Investigation on Chloride-Induced Corrosion Reduction Strategies for Offshore Reinforced Concrete Structures

The corrosion of reinforcement by chloride ions is a significant issue for reinforced concrete (RC) structures, which causes instability and loss of strength of the structure. In this study, the efficacy of various strategies for limiting the effects of chloride-induced corrosion on offshore RC structures was investigated experimentally through a series of experimental tests, including uniaxial compression test, half-cell potential test, and chloride ion penetration test. The tests have been conducted on concrete cube specimens with water/cement (w/c) ratios of 0.38, 0.45, and 0.50, which, for each w/c, the effect of normal cement (control specimens), engineered cementitious composite, self-compacting concrete (SCC), migration corrosion inhibitor (MCI), and microsilica (MS) were separately considered. The compressive strength of the specimens was obtained by uniaxial compression test at 7 and 28 days. Furthermore, to simulate wetting-drying cycles in marine environment, their corresponding 28 days cured specimens were exposed to the marine tidal zone at Technology and Durability Research Centre of Amir Kabir University, located at Bandar-e-Imam Khomeini, Iran, for 16 months and then were tested by half-cell potential and chloride ion penetration tests. The results revealed that, among all the specimens, the specimens with MCI and SCC achieved the highest and lowest compressive strength. In addition, the quantity of chloride ions that penetrate to the specimens indicates a low-risk corrosion for the specimens with MS and MCI and high-risk corrosion for the specimens with SCC. Moreover, it was concluded that using MCI was the most successful strategy for preventing reinforcement corrosion in maritime concrete structures.