Abstract: In high-altitude, cold regions, hydraulic structures endure prolonged exposure to intense ultraviolet radiation, extreme temperatures, and freeze-thaw cycles. Consequently, they are more susceptible to cracking, leakage, and deterioration from freeze-thaw cycles, corrosion, carbonation, steel erosion, and other factors compared to lower-altitude regions, significantly compromising project safety. To address this challenge, we investigated the weathering resistance of epoxy mortar through indoor UV wet heat aging, freeze-thaw cycles, and natural aging in Xizang autonomous region. Results revealed that the modified epoxy mortar exhibited resilience, with no cracking observed after 2000 hours of accelerated UV and wet heat aging, retaining a tensile strength of 74%. Moreover, it attained a frost resistance grade of F250. After 960 days of natural aging, minimal color change and no surface powdering were observed. This material was utilized for surface protection and repair in the spillway tunnel stilling pool of the Laluo Water Conservancy Project in Xizang autonomous region. Over four years of service, the modified epoxy mortar demonstrated exceptional resistance to freezing, ultraviolet exposure, and weathering, showcasing promising application prospects for similar projects in high-altitude and cold regions.

Key words: epoxy mortar, weather resistance, hydraulic structure, alpine regions, engineering application