关键词: 大体积混凝土, 温度裂缝, 温度演化, 空间分布, 保温措施, 风电基础

Abstract:

Mass concrete structures are extensively used in large-scale infrastructure projects; however, temperature cracks after concrete pouring severely affect structural durability and pose safety risks. This study focuses on a 5 MW wind turbine foundation at the Changqing Oilfield, China, to investigate the temperature evolution and spatial distribution of mass concrete after pouring. Based on the dynamic balance between hydration heat release and heat dissipation, the temperature evolution of mass concrete can be divided into three phases: rapid heating, peak maintenance, and slow cooling. The internal temperature of the concrete exhibits a distinct spatial heterogeneity, with higher temperatures at the center and lower temperatures at the edges. The maximum central temperature reaches 74.3 ℃, whereas the edge regions are considerably affected by ambient temperature(5 ℃ to 23 ℃). Theoretical calculations show that the temperature difference between the interior and exterior of the mass concrete after 3 days of pouring is 30.15 ℃. However, when plastic films and burlap are used as insulators, the maximum temperature difference within 10 days after pouring is only 25.2 ℃, thus indicating an effective reduction in the risk of temperature cracks. These findings offer theoretical and practical guidance for temperature control of mass concrete in similar environments, and the proposed insulation measures after pouring are critical for enhancing the durability of large-scale infrastructure projects, such as wind power foundations.

Key words: mass concrete, temperature cracks, temperature evolution, spatial distribution, insulation measures, wind turbine foundation