水电能源科学

冻融损伤是寒区混凝土破坏的主要形式之一，合理计算不同深度冻融循环次数和损伤是评价混凝土构件耐久性和安全性的依据。为了得到混凝土构件不同深度处的年冻融循环次数及损伤分布规律，基于传热学基本原理构建了混凝土板温度场解析解模型，通过实例分析混凝土板内部不同深度处的温度变化规律。结果表明，导温系数为0.003 m²/h时，混凝土板表面的年冻融循环次数为144次，而深度为0.5 m处的年冻融循环次数仅6次，不同深度处的降温速率及年冻融循环次数随着混凝土板深度的增大而减小；混凝土板的冻融损伤主要发生在表层，深度为0.2 m以下的区域几乎无冻融损伤。

Freeze-thaw damage is one of the main forms of concrete damage in cold areas. Reasonable calculation of freeze-thaw cycles and damage at different depths is the basis for evaluating the durability and safety of concrete components. In order to obtain the annual freeze-thaw cycles and damage distribution law of concrete members at different depths, an analytical solution model of the temperature field of concrete slabs was established based on the basic principle of heat transfer. The temperature variation law at different depths of concrete slabs was studied by case analysis. The results show that when the temperature conductivity is 0.003 m²/h, the annual freeze-thaw cycles on the surface of the concrete slab are 144 times, while the annual freeze-thaw cycles at the depth of 0.5 m are only 6 times. The cooling rate and the annual freeze-thaw cycles at different depths decrease with the increase of the depth of the concrete slab. The freeze-thaw damage of concrete slab mainly occurs in the surface layer, and there is almost no freeze-thaw damage in the area below 0.2 m depth.