Preperties of Linear Polyaspartic Polyurea Coated Concrete under NaCl Solution Immersion and Co-Action of Load and NaCl Solution Immersion

Abstract

In this paper both the NaCl immersion and the co-action of load and NaCl solution immersion were employed to analyze the wet adhesive property and resistance of chlorion diffusivity of two types of linear polyaspartic ester (PAE) polyureas coated concrete: B2（PAE-b-H12MDI prepolymerH66）coated concrete and F2（PAE-f-H12MDI prepolymerH62） coated concrete. The research on the adhesion of B2 and F2 coated concrete showed that the adhesion were about 2N/mm and 1.5N/mm respectively before exposure, and the adhesion reduced about 6.8% and 11.8% respectively after 10% NaCl immersion for 300 days and made 8% and 5% further decrease under the co-action of load and NaCl solution immersion, double-factor exposure for 300 days. Compared with single NaCl solution immersion, the co-action of load and NaCl solution immersion also had more influence on the chlorion diffusivity of the coated concrete. The average chlorion content of B2 and F2 coated concrete increased about 19-21%, and the diffusion coefficient of chlorion of B2 and F2 coated concrete was 10－13-10－14m2/s, due to the micro-crack of concrete in tensile area increased under bending load, accelerating chlorion diffusion and permeation. The research showed that chlorion diffusion behaviour of B2 and F2 coated concrete under the NaCl immersion and the co-action of load and NaCl solution immersion satisfied second Fick’s law.