Effect of superficial insulation on roller-compacted concrete dams in cold regions

► Surface temperatures with and without heat insulation during the overwintering period are calculated. ► Calculation principle for superficial insulation was deduced. ► We simulate and analyze the temperature field and thermal stress of certain RCC gravity dams in cold regions. ► The effects of superficial insulation and different thicknesses on the temperature field and thermal stress are analyzed. ► An 8 cm polystyrene slab is used for warmth, the maximum principal stress is less than the allowable stress. Superficial insulation is often used to prevent cracking of concrete dams located in cold regions. In this study, surface temperatures with and without heat insulation during the overwintering period are calculated. Using the material properties of roller-compacted concrete (RCC) as bases, we simulate and analyse the temperature field and thermal stress of certain RCC gravity dams in cold regions. The simulation and analysis are performed by three-dimensional finite element relocating mesh method under the following conditions: under the absence of heat insulation, and with the application of a 5 or 8 cm polystyrene slab for heat conservation. Moreover, the effects of superficial insulation and different thicknesses on the temperature field and thermal stress are analysed. Results show that superficial insulation can considerably increase the superficial temperature of RCC dams in cold regions, thereby decreasing superficial temperature difference and maximal tensile stress. These conditions prevent surface cracks from forming.