To safeguard concrete from destruction throughout freezing, bubbles will need to have the right sizing, distribution and volume. ASTM C 260 specifies needs for air entraining admixtures. They can be either anodic, cathodic, or a combination. Some work to create a protective barrier that stabilizes the layer of rust surrounding https://www.tjcyindustrialchem.com/news/cement-additives-and-concrete-admixtures-key-differences.html