ASTM C-231 (Air Content of Freshly Mixed Concrete)

ASTM C-231 is a standard method used to measure the amount of air trapped in freshly mixed concrete. This air content is important because it affects the concrete’s strength and durability. The test involves filling a sealed container with a sample of wet concrete, then applying vacuum pressure to remove excess air. The amount of air removed, calculated from pressure differences, indicates how much air is present in the concrete. Proper air content helps ensure the concrete can resist freeze-thaw cycles and achieves desired performance standards.