A Method for Producing Fine-Grained Ice
from Snow by Compaction
DEBORAH DIEMAND AND VALERY KLOKOV
INTRODUCTION
6.87 MPa (about 1000 psi) to produce ice of high
strength that could be used to produce structures or
The use of snow as an engineering material in polar
pavements that could not be prepared using
regions is not new. Aboriginal populations in northern
conventional techniques.
areas have used snow for the construction of shelters
It is often the case that a compacted snow pavement
such as Kinsey huts (by agitating and sintering the
made by conventional means is adequate for its task
snow) and igloos (using blocks of unprocessed snow
over most of its length, but becomes impassable over
cut from the natural snow cover). These techniques use
short transitional areas. Our proposal is to use highly
relatively low-density, and therefore low-strength,
compacted snow building blocks for these areas. Blocks
material unsuitable for load-bearing applications
with a density range on the order of 800 to 900 kg/m3
such as pavements or long-term usage such as
should have the strength of ice, and would also
semipermanent buildings.
minimize problems of vapor movement and infiltration
Compacted snow roads and runways have been
of fluids, since these densities are very close to or
studied and used for many years in polar areas. Many
beyond the density of pore close-off. Such blocks could
techniques have been used with varying degrees of
also be used for making or crossing obstacles, as well
success, but the aim of all these techniques is to
as building semipermanent structures of many types,
compact the snow and allow it to sinter to increase its
such as retaining walls and abutments, and snow
strength. The density of the resultant material is
generally in the range of 500 to 700 kg/m3, and many
shelters of greater size than are presently feasible--
for example, for equipment storage or instrumentation.
months may be needed to reach maximum strength.
This report describes the hot pressing technique we
The most difficult aspect of the process is that, for
used to produce very strong, tough material suitable
maximum strength, the snow should be compacted at
for these purposes, and gives the results of our
relatively warm temperatures and sintered at much
compressive and flexural strength tests. Hot pressing,
lower temperatures. At low temperatures, compaction
in which particles of parent material near its melting
is difficult because of the lack of moisture in the snow,
point are compacted at high pressures, is often used in
and the strengthening process is protracted. Techniques
metal and ceramic manufacture because it reduces
involving the addition of heat and/or water have been
defect size and grain growth over the standard method
used with uneven results, and are often so fuel-intensive
of forming the material under pressure followed by
as to make them practically unfeasible for large-scale
heating to complete the sintering.
use.
The crystallography of the material is of interest in
While the behavior of compacted snow has been
its own right and is also discussed. The hot sintering
the focus of much research, little systematic
method we used produced a material with consider-
consideration has been given to very high compression
ably smaller grain size and greater uniformity than the
pressures such as those used in this study. We explored
parent material.
the feasibility of compacting snow at pressures up to
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