Corrosion Assessment of Coupled Steel Reinforcement with Ni-Ti-Based Shape Memory Alloy in Simulated-Concrete Pore Solution

摘要

Though the mechanical properties of shape-memory alloys (SMAs) make them a promising material for reinforcement in concrete structures, their electrochemical behavior in concrete environments has not previously been studied. This study investigated the influence of galvanic coupling between a nickel-titanium (Ni-Ti)-based SMA and a low-carbon steel on their corrosion performance in simulated concrete pore solution. Three measurement cells were considered: SMA alone, low-carbon steel alone, and one with the coupled SMA and carbon steel. The specimens were immersed in the chloride-free pore solution for 20 days and then 3% by weight of NaCl was added to the solution. The specimens were then kept in the chloride-contaminated solution for 70 days. The corrosion resistances of the specimens were assessed by different electrochemical measurement techniques. The results of the electrochemical experiments showed a significant increase in corrosion activity of the coupled specimens compared with that for other measurement cells.