Urban construction and architectureUrban construction and architecture2542-01512782-2109Eco-vector12755810.17673/Vestnik.2022.04.10Research ArticleApproximate analytical method for calculating the heating process of concrete structures in heating formworkVytchikovYuri S.<p>PhD in Engineering Science, Professor of the Heat and Gas Supply and Ventilation Chair, Academy of Civil Engineering and Architecture</p>git.2008@mail.ruNedosekoIgor' V.<p>Doctor of Technical Sciences, Professor of the Building Structures Chair, Architectural and Construction Institute</p>nedoseko1964@mail.ruSaparevMikhail E.<p>PhD in Engineering Science, Associate Professor of the Heat and Gas Supply and Ventilation Chair, Academy of Civil Engineering and Architecture</p>msx072007@yandex.ruChulkovAleksandr A.<p>Engineer of the Center Energy Saving in Construction, Academy of Civil Engineering and Architecture</p>ch_aleks01@mail.ruSamara State Technical UniversityUfa State Petroleum Technical University2001202312475841901202319012023Copyright © 2023, Vytchikov Y.S., Nedoseko I.V., Saparev M.E., Chulkov A.A.2023<p>The use of electric heating of concrete during construction in winter makes it possible to create an optimal thermal regime in which the hardening process takes place, and to obtain a structure of the required quality. When developing a system for automatic control of the heating process, it is necessary to determine the law of regulating the power of heaters. This article presents a method for calculating the thermal heating regime of concrete structures in heating formwork, the essence of which is to reduce the boundary value problem of thermal conductivity to a system of equivalent integral equations. To solve this problem, a theoretical study was carried out, a theoretical study of the heat transfer process in concrete structures heated during winter concreting was carried out, and a mathematical description of this process was presented in the form of a system of differential equations. After the transformations of the above system of equations and the application of the Green function of the second kind to it for the plate and rod, an approximate solution of the equivalent equation was obtained. As a result of the application of the asymptotic method to the solution of the integral equation, an analytical solution of the problem under consideration is obtained. The resulting solution makes it possible to determine the temperature fields on the concrete surface, as well as the value of the specific heat flux from electric heaters. In order to automate the process of performing the thermal calculation of heating concrete structures with the help of heating forms, a program for calculating temperature fields in heating forms has been developed based on the solution obtained, which makes it possible to effectively solve the tasks of monitoring and controlling the concrete hardening process. The developed program makes it possible to calculate temperature fields not only at constant heater power, but also when it changes with the help of regulators. The presented method of thermal calculation with a hardware and software complex for regulating the power of electric heaters allows solving a fairly wide range of tasks related to maintaining a constant temperature field.</p>thermal regimecontrol of the hardening processconcreteheating formworktemperature fieldtemperature controlтепловой режимуправление процессом твердениябетонгреющая опалубкатемпературное полетемпературный контроль[Akhanov V.S. Elektrotermiya v tekhnologii betona [Electrothermia in concrete technology]. Makhachkala, Dagestanskoe knizhnoe izdatel'stvo, 1971. 252 p.][Sokova S.D. Zimnee betonirovanie monolitnykh konstruktsiy [Winter concreting of monolithic structures]. Moscow, 2013. 56 p.][Zinevich L. V., Galumyan A. V. High-speed monolithic housing construction: conditions for achieving high rates of construction and quality of concrete of the resulting structures. Beton i zhelezobeton [Concrete and Reinforced Concrete], 2009, no. 5, pp. 23-26. (in Russian)][Mavlyuberdinov A. R., Sungatullina G. A. Studying the processes of concrete mixture hardening in thermoactive formwork. Vestnik tekhnologicheskogo universiteta [Bulletin of the Technological University], 2015, vol.18, no. 7, pp. 181-183. (in Russian)][Mironov S.A. Teoriya i metody zimnego betonirovaniya [Theory and methods of winter concreting]. 3rd ed. Moscow, Stroyizdat, 1975. 700 p.][Osipov A.M. Concreting at low temperatures. Inzhenernyy vestnik Dona [Engineering Bulletin of the Don], 2012, no. 4 (Part 2). (in Russian)][Vinogradova E.V. Problems of quality management of concrete works // Inzhenernyy vestnik Dona [Engineering Bulletin of the Don], 2012, no 3. (in Russian)][Usov B.A. Concreting of monolithic structures from cast mixtures in winter conditions. Sistemnye tekhnologii [System technologies], 2016, no. 4, pp. 5-17. (in Russian)][Costantino Mennaa, Jaime Mata-Falcón, Freek P. Bos, Gieljan Vantyghem, Liberato Ferrara, Domenico Asprone, Theo Salet, Walter Kaufmann, Opportunities and challenges for structural engineering of digitally fabricated concrete. Cement and Concrete Research, 2020, vol. 133.][Krylov V. A. Temperature Influence on Concreting Structures and Its Hardenings. International Simposium in Japan E&FN Spook, 1995, vol. 2, pp. 917-925.][Krylov B. A. et al. Rukovodstvo po progrevu betona v monolitnykh konstruktsiyakh [Manual for heating concrete in monolithic structures]. Moscow, 2005. 275 p.][Doladov M. Yu., Doladov Yu. I. Program for calculating concrete heating during winter concreting. Stroitel'nyy vestnik Rossiyskoy inzhenernoy akademii [Construction Bulletin of the Russian Engineering Academy], 2006, vol. 7, pp. 52-56. (in Russian)][Anja Estensen Klausen, Terje Kanstad and Øyvind Bjøntegaard. Hardening Concrete Exposed to Realistic Curing Temperature Regimes and Restraint Conditions: Advanced Testing and Design Methodology. Advances in Materials Science and Engineering, 2019.][Vishwanath P. Singh1, Huseyin O. Tekin, Nagappa M. Badiger1, Tubga Manici, Elif E. Altunsoy, Effect of Heat Treatment on Radiation Shielding Properties of Concretes. Journal of Radiation Protection and Research, 2018, vol. 43, no. 1, pp. 20-28.][Telichenko V.I. Tekhnologiya stroitel'nykh protsessov [Technology of construction processes]. Moscow, 2005. 392 p.][Imaykin D. G., Ibragimov R. A., Martynov M. M., Sungatullina A. R. Technology of winter concreting of building structures using thermoactive formwork. Vestnik KGTU [Bulletin of KSTU], 2014, no. 24, pp.96-99. (in Russian)][Gnyrya A.I., Korobkov S.V. Tekhnologiya betonnykh rabot v zimnikh usloviyakh [Technology of concrete works in winter conditions]. Tomsk: Publishing House of the Tomsk State University of Architecture and Civil Engineering, 2011. 412 p.][Chi-Hyung Ahn, Jinbok Lee, Dong-Jin Kim, Hyun-Oh Shin, Development of a Novel Concrete Curing Method Using Induction Heating System. Science, 2021, no. 11(1).][Galitskov S.Y., Galitskov K.S., Bolkhovetsky A.S. Modeling the process of autoclaving treatment of cellular concrete products as control object. IOP Conference Series: Materials Science and Engineering. International Scientific Conference Interstroymeh. ISM 2019, 2019. (in Russian)][Perfilov V.A., Gabova V.V., Tomareva I.A. Impact of superplasticizing agents on physical and mechanical properties of cellular concrete. Materials Science Forum, 2020, vol. 974, pp. 181-186.][Kuchin V.N., Shilonosova N.V. Features of peripheral heating of monolithic reinforced concrete structures. IOP Conference Series: Materials Science and Engineering, 2018.]