Controlling the air content through air entertainment is essential in many types of concrete. With an air-entraining meter, small, uniform air bubbles are deliberately created within a concrete mixture. These bubbles are between 0.1mm and 1mm in diameter and protect concrete exposed to freezing and thawing from damages caused by freezing water. By serving as air voids in the hardened concrete, the bubbles relieve pressure without causing damage and thus extend a mix’s lifetime.
Air meters and indicators are used to determine the air content of fresh concrete at the point of placement. Because mixing, transporting, pumping and handling a mix can take out valuable air bubbles, the final air content of concrete must be tested at the right time and place. Therefore, mix evaluations throughout the settling process is essential. A complete air content reading guarantees that the concrete will be durable under freeze/thaw conditions when insitu.