Corrosion Features of the Reinforcing Bar in Concrete with Intelligent OH^- Regulation of Microcapsules

Corrosion is a challenging problem for marine concrete infrastructure projects. In this study, an intelligent OH^--regulated microcapsule is designed to prevent reinforcement corrosion, taking ethylcellulose (EC) as shell material and calcium oxide (CaO) as core material. X-ray computed tomography (XCT) is used to trace and contrast the corrosion profiles of the concrete reinforcement bar with and without the microcapsule. The results show that the OH^--regulated microcapsule exhibits effective corrosion protection by delaying corrosion initiation and cracking. An SEM study revealed that the microcapsule could be broken as Cl^- invades the concrete. However, intelligent OH^- regulation was realized by releasing CaO.