russian Federation)

1. Wang D., Hou P., Stephan D., Huang S., Zhang L., Yang P., Cheng X. SiO₂/TiO₂ composite powders deposited on cement-based materials: Rhodamine B removal and the bonding mechanism. Construction and Building Materials. 2020. Vol. 241. 118124. https://doi.org/10.1016/j.conbuildmat.2020.118124
2. Giada M.C. Gemelli, Manuel Luna, Rafael Zarzuela, M.L. Almoraima Gil Montero, Maria Carbu, Ignacio Moreno-Garrido, María J. Mosquera. 4-Year in-situ assessment of a photocatalytic TiO₂/SiO₂ antifouling treatment for historic mortar in a coastal city. Building and Environment. 2022. Vol. 225. 109627. https://doi.org/10.1016/j.buildenv.2022.109627
3. Sun J., Xu K., Shi C., Ma J., Li W., Shen X. Influence of core/shell TiO₂–SiO₂ nanoparticles on cement hydration. Construction and Building Materials. 2017. Vol. 156, рр. 114–122. https://doi.org/10.1016/j.conbuildmat.2017.08.124
4. Shchelokova E.A., Tyukavkina V.V., Tsyryatyeva A.V., Kasikov A.G. Synthesis and characterization of SiO₂–TiO₂ nanoparticles and their effect on the strength of self-cleaning cement composites. Construction and Building Materials. 2021. Vol. 283. 122769. https://doi.org/10.1016/j.conbuildmat.2021.122769
5. Bjornstrom J., Martinelli A., Matic A. et al. Accelera-ting effects of colloidal nano-silica for beneficial calcium-silicate-hydrate formation in cement. Chemical Physics Letters. 2004. Vol. 392 (1), pp. 242–248. https://doi.org/10.1016/j.asej.2020.07.016
6. Han B., Ding S., Wang J., Ou J. Nano-engineered cementitious composites. Principles and Practices. 2019, p. 731. https://doi.org/10.1016/j.compositesa.2017.01.008
7. Li Z., Wang J., Han B., Yu X., Ou J. Investigating size effect of anatase phase nano TiO₂ on the property of cement-based composites. Materials Research Express. 2018. Vol. 5. No. 8. https://doi.org/10.1088/2053–1591/aad4e3
8. Sun J., Xu K., Shi C., Ma J., Li W., Shen X. Influence of core/shell TiO₂–SiO₂ nanoparticles on cement hydration. Construction and Building Materials. 2017. Vol. 156, pp. 114–122. https://doi.org/10.1016/j.conbuildmat.2017.08.124
9. Khannyra S., Luna M., Almoraima M.L., Addou M., Mosquera M. J. Self-cleaning durability assessment of TiO₂/SiO₂ photocatalysts coated concrete: Effect of indoor and outdoor conditions on the photocatalytic activity. Building and Environment. 2022. Vol. 211. 108743. https://doi.org/10.1016/j.buildenv.2021.108743
10. Zanfir A.-V., Voicu G., Badanoiu A.-I., Gogan D., Oprea O., Vasile E. Synthesis and characterization of titania-silica fume composites and their influence on the strength of self-cleaning mortar. Composites Part B: Engineering. 2018. Vol. 140, pp. 157–163. https://doi.org/10.1016/j.compositesb.2017.12.032
11. Wu J., Wang H., Bao L., Zhong J., Chen R., Sun L. Novel raspberry-like hollow SiO₂@TiO₂ nanocomposites with improved photocatalytic self-cleaning properties: towards antireflective coatings. Thin Solid Films. 2018. Vol. 651, pp. 48–55. https://doi.org/10.1016/j.tsf.2018.02.009
12. Тюкавкина В.В., Герасимова Л.Г., Цырятьева А.В. Синтетические титаносиликатные добавки для специальных цементных композитов // Перспективные материалы. 2019. № 4. С. 40–48. https://doi.org/10.30791/1028-978X-2019-4-40-48
12. Tyukavkina V.V., Gerasimova L.G., Tsyratyeva A.V. Synthetic titanosilicate additives for special cementitious composites. Perspektivnye materialy. 2019. No. 4, pp. 40–48. (In Russian). https://doi.org/10.30791/1028-978X-2019-4-40-48
13. Tyukavkina V.V, Shchelokova E.A., Tsyryatyeva A.V., Kasikov A.G. TiO₂–SiO₂ nanocomposites from technological wastes for self-cleaning cement composition. Journal of Building Engineering. 2021. Vol. 44. 102648. URL: https://doi.org/10.1016/j.jobe.2021.102648
14. Тюкавкина В.В., Щелокова Е.А., Поживина К.А., Касиков А.Г. Нанодобавки на основе диоксида титана и диоксида кремния для самоочищающихся бетонов // Строительные материалы. 2021. № 5. С. 47–53. https://doi.org/10.31659/0585-430X-2021-791-5-47-53
14. Tyukavkina V.V., Shchelokova Е.А., Pozhivina К.А., Kasikov A.G. Nano-additives based on titanium dioxide and silicon dioxide for self-cleaning concretes. Stroitel’nye Materialy [Construction Materials]. 2021. No. 5, pp. 47–53. (In Russian). https://doi.org/10.31659/0585-430X-2021-791-5-47-53
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16. Wang D., Hou P., Zhang L., Xie N., Yang P., Cheng X. Photocatalytic activities and chemically-bonded mechanism of SiO₂–TiO₂ nanocomposites coated cement-based materials. Materials Research Bulletin. 2018. Vol. 102, pp. 262–268. https://doi.org/10.1016/j.materresbull.2018.02.013
17. Самбуров Г.О. Технология и применение титаносиликатных сорбентов каркасной структуры для очистки стоков от радионуклидов и катионов токсичных металлов // Теория и практика проектного образования. 2019. № 3 (11). С. 75–80.
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One of the directions of development of concrete science is the combination of positive qualities of heavy and lightweight concretes. The problem of optimizing the structural properties of heavy concrete and the thermal properties of lightweight concrete is solved in a large number of scientific papers. In Russia, the most popular structural lightweight concretes are those based on expanded clay aggregate. Recently, there has been experience in reconstructing bridges made of lightweight concrete on hollow microspheres. Over the past 10 years, the possibilities for producing lightweight concrete with increased strength have improved significantly. The paper presents models demonstrating the features of the formation of the structure of lightweight concrete on hollow and porous aggregates. The advantages and limitations are described for each of the aggregates for obtaining lightweight concrete with a given average density and strength. The described models show that it is advisable to use porous filler to obtain high-strength lightweight concrete with an average density of more than 1600 kg/m³, and hollow filler at ρ_lb<1600 kg/m³. The thickness of the filler shell becomes the determining factor in achieving the required specific strength of lightweight concrete

A.S. INOZEMTCEV¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
E.V. KOROLEV², Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ National Research Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, Moscow, 400074, Russian Federation)
² Saint Petersburg State University of Architecture and Civil Engineering (4, 2nd Krasnoarmeyskaya Street, Saint Petersburg, 190005, Russian Federation)

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3D concrete printing (3DCP) is one of the most important priorities for the development of the construction industry around the world. Despite optimistic forecasts for the growth of additive construction technology in the long term, there are various risks that can influence the pace of this development, which are associated, first of all, with the need to develop the regulatory framework, train qualified personnel, create and improve equipment and materials for 3DCP – seal. There is a lot of research aimed at creating and developing the scientific basis for the design of concrete for construction 3D printing; compositions of dry mortars for additive manufacturing based on mineral binders, mainly cement, have been proposed; much less attention is paid to composites based on gypsum and mixed – gypsum-cement-pozzolan binders (GCPB). The purpose of this work is to study the structure and properties of fine-grained concrete for 3DCP based on gypsum-cement-pozzolan dry mortars. The molding of samples during experimental studies was carried out using the layer-by-layer extrusion method on a workshop construction 3D printer “AMT S-6044”. The rationality of using concrete with a ratio of GCPB:aggregate = 1:2 in the additive manufacturing technology with a sand fineness modulus of Mk 3 has been substantiated. A composition of gypsum-cement-pozzolanic concrete (GCPC) modified with a multifunctional complex additive has been developed, which allows increasing the compressive strength by 35.3%, water resistance – by 73% (up to 0.85) compared to the control unmodified composition. It has been established that modification of GCPB with the developed multifunctional complex additive leads to a decrease in the volume of open capillary pores by 20.5%, the volume of open non-capillary pores – by 66.7%, an increase in the volume of conditionally closed pores by 28.1%, and the microporosity index – from 0.22 to 0.89. The synergistic interaction of chemical additives in complex additive composition is confirmed by the results of studies performed to determine the electrokinetic potential on the surface of GCPB particles and the kinetics of heat release during its hydration.

R.Z. RAKHIMOV, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
R.Kh. MUKHAMETRAKHIMOV, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
A.R. GALAUTDINOV, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
L.V. ZIGANSHINA, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Kazan State University of Architecture and Engineering (1, Zelenaya Street, Kazan, 420043, Russian Federation)

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The effectiveness of using 3D printing technology for the construction of exterior and interior walls, especially for low-rise residential and civil buildings of social purpose, is substantiated. The domestic experience in the construction of single-storey frameless buildings with load-bearing external walls printed on a 3D printer (with filling their internal space with inorganic insulation materials on a monolithic (foam concrete, foam gypsum) or backfill (expanded perlite, especially light expanded clay gravel) basis) is analyzed. The use of dry mixes on a gypsum and mixed basis for printing walls of low-rise buildings is justified for technological and economic reasons. On the basis of laboratory and field experiments to assess the durability of gypsum cement-pozzolan compositions (from dry mixtures) for 3D printing to change the temperature and humidity regime, it was established that the reason for the destruction and demolition of prototypes according to quantitative X-ray phase analysis was an increased content of ettringite during their hydration and hardening at a reduced temperature.

R.I. SHIGAPOV¹, Assistant Professor (This email address is being protected from spambots. You need JavaScript enabled to view it.),
G.Yu. SHAGIGALIN¹, Assistant (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.V. KLYUEV², Candidate of Sciences (Engineering), Associate Professor;
B.G. BULATOV³, Senior Lecturer (This email address is being protected from spambots. You need JavaScript enabled to view it.);
D.V. METLITSKAYA¹, Student of Group MPG05-23-01 (This email address is being protected from spambots. You need JavaScript enabled to view it.),
I.V. NEDOSEKO¹, Doctor of Sciences (Engineering), Professor (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Ufa State Petroleum Technical University (195, Mendeleev Street, Ufa, 450080, Russian Federation)
² Belgorod State Technological University named after. V.G. Shukhov (46, Kostyukova Street, 308012, Belgorod, Russian Federation)
³ Bashkir State Agrarian University (34, 50-letiya Oktyabrya Street, 450001, Ufa, Russian Federation)

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15. Mukhametrakhimov R.Kh., Ziganshina L.V. Technology and quality control of construction 3D printing. Izvestiya of the Kazan State University of Architecture and Civil Engineering. 2022. No. 1 (59), pp. 64–79. https://doi.org/10.52409/20731523_2022_1_64 EDN BZJGUO.
16. Mukhametrakhimov R., Ziganshina L., Kadyrov R., Statsenko E. Structure of 3D-printed concrete by x-ray computed tomography. In: Proceedings of STCCE 2022. STCCE 2022. Lecture Notes in Civil Engineering. 2023. Vol. 291. https://doi.org/10.1007/978-3-031-14623-7_37
17. Pustovgar A.P., Adamtsevich L.A., Adamtsevich A.O. International research experience in the field of additive construction manufacturing. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2023. No. 11, pp. 4–10. (In Russian). DOI: https://doi.org/10.31659/0044-4472-2023-11-4-10
18. Bessonov I.V., Shigapov R.I., Babkov V.V. Thermal insulating foam gypsum in low-rise construction. Stroitel’nye Materialy [Construction Materials]. 2014. No. 7, pp. 9–13. (In Russian).
19. Mirsaev R.N., Babkov V.V., Nedoseko I.V., Yunusova S.S. at al. Experience in the production and operation of gypsum wall products. Stroitel’nye Materialy [Construction Materials]. 2008. No. 3,pp. 78–80. (In Russian).
20. Larionova Z.M., Nikitina L.V., Garashin V.R. Fazovyy sostav, mikrostuktura i prochnost’ tsementnogo kamnya i betona [Phase composition, microstructure and strength of cement stone and concrete]. Moscow: Stroyizdat. 1977. 254 p.
21. Alksnis F.F. Tverdeniye i destruktsiya gipsotsementnykh kompozitsionnykh materialov [Hardening and destruction of gypsum-cement composite materials]. Leningrad: Stroyizdat. 1988. 103 p.
22. Mukhametrakhimov R.Kh. Study of plasticizing additives based on polycarboxylate esters on the properties of concrete molded by 3D printing. Stroitel’nyye materialy i izdeliya. 2022. Vol. 5. No. 5, pp. 42–58. https://doi.org/10.58224/2618-7183-2022-5-5-42-58 EDN CLDKGL.

The issue of the limit of technical and economic optimization of dry building mixes compositions does not lose its relevance and remains one of the main and priority issues in the industry. One of the ways to solve this issue is to use the most advanced chemical additives that minimize the cost of mixtures while maintaining the characteristics of the products. This paper discusses the use of rheological additive REOLIN RA 120 to optimize the compositions of plaster mixtures based on gypsum binder. It is shown that the use of REOLIN RA 120 in gypsum compositions reduces the complexity of plastering by increasing the range of permissible water-solid ratio, reducing the consumption of dry mix and improving the surface texture. The algorithm of introducing the additive and its effect on the indicators characterizing the complexity of preparation, application, leveling of the solution and subsequent treatment of the plaster surface is described.

S.V. ARASLANKIN¹, CEO (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.F. BURYANOV², Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
M.V. SHCHANKIN¹, Candidate of Sciences (Biology), Senior Scientist (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ «Exponenta» LLC (26A, Stanislavskogo Street, Ruzaevka, Republic of Mordovia 431448, Russian Federation)
² National Research Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, Moscow, 129337, Russian Federation)

1. Dergunov S.A., Rubtsova V.N. Proyektirovaniye sostavov sukhikh stroitelnykh smesey [Design of formulations of dry building mortars]. Orenburg: OGU, 2007. 97 p.
2. Denisov G.A. Manufacturing and using of dry mixes. Suxie stroitel’nye smesi. 2011. No. 1, pp. 14–17. (In Russian).
3. Zagorodnyuk L.X., Lesovik V.S., Gajnutdinov R. Specifics of hardening of mortars based on dry mixtures. Vestnik of the Central Regional Branch of the RAASN. Belgorod. 2014. Iss. 13, pp. 93–98. (In Russian).
4. Chen X., Wu S. Influence of water-to-cement ratio and curing period on pore structure of cement mortar. Construction and Building Materials. 2013. Vol. 38. No. 6, pp. 804–812.
https://doi.org/10.1016/j.conbuildmat.2012.09.058
5. Chen N., Wang P., Zhao L., Zhang G. Water retention mechanism of HPMC in cement mortar. Materials. 2020. Vol. 13. No. 13, 2918.
https://doi.org/10.3390/ma13132918
6. Elistratkin M.Yu., Minakova A.V., Dzhamil A.N., Kukoviczkij V.V., Elyan I.Zh.I. Composite binders for finishing compositions. Stroitel’ny’ materialy i izdeliya. 2018. No. 1 (2), pp. 37–44. (In Russian).
7. Wong H. H. C., Kwan A. K. H. Rheology of cement paste: role of excess water to solid surface area ratio. Journal of materials in civil engineering. 2008. Vol. 20. No. 2, pp. 189–197. https://doi.org/10.1061/(ASCE)0899-1561(2008)20:2(189)
8. Dvorkin L.I., Dvorkin O.L. Stroitel’noe materialovedenie [Construction materials science]. Moscow: Infra-Inzheneriya. 2013. 832 p.
9. Araslankin S.V., Kostryukov S.G., Tomilin O.B. Modern methods in technical and economic optimization of compositions of dry mixtures (Part I). ALITinform: Cement. Beton. Suxie smesi. 2018. No. 3 (52), pp. 54–66. (In Russian).
10. Araslankin S.V., Kostryukov S.G., Tomilin O.B. Modern methods in technical and economic optimization of compositions of dry mixtures (Part II). ALITinform: Cement. Beton. Suxie smesi. 2019. No. 1 (54), pp. 56–65. (In Russian).
11. Araslankin S.V., Kostryukov S.G., Tomilin O.B. Kinetic model of structure formation of dispersed systems based on calcium sulphate halfhydrate in the presence of mixed cellulose ethers. Increasing the efficiency of production and use of gypsum materials and products: materials of the IX International Scientific and Practical Conference. Minsk. 2018, pp. 20–28. (In Russian).
12. Gumerova E.I., Gamayunova O.S. Methods of plastering works. Stroitel’stvo unikal’nyx zdanij i sooruzhenij. 2016. No. 7 (46), pp. 7–16. (In Russian).
13. Murtazaev S.-A.Yu., Uspanova A.S., Khadzhiev M.R. Analysis of technology for producing plastering works by manual and mechanized methods. Vestnik GGNTU. Texnicheskie nauki. 2020. No. 16 (3), pp. 59–64. (In Russian).
14. Pol’nikov A.A. Features of determining the quality of dry construction mixture. Stroitel’nye Materialy [Construction Materials]. 2010. No. 2, pp. 40–41. (In Russian).
15. Dvorkin O.L. Application of dry building mixes at the present stage. Suxie stroitel’nye smesi. 2011. No. 2, pp. 20–23. (In Russian).
16. Cherednichenko T.F., Mamirgov M.U. Improvement of modern technologies for the production of plastering works. Vestnik of the Volgograd State University of Architecture and Civil Engineering. Series: Construction and Architecture. 2020. No. 4 (81), pp. 274–282. (In Russian).
17. Nekrasova S.A., Garkavi M.S., Buldy’zhova E.N. Dry building mixtures based on stabilized gypsum binder. Stroitel’nye Materialy [Construction Materials]. 2014. No. 7, pp. 32–33. (In Russian).
18. Potapova E. Texnologiya suxix stroitel’ny’x smesej [Technology of dry building mixtures]. Moscow: Infra-Inzheneriya. 2023. 376 p.
19. Zagorodnyuk L.H., Lesovik V.S., Glagoev E.S., Volodchenko A.A., Voronov V.V., Kucherova A.S. Theoretical foundations of the creation of dry building mixes. Vestnik of the Belgorod State Technological University named after V.G. Shukhov. 2016. No. 9, pp. 40–52. (In Russian).
20. Patent № 2659432 C1. Regulyator reologicheskix svojstv dispersny’x sistem na osnove neorganicheskix vyazhushhix veshhestv [Rheology regulator for inorganic binder-based dispersion systems]. Araslankin S.V., Tomilin O.B. Declared 10.04.2017. Published. 02.07.2018.

A fairly large number of works by both Russian and foreign researchers have been devoted to the development of building materials based on anhydrite binders. An astringent based on insoluble anhydrite refers to slow-hardening. This fact often deters manufacturers of building materials from using this binder. To date, there are many activators for the hardening of insoluble anhydrite. The efficiency of accelerators depends on a number of factors. But there is no unambiguous explanation for the action of additives used to obtain anhydrite materials with optimal properties, and this problem needs a comprehensive study. The use of anhydrite in the production of building products and materials is a promising direction in construction, since anhydrite binder is an interchangeable local material and can be used instead of cement or gypsum binders.

A.F. BURYANOV¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
N.A. LUKYANOVA¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
E.N. BULDYZHOVA², Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
S.S. REBROV³, Engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ National Research Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, Moscow, 129337, Russian Federation)
² Moscow Institute of Psychoanalysis NIGHT VO (34, building 14, Kutuzovsky Avenue, Moscow, 121170, Russian Federation)
³ «GIPSTECH» LLC (4A, Stroiteley Street, Latnaya working village, Voronezh region, 396950, Russian Federation)

1. Buryanov A.F., Lukyanova N.A., Buldyzhova E.N., Rebrov S.S. Increasing the efficiency of production and use of gypsum materials and products. Collection of materials from the XI International Scientific and Practical Conference «Increasing the efficiency of production and use of gypsum materials and products». Karachay-Cherkess Republic, Arkhyz village, September 20–21, 2023, pp. 44–50. (In Russian).
2. Vtorov B., Fischer H.B. Influence of hardening activators on the properties of anhydrite binders. Materials of the Second International Scientific and Technical Seminar: Non-traditional technologies in construction. 2001, pp. 371–376. (In Russian).
3. Klimenko V.G. The role of double salts based on Na⁺, K⁺, Ca²⁺, NH⁴⁺ sulfates in the technology of producing anhydrite binders. Vestnik BSTU named afterV.G. Shukhova. 2017. No. 12, pp. 119–125. (In Russian).
4. Golosovker I.Ya. Issledovaniye svoystv angidritovogo tsementa na baze Severnykh gipsov [Study of the properties of anhydrite cement based on Northern gypsum]. Arkhangelsk: Arkhangelsk Forestry Engineering Institute named after. V.V. Kuibysheva, 1948. 39 p.
5. Conley R.F., Bundy W.M. Mechanism of gypsification. Geochimica et Cosmochimica Acta. 1958. Vol. 15. Iss. 1–2, pp. 57–72.
https://doi.org/10.1016/0016-7037(58)90010-3
6. Daumantas E.P. Study of solubility, hydration and hardening of anhydrite. Dis... Candidate of Sciences (Engineering). Kaunas. 1965. (In Russian).
7. Tkacheva O.A. Hydration and hardening of anhydrite binder based on phosphogypsum. Candidate of Sciences (Engineering). Moscow, 1997. 203 p. (In Russian).
8. Kudyakow A., Anikanowa L. Fluorahydritbindemitel fur die herstellung von baumaterialien. In 14. Internationale Baustofftagung «Ibausil». Tagungsbericht_Band 1. Weimar, 2000, pp. 269–275
9. Klimenko V.G., Pavlenko V.I., Gasanov S.K. The Role of pH medium in forming binding substauces on base of calcium sulphate. Middle-East Journal of Scientific Research. 2013. Vol. 17. No. 8, pp. 1169–1175.
10. Novichenkova T.B. Modeling of dispersed systems from gypsum technogenic resources for the production of composites for construction purposes. Dis... Candidate of Sciences (Engineering). Kazan. 2012. 212 p. (In Russian).
11. Fischer H.B., Vtorov B. Influence of hardening activators on the properties of natural anhydrite. II International Meeting on Cement Chemistry and Technology. Vol. 2. Moscow. December 4–8, 2000, pp. 53–61. (In Russian).

The abstract generalization of the specifics of fatigue degradation of cement composites due to structural and physical heterogeneity, ambiguity of energy and mechanical effects of induced changes, interdependence of impacts and response, etc., is presented, which together do not make it possible to use the methodology and principles of the limit state method for its assessment. A phenomenological approach to the design accounting of fatigue is proposed by introducing a normative classification of the resistance of composites to non-stationary influences. In the experimental part of the work, prismatic samples of two series were tested: concrete and fiber concrete with polypropylene fibers. All tests were carried out in automatic mode according to a specially developed program at the Instron 5989 test complex, in compliance with the constancy of the deformation rate of the samples of 0.04 mm/s. External influences are modeled by 50 load-unloading cycles with an amplitude of η=0.8 and zero asymmetry (ρ=0). Cyclic loading was completed by monotonous compression until complete destruction of the samples. The acceptability of the laws of the kinetic concept of strength and its criterion (failure time) for assessing fatigue durability is experimentally and analytically substantiated. The practical identity of the kinetics of resistance time and significant indicators of operational suitability is confirmed.

B.I. PINUS, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)
I.G. KORNEEVA, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Irkutsk National Research Technical University (83, Lermontov Street, Irkutsk, 6640074, Russian Federation)

1. Заалишвили В.Б., Одишария А.В., Тимченко И.Э. и др. Инженерное макросейсмическое обследование эпицентральной зоны землетрясения 14 декабря 2000 г. // Геология и геофизика Юга России. 2014. № 1. С. 30–38. DOI: https://doi.org/10.23671/VNC.2014.1.55405
1. Zaalishvili V.B., Odishariya A.V., Timchenko I.E. et al. Engineering macroseismic survey of epicentral area of the earthquake on 14 December 2000. Geologiya i geofizika Yuga Rossii. 2014. No. 1, pp. 30–38. (In Russian). DOI: https://doi.org/10.23671/VNC.2014.1.55405
2. Басов А.Д., Черных Е.Н., Шагун А.Н., Капралов А.П. Микродеформации на Иркутской ГЭС при землетрясении 27 августа 2008 года на южном Байкале // Сейсмостойкое строительство. Безопасность сооружений. 2009. № 4. С. 52–54.
2. Basov A.D., Cherny`x E.N., Shagun A.N., Kapralov A.P. Microdeformations at the Irkutsk hydro electric station during the south Baikal earthquake on August 27, 2008. Sejsmostojkoe stroitel`stvo. Bezopasnost` sooruzhenij. 2009. No. 4, pp. 52–54. (In Russian).
3. Рабинович Ф.Н. Композиты на основе дисперсно-армированных бетонов. Вопросы теории и проектирования, технология, конструкции. М.: АСВ, 2011. 639 c.
3. Rabinovich F.N. Kompozity na osnove dispersno-armirovannykh betonov. Voprosy teorii i proektirovaniya, tekhnologiya, konstruktsii [Composites based on dispersed reinforced concrete. Theory and design issues, technology, constructions] Moscow: ASV. 2011. 639 p.
4. Liang J., Nie X., Masud M. et all. A study on the simulation method for fatigue damage behavior of reinforced concrete structures. Engineering Structures. 2017. No. 150, pp. 25–38. DOI: https://doi.org/10.1016/j.engstruct.2017.07.001
5. Baktheer A., Chudoba R. Classification and evaluation of phenomenological numerical models for concrete fatigue behavior under compression. Construction and Building Materials. 2019. No. 221 (1), pp. 661–677. DOI: https://doi.org/10.1016/j.conbuildmat.2019.06.022
6. Chen Y., Chen X., Bu J. Nonlinear damage accumulation of concrete subjected to variable amplitude fatigue loading. Bulletin of the Polish Academy of Sciences Technical Sciences. 2018. Vol. 66. No. 2. DOI: https://doi.org/10.24425/119070
7. Haar C., Marx S. Ein additives dehnungsmodell für ermüdungsbeanspruchten beton. Beton- und Stahlbetonbau. 2017. No. 112 (1), pp. 31–40. DOI: https://doi.org/10.1002/best.201600048
8. Huang B.-T., Li Q.-H., Xu S.-L. Fatigue deformation model of plain and fiber-reinforced concrete based on weibull function. Journal of Structural Engineering. 2019. No. 145 (1). DOI: https://doi.org/10.1061/(ASCE)ST.1943-541X.0002237
9. Poveda E., Ruiz G., Cifuentes H. et all. Influence of the fiber content on the compressive low-cycle fatigue behavior of self-compacting SFRC. International Journal of Fatigue. 2017. No. 101, pp. 9–17. DOI: https://doi.org/10.1016/j.ijfatigue.2017.04.005
10. Isojeh B., El-Zeghayar M., Vecchio F.J. Concrete damage under fatigue loading in uniaxial compression. ACI Materials Journal. 2017. No. 114 (2), pp. 225–235. DOI: https://doi.org/10.14359/51689477
11. Keerthana K., Kishen J.C. An experimental and analytical study on fatigue damage in concrete under variable amplitude loading. International Journal of Fatigue. 2018. No. 111, pp. 278–288. DOI: https://doi.org/10.1016/j.ijfatigue.2018.02.014
12. Liang J., Ren X., Li J. A competitive mechanism driven damage plasticity model for fatigue behavior of concrete. International Journal of Damage Mechanics. 2016. No. 25 (3), pp. 377–399. DOI: https://doi.org/10.1177/1056789515586839
13. Liu F., Zhou J. Fatigue strain and damage analysis of concrete in reinforced concrete beams under constant amplitude fatigue loading. Shock and Vibration. 2016. DOI: https://doi.org/10.1155/2016/3950140
14. Liu F., Zhou J. Research on fatigue strain and fatigue modulus of concrete. Advances in Civil Engineering. 2017, pp. 1–7. DOI: https://doi.org/10.1155/2017/6272906
15. Oneschkow N. Fatigue behaviour of high-strength concrete with respect to strain and stiffness. International Journal of Fatigue. 2016. No. 87, pp. 38–49. DOI: https://doi.org/10.1016/j.ijfatigue.2016.01.008
16. Korneeva I.G., Pinus B.I. Energy aspects of low-cycle fatigue оf fibropolypropylene concrete. IOP Conf. Series: Materials Science and Engineering International Conference on Construction, Architecture and Technosphere Safety. Sochi, 6–12 September 2020. No. 962 DOI: https://doi:10.1088/1757-899X/962/2/022020
17. Korneyeva I. Extensibility of the fibre concrete. IOP Conference series: materials science and engineering “Investments, Construction, Real Estate: New Technologies and Special-Purpose Development Priorities”. Irkutsk, April 25, 2019. No. 667. DOI: https://doi.org/10.1088/1757-899X/667/1/012044

The use of special knowledge in the field of building materials science is increasingly in demand in modern legal proceedings when conducting judicial construction and technical examinations in order to obtain an evidence base, in particular, on determining the timing of construction work. It is known that when conducting expert studies, it is possible to assess the increase in concrete strength due to the continued hydration of cement and a decrease in the basicity (pH) of the surface layer of concrete due to the processes of carbonization of cement stone in interaction with the atmosphere. The paper presents proven mathematical dependencies that make it possible to link the temporary change in the strength of concrete and the carbonation of the surface layer of concrete laid in monolithic structures with the structural parameters of concrete and its durability. These dependencies give the construction expert a fundamental opportunity to determine the age of concrete by changing the specified characteristics of concrete and, consequently, to determine the time period in which the construction structure was created from this concrete. Thus, expert determination of the production time of monolithic concrete structures is possible and is based on conducting research to establish the actual strength of concrete and determine the depth of its surface carbonation at the time of expert research. The described methodology for determining the timing of construction work on the manufacture of monolithic concrete structures in building conditions was used when conducting forensic examination.

B.A. BONDAREV¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
V.N. KOZOMAZOV¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
A.B. BONDAREV¹, Candidate of Sciences (Engineering),
A.V. KOZOMAZOV¹, Bachelor (This email address is being protected from spambots. You need JavaScript enabled to view it.);
V.K. ZHIDKOV², Postgraduate Student (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Lipetsk State Technical University (30, Moskovskaya Street, Lipetsk, 398055, Russian Federation)
² Tambov State Technical University (106/5, Sovetskaya Street, Tambov, 392000, Russian Federation)

1. Alekseev S.N., Ivanov F.M., Modry S., Shissl’ P. Dolgovechnost’ zhelezobetona v agressivnykh sredakh [The durability of reinforced concrete in aggressive environments]. Moscow: Stroyizdat. 1990. 320 p.
2. Shalyi E.E., Leonovich S.N., Kim L.V. Degradation of reinforced concrete structures of marine works from the combined impact of carbonation and chloride aggression. Stroitel’nye Materialy [Construction Materials]. 2019. No. 5, pp. 67–72. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2019-770-5-67-72
3. Leonovich S.N. Mechanics of durability of structural concrete: a new approach to the phenomenon of degradation. Part 1. Shrinkage. Stroitel’nye Materialy [Construction Materials]. 2024. No. 1–2, pp. 74–78. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2024-821-1-2-74-78
4. Langner E.A., Shikhovtsov A.A., Tsarev A.A., Petrosyan V.V. Modern technologies for accelerating the strength gain of concrete. Vestnik Evrazijskoj nauki. 2020. Vol. 12, No. 5, p. 36. (In Russian).
5. Karpenko N.I., Yarmakovsky V.N., Karpenko S.N., Kadiev D.Z. About the diagram method of determination of parametric points of microcracking formation process in concrete elements under axial compression in conditions of low negative temperatures action. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2019. No. 6, pp. 3–9. (In Russian). DOI: https://doi.org/10.31659/0044-4472-2019-6-3-9
6. Marinin A.N., Garibov R.B., Ovchinnikov I.G. Soprotivlenie zhelezobetonnyh konstrukcij vozdejstviyu hloridnoj korrozii i karbonizacii [Resistance of reinforced concrete structures to chloride corrosion and carbonization]. Saratov: IC “Rata”, 2008. 200 p.
7. Goglev I.N., Loginova S.A. A new indicator method for determining carbonization zones in concrete and reinforced concrete structures. Vestnik BSTU im. V.G. Shukhova. 2022. No. 8, pp. 8–16. (In Russian). DOI: https://www.doi.org/10.34031/2071-7318-2022-7-8-8-16.
8. Alekseev S.N. Korrozionnaya stojkost’ zhelezobetonnyh konstrukcij v agressivnoj promyshlennoj srede [Corrosion resistance of reinforced concrete structures in an aggressive industrial environment]. Moscow: Stroyizdat, 1976. 205 p.
9. Stepanova V.F., Falikman V.R. Modern problems of ensuring durability of reinforced concrete structures. BST: Bjulleten’ stroitel’noj tehniki. 2015. No. 2 (966), pp. 55–61. (In Russian).
10. Fedorov P.A., Anvarov B.R., Latypova T.V., Anva-rov A.R., Latypov V.M. Carbonization of concrete. What is the formula to calculate the depth of corrosion? ALITinform: Cement. Beton. Suhie smesi. 2010. No. 4–5 (16), pp. 54–60. (In Russian).
11. Vasiliev A. A. Raschetno-eksperimental’naya model’ karbonizacii betona [Calculation and experimental model of concrete carbonization]. Gomel: BelGUT, 2016. 263 p.
12. Vasiliev A.A. Assessment of the maximum corrosion indicators of concrete of compressive strength class C20/25. Nauchnoe obozrenie. Tekhnicheskie nauki. 2023. No. 2, pp. 5–10. (In Russian).

The scientific works of an outstanding scientist, A.M. Ivanov, devoted to the development of new methods for calculating wooden elements taking into account the time – creep factor have so far aroused great interest among modern researchers. The Voronezh Scientific School of Polymer Concrete A.M. Ivanov has substantiated and created universal models called “structural diagrams”, which lay the probabilistic foundations for evaluating the properties of materials, as well as polymer concrete and other composites. The article describes the life path, the formation of scientific activity and teaching of an outstanding scientist, Dr. of Technical Sciences, Professor A.M. Ivanov, a participant in the Great Patriotic War. Grateful students and followers showed that the issues of reinforcement of steel-polymer concrete structures, anchoring of reinforcement in polymer concrete and calculation of joints of prefabricated steel-polymer concrete structures of solid and annular cross-section with various types of reinforcement; the development of a whole range of polymer materials reinforced with fiberglass reinforcement and wood chips is the result of mentoring activities of an outstanding teacher and scientist.

B.A. BONDAREV¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
N.S. SOVA², Senior Researcher (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.B. BONDAREV¹, Candidate of Sciences (Engineering);
I.I. USHAKOV², Candidate of Sciences (Engineering),
V.K. ZHIDKOV³, Postgraduate Student (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Lipetsk State Technical University (30, Moskovskaya St., Lipetsk, 398055, Russian Federation)
² Voronezh State Technical University (84, 20th Anniversary of October St., Voronezh, 394006, Russian Federation)
³ Tambov State Technical University (106/5, Sovetskaya St., Tambov, 392000, Russian Federation)

1. Carlsen G.G. Derevyannye konstruktsii [Wooden structures]. Moscow: Gostekhizdatel’stvo. 1929. 55 p.
2. Konstruktsii iz dereva i plastmass. Pod red. G.G. Karlsena [Structures made of wood and plastics. Edited by G.G. Carlsen]. Moscow: Stroyizdat. 1986. 543 p.
3. Ivanov A.M. Raschet stalepolimerbetonnykh stroitel’nykh konstruktsii [Calculation of steel-polymer-concrete building structures]. Voronezh: Voronezh University Publishing House. 1972. 62 p.
4. Ivanov A.M. Stroitel’nye konstruktsii iz polimernykh materialov [Building structures made of polymer materials]. Moscow: Vysshaya shkola. 1978. 239 p.
5. Bondarev B.A. Stanovlenie i razvitie nauki o kompozicionny`x materialax v LGTU 1956–2021 gg. [Formation and development of the science of composite materials at Lipetsk State Technical University 1956–2021]. Lipetsk: Lipetsk State Technical University. 2021. 69 p.
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The quantitative description of the effect of the resulting chemical structures of polyepoxyurethaneisocyanurates on the glass transition temperature T_g was carried out. This is done by selecting copolymer structures whose T_g value is comparable to the calculated one, and the error does not exceed 1.8–2%. The theoretical data were obtained on the basis of calculations of model structures using the “Cascade” computer program (INEOS RAS).

M.D. KEJMAKX¹, Candidate of Sciences (Chemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
M.G. EZERNITSKAYA¹, Candidate of Sciences (Chemistry), (This email address is being protected from spambots. You need JavaScript enabled to view it.),
I.V. KARANDY¹, Candidate of Sciences (Chemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.A. ASKADSKII^1,2, Doctor of Sciences (Сhemistry) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS) (28, Vavilova Street, Moscow, 119991, Russian Federation)
² National Research Moscow State University of Civil Engineering (26, Yaroslavskoye Highway, Moscow, 129337, Russian Federation)

1. Kejmakh M.D., Ezernitskaya M.G., Karandy I.V., Askadskii A.A. Experimental data on the study of the formation processes of polyepoxyurethane isocyanurates. Part 1. Stroitel’nye Materialy [Construction Materials]. 2024. No. 5, pp. 4–11. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2024-824-5-4-11
2. Askadskii A.A. Physical properties of polymers. Prediction and control. Amsterdam: Gordon and Breach Publishers. 1996. 336 p.
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6. Askadskii А.А., Goleneva L.M., Konstantinov K.V., Bychko К.А. Synthesis and investigation of properties of the gradient-modulus material based on polypropylene glycols and 2,4-toluylendiisocyanate. Russian Polymer News. 2001. No. 6 (2), pp. 6–11.
7. Askadskii A.A., Konstantinov K.V., Goleneva L.M., Bychko K.A. Synthesis and properties of variable-modulus polyisocyanurate materials based on poly(propylene glycol) and 2,4-tolylene diisocyanat. Vysokomolekulyarnye soedineniya. Seriya A. 2002. No. 44 (4), pp. 567–576. (In Russian).
8. Askadskii A.A., Goleneva L.M., Afanasyev E.S., Petunova M.D. Gradient polymer materials. Obzornyi zhurnal po khimii. 2012. No. 2 (4), pp. 263–318. (In Russian).
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10. Askadskii A.A. Gradientnye polimernye materialy [Gradient polymer materials]. Moscow: ASV. 2024. 238 p.
11. Petunova M.D., Askadskii A.A., Luchkina L.V., Goleneva L.M., Kazanceva V.V., Kovriga O.V. Single-stage synthesis and mechanical properties of network polyurethane-isocyanurate polymer materials. Plasticheskie massy. 2010. No. 1, pp. 30–39. (In Russian).
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13. Patent RF 2252947. MPK C08J 5/04. Kompoziciya dlya polucheniya polimernyh konstrukcionnyh materialov na osnove poliizocianuratov [Composition for the production of polymer structural materials based on polyisocyanurates]. Askadskii A.A., Goleneva L.M., Kiseleva T.I Declared 25.06.2003 Published 27.05.2005. (In Russian).
14. Askadskii A.A., Luchkina L.V., Bychko K.A., Goleneva L.M., Konstantinov K.V. Synthesis, structure and properties of polymeric materials based on olicomeric poly(propylene glycol) and 2,4-tolylene diisocyanat. Vysokomolekulyarnye soedineniya. Seriya A. 2004. No. 46 (4), pp. 569–582. (In Russian).
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The review of existing mathematical models for humidity conditions was carried out. Methods giving an opportunity to calculate moisture transfer in the sorption zone of humidification and in the supersorption zone are described. The features of calculating moisture distribution using the theory of moisture potential are shown. The new discrete-continuous method for calculating the moisture state of a fence is proposed, which makes it possible to determine the unsteady-state moisture regime using an analytical expression without using various numerical methods. Two formulas for a single-layer and a multi-layer building envelope are derived. The formula allows us to determine the distribution of moisture potential in various sections of building envelopes. The effectiveness of the method is proven by comparing the results obtained with calculations using non-stationary and engineering quasi-stationary calculation methods. The humidity regime of a single-layer enclosing structure in the city of Moscow made of aerated concrete blocks, as well as a two-layer enclosing structure with a clay brick base and silicate brick cladding was calculated. It is shown that the calculation results using the proposed method are both quantitatively and qualitatively close to the distribution obtained using the non-stationary calculation method for both single-layer and multi-layer enclosing structures. The method is recommended for use in engineering work, because it gives a possibility to take into account the inertia of moisture in the building envelope.

K.P. ZUBAREV^1,2,3, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ National Research Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, Moscow, 129337, Russian Federation)
² Scientific-Research Institute of Building Physics of RAACS (21, Lokomotivniy Driveway, Moscow, 127238, Russian Federation)
³ RUDN University (6, Miklouho-Maclaya Street, Moscow, 117198, Russian Federation)

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