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Soil Stabilisation
Description:
The CONSOLID Soil Stabilisation system was demonstrated in the yard of ENIT, using the in-situ soil. An adequate degree of cohesion in the soil was required to give the soil mix a high mechanical stability. This will be preserved by the CONSOLID soil stabilisation system, which will also prevent the softening of the soil by
moisture, making it to a high degree impervious.
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The Single Steps:
The existing plot has to be prepared by ripping-off the ground and levelling the area ahead of any treatment. When required the
underlying sub-grade has to be properly compacted to obtain enough
resistance for the compaction of the treated soil layer.
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This operation is carried out with a well-equipped grader, as shown in
the photo. The same grader will subsequently be used to support the
other machinery equipment to get the proper level prior to compacting,
but also to support the mixing process by ripping-off the soil mix, if
it should be too much compacted by the tractor, operating the disc
harrow.
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On the well-prepared loose soil mix, CONSOLID is applied with a tank
car (200 ml CONSOLID per m2, diluted in as much water as the soil can
accept to come close to the O.M.C. for proper compaction). In a hot
climate, it always has to be observed that the moisture content is
maintained at O.M.C. to avoid too dry conditions, particularly during
compaction.
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With the CONSOLID SYSTEM, the mixing process is always the most
important aspect - the additives work like catalysts mainly by
their presence and enact in this way the permanent change of the soil
behaviour toward petrification. The better the mixing, the lower the
amount of additives required. Therefore only the best mixing equipment
should be used - a disc harrow is conceivable, but there exist much
better machinery for this purpose.
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After the mixing-in of CONSOLID, SOLIDRY is applied, due to the
relatively small area distributed by hand. On road, applicators for
the dry powder are used. In our case, 4 kg SOLIDRY per m2 has been
applied for a mixing depth of 200 to 250 mm. The required quantity of
CONSOLID and SOLIDRY can easily be determined in laboratory tests
ahead of the field application. So you know exactly what result you
can obtain in the field and therefore a failure is impossible.
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SOLIDRY is also thoroughly mixed into the soil. The mixing process is
accomplished when there are no more sparks of the white-grey SOLIDRY
powder visible and the colour of the mixed soil is uniform. As
mentioned above, the better the mixing, the better is the
performance of the treatment. Disc harrows can do the job, but
have to perform several passes. The tractor will start tire compaction
and therefore it is necessary with this equipment to reopen the soil
with the ripper during the mixing process.
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The proper compaction of the cohesive soil mix starts with a sheep's
foot roller. This allows a really good compaction in the depth. The
'feet' will 'grow' out of the soil during compaction - a proof that a
thorough compaction has been reached. The grader will have to re-level
the area to fill the roller marks before any other type of roller
starts operating.
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A flat roller (static roller) or preferably a vibration roller will
secure the final rolling, assisted by the grader, which takes care of
the fine level by of 'shaping' the surface and making it absolutely
smooth. It is important at this stage that the soil mix is not too
dry for compaction. If required, water has to be sprinkled onto
the surface of the compacted soil to enable the final compaction.
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Once the treated soil is properly compacted, it is fully stable and no
further movements (up and down) under loading occur. If this condition
is reached,any type of wearing course can right away be applied on the
compacted surface.In our case, an asphalt hot mix, 1.5 thick, is
applied, resulting in a very pleasant- looking, stable demonstration
plot.
The
soaked CBR of the untreated soil is <10%; the treated soil will
have a soaked CBR >60%.
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It was the aim of this demonstration to
show on a plot with no selected soil base how simple it is to improve
and upgrade in-situ soil with the CONSOLID SYSTEM. The experience of
the last decades and more than 8'000 tested soil samples from all over
the world have proved that 100% of all existing soil types work
perfectly with the CONSOLID SYSTEM. Soils with too low cohesion can be
improved by adding clayey soil up to 50%, while too heavy clays with a
high swelling / shrinkage rate can be made fully acceptable as
construction material by adding sufficient quantities of sand and/or
coarse material. In this way, any user can bring his in-situ soils
exactly to the required performance of the soil parameters. This
report shows an application 'in place' with the in-situ soil. The
special character of the CONSOLID SYSTEM makes it also possible to
prepare any desired soil mix 'in plant', at a central mixing place. In
this case, the treated soil mix can be stock piled for unlimited time
without loss of the improvement. Once treated, the soil remains
treated - this even enables a re-use, e.g. of treated material from
temporary roads on other sites without additional treatment.
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