SECTIONS 15 AND 16 REFERENCE or detail the specifics of determining the air content of freshly mixed concrete. Three ASTM methods are available for the measurement of air in the concrete: 1. ASTM Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method (C 231) 2. ASTM Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method (C 173/C 173M) 3. ASTM Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete (C 138/C 138M)