Preventing rusting of rebar inside concrete columns

Applying anti-corrosion paint will do. Polyaniline will do. :)

(1) Preparation of high-performance concrete: To comprehensively improve the crack resistance and chloride ion penetration resistance of concrete in marine engineering structures. The main measures include a lower water-cement ratio, high-efficiency water reducers, and an appropriate amount of mineral admixtures. (2) Concrete coating protection: By using film-forming or penetrating coatings, the ability of concrete to resist the penetration of chloride ions is enhanced over a certain period of time. (3) Use of highly corrosion-resistant steel bars. Its corrosion resistance is primarily improved through epoxy-coated rebar. (4) Use of rust inhibitors. By using rust inhibitors, the critical value for steel bar corrosion in concrete can be increased, thereby delaying the formation of rust spots on the steel bars. (5) Concrete cathodic protection: It primarily relies on sacrificial anodes or external current supply to provide protection, either by actively protecting the rebar or by repairing damaged concrete and then providing protection. This is a proactive form of protection against harmful ions from the outside environment, and it represents an effective method for providing protection that lasts as long as the components used in marine engineering.

If no measures are taken before pouring, there’s nothing but waiting for death! Try cathodic protection at most!