Unsteady model of the hydration process of a reinforced concrete product at software-controlled heating

The development of mathematical models for design of the thermal technology equipment intended for accelerated hydration of concrete products is an urgent task of industrial heat power engineering. The introduction of mathematical modeling methods can reduce the time and the resources spent for the development of technological regimes that reduce energy consumption in the production of building structures and, ultimately, in the construction of buildings and structures for various purposes. There is not yet a generally accepted mathematical model of thermal processes occurring in thermal technological installations in the case of accelerated hardening of a three-dimensional concrete object. The purpose of this work is to develop an unsteady model of the concrete hydration process applied to a symmetrical three-dimensional reinforced concrete product at software-controlled heating. By using the numerical finite-volume method in the case of a 0.3 × 0.3 ×0.3 mcube, a three-dimensional feld of hydration in a concrete object at a given operation mode of a heater is calculated. The following heating mode was used: “heating–maintaining at a constant temperature–cooling”. The dependences of a temperature difference between reinforced and non-reinforced cubic products on the hardening time at the corresponding space points in the direction from the surface to the center of the product have been obtained. By the example of the numerical simulation results, it is shown that the evolution of the hydration degree at these points during the hardening of non-reinforced concrete differs from the hardening of reinforced concrete. The time dependences of heat treatment of a rate of temperature change and the hydration coefficient at the selected points of a product are presented. The obtained results are analyzed.

1. Mironov S. A., Malinina L. A. Acceleration of hardening of concrete. Moscow, 1964. 348 p. (in Russian).

2. BabickiiV. V., Semenyuk S. D., Bibik M. S. Forecasting of characteristics of the hardening heavy concrete. Resursoekonomnі materіali, konstruktsії, budіvlі ta sporudi [Resource Saving of Materials, Structures, Buildings and Structures]. Rovno, 2009, pp. 3–12 (in Russian).

3. Usherov-Marshak A. V., Sinyakin A. G. Information technology of concrete accelerated curing. Beton i Zhelezobeton [Concrete and Reinforced Concrete], 1994, no. 6, pp. 2–4 (in Russian).

4. Aksenchik k. V. Improvement of the thermal operation of curing chambers for curing of concrete products. Ivanovo, 2014. 20 p. (in Russian).

5. Fedosov S. V., Ibragimov A. M., Guschin A. V. Application of methods of mathematical physics for the simulation of mass- and energy transfer in technological processes of the construction industry. Stroitel’nye materialy = Construction Materials, 2008, no. 4, pp. 65–67 (in Russian).

6. Ge Zhi. Predicting temperature and strength development of the feld concrete: Retrospective Theses and Dissertations, 2005. https://doi.org/10.31274/rtd-180813-15373

7. Zakoutsky J., Tydlitat V., Cherny R. Effect of temperature on the early-stage hydration characteristics of Portland cement: A large-volume calorimetric study. Construction and Building Materials, 2012, no. 36, pp. 969–976. https://doi.org/10.1016/j.conbuildmat.2012.06.025

8. Fedosov S. V., Bobylev V. I., Ibragimov A. M., kozlov V. k., Sokolov A. M. Modeling of a set of strength at hydration of cement. Stroitel’nye materialy = Construction Materials, 2011, no. 11, pp. 38–41 (in Russian).

9. kuriakose B., Rao B. N., Dodagoudar G. R. Modelling of heat of hydration for thick concrete constructions – a note. Journal of Structural Engineering, 2015, vol. 42, no. 4, pp. 348–357.

10. Goncharov E. I., Niyakovski A. M., Shavlyugo O. D. Two-stage heat and moisture treatment of heavy concrete. Tezisy dokladov 47 Mezhdunarodnoi nauchno-tekhnicheskoi konferentsii prepodavatelei i studentov [Abstracts of 47 International Scientifc and Technical Conference of Teachers and Students]. Vitebsk, 2014, pp. 172–173 (in Russian).

11. Goncharov E. I., Niyakovski А. М. The temperature felds in hardening concrete. Tezisy dokladov 48 Mezhdunarodnoi nauchno-tekhnicheskoi konferentsii prepodavatelei i studentov, posvyashchennoi 50-letiyu universiteta [Abstracts of 48 International Scientifc and Technical Conference of Teachers and Students, dedicated to the 50th Anniversary of the University]. Vitebsk, 2015, pp. 103–104 (in Russian).

12. Niyakovski А. М. Optimal conditions of heat treatment as a factor in the formation of a rational heat power system of enterprises of reinforced concrete products. Nauka – obrazovaniyu, proizvodstvu, ekonomike: materialy 16-i Mezhdunarodnoi nauchno-tekhnicheskoi konferentsii. T. 1 [Science – Education, Production, Economics: Proceedings of the 16th International Scientifc and Technical Conference. Vol. 1]. Minsk, 2018, pp. 93 (in Russian).

13. Maryamov N. B. Heat treatment of products at the plant of precast concrete (processes and installations). Мoscow, 1970. 272 p. (in Russian).

14. krasulina L. V. Structural and thermophysical properties of hardening concrete. Nauka i tekhnika = Science and Technique, 2012, no. 2, pp. 29–34 (in Russian).

15. Aleksandrovskii S. V. Calculation of concrete and reinforced concrete structures for changes in temperature and humidity, taking into account the creep of concrete. Мoscow, 2004, p. 712 (in Russian).