When installing floors, stairs, overpasses, it is necessary to determine the values of resistance to stone impact. Determining this parameter when the material arrives at the object is not always possible promptly, due to the discrepancy between the thickness of the plates and the required thickness of the test specimens. An express method for determining the dynamic strength of facing slabs made of natural stone, taking into account their geometric dimensions, is proposed. Based on the proportional ratio of the forces of dynamic and static impact, correction factors are calculated and given to the values of the impact strength of the stone, depending on the thickness and length of the samples. In cases where there are no laboratory data on the impact strength of the stone, an analytical method for determining this parameter is given, based on the functional dependences of the dynamic strength of the stone on the speed of propagation of the ultrasonic pulse through the stone, compressive strength and average density. Based on the approximation of the point values of the functions by the least squares method, the polynomials describing the function of the dependence of the impact strength on the ultrasound velocity, average density and compressive strength for limestones, marmorized limestones and granitoids are calculated. According to such polynomials, the reduced values of the impact strength of natural stone slabs can be determined by calculation as the average given, taking into account the significance of the indicators obtained for each of the polynomials for the same type of stone. In conclusion, the calculated values of impact strength are determined taking into account the correction coefficients introduced on the basis of deviations of the calculated values from the laboratory ones. Verification of the calculated data was carried out by laboratory tests and comparison of the data obtained by calculation with the data of laboratory tests. Such a comparison shows a close convergence of the results. The mathematical dependences given by the authors, as new laboratory data become available, can be improved. The information presented in the article will be useful to organizations designing stone cladding, construction organizations carrying out work on the installation of stone cladding, specialists conducting research in the field of quality assessment of stone materials.

N.I. MOTORNY, Candidate of Sciences (Geology and Mineralogy) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
G.L. LEVKOVSKY, Candidate of Sciences (Engineering)

Research and Design and Survey Institute for Problems of Extraction, Transportation and Processing of Mineral Raw Materials in the Industry of Building Materials (VNIPIIstromsyre) (1, building 1, Volokolamskoe Highway, Moscow,125080,Russian Federation)

1. Davidenko A.Yu., Litova K.V. Facing works from stone materials and their relevance in modern construction. Traditions and innovations in construction and architecture. Construction. Samara State University of Architecture and Civil Engineering. Samara, 2016, pp. 302–304. (In Russian).
2. Aligadzhiev Sh.L. Natural stone in the decoration of the facade of the building. Tools of modern scientific activity. Collection of articles of the International scientific-practical conference. Managing editor Sukiasyan A.A. 2015, pp. 124–126. (In Russian).
3. Grishina N.A. Determination of the causes of defects in the cladding of facades with natural stone. Days of Student Science. Collection of reports of the scientific and technical conference on the results of research work of students of the Institute of Economics, Management and Information Systems in Construction and Real Estate. Moscow. 2019, pp. 714–717. (In Russian).
4. Kostenok M.A., Konovalova O.N. Facade stone as an actual material for facade cladding. In the collection: Current state, problems and prospects for the development of branch science. Materials of the All-Russian conference with international participation. Under the general editorship of T.V. Shepitko. 2020, pp. 89–91. (In Russian).
5. GOST 9479–2011. Rock blocks for the production of facing, architectural, construction, memorial and other products. Specifications. FSUE STANDARTINFORM. (In Russian).
6. Strength of materials. Electronic training course for full-time and part-time students. Compiled by: Ph.D., Associate Professor of the Department of Mechanics and Design of Machines Karimov Ildar. 2021. (In Russian).
7. Kotlyarov A.A. Teoreticheskaya mekhanika i soprotivleniye materialov: komp’yuternyy praktikum [Theoretical mechanics and strength of materials: computer workshop]. Rostov-on-Don: Phoenix, 2017. 384 p.
8. Sidorin S.G., Khairullin F.S. Soprotivleniye materialov. Teoriya, testovyye zadaniya, primery resheniya. Uchebnoye posobiye [Strength of materials. Theory, test tasks, examples of solutions. Tutorial]. Moscow: Rior. 2017. 352 p.
9. Sotnikov V.V., Komarov P.I., Ulanov V.N. Grafo-analiticheskoye predstavleniye eksperimental’noy informatsii: Metodicheskiye ukazaniya [Grapho-analytical representation of experimental information: Guidelines]. Leningrad: LTI im. Lensoveta, 1987.
10. Krylov V.I., Bobkov V.V., Monastyrny P.I. Vychislitel’nyye metody [Computational methods]. Moscow: Nauka. 1976–1977. In 2 vol.
11. Bakhvalov N.S. Chislennyye metody [Numerical methods]. Moscow: Nauka, 1975.
12. Lvovsky E.N. Statisticheskiye metody postroyeniya empiricheskikh formul [Statistical methods for constructing empirical formulas]. Moscow: Vysshaya shkola. 1988.

The experience of operating mining and technological equipment at enterprises of the main branches of the national economy of Russia and the CIS states indicates that when working on moistened sticky rocks and raw materials, the throughput of units and the productivity of the equipment as a whole drops sharply and as well as the number of unscheduled downtime associated with the need to clear work surfaces from adhering masses of materials is increasing. Using the example of the pelletizing factory of JSC Mikhailovsky GOK named after A.V. Varichev, the solution to the problem of сontrolling the sticking of iron ore concentrate and raw materials on the working surfaces of technological equipment is shown by using a long-term (more than 20 years) highly effective method for the use of polymer anti-sticking lining plates of PPFP-Astika brands. It is noted that all PPFP-Astiki products manufactured by As-Tik KP LLC are certified and comply with the requirements of the regulatory document TU 2246-001-22711279–2008. The positive experience of the pelletizing plant of the combine in controlling the sticking of moistened raw materials on the working surfaces of technological equipment is recommended for wide implementation both at related enterprises and at other mining and processing enterprises.

V.G. KUZNETSOV¹, President, Director for Economics and Finance (This email address is being protected from spambots. You need JavaScript enabled to view it.),
I.P. KUZNETSOV¹, General Director (This email address is being protected from spambots. You need JavaScript enabled to view it.);
P.V. PUZAKOV², Chief Engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.),
D.V. VASHCHENKO², Head of the Pelletizing Plant (This email address is being protected from spambots. You need JavaScript enabled to view it.),
Yu.N. OVSYANNIKOV², Mechanic of the Shop for the maintenance of the mechanical equipment of the factory,
V.A. GANZHOV², Leading Specialist of the Factory Repair Department

¹ LLC «As-Tik KP» (16, Teterinsky pereulok, 109004, Moscow. Russian Federation)
²¹ JSC “Mikhailovsky GOK imeni A.V. Varicheva (25 Lenina Street, Zheleznogorsk 307170, Kursk region, Russian Federation)

1. Kuznetsov V.G., Kiselev N.N., Kochetov E.V., Kuznetsov I.P. Reducing the influence of stickiness of rocks and raw materials on working efficiency of equipment due to application of PPFP-Astiki. Stroitel’nye Materialy [Construction materials]. 2017. No. 1–2, pp. 99–103. (In Russian).
2. Kuznetsov V.G., Kuznetsov I.P. To the issue of reliable and efficient application of PPFP-Astiki at equipment operating with damp materials. Stroitel’nye Materialy [Construction Materials]. 2017. No. 8, pp. 45–48. (In Russian).
3. Pazynich G.P., Kuchin A.N., Krivonos M.V., Kuznetsov V.G., Kuznetsov I.P. The use of polymeric anti-adhering plates for lining the walls of bunkers of reloading devices. Gornyy zhurnal. 2003. No. 9, pp. 59–60. (In Russian).
4. Kuznetsov V.G., Zatkovetsky V.M., Kuznetsov I.P., Krivonos M.V., Tarasov S.N. Polymeric anti-adhesive lining plates – an effective means of combating the sticking of rocks on the working surfaces of excavator and technological equipment. Gornyy zhurnal. 2006. No. 4, pp. 56–57. (In Russian).
5. Kuznetsov V.G., Kuznetsov I.P., Kopylov S.V., Sitnikov S.N., Plemyashov A.V., Pazynich G.P., Krivonos M.V. Proper selection of polymeric anti-adhesive lining plates is the key to efficient operation of technological equipment. Gornyy zhurnal. 2008. No. 4, pp. 80–81. (In Russian).
6. Kuznetsov V.G., Novikova T.N., Kuznetsov I.P., Kochetov E.V. Efficient operation of process equipment in the factory pelletizing JSC «Mikhailovsky GOK» when working on moist raw materials. Gornyi zhurnal. 2013. No. 12, pp. 71–73. (In Russian).
7. Kuznetsov V.G., Kuznetsov I.P., Borodin A.A. i dr. Factory production of bunkers equipped with efficient means of struggle with adhering of materials – PPFP-Astiki. Stroitel’nye Materialy [Construction Materials]. 2013. No. 5, pp. 54–56. (In Russian).

The deformation properties of self-compacting concrete, including the modulus of elasticity and shrinkage, are determined. As part of the research work, CEM II/A-P 42.5R (Azerbaijan), granodiorite crushed stone of 5–10 mm fraction from the Shamkir district of Azerbaijan, as well as crushed stone from gravel mined in the Kubinsky district were used as a binder. As a fine aggregate, natural sand, screening with a size modulus of 3.5, as well as silica as a mineral additive and SF-20 modifier to give the concrete high fluidity to increase segregation resistance and achieve strength and other construction and technical properties of concrete are used in all concrete compositions. The research studied the technological and rheological properties of self-compacting concrete using a V-funnel, L-box and J-ring. High-strength concrete was obtained on the basis of a self-compacting mixture of the appropriate composition. The main purpose of the research is to obtain self-compacting concrete mixtures. The compressive strength of concrete obtained on the basis of Velvelichay and Shamkir granodiorite rubble, after 28 days, was 67.1 and 69.8 MPa, respectively. It is shown that the use of superplasticizer contributes to eliminate corrosion problems in the manufacture of reinforced concrete structures by reducing the water resistance of concrete.

S.M. AKBEROVA, Candidate of Sciences (Engineering), (This email address is being protected from spambots. You need JavaScript enabled to view it.);
S.G. GAKHRAMANOV, Engineer, (This email address is being protected from spambots. You need JavaScript enabled to view it.);
R.A. KURBANOVA, Candidate of Sciences (Engineering), (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Azerbaijan University of Architecture and Construction (11, Sultanova Street, Baku AZ 1073 Azerbaijan)

1. Kalashnikov V.I. Evolution of the development of compositions and changes in the strength of concrete. Concretes of the present and the future Part 1. Changing the composition and strength of concrete. Stroitelnye Materialy [Construction Materials]. 2016. No. 1–2, pp. 96–104. (In Russian).
2. Nesvetaev G.V. Technology of self-compacting concretes. Stroitelnye Materialy [Construction Materials]. 2008. No. 3, pp. 24–28. (In Russian).
3. Sapacheva L.V. Actual problems of construction materials science and ways to solve them. Stroitelnye Materialy [Construction Materials]. 2019. No. 1–2, pp. 83–85. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2019-767-1-2-83-85
4. Terkin N.N., Kodysh E.N. Prospects for the use of high-strength concrete in the structures of buildings and structures. Vestnik MGSU. 2011. No. 2, pp. 39–43. (In Russian).
5. Kaprielov S.S., Sheinfeld A.V. New concretes and technologies in the structures of high-rise buildings. Vysotnye zdaniya. 2007. No. 5, pp. 94–101. (In Russian).
6. Tarakoglu V., Baradan B. Mechanical properties of high-strength concrete. Istanbul: Kongre Bildirileri, 2004. 239 p.
7. Erdoğan T.Y. Beton. Ankara: Middle East Technical University Press, 2003.
8. Korotkov D.N., Kokosadze A.E., Kulinich Yu.I., Panikin D.A. Technology of concreting the inner protective shell of the reactor building of the Belarusian NPP. Stroitelnye Materialy [Construction Materials]. 2016. No. 5, pp. 10–16.(In Russian).
9. Bazhenov Yu.M., Chernyshov E.M., Korotkov D.N. Designing structures of modern concrete: defining principles and technological platforms. Stroitelnye Materialy [Construction Materials]. 2014. No. 3, pp. 6–14.(In Russian).
10. Nelyubova V.V., Usikov S.A., Strokova V.V., Netsvet D.D. Composition and properties of self-compacting concrete using a complex of modifiers. Stroitelnye Materialy [Construction Materials]. 2021. No. 12, pp. 48–54. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2021-798-12-48-54
11. TS 3502, Betonda E-modül ve poisson Oranının Belirlenmesi, Türk Standartları Enstitüsü, Ankara 1981.
12. ASTM C 469, Sıkıştırmada Betonun Statik Elastisite Modülleri ve Poisson Oranı için Standart Test Yöntemi, Yıllık ASTM Standartları Kitabı, 1994.
13. TS 500, Betonarme Yapıların Hesaplama ve Tasarım Kuralları, Türk Standartları Enstitüsü, Ankara, 2000.

Information is provided on amendment No. 2 to SP 63.13330.2018 “Concrete and reinforced concrete structures. The main provisions”. The list of changes made to the set of rules is given. Some of the changes were adopted in order to eliminate unnecessary requirements and are of an editorial and clarifying nature. Another part of the changes concerns the refinement of methods for calculating reinforced concrete structures. The list of reinforced concrete structures to which the requirement for the absence of cracks in the section is clarified. The requirements for the assignment of minimum classes of concrete of structures, including structures exposed to repeated loads, are clarified and supplemented. The list of methods for anchoring transverse reinforcement is expanded. The main part of the changes concerns the clarification of the instructions for the calculation of reinforced concrete structures. The provisions are clarified and new dependencies are included for calculating inclined sections of reinforced concrete structures on the effect of transverse forces, taking into account the influence of longitudinal compressive and tensile forces. The main provisions and dependencies for calculating the endurance of structures operating under the influence of multitime repeated load are given. The rules and procedure for determining the coefficients of working conditions for concrete and reinforcement when exposed to multitime repeated load are included.

T.A. MUKHAMEDIEV, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
S.A. ZENIN, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Research, Design and Technological institute of Concrete and Reinforced Concrete – NIIZHB named after A.A. GvozdevJSC “Research Center “Stroitel’stvo” (6, build. 5, 2-nd Institutskaya Street, Moscow, 109428, Russian Federation)

1. Zenin S.A., Sharipov R.Sh., Kudinov O.V. Influence of compressive stresses on the strength of inclined sections of non-centrally compressed reinforced concrete elements. Beton i Zhelezobeton [Concrete and Reinforced Concrete]. 2021. No. 1 (603), pp. 44–52.
2. Mukhamediev T.A., Zenin S.A. Taking into account the influence of longitudinal forces in the calculation of reinforced concrete structures on inclined sections. Collection of reports Modern problems of calculation and design of reinforced concrete structures of multi-storey buildings: collection of reports of the International Scientific Conference dedicated to the 100th anniversary of the birth of P.F. Drozdov. Moscow: MGSU, EBS DIA, 2013. 328 р. (In Russian).
3. Zenin S.A., Krylov S.B., Sharipov R.Sh., Kudinov O.V. To update of the methodology for calculating reinforced concrete structures for endurance. Beton i Zhelezobeton [Concrete and Reinforced Concrete]. 2021. No. 1 (603), pp. 17–22. (In Russian).
4. Sharipov R.Sh., Volkov Yu.S., Zenin S.A., Krylov S.B. On the issue of developing requirements for the method of calculating reinforced concrete structures under the action of repeatedly repeated loads. Bulleten stroitelnoy tehniki. 2020. No. 7, pp. 53–56. (In Russian).
5. Sharipov R.Sh., Zenin S.A., Krylov S.B., Volkov Yu.S. Evaluation of methods for calculating reinforced concrete structures for the ultimate state of fatigue. Vestnik NITS “Stroitelstvo”. 2020. No. 4 (27), pp. 148–159. (In Russian).
6. Krylov S.B., Zenin S.A., Sharipov R.Sh., Volkov Yu.S., Tsigulev A.O. Determination of stresses in the reinforcement of reinforced concrete structures for calculating the limit state for fatigue. Stroitelnaya mehanika i raschet sooruzheniy. 2020 No. 5 (292), pp. 4–11. (In Russian).

The expansion of the nomenclature at existing production facilities inevitably raises the question of increasing the raw strength and competitiveness of silicate products. New productions are developing raw materials sources and there are questions about send: the possibility of using several types of sand in production. Properly selected sand mixture in the production of silicate pressed products contributes to good formability, sufficient density, strength and economy. The best granulometry of sand is the one in which the presence of a larger fraction in quantitative terms prevails over a small one. Studies of the compositions of sand mixtures are given. Mixtures of sands within one group, adjacent groups and with an interval through the group were considered. By mathematical modeling, calculations of the grain composition were carried out on the framework-forming grain residues of sizes 0.16 and 0.315 mm. The results obtained show that sand mixtures within one group are characterized by an increase in the size modulus and the absence of changes in the structure of the framework formation, which indicates the inexpediency of mixing them. Sand mixtures of sands of neighboring groups give a positive result with a ratio of at least 50/50. Sand mixtures with an interval through the group increase the ratio in favor of coarse sand from 70 to 90%. Based on the calculations, the density and raw strength of the pressed samples were determined on the basis of the sand ratios considered and the calculated results were confirmed.

G.V. KUZNETSOVA¹, Engineer, (This email address is being protected from spambots. You need JavaScript enabled to view it.);
N.N. USMANOV², Candidate of Sciences (Pedagogy), representative;
D.I. MIFTAHOVA¹, student,
N.E. KADYROVA¹, student

¹ Kazan State University of Architecture and Engineering (1, Zelenaya Street, 420043, Kazan, Russian Federation)
² HAIYUAN GROUP in the Russian Federation and the CIS (14, Jaudata Faizi St., 142025, Kazan, Russian Federation)

1. Kuznetsova G.V., Babushkina D.A., Gaynutdinova G.Kh. A complex lime­siliceous binder for improving raw strength of silicate brick. Stroitel’nye Materialy [Construction Materials]. 2017. No. 8, pp. 19–22. (In Russian).
2. Volodchenko A.N. Influence of clay minerals on the properties of autoclaved silicate materials. Innovations in science: a collection of articles based on the materials of the XXI International Scientific and Practical Conference. Novosibirsk: SibAK, 2013. (In Russian).
3. Volodchenko A.N. The use of non-traditional clay raw materials for the production of silicate materials using energy-saving technology. Uspekhi sovremennogo yestestvoznaniya. 2015. No. 1 (part 4), pp. 644–647. (In Russian).
4. Kuznetsova G.V., Gaynutdinova G.Kh. Effect of sand fineness on selection of a lime binder type. Stroitel’nye Materialy [Construction Materials]. 2017. No. 12, pp. 33–37. (In Russian).
5. Khavkin L.M. Tekhnologiya silikatnogo kirpicha [Silicate brick technology]. Moscow: Stroyizdat. 1982. 384 p.
6. Bozhenov P.I. Tekhnologiya avtoklavnykh materialov [Technology of autoclave materials]. Leningrad: Stroyizdat. 1978. 368 p.

Substantiated and experimentally confirmed the possibility of using expanded perlite sand, pre-activated in a planetary mill, as a mineral additive to white cement to improve the technical and economic efficiency of small architectural forms based on it. It is shown that a slight grinding of perlite sand leads to its activation, which is expressed by an increase in the sorption capacity for the absorption of free CaO from solution (Zaporozhets method) and active Brönsted centers (indicator method). The addition of activated expanded sand provides a reduction in the setting time without making significant changes to the cement hydration processes in the early stages (up to 72 hours); an increase in the normal density of the dough; thickening of the system. The impact on the mobility of the cement paste is due to the peculiarities of the structure of the mineral additive: a developed angular surface with high dispersion and porosity of the particles. At the same time, the plasticization of dough based on cement with an active additive reduces water demand and makes it possible to obtain a cement stone with comparable strength at a reduced consumption of cement.

V.V. STROKOVA¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
V.V. NELUBOVA¹, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
N.O. KHMARA¹, Engineer Senior Lecturer (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.I. BUKOVSOVA², Candidate of Sciences (Engineering);
Yu.V. DENISOVA¹, Candidate of Sciences (Engineering)

¹ Belgorod State Technological University named after V.G. Shukhov (46, Kostyukova Street, Belgorod, 308012, Russian Federation)
² Starooskol Technological Institute named after A.A. Ugarova (42, Microdistrict named after Makarenko, Stary Osko, Belgorod Region,309516, Russian Federation)

1. Bazhenova O.Yu., Fetisova A.A., Shcherbeneva O.A. Fine-grained concrete for architectural details and small forms. Innovatsii i investitsii. 2020. No. 7, pp. 144–147. (In Russian).
2. Strokova V.V., Khmara N.O., Nelyubova V.V., Shapovalov N.A. Small architectural forms: composition and properties of concrete for their production. Vestnik BGTU im. V.G. Shukhova. 2021. No. 11, pp. 8–31. (In Russian). DOI: https://doi.org/10.34031/2071-7318-2021-6-11-8-31
3. Baranov E.V., Shelkovnikova T.I., Khorunzhii T.M. Modified decorative fine-grained concrete with addition of plasticizer and filler. Vestnik BGTU im. V.G. Shukhova. 2018. No. 4, pp. 13–17. (In Russian). DOI: https://doi.org/10.12737/article_5ac24a27c93945.06235016
4. Suleymanova L.A., Maliukova M.V., Ryabchevskiy I.S., Koryakina A.A., Levshina D.E. Illuminated concrete using rock crushing waste. Vestnik BGTU im. V.G. Shukhova. 2020. No. 12, pp. 8–16. (In Russian). DOI: https://doi.org/10.34031/2071-7318-2020-5-12-8-16
5. Marchenko I.N. The practice of using white cement. Cement i ego primenenie. 2010. No. 3, pp. 46–49 (In Russian).
6. Morozova N.N., Kuznetsova G.V., Maysuradze N.V., Akhtariev R.R., Abdrashitova L.R., Nizamutdinova E.R. Research in the activity of a pozzolanic component and superplasticizer for gypsum cement pozzolanic binder of white colour (GCPB). Stroitel’nye Materialy [Construction Materials]. 2018. No. 8, pp. 26–30. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2018-762-8-26-30
7. Di Marino M., Nil’sen E.P., Bi Ch.Ts. New generation ultra-high strength Aalborg extreme® concrete based on white cement. Tsement i ego primenenie. 2019. No. 4, pp. 96–101. (In Russian).
8. Ashteyata A., Haddadb R., Obaidatb Y. Case study on production of self compacting concrete using white cement by pass dust. Case Studies in Construction Materials. 2018. No. 9, pp. 1–11. DOI: https://doi.org/10.1016/j.cscm .2018.e00190
9. Potapova E.N., Guseva T.V., Tihonova I.O., Kanishev A.S., Kemp R.G. Cement production: aspects of increasing resource efficiency and reducing the negative impact on the environment. Stroitel’nye Materialy [Construction Materials]. 2020. No. 9, pp. 15–20. (In Russian). DOI: 10.31659/0585-430X-2020-784-9-15-20
10. Yakovlev G.I., Kalabina D.A., Grakhov V.P., Buryanov A.F., Gordina A.F., Bazhenov K.A., Nikitina S.V. Fluoro-anhydrite compositions with a light filler based on expanded perlite sand. Stroitel’nye Materialy [Construction Materials]. 2019. No. 5, pp. 57–61. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2019-770-5-57-61
11. Zagorodnjuk L.H., Rahimbaev Sh.M., Sumskoj D.A., Ryzhih V.D. Features of the processes of hydration of binder compositions using expanded perlite sand waste. Vestnik BGTU im. V.G. Shuhova. 2020. No. 11, pp. 75–88 (In Russian). DOI: 10.34031/2071-7318-2020-5-11-75-88
12. Pokorný J., Pavlíková M., Pavlík Z.Properties of cement-lime render containing perlite as lightweight aggregate. IOP Conference Series: Materials Science and Engineering. 2019. Vol. 596. Iss. 1. 012015. DOI: http://doi.org/10.1088/1757-899X/596/1/012015
13. Vyšvařil M., Pavlíková M., Záleská M., Bayer P., Pavlík Z.Non-hydrophobized perlite renders for repair and thermal insulation purposes: Influence of different binders on their properties and durability. Construction and Building Materials. 2020. No. 263. 120617. DOI: https://doi.org/10.1016/j.conbuildmat.2020.120617
14. Panagiotopoulou Ch., Angelopoulos P.M., Kosmidi D., Angelou I., Sakellariou L., Taxiarchou M. Study of the influence of the addition of closed- structure expanded perlite microspheres on the density and compressive strength of cement pastes. Materials Today: Proceedings. No. 54. P. 1, 2022, pp. 118–124. DOI: https://doi.org/10.1016/j.matpr.2022.02.149
15. Gencel O., Bayraktar O.Y., Kaplan G., Arslan O., Nodehi M., Benli A., Gholampour A., Ozbakkaloglu T. Lightweight foam concrete containing expanded perlite and glass sand: Physico-mechanical, durability, and insulation properties. Construction and Building Materials. No. 320. 2022. 126187. DOI: https://doi.org/10.1016/j.conbuildmat.2021.126187
16. Szabó R., Dolgos F., Debreczeni Á., Mucsi G. Characterization of mechanically activated fly ash-based lightweight geopolymer composite prepared with ultrahigh expanded perlite content. Ceramics International. 2022. No. 48. Iss. 3, pp. 4261–4269. DOI: https://doi.org/10.1016/j.ceramint.2021.10.218

The rapid growth in the construction of individual housing requires the introduction of new technologies for the construction of buildings. These technologies must meet the basic requirements: high speed of construction, affordable cost, quality, durability and energy saving. Polystyrene concrete is an ideal material both in terms of application and in terms of production. The construction technology with the use of large-format polystyrene concrete panels will make it possible to build energy-efficient houses of the highest quality in the shortest possible time.

D.G. ZYUKIN, Head of Technical Department (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Production and Construction Enterprise “BlockPlastBeton” LLC (BlockPlastBeton) (1, Tsvetaevoy Street, Korolev, 141075, Moscow Region, Russian Federation)

To reduce the time of housing construction, advanced technologies of industrial housing construction are considered. Given the design features of the joints of reinforced concrete structures of modernized large-panel buildings, preference is given to in-situ joints. To ensure a high speed of installation of precast concrete products, including in winter conditions of work, the use of Ultra High Performance Concretes (UHPC) with specified characteristics is required. The article discusses the issues of improving the technology of winter concreting of joints through the use of fresh of self-compacting fine-grained concrete (SCFGC) based on dry constructional mixes (DCM) with the required intensity of curing and stiffness of concrete for pouring. The main types of in-situ joints of prefabricated reinforced concrete structures of large-panel buildings are considered. As a result of the generalization of experimental studies and extensive industrial experience in the use of SCFGC in the construction of prefabricated buildings, recommendations are given on the designation of structural and technological parameters of the quality of fresh of SCFGC, hardened concretes based on them, the features of the technology for the preparation of fresh of SUMBS, concreting and quality control. The successful application of SCFGC based on DCM allows to ensure the quality of large-panel housing construction, taking into account the all-weather nature of the production of in-situ work on sealing the joints of prefabricated structures, allows you to increase the pace of construction and reduce its time by 2–3 times compared to in-situ buildings.

E.V. RUMYANTSEV¹, Chief Designer of Product Department (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.Kh. BAYBURIN², Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ LLC “PIK-Constructional Technologies” (19/1, Barricadnaya Street, Moscow, 123242, Russian Federation)
² 2 National Research South Ural State University (76, Lenina Avenue, Chelyabinsk, 454080, Russian Federation)

1. Singhal S., Chourasia A., Chellappa S., Parashar J. Precast reinforced concrete shear walls: State of the art review. Structural Concrete. 2019. https://doi.org/10.1002/suco.201800129
2. Alfred A. Yee, Hon. D. Structural and economic benefits of precast/prestressed concrete construction. PCI Journal. 2001. Vol. 46. No. 4, pp. 34–42.
3. Nikolaev S.V., Shreiber А.К., Etenko V.P. Panel-frame housing construction – a new stage in the development of frame-panel housing construction. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2015. No. 2, pp. 3–7. (In Russian).
4. Dubynin N.V. From large-panel housing construction of the 20th century to the system of panel-frame housing construction of the 21st century. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2015. No. 10, pp. 12–19. (In Russian).
5. Sapacheva L.V. Modernization of large-panel housing construction – the locomotive of economy-class housing construction. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2011. No. 6, pp. 2–6. (In Russian).
6. Muhamediev T.A., Kudinov O.V. Increasing the number of storeys of prefabricated large-panel buildings. Beton i zhelezobeton [Concrete and reinforced concrete]. 2006. No. 3, pp. 7–9. (In Russian).
7. Falikman V.R. Concretes of established functionality – «Smart concretes». Conference Proceedings ICCX Russia. 3–6 December 2019. St. Petersburg, pp. 52–63. (In Russian).
8. Nikolaev S.V. The revival of large-panel housing construction in Russia. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2012. No. 4, pp. 2–8. (In Russian).
9. Blazhko V.P. Trends in the development of structural systems of panel housing construction. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2012. No. 4, pp. 43–46. (In Russian).
10. Abramov M.A. A new series of panel houses up to 25 floors. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 3, pp. 9–14. (In Russian).
11. Kireeva E.I. Strength of horizontal joints of panels and multi-hollow floor slabs. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 10, pp. 2–6. (In Russian).
12. International Federation for Structural Concrete (fib). Special design considerations for precast prestressed hollow core floors. bulletin 2000. No. 6. 172 p.
13. Kireeva E.I. Large-panel buildings with loop connections of structures. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 9, pp. 47–51. (In Russian).
14. Danel’ V.V. Improvement of loop joints of wall panels. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2014. No. 1–2, pp. 11–15. (In Russian).
15. Suur-Askola P. Technologically improved product from the company Peikko – PVL cable loop. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 3, pp. 21–23. (In Russian).
16. Zenin S.A. Designing residential large-panel houses using non-welded joints on cable loops. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2013. No. 7, pp. 14–15. (In Russian).
17. PVL Connecting Loop. Technical Manual. Peikko Group. 2019, 30 p.
18. Zenin S.A., Sharipov R.Sh., Kudinov O.V. Investigation of the work of plug joints in large-panel constructive systems of buildings. Beton i zhelezobeton [Concrete and reinforced concrete]. 2021. No. 5–6 (607–608), pp. 60–66. (In Russian).
19. Provost-Smith Douglas J. Investigation of grouted dowel connection for precast concrete wall construction. Electronic Thesis and Dissertation Repository. 2016. 4298 https://ir.lib.uwo.ca/etd/4298
20. Nehdy M., Elsayed M., Provost-Smith D. J. Investigation of grouted precast concrete wall connections at subfreezing conditions. Material of Conference “Resilient infrastructure”. London, GB. 2016, pp. 1–10. https://www.researchgate.net/publication/304115263_INVESTIGATION_OF_GROUTED_PRECAST_CONCRETE_WALL_CONNECTIONS_AT_SUBFREEZING_CONDITIONS#fullTextFileContent
21. Rumyantsev E.V., Vidyakin A.A., Bayburin A.Kh. Temperature monitoring of monolithic joints of large-panel buildings during winter concreting. Beton i zhelezobeton [Concrete and reinforced concrete]. 2020. No. 1 (601), pp. 42–48. (In Russian).
22. Okamura M., Ouchi H. Self-compacting high performance concrete. Progress in Structural Engineering and Materials. 1998. Vol. 1. Iss. 4, pp. 378–383. DOI: https://doi.org/10.1002/pse.2260010406
23. Self-Compacting Concrete. Procedings of the First International RILEM Symposium. Editied by A. Skarendahl and O. Petersson. RELEM Publication S.A.R.L. Stockholm, Sweden. 1999. 578 p.
24. Khayat K.H. Workability, testing, and performance of self-consolidating concrete. ACI Materials Journal. 1999. Vol. 96. No. 3, pp. 346–353.
25. Batudaeva A.V., Kardumyan G.S., Kaprielov S.S. High-strength modified concrete from self-compacting mixtures. Beton i zhelezobeton [Concrete and reinforced concrete]. 2005. No. 4, pp. 14–18. (In Russian).
26. Nesvetaev G.V., Lopatina Yu.Yu. Designing the macrostructure of a self-compacting concrete mix and its mortar component. Internet-zhurnal «Naukovedeniye». 2015. Vol. 7. No. 5. (In Russian). DOI: http://dx.doi.org/10.15862/48TVN515
27. Mozgalev K.M., Golovnev S.G., Mozgaleva D.A. Efficiency of use of self-compacting concretes in the construction of monolithic buildings in winter conditions. Vestnik Yuzhno-Ural’skogo gosudarstvennogo universiteta. Seriya “Stroitel’stvo i arhitektura”. 2014. Vol. 14. No. 1, pp. 33–37. (In Russian).
28. Minakov Yu.A., Kononova O.V., Anisimov S.N., Gryazina M.V. Management of concrete hardening kinetics at negative temperatures. Fundamental’nye issledovaniya. 2013. No. 4, pp. 307–311. (In Russian).
29. Kaprielov S., Sheynfeld A., Arzumanov I., Chilin I. New national standard for self-compacting concrete mixes. Bulletin of Science and Research Center of Construction. 2021. Vol. 30 (3), pp. 30–40. DOI: https://doi.org/10.37538/2224-9494-2021-3(30)-30-40. (In Russian).
30. Titova L., Beylina M., Khlopuk V., Shabalin V. Development of a national standard fortesting methods for self-compacting concrete mixture. Bulletin of Science and Research Center of Construction. 2021. Vol. 30 (3), pp. 108–116. DOI: https://doi.org/10.37538/2224-9494-2021-3(30)-108-116. (In Russian).
31. Rumyantsev E.V., Bayburin A.Kh., Solov’ev V.G., Ahmed’yanov R.M., Bessonov S.V. Technological parameters of the quality of self-compacting fine-grained fresh concrete for winter concreting. Stroitel’nye Materialy [Construction Materials]. 2021. No. 5, pp. 4–14. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2021-791-5-4-14
32. Rumyantsev E.V., Bayburin A.Kh., Solov’ev V.G., Ahmed’yanov R.M., Bessonov S.V. Dynamics of strength gain of “cold” self-compacting fine-grained concretes during winter concreting of joints. Stroitel’nye Materialy [Construction Materials]. 2021. No. 10, pp. 12–20. (In Russian). DOI: https://doi.org/10.31659/0585-430X-2021-796-10-12-20
33. Kuznecova T.V. Composition, properties and application of sulfoaluminate cement // Vestnik nauki i obrazovaniya Severo-Zapada Rossii. 2018. Vol. 4. No. 1, pp. 1–7. (In Russian).
34. Bazhenov Yu.M., Demyanova V.S., Kalashnikov V.I. Modificirovannye vysokokachestvennye betony [Modified high-quality concrete]. Moscow: ASV. 2006. 368 p.
35. Batrakov V.G. Concrete modifiers: new opportunities and prospects. Stroitel’nye Materialy [Construction Materials]. 2006. No. 10 (622), pp. 4–7. (In Russian).
36. Bikbau M.YA., Nefedov A.S. Nanomodified cement and concrete based on it. ALITinform. 2020. No. 2 (59), pp. 2–13. (In Russian).
37. Kaprielov S.S., Travush V.I., Karpenko N.I., Shejnfeld A.V., Kardumyan G.S., Kiseleva YU.A., Prigozhenko O.V. Modified concretes of a new generation in the structures of the MIBC “Moscow-City”. Stroitel’nye Materialy [Construction Materials]. 2006. No. 10 (622), pp. 13–17. (In Russian).
38. Krasnovskiy B.M., Dolgopolov N.N, Zagrekov V.V., Suhanov V.A., Lorettova R.N. Hardening of concretes on VNV at negative temperatures. Beton i zhelezobeton [Concrete and reinforced concrete]. 1991. No. 2, pp. 17–18. (In Russian).
39. Nesvetaev G.V. The effectiveness of the use of superplasticizers in concrete. Stroitel’nye Materialy [Construction Materials]. 2006. No. 10 (622), pp. 23–25. (In Russian).
40. Sorokin Yu.V., Kalashnikov O.O., Falikman V.R. Structural and technical properties of especially high-strength fast-hardening concretes. 80th anniversary of NIIZhB named after A.A. Gvozdev Proceedings. Moscow. 2007, pp. 178–194. (In Russian).
41. Usherov-Marshak A.V. Additives in concrete: progress and problems // Stroitel’nye Materialy [Construction Materials]. 2006. No. 10 (622), pp. 8–12. (In Russian).
42. Yuan Yu., Lin V., Pe T. Vysokokachestvennyj cementnyj beton s uluchshennymi svojstvami [High-performance cement concrete with improved properties] Moscow: ASV. 2014. 448 p.
43. Han B., Ding D, Wang J., Ou J. Nano-engineered cementitious composites. principles and practices. Singapore, Springer Nature Singapore Pte Ltd. 2019. 731 p.

The article is devoted to the calculation method for a new objective room acoustics criterion – “height measure” (LH), which derives from specific features of temple buildings in view of the architectural features of their internal volume and the resulting subjective effect of the arrival of sound from above (the so-called “Voice of Heaven”). The proposed criterion makes it possible to set a subjective-objective correspondence for the degree of spatial sensation of the acoustic features of the temple premises and predict it as objective parameter values at the stage of acoustic design of religious buildings and structures. The definition of the parameter and the prerequisites for its introduction are given in previous publications of the authors. This article proposes a method for the analytical calculation of the height measure parameter (LH), based on statistical theory of room acoustics. The obtained ratios make it possible to calculate this parameter for the cases of near and far fields, based on the basic geometric parameters of the room and the average sound absorption coefficient. Conclusions are drawn about the possibility of using such a technique for the initial assessment of the influence of the upper volumes of temple premises on the subjective sensation of the “voice of heaven” and the need for experimental verification of the calculation of the proposed criterion.

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

Research Institute of Building Physics of RAACS (21, Lokomotivny Driveway, Moscow, 127238, Russian Federation)

1. Shchirzhetsky Kh.A., Sukhov V.N., Aleshkin V.M. On the issue of providing conditions for acoustic comfort in the design and construction of buildings and structures in the complexes of Orthodox churches in Russia. BST: Byulleten’ stroitel’noy tekhniki. 2020. No. 6 (1030), pp. 26–27. (In Russian).
2. Aleshkin V.M., Shchirzhetsky H.A., Sukhov V.N. Problems of the current state of acoustic design of prayer halls of mosques. Stroitel’stvo i rekonstruktsiya. 2016. No. 3 (65), pp. 88–95. (In Russian).
3. Aleshkin V.M., Shchirzhetsky H.A., Sukhov V.N. On the issue of solving the problems of acoustics of prayer halls of mosques on the example of a cathedral mosque in Moscow. Fundamental, exploratory and applied research of the RAASN on scientific support for the development of architecture, urban planning and the construction industry of the Russian Federation in 2016. Collection of scientific papers RAASN. Ser. “Scientific works of RAASN”. Russian Academy of Architecture and Building Sciences. Moscow, 2017, pp. 61–67. (In Russian).
4. Shchirzhetsky Kh.A., Sukhov V.N. Theory and prac- tice of using low-frequency resonators to solve rever- beration problems in Orthodox churches. Izvestiya vysshikh uchebnykh zavedeniy. Tekhnologiya tekstil’noy promyshlennosti. 2018. No. 3 (375), pp. 241–247.
5. Aleshkin V.M. et al. Acoustics of the Ketchaoua Mosque in Algeria. Akusticheskij Zhurnal. 2021. Vol. 67. No. 3, pp. 302–311. (In Russian). DOI: 10.31857/S0320791921030011
6. Aleshkin V., Schirjetsky Сh., Subbotkin A. Estimating sound absorption coefficient of prayers in mosques. Akustika. 2019. Vol. 32, pp. 227–230.
7. Shchirzhetsky Kh.A., Aleshkin V.M., Shchirzhet-sky A.Kh. Features of acoustic requirements for prayer halls of canonical confessional buildings and structures. Proceedings of the All-Russian Acoustic Conference. Materials of the III All-Russian Conference. 2020, pp. 475–482. (In Russian).
8. Shchirzhetsky Kh.A., Aleshkin V.M., Subbotkin A.O. Evaluation of the acoustics of temple buildings and structures based on the height measure parameter. Stroitel’stvo i rekonstruktsiya. 2021. No. 5 (97), pp. 115–121. (In Russian). DOI: 10.33979/2073-7416-2021-97-5-115-121
9. Furduev V.V. Akusticheskiye osnovy veshchaniya [Acoustic fundamentals of broadcasting]. Moscow: Svyazizdat, 1960. 320 p.
10. Vyatchanina T.N. On the interaction of architectural form and religious consciousness in Russian temple architecture of the 15th century. Light symbol. Academia. Arkhitektura i stroitel’stvo. 2008. No. 4, pp. 30–36. (In Russian).
11. Anert V., Steffen F. Tekhnika zvukousileniya [Sound amplification technique]. Moscow: “ERA”, “Lerusha”. 2003. 416 p.
12. Beranek L. Concert Halls and Opera Houses: Music, Acoustics and Architecture. 2nd edition. New York: Springer Verlag. 2004. 684 p.
13. Vakhitov Ya.Sh. Slukh i rech’ [Hearing and speech]. Leningrad: Soyuzpoligrafprom. 1973. 124 p.

It is known that sound attenuation in dissipative plate noise silencers increases with an increase in their length and with a decrease in the hydraulic diameter of the noise silencer cell. To increase the efficiency of sound attenuation in plate noise suppressors, it was proposed to use the surface of plates with volumetric elements. In this case, the hydraulic diameter of the silencer cell decreases, and additional attenuation occurs due to the phenomenon of diffraction. Prototypes of noise silencers were made from plates with volumetric elements in the form of semi-cylindrical concavities. Within the framework of bench acoustic tests, the characteristics of noise silencers made of plates with flat side walls and the proposed noise silencers made of plates with volumetric elements were investigated with the same density of the plates with sound-absorbing material and the constancy of the free area factor. Based on the results of field tests, an increase in the effectiveness of noise reduction was confirmed. Additionally, by numerical simulation, the aerodynamic characteristics of the studied plate noise silencers were determined. According to the results of studies for the proposed noise silencers with volumetric elements, sound attenuation values were obtained for several variants of the free area factor and the orientation of the volumetric elements of the plates – along and across the channel, as well as pressure loss depending on the flow velocity of the medium.

D.V. CHUGUNKOV¹, Ph.D. tech. sciences, associate professor (This email address is being protected from spambots. You need JavaScript enabled to view it.),
E.A. ZHURAVLEV¹, junior researcher (This email address is being protected from spambots. You need JavaScript enabled to view it.);
M.Yu. LESHKO², engineer (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ National Research University «Moscow Power Engineering Institute» (14, Krasnokazarmennaya Street, Moscow, 111250, Russian Federation)
² Research Institute of Building Physics, Russian Academy of Architecture and Construction Sciences (21, Lokomotivniy Driveway, Moscow, 127238, Russian Federation)

1. Abramov A.I., Elizarov D.P., Remezov A.N. et al. Povyshenie ekologicheskoi bezopasnosti TES [Increasing the environmental safety of thermal power plants]. Moscow: MPEI Publishing House. 2002. 378 p.
2. Zhuravlev E.A. Silencers of noise of power objects. International scientific and practical conference “Scientific and practical research”. Omsk. 2020. Vol. 1, pp. 87–91. (In Russian).
3. Drokonov A.M., Drokonov A.E. Reducing the noise of power plants. Fundamental’nye i prikladnye problemy tekhniki i tekhnologii. 2014. No. 3, pp. 65–75. (In Russian).
4. Zhuravlev E.A., Chugunkov D.V. Acoustic inspection of the gas path of the CHP boiler. Conference “Priority directions of innovative activity in industry”. Kazan. 2020. Vol. 1, pp. 105–107. (In Russian).
5. Krasnov V.I. Development of methods for reducing noise from gas paths during the modernization of water-heating boilers of the PTVM type to the surrounding area. Diss. Candidate of Sciences (Engineering). Moscow, 2005. 139 p.
6. Ivanov N.I. Inzhenernaya akustika. Teoriya i praktika bor’by s shumom [Engineering acoustics. Theory and practice of noise control]. Moscow: Logos, 2016. 422 p.
7. Gusev V.P. Acoustic characteristics of absorption mufflers for protection of buildings and development areas from ventilation noise. Bezopasnost’ zhiznedeyatel’nosti. 2003. No. 8, pp. 16–20. (In Russian).
8. Gusev V.P. Means of reducing airborne and structural noise in ventilation, air conditioning and refrigeration systems. AVOK. 2005. No. 4. pp. 86–90. (In Russian).
9. Gusev V.P., Leshko M.Yu. Lamellar mufflers of noise of ventilating installations. AVOK. 2006. No. 8, pp. 34–38. (In Russian).
10. Gusev V.P. From the experience of combating the noise of engineering systems equipment. AVOK. 2012. No. 2, pp. 38–42. (In Russian).
11. Patent RF 187890. Sound-absorbing cassette for noise suppressors of gas-air paths. Chugunkov D.V., Seifelmlyukova G.A., Zhuravlev E.A., Fomenko K.S., Skurikhina A.D., Bogdanova A.E. Declared 21.02.2018; Published 21.03.2019. Bulletin No. 9. (In Russian).
12. Zhuravlev E.A., Chugunkov D.V. Development of a noise suppression system of an original design for the gas path of a CHP boiler. International scientific conference “Priority directions of innovative activity in industry”. Kazan. 2020. Vol. 1. Book. 1, pp. 114–116. (In Russian).
13. Zhuravlev E.A., Chugunkov D.V., Seyfelmlyuko-va G.A. Improving the acoustic efficiency of laminated dissipative noise silencers for boiler gas-air paths. E3S Web of Conferences. 2019. No. 140, pp. 1–5. DOI: https://doi.org/10.1051/e3sconf/201914002005.
14. Chugunkov D.V., Zhuravlev E.A., Seifelmlyukova G.A. Research results of a lamellar noise suppressor with three-dimensional elements for gas-air channels. All-Russian scientific and practical conference with international participation “Protection against increased noise and vibration”. St. Petersburg. 2021. Vol. 1, pp. 147–155. (In Russian).
15. Zhuravlev E.A., Chugunkov D.V. Approaches to the improvement of plate noise silencers for gas-air paths of boilers. International Scientific Conference “Advanced Innovative Developments. Prospects and experience of use, problems of implementation in production. Kazan. 2019. Vol. 1, pp. 74–78. (In Russian).
16. GOST 28100–2007 Acoustics. Laboratory measurements for silencing devices installed in air ducts and air distribution equipment. Moscow: Standartinform. 2008. (In Russian).

Supporters and fans are an integral part of the emotional and subjective component of the mood of spectators in the stands during modern sporting events at large sports facilities. But each sports facility gives its own unique response to the acoustics of the room when chanting fan chants, depending on the air volume, dimensions, shape and properties of the finishing materials of the room’s enclosing structures. Within the framework of this work, the concept of the fan support index for sports facilities, in particular football stadiums, is considered, an analytical model for evaluating the fan support index is developed. A simplified method for calculating the fan support index is presented, which makes it possible for specialists who do not have special computer software for mathematical modeling of room acoustics to conduct a comparative assessment of the support of this parameter by sound fields created with various configurations of space-planning solutions of large sports facilities, primarily their shape in plan. In accordance with the methodology of this work and the data of comparative calculations of the fan support index, obtained by computer and analytical calculation of the sound fields of stadiums of various shapes in the plan, gradations of quality classes of this index are introduced.

Kh.A. SHCHIRZHETSKII¹, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
A.V. PERETOKIN^1,2 (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Research Institute of Building Physics of RAACS (21, Lokomotivniy Driveway, Moscow, 127238, Russian Federation)
² Acoustic Materials LLC (33 building 2, Novokuznetskaya Street, 115054, Moscow, Russian Federation)

1. Peretokin A., Livshits A., Orlov A., Shirgina N. Acoustics features of sports facilities on the example of FIFA 2018 football stadiums in Russia. Proceedings of the 23rd International Congress on Acoustics. 9–13 September 2019. Aachen, Germany.
2. Barnard A., Hambric S. Evaluation of crowd noise in Beaver Stadium during Penn State football games. The Journal of the Acoustical Society of America. 2010. Vol. 127. Iss. 3. https://doi.org/10.1121/1.3383777
3. Valmont E., Wilkinson M., Thomas A. Stadia acoustic atmosphere and spectator experience: Quantifying crowd noise with architectural form. The Journal of the Acoustical Society of America. 2016. Vol. 140. Iss. 4. https://doi.org/10.1121/1.4970463
4. Code of Practice 415.1325800.2018 Public buildings. Acoustic design rules. Moscow: Standartinform. 2019. (In Russian).
5. Shchirzhetsky Kh.A., Sukhov V.N. Problems of acoustic design of sports and entertainment halls of various sizes and capacities. BST. 2017. No. 6, pp. 26–28.
6. Shchirzhetskii Kh.A., Soukhov V.N., Shchirzhet-skii A.Kh., Aleshkin V.M. On the problem of acoustic design of modern multipurpose halls. Zhilishchnoe Stroitel’stvo [Housing Construction]. 2019. No. 7, pp. 16–24. (In Russian). DOI: https://doi.org/10.31659/0044-4472-2019-7-16-24
7. Furduev V.V. Akusticheskiye osnovy veshchaniya [Acoustic foundations of broadcasting]. Moscow: Kniga po Trebovaniyu. 2013. 319 p.
8. Anert V., Shteffеn F. Tekhnika zvukousileniya [Sound amplification technique]. Moscow: PKF Lerusha LLC. 2003. 416 p.
9. Shchirzhetsky H.A. Express assessment of speech intelligibility zones in rooms. Collection of works of scientific and technical seminar in Sevastopol. 2012.
10. Makrinenko L.I. Akustika pomeshcheniy obshchestvennykh zdaniy [Acoustics of public buildings]. Moscow: Stroyizdat. 1986. 173 p.
11. Vakhitov Ya.Shch. Slukh i rech’ [Hearing and speech] Leningrad: LIKI, 1973. 110 p.
12. Furduev V.V. Elektroakustika [Electroacoustics]. Moscow-Leningrad: State publishing house of technical and theoretical literature. 1948. 516 p.

The article is devoted to the description of complex studies of changes in the thermal conductivity of boards made of polyisocyanurate foam (PIR) of modern production, lined on both sides with foil. A comparison of two methods for determining the steady–state thermal conductivity is carried out – it is shown that the NIISF method is preferable to the method set out in GOST R 56590–2016. According to the results of a series of experiments on the most modern test equipment in the Russian Federation, the law of the change in thermal conductivity over time of the tested PIR brand and the values of the steady-state thermal conductivity at an average temperature in the sample of 10оC and 25оC was found. When using the most accurate device for determining thermal conductivity, almost absolute convergence of the experimental results with the results of mathematical modeling using the NIISF method was obtained. The differences in the values of the steady-state thermal conductivity, which are obtained during tests on different devices, are explained. The conversion coefficient between the values of thermal conductivity PIR at an average temperature of 25оC and 10оC is found. The obtained new results and methodological developments are of great practical importance in connection with the widespread use of PIR boards in modern construction.

P.P. PASTUSHKOV^1,2, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
V.G. GAGARIN^1,2,3, Doctor of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
D.A. IL’IN^3,4, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
I.F. NAGAEV⁴, Head of Technical Support Division SM and PIR (CTO) (This email address is being protected from spambots. You need JavaScript enabled to view it.)

¹ Research Institute of Building Physics Russian Academy Architecture and Construction sciences (21, Lokomotivniy Driveway, Moscow, 127238, Russian Federation)
² Institute of Mechanics Lomonosov Moscow State University (1, Michurinsky Avenue, Moscow, 119192, Russian Federation)
³ Moscow State University of Civil Engineering (National Research University (26, Yaroslavskoye Highway, Moscow, 129337, Russian Federation)
⁴ LLC “TechnoNICOL-Construction Systems” (room 13/ I, floor 5, 47/5 Gilyarovskogo Street, Moscow, 129110, Russian Federation)

1. Grünbauer H.J.M., Bicerano J., Clavel P., Daussin R.D., de Vos H.A., Elwell M.J., Kawabata  H., Kramer H., Latham D.D., Martin C.A., Moore S.E., Obi B.C., Parenti V., Schrock A.K., van den Boschvan R. Rigid Polyurethane Foams. In book: Polymeric Foams. 2004.
2. Ashida K. Polyurethane and related foams: chemistry and technology (1st ed.). CRC Press. 2006.
3. Гагарин В.Г., Пастушков П.П. Изменение во времени теплопроводности газонаполненных полимерных теплоизоляционных материалов // Строительные материалы. 2017. № 6. С. 28–31.
3. Gagarin V.G., Pastushkov P.P. Change in time of thermal conductivity of gas-filled polymer thermal insulation materials. Stroitel’nye Materialy. [Construction Materials]. 2017. No. 6, pp. 28–31. (In Russian).
4. Wiedermann R.E., Adam N., Kaufung R. Flame-retarded, rigid pur foams with a low thermal conductivity. Journal of Thermal Insulation. 1988. Vol. 11 (4), pp. 242–253.
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