How does an increase in mix temperature affect air entrainment?

An increase in mix temperature generally leads to increased air entrainment in concrete due to the influence of the temperature on the properties of the materials involved. As the temperature of the concrete mix rises, the viscosity of the mixing water decreases, allowing for better distribution and stabilization of air bubbles introduced by air-entraining agents. This enhanced flow enables a more effective incorporation of air into the mix, resulting in a greater volume of air being entrained.

Higher temperatures can also lead to a prolongation of the setting time, which allows for more effective mixing and dispersion of air bubbles throughout the concrete, contributing to the overall stability of the entrained air. Thus, the relationship between higher temperatures in the concrete mix and the increased air entrapment reflects the interactions of temperature with the physical properties of the materials used.