高海拔寒冷地区碾压混凝土筑坝保温材料比选及应用

Selection and Application of the Thermal Insulation Materials for Roller Compacted Concrete Dam in High Altitude and Cold Area

为防止高海拔寒冷地区碾压混凝土裂缝产生,确定保温保湿效果最佳、适用性高的材料,通过在大坝混凝土表面对粘贴聚苯乙烯板、喷涂发泡聚氨酯及橡塑海绵保温卷材等方式的保温保湿效果、施工工艺及成本等的试验对比分析,橡塑海绵搭配压条式最佳,且拆除后无需二次清理、外观好、二次利用率高;经2019~2020年大坝越冬监测及外观检查表明,混凝土内外温差及表面湿度始终保持在设计指标值内,无裂缝发生,达到了大坝混凝土温控防裂的目的。

To prevent the thermal cracks in roller compacted concrete dam in high altitude and cold area,thermal insulation materials with the best insulation and moisturizing performance and high applicability should be selected.The performance,construction technique and cost of several materials,including the pasted polystyrene board,sprayed foamed polyurethane and NBR/PVC coils,are tested and compared.It shows that the NBR/PVC material combined with batten strips is the best.It is of a good appearance,high secondary utilization rate and no need for secondary cleaning after its removal.The over-winter monitoring and appearance inspection of the dam from 2019 to 2020 show that the internal and external temperature difference and the surficial humidity of the concrete are kept within the design values and no crack is found.The temperature control and crack prevention goal is successfully achieved.