The amount of concrete production for highway construction and maintenance is very high. In cold climate regions, the most persistent problem is the concrete deterioration caused by freezing and thawing. Air-entraining cements and admixtures have been used to impart freeze-thaw resistance to concrete because air decreases some concrete properties such as strength and permeability resistance. The goal of air-entrainment is to provide a sufficient amount of air in the concrete to ensure freeze thaw resistance. In non-freeze-thaw exposures, some air is often used to improve workability. The course material explains air-entrainment requirements for freeze-thaw resistance of concrete. The course material is based on FHWA Publication Number FHWA-HRT-06-117: Freeze-Thaw Resistance of Concrete with Marginal Air Content.

At the conclusion of this course, the learner will have a better understanding of the Effect of Air-Content and Water-Cement ratio on Freeze-Thaw Resistance of Concrete as well as an understanding of the following topics:

• Concrete microstructure
• Freeze-thaw damage mechanisms
• Synthetic air-entraining admixture