Time dependence and service life prediction of chloride resistance of concrete coatings

Abstract This study aims to determine the effects of coating category and degradation on chloride resistance and service life of concrete coatings. Four typical coatings were applied on concrete specimens, and aged under outdoor natural climate conditions and indoor artificial accelerated experiments using ultraviolet light radiation and wetting/drying cycle. Coulomb electric fluxes of the specimens were periodically tested to determine their chloride resistance before and during aging. The chloride resistance of concrete is remarkably improved with the use of coatings, and organic film coatings provide superior improvement to infiltrating coatings. The chloride resistance of coatings is time-dependent, and organic film coatings exhibit faster aging than infiltrating coatings. The experimental time needed for coating degradation can be shortened through artificial accelerated aging experiments. The service lives of concrete coatings against chloride resistance are closely related and can be predicted through sunlight irradiance of the service environment.