To guard concrete from destruction in the course of freezing, bubbles will need to have the right measurement, distribution and volume. ASTM C 260 specifies specifications for air entraining admixtures. They can be both anodic, cathodic, or a mix. Some perform to make a protecting barrier that stabilizes the layer https://www.tjcyindustrialchem.com/news/cement-additives-and-concrete-admixtures-key-differences.html