1988

Salparanta, Liisa

Epoxy coating has proven to be an effective corrosion prevention method of concrete reinforcements during the some 15 years the method has been applied for concrete construction in the USA. There are two types of epoxy-coating: liquid coatings and powder coatings. In this study the corrosion prevention ability of one powder epoxy coating: applied by electrostatic spraying; applicable for construction of new buildings, and three liquid epoxy paints applicable also for rebuilding, was studied. The liquid epoxy coatings included in this research were: - a commercial coal tar epoxy paint, - a commercial water dispersible epoxy paint and - a water tolerant glass flake filled epoxy which was formulated in the laboratory of the Associated Octel Co. Ltd. The powder epoxy coating and the coal tar epoxy paint turned out to have an outstanding corrosion prevention ability, but the other two liquid epoxy coatings even increased corrosion in some cases. The test results showed that the integrity of the coating is necessary for its corrosion prevention ability and the careful cleaning and roughening of the surface of the bars to be coated is a prerequisite for the good adhesion of the coating to the steel surface. Both these facts have been reported in literature.