Comparison and Selection of Thermal Insulation Materials for RCC Dam Construction in Dry and Cold Valleys at High Altitudes in Tibet

Abstract

Abstract Effective temperature preservation and moisture retention measures are key techniques in ensuring concrete quality and preventing cracks formation in RCC dams and the concrete surface in the middle reaches of the Yarlung Tsangpo River in dry and cold river valleys. Insulation and moisture retention effect, construction technology, and cost of pasting polystyrene board, spraying foam polyurethane, and rubber plastic sponge insulation membrane on the dam concrete surface were compared and analyzed to determine the thermal insulation material with the best temperature preservation, best moisture retention effect, and high applicability. Finally, the rubber plastic sponge, which matched the trim strip process, was determined as the best insulation material. It features temperature preservation, moisture preservation, no secondary cleaning after removal, good appearance, and high secondary utilization rate. The results of dam overwintering monitoring and uncovering inspection in 2019 showed that the internal and external temperature differences and surface humidity indexes of concrete were within the design index value, and cracks were absent. The purpose of temperature control and crack prevention of dam concrete was achieved, and the material has high application value.