AASHTO T 121M/T 121-23 PDF

This method covers determination of the density (see Note) of freshly mixed concrete and gives formulas for calculating the yield, cement content, and the air content of the concrete. Yield is defined as the volume of concrete produced from a mixture of known quantities of the component materials.

Nonplastic concrete, such as is commonly used in the manufacture of pipe and unit masonry, is not covered by this test method.

The values stated in either SI or inch-pound units shall be regarded separately as standard. The inch-pound units are shown in brackets. The values stated might not be exact equivalents; therefore, each system must be used independently of the other.

Note—"Unit weight" was the previous terminology used to describe the property determined by this test method, which is mass per unit volume.