Evaluation of Corrosion Resistance Performance of Anti-Corrosion Reinforcements with Surface Damage

Abstract

This study aimed to examine corrosion-resistance performance of epoxy-coated reinforcements and galvanized reinforcements, among the most widely used anti-corrosion reinforcements. Five types of specimens were used, as follows: (a) Black bar, (b) Black bar coated with epoxy, (c) Black bar galvanized, (d) Black bar coated with epoxy with surface damage, and (e) Black bar galvanized with surface damage. Epoxy-coated bar specimen showed excellent corrosion resistance performance. In the presence of a surface damage, however, corrosion was intensively concentrated near the damage. In the galvanized bar specimen, a trace of light corrosion was observed throughout the surface. This meant that its corrosion resistance performance was rather inferior compared to the epoxy-coated bar specimen. However, the performance remained almost the same with or without a surface damage due to the sacrificial anode effect of zinc. The relative corrosion current density of the galvanized bar specimen was about 1/7 that of the epoxy-coated bar specimen on average. Galvanized reinforcements were capable of continuously providing excellent anti-corrosion performance even in the presence of surface damage formed at the construction field. The suspension concentration density of corrosion products in the cell solution showed a high correlation with other corrosion data.