Performance of Migrating Corrosion Inhibitors in Cracked Reinforced Concrete Exposed to Marine Environment

The coastal areas contain high concentrations of chlorides and other corrosive agents which frequently extend far from the shoreline. Together with wetting-drying cycles caused by wind, rain, tides, etc., these concentrations lead to severe degradation and loss of durability of marine structures. The current study focuses on durability of the parapet beam made of reinforced concrete as a part of the wave breaking structures in the Haifa Bay Port, Israel, and includes durability-related observations and measurements conducted both in situ and in the laboratory. To determine the corrosion potential of reinforced concrete, the study followed the guidelines of the ASTM G-109 and ASTM C-876 standards. A part of the samples cast in the laboratory contained artificially made cracks of different depth (½ and one cover thickness), while another part of the samples was crack-free. The accelerated durability tests in the lab included exposure to the saltwater combined with wetting-drying cycles. It was concluded, that on the one hand, in the presence of small cracks which even did not reach the rebars, using migrating corrosion inhibitor did not show satisfactory results in terms of steel protection and even increased the corrosion risk. On the other hand, in both non-cracked parts of the parapet beam and laboratory samples, migrating corrosion inhibitor did provide effective corrosion protection. This result is significant for assessment of durability of cracked reinforced elements made of concrete containing migrating corrosion inhibitors, because cracking in concrete occurs frequently, and its existence is confirmed and considered by the building codes.