BACK
- BASES AND FOUNDATIONS, UNDERGROUND STRUCTURES
- Features Of Winter Concreting Of Medium-Mass Monolithic Foundations Of High-Rise Buildings
- UDC 693.54.021.15"324" DOI: 10.33622/0869-7019.2020.10.78-86
Mark Yu. ABELEV, e-mail: int207@mail.ru
Moscow State University of Civil Engineering (National Research University), Yaroslavskoe shosse, 26, Moscow 129337, Russian Federation
Boris M. KRASNOVSKIY, e-mail: bmk-001@yandex.ru
Center for Assistance in the Development of Education and Research "Expert", pereulok Astrahanskiy, 1/15, Moscow 129090, Russian Federation
Abstract. For the cooling period as the final stage of heat treatment in winter conditions of monolithic concrete and reinforced concrete structures, the norms set fairly clear limits on the cooling rate and the maximum difference between the concrete surface temperature and the ambient temperature. As for the structures of medium massiveness that are typical for the foundations of high-rise buildings, the standards recommend setting these parameters separately. A method proposed makes it possible to calculate the permissible cooling rate and the permissible temperature drop for structures of any massiveness, depending on the tensile strength of concrete at the moment of cooling. The calculation is carried out in two stages (mode) of cooling. For the first stage, starting from the end of the isothermal heating of concrete, an extremely high cooling rate is set. depending on the tensile strength achieved by the concrete and determined by the heat transfer coefficient of the fence, and the moment (time and temperature) of possible removal of the thermal fence, which is the beginning of the second stage. The moment when the thermal barrier is removed is determined by environmental conditions - the predicted wind speed, which determines the intensity of surface heat transfer, and the outdoor air temperature. The total duration of the two stages gives the total duration of cooling of the structure from the heating temperature to the outdoor temperature.
Key words: winter concreting, massiveness of structures, concrete tensile strength, crack formation in cooling concrete, heat transfer coefficient of fence, surface heat transfer coefficient, cooling rate after heat treatment, maximum temperature difference between concrete and air, cooling time. - REFERENCES
1. Abelev M. Yu. Avarii fundamentov promyshlennyh i grazhdanskih sooruzhenij [Design, construction and operation of high-rise buildings]. Moscow, GASIS Publ., 2011. 76 p. (In Russian).
2. Haritonov V. A. Proektirovanie, stroitel'stvo i ekspluataciya vysotnyh zdanij [Design, construction and operation of high-rise buildings]. Moscow, ASV Publ., 2018. 346 p. (In Russian).
3. Rukovodstvo po proizvodstvu betonnyh rabot v zimnih usloviyah, rajonah Dal'nego Vostoka, Sibiri i Krajnego Severa [Guide to the production of concrete works in winter conditions, regions of the Far East, Siberia and the Far North]. Moscow, Strojizdat Publ., 1982. 313 p. (In Russian).
4. Timoshenko S. P., Gud'er Dzh. Teoriya uprugosti [Theory of elasticity]. Moscow, Nauka Publ., 1975. 576 p. (In Russian).
5. Lykov A. V. Teoriya teploprovodnosti [Theory of thermal conductivity]. Moscow, Gostekhizdat Publ., 1952. 600 p. (In Russian).
6. Kondrat'ev G. M. Regulyarnyj teplovoj rezhim [Regular heat regime]. Moscow, Gostekhizdat Publ., 1954. 408 p. (In Russian).
7. Krasnovskij B. M. Inzhenerno-fizicheskie osnovy metodov zimnego betonirovaniya [Engineering and physical bases of winter concreting methods]. Moscow, GASIS Publ., 2007. 509 p. (In Russian).
8. Olejnik P. P., Zhadanovskij B. V., Kuzhin M. F., et al. Vozvedenie monolitnyh konstrukcij zdanij i sooruzhenij [Construction of monolithic structures of buildings and stru]. Moscow, MISI-MGSU, 2018. 494 р. (In Russian).
9. Trapeznikov L. P. Temperaturnaya treshchinostojkost' massivnyh betonnyh sooruzhenij [Temperature crack resistance of massive concrete structures]. Moscow, Energoatomizdat Publ., 1986. 272 p. (In Russian).
10. Kusainov M. Miny zamedlennogo dejstviya v stroitel'nom proizvodstve [Delayed-action mines in construction production]. Astana, Saryarka Publ., 2009. 336 p. (In Russian). - For citation: Abelev M. Yu., Krasnovskiy B. M. Features of Winter Concreting of Medium-Mass Monolithic Foundations of High-Rise Buildings. Promyshlennoe i grazhdanskoe stroitel'stvo [Industrial and Civil Engineering], 2020, no. 10, pp. 78-86. (In Russian). DOI: 10.33622/0869-7019.2020.10.78-86.
BACK