What are the dimensions of a slump cone as per standard C143?

The slump cone, as specified in ASTM C143, has precise dimensions that are critical for ensuring uniformity in testing concrete workability. The standard dimensions for the slump cone are a base diameter of 8 inches, a top diameter of 4 inches, and a height of 12 inches. These specifications are designed to provide a consistent shape and volume for the concrete when conducting the slump test, which measures the consistency and workability of the concrete mix.

When the cone is filled with concrete, it is important that these dimensions remain consistent to guarantee reliable test results. A cone with the correct measurements allows for an accurate assessment of how well the concrete will flow and fill forms.

The other choices provide incorrect dimensions, which would not conform to the standards set by ASTM C143 and could result in unreliable slump test outcomes. Proper adherence to these dimensions is crucial for maintaining the integrity of concrete testing procedures.