Figure 15-18.-Cylinder in position before cutting a sample.
Figure 15-19.-Cutting off a cylindrical sample.
Figure 15-20.-Sealing a sample in a CBR mold.
sample. You actually do the cutting to size
with the sampling collar. You can force
the sampler down with the field CBR jack;
however,
since this jack has only about
2 in. of travel, you would do better to use
a truck jack, if available. In either case,
you should not force the sampler down ahead
of the trimming on the outside of the cylin-
der. Then excavate the trench deeper and
repeat the process until the soil penetrates
well into the extension collar. Finally, as
shown in figure 15-19, cut off the sample at
the bottom of the mold with a shovel, knife, or
wire, and remove the mold and sample from the
hole.
After removing the mold and sample from
the hole, remove the upper collar of the mold,
and trim the top surface of the sample down
to approximately 1/2 in. from the top of the
mold. Then fill this recess with paraffin, as
shown in figure 15-20, to seal the end of the
sample. Then, after you turn the mold over
and remove the cutting edge, a similar recess
is formed in the bottom of the sample. Fill
this recess with paraffin also. If the sample
is to be handled a great deal, you should
overfill the ends with paraffin and then
trim
edge.
them
them exactly flush, using a straight-
Place boards over both ends and clamp
in place, using bolts, string, or wire, as
15-15
