- 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: email@example.com
Moscow State University of Civil Engineering (National Research University), Yaroslavskoe shosse, 26, Moscow 129337, Russian Federation
Boris M. KRASNOVSKIY, e-mail: firstname.lastname@example.org
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.
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- 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.