Consolidation Test - Soil Properties: Testing, Measurement, and Evaluation - page 289

(1) Reduce as much as practical any disturbance of the soil or
changes in moisture and density during specimen preparation.
Avoid vibration, distortion, and compression.

SPECIMEN
PREPARATION [1]

(2) Prepare test specimens in an environment where soil moisture
change during preparation is minimized.

Note 2 —A high humidity environment is usually used for this
purpose.

(3) Trim the specimen and insert it into the consolidation ring.
When specimens come from undisturbed soil collected using sam-
ple tubes, the inside diameter of the tube shall be at least 5 mm
(0.25 in.) greater than the inside diameter of the consolidation
ring, except as noted in (4) and (5). It is recommended that either
a trimming turntable or cylindrical cutting ring be used to cut the
soil to the proper diameter. When using a trimming turntable,
make a complete perimeter cut, reducing the specimen diameter
to the inside diameter of the consolidation ring. Carefully insert
the specimen into the consolidation ring, by the width of the cut,
with a minimum of force. Repeat until the specimen protrudes
from the bottom of the ring. When using a cylindrical cutting ring,
trim the soil to a gentle taper in front of the cutting edge. After the
taper is formed, advance the cutter a small distance to form the
final diameter. Repeat the process until the specimen protrudes
from the ring.

(4) Fibrous soils, such as peat, and those soils that are easily dam-
aged by trimming, may be transferred directly from the sampling
tube to the ring, provided that the ring has the same diameter as
the sample tube.

(5) Specimens obtained using a ring-lined sampler may be used
without prior trimming, provided they comply with the require-
ments of ASTM Practice D 3550 and this test method.

(6) Trim the specimen flush with the plane ends of the ring. The
specimen may be recessed slightly below the top of the ring to
facilitate centering of the top stone by partial extrusion and trim-
ming of the bottom surface. For soft to medium soils, a wire saw
should be used for trimming the top and bottom of the specimen
to minimize smearing. A straightedge with a sharp cutting edge
may be used for the final trim after the excess soil has first been
removed with a wire saw. For stiff soils, a sharpened straightedge
alone may be used for trimming the top and bottom. If a small
particle is encountered in any surface being trimmed, it
should be removed and the resulting void filled with soil from the
trimmings.