ing. A variety of tapes are available from various
TEST DEMONSTRATIONS
manufacturers. The drawback to tapes is that
The demonstrations were conducted at Fort
they are best applied when the temperature is
Drum, New York, and at the Ethan Allen Firing
above 10C (50F). This can be overcome in a vari-
Range (EAFR), Jericho, Vermont. A different engi-
ety of ways. The tapes can be kept warm in a heat-
neering unit was used at each site.
ed vehicle and applied quickly before they cool,
or they could be heated with a heat gun or electric
Materials manufacturers
hair drier. (This would require using a small gen-
Following is a list of manufacturers and prod-
erator.)
ucts used in the demonstrations.
Raven Industries, Sioux Falls, South Dakota:
Polyethylene lower membrane
RUFCO 610B, 1010B, 2010B, and 3010B;
The lower membrane will be 0.152- to 0.23-mm
DURA-SKRIM 12 BBR membranes; and Poly
(6- to 9-mil) polyethylene membrane. Tapes will
Seal tape.
be used for the seams. The membranes can be
Reef Industries, Houston, Texas: Permalon
purchased in long lengths (152 m [167 yd]) to
Ply X-150, Ply X-210, Ply X-210G membranes,
minimize seams. It is important to purchase qual-
and Fab tape.
ity membranes from reputable manufacturers.
Webtec, Inc., Charlotte, North Carolina:
Low-quality membranes can contain defects and
TerraTex N08 geotextile.
additives that can reduce their life.
Stockhausen, Inc., Greensboro, North Carol-
ina: AP 88 superabsorbent.
Soil drying methods
Specialty Minerals Company, Adams, Massa-
Various methods can be used to dry the soils.
chusetts: commercial-grade quicklime.
Chemical methods can be done quickly and, if
properly done, are well suited for Army engi-
MESL materials
neers. Lime is the best chemical to use with clayey
The materials are separated by the project in
soils. A method to dry silty sands needs to be
which they were used and the function they per-
developed.
formed.
A potential method to make silty sands act
drier involves the use of commercially available
MESL test materials
superabsorbent polymers. The polymers don't
Upper membrane. Two different membranes,
actually dry the soil; they concentrate the water in
DURA-SKRIM 12 BBR and RUFCO 2010B, were
the absorbent and dry the surrounding soil
used for the top membrane.
matrix. They have potential benefits and draw-
The DURA-SKRIM 12 BBR is 0.31 mm (12 mil)
backs. The benefits are that (1) only a small
thick. Its manufacturer describes it as two sheets
amount (between .15 and .5 percent) of absorbent
of high-strength polyethylene film laminated
is needed, (2) they are relatively safe to handle, (3)
together with a third layer of molten polyethylene,
they have a minimal impact on the environment,
with a heavy polyester skrim reinforcement
(4) they are very fast acting, and (5) they are unaf-
placed between the plies to enhance tear resis-
fected by the cold.
tance (Raven Industries undated b). The machine
A drawback is that the swelled absorbent is
width of the membrane is 1.83 m (6 ft). If widths
spongy, thereby making the soil spongy. The wetter
greater than 1.83 m (6 ft) are desired, the factory
the soil is to begin with, the spongier the soil will be
can seam several sheets together. The final mem-
after the absorbent is added. The absorbents absorb
brane is accordion-folded and rolled on a core.
less as confining pressure is increased. This
The RUFCO 2010B is a 0.51-mm- (20-mil-) thick
means a truck could not park on the absorbent-
monolayer membrane consisting of a blend of
treated soil because it would force the water out
medium-density polyethylene manufactured
of the absorbent. Absorbents also degrade with
from virgin and selected reprocessed resins
time. It is possible to add too much absorbent,
(Raven Industries undated c).
which would over-dry the soil and make it fria-
Lower membrane. The RUFCO 610B is 0.152
ble. However, even with the disadvantages,
mm (6 mil) thick. It is a monolayer membrane
absorbents are a potential drying agent for MESLs
consisting of a blend of high-strength, medium-
with a short design life and a silty sand fill soil.
density polyethylene manufactured from virgin
and selected reprocessed resins. According to its
4
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