7.4.3.1 Internal Vibration—In compacting the specimen
insert the vibrator slowly and do not allow the vibrator to rest
on or touch the bottom or sides of the mold or strike embedded
items such as strain meters. Slowly withdraw the vibrator so
that no large air pockets are left in the specimen.
7.4.3.2 Cylinders—The number of insertions of the vibrator
is given in Table 3. When more than one insertion per layer is
required, distribute the insertions uniformly within each layer.
Allow the vibrator to penetrate into the layer below approximately
1 in. [25 mm]. After each layer is vibrated, tap the
outside of the mold at least 10 times with the mallet to close the
holes that remain and to release entrapped air voids. Use an
open hand to tap cardboard or single-use metal molds that are
susceptible to damage if tapped with a mallet