: C172 currently includes fresh sampling techniques for only batch mixing equipment. A second type of mixer that is widely in use is a continuous mixer as described in C685. This mixer is usually associated with volumetric batching (proportioning) in what has come to be called mobile mixers or volumetric mixers. C172 provides no guidance on sampling procedures for concrete produced by a continuous mixer. The proposed changes and additions to ASTM C172 provide for the required sampling to take place by methods and within a time frame consistent with the equipment used to make this concrete.
Keywordsair content; batch; composite sample; concrete; slump; temperature; wet-sieving; Sampling concrete/mortar/aggregates; Ready-mixed concrete; Wet sieving;
Ballot Item Approved as C172/C172M-2014 and Pending Publication