Properties of Aliphatic Polyurea Coated Concrete under Salt Fog Exposure

摘要

Coating protection becomes the primary and available method for the protection of marine concrete. Aliphatic polyurea is a new genre of polyurea. In the present study, the frost resistance property and adhesion property of 2 different aliphatic polyurea coated concretes under salt fog exposure were studied for the first time. The surface morphology and molecular structure of the coating under the salt fog exposure were investigated through SEM and FTIR. The investigations on the influence of the salt fog exposure to the PAE-t-HDI prepolymer-D2000H65 aliphatic polyurea (T3) coated concrete and T3 finishing coat/ MDI emulsion primer aliphatic polyurea (TM) coated concrete reported that after 300 days salt fog exposure, the relative dynamic elastic modulus of T3 and TM coated concrete were more than 85%, and their wet adhesion were 1.0 N/mm and 2.5N/mm respectively. SEM and FTIR researches showed that no obvious changes were observed in the surface morphology and structure of the coating after 200 days salt fog exposure. The results indicate that aliphatic polyurea coated concretes have favorable salt fog resistance, and are suitable for applying in marine concrete structures.