7.4.2 Rodding—Place the concrete in the mold, in the
required number of layers of approximately equal volume. Rod
each layer with the rounded end of the rod using the number of
strokes and size of rod specified in Table 2. Rod the bottom
layer throughout its depth. Distribute the strokes uniformly
over the cross section of the mold and for each upper layer
allow the rod to penetrate through the layer being rodded and
into the layer below approximately 1 in. [25 mm]. After each
layer is rodded, tap the outsides of the mold lightly 10 to 15
times with the mallet to close any holes left by rodding and to
release any large air bubbles that may have been trapped. Use
an open hand to tap light-gage single-use molds which are
susceptible to damage if tapped with a mallet. After tapping,
spade the concrete along the sides and ends of beam and prism
molds with a trowel or other suitable tool