关键词: 单组份聚脲;防护涂层;紫外辐射;高海拔地区;

Abstract: In high altitude areas, the ordinary polymer surface protective coating materials for hydraulic concrete are easy to discoloration, pulverization, cracking because of strong ultraviolet radiation and their service lives are obviously shorten.In this paper, a monocomponent polyurea material with better comprehensive performance was selected, and the indoor simulation test of ultraviolet radiation-condensation accelerated aging was designed.The tensile properties of polyurea material and the bonding properties of polyurea/mortar system were tested.The changes of microstructure and the coating structure were analyzed by scanning electron microscopy(SEM) and infrared spectroscopy.It was found that during the ultraviolet radiation-condensation aging process, the polymer in the polyurea material decomposed, resulting in the pulverization of the coating surface, and the chemical bonds of N-H,C-H and-OH on the surface changed.The bonding strength, tensile strength and elongation at break were exponentially correlated with the aging time.The research results provide a theoretical basis for improving the UV resistance of polyurea coatings and more accurately predict the service life of polyurea protective coatings for hydraulic concrete.

Key words: monocomponent polyurea; protective coating; ultraviolet radiation; high altitude area;