Air-Entraining Admixture

An air-entraining admixture creates billions of microscopic, evenly distributed air bubbles throughout a concrete mix. Those bubbles give freezing water inside the concrete somewhere to expand into, which is what makes air-entrained concrete far more resistant to freeze-thaw scaling and deterioration than non-air-entrained mixes.

Air content is verified in the field with a pressure-meter air test, typically targeting 5–8% for exterior flatwork in freeze-thaw climates like Colorado's Front Range.