寒冷环境下国内大坝混凝土的保温抗冰技术现状

大体积混凝土大坝施工时内外大温差会造成混凝土的开裂，寒冷环境下大坝运行时冰的冻融过程会对混凝土造成胀裂破坏，因此寒冷环境下混凝土大坝浇筑时必须采取临时保温措施，大坝运行时必须采取永久保温措施。大坝上游面与冰层接触部位水结冰过程中的推力、剪切力和拉拔力会破坏保温材料，所以大坝上游面必须采取抗冰措施。从保温材料种类、抗冰技术、应用案例和调研结果等方面回顾了寒冷环境下国内混凝土大坝的保温和抗冰技术的现状，目前主要采用泡沫塑料作为临时保温材料，采用聚苯板和聚氨酯泡沫作为大坝永久保温材料，采用在保温材料表面涂布涂料或砂浆的方式以及采用抗冰装置的方式抵抗冰的破坏。抗冰技术尚处于起步阶段，最后提出了目前大坝保温抗冰技术存在的问题和需要继续研究的内容。

Current situations of thermal insulation and ice resistance technology of dam concrete in China under cold environment

During the construction of dams with mass volume concrete, the higher temperature difference between the inside and outside of concrete will cause the cracking of concrete. During the operation of dams under cold environment, the freezing and thawing process of ice will cause the expansion and cracking of concrete. Therefore, temporary thermal insulation measures must be taken when pouring the concrete, and permanent thermal insulation measures must be taken when operating the dam. Since the thrust force, shear force and drawing force in the process of water icing will damage the thermal insulation materials at the upstream of the dam, ice resistance measures are indispensable. This paper reviews the current situations of thermal insulation and ice resistant technology of domestic concrete dams under the cold environment from the aspects of insulation materials, ice resistant technology, application cases and survey results. It is concluded that foam plastics are used as temporary thermal insulation materials, and polystyrene and polyurethane foam plastics are used as permanent insulation materials for the dam. Anti-ice devices and coatings or mortar coated on the surface of insulation materials are used to resist ice damage, but the ice resistant technology is still in infancy by now. At last, this paper puts forward the existing problems and the contents to be further studied in current thermal insulation and ice resistance technology of dams.