Abstract: Due to complex conditions such as large temperature difference, extremely low temperature, strong radiation, strong wind and drying, hydraulic concrete structures in high and cold region are prone to suffer from deterioration diseases represented by freeze-thaw damage. Protection and repair technology is a commonly used preventive measure against deterioration. The degradation process and the law of influence on hydraulic building materials under freezing-thawing cycle are simulated by finite element method. Results suggest that the frost heave stress caused by freezing of pore water is the main factor leading to the decrease of its durability under cyclic varying temperature-caused load. In addition to improving the antifreeze capacity of concrete, surface anti-seepage treatment such as surface coating protection should also be taken to control the interior water content and frost heaving stress in concrete and to improve freeze-thaw resistance. Moreover, the selection principles, types and characteristics as well as construction techniques of protective repair material for hydraulic structure in high and cold region are summarized, and some typical engineering applications of protective repair technology in high and cold region are introduced for reference. The development trends of material performance, equipment, technique extension, and standard formulation are also discussed.

Key words: hydraulic concrete, freeze-thaw damage, protective repair, engineering application, high and cold region