We will determine the feasibility of improved methods for determine air content in fresh concrete. We expect that a study of volume change with varying pressure and vacuum will lead to a method that will indicate both air content and void size, and yield air contents that are unaffected by the nontheoretical compressibility of small voids. We will determine the feasibility of simpler methods of determining air content; through measurement of samples ultrasonic properties, through a color indicator, and through detraining air in the roll-a-meter by vibration and vacuum. Res: this will lead to air determination methods for fresh concrete that will either be simpler and faster or yield more information about the void system than do current standard methods.
