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The
structure of a clay court
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The aim of the sub grade is to facilitate
fixing the structure to the existing ground. With this in mind the
ground is first excavated, then cleared preferably by stripping the
earth. The remaining roots are then removed and the soil is treated
with a weed-killer. Finally it is leveled then compressed by means
of a heavy roller, which hardens it in order to avoid any future collapse
within the court. It is sometimes necessary to add a layer of unwoven
fiber (geotextile) as a filter to avoid the foundations of the court
being plugged by fine particles of clay rising.” Rabbit”
sand can perform this function. A drainage network should be installed
if the existing soil does not allow the natural evacuation of any
water infiltrating the court.
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The stones chosen for the foundation
layer are hard, non freezable and preferably crushed. The thickness
of this layer varies from 12 to 60 cm, depending on the degree of
permeability of the foundation base. It is rollered until it is perfectly
compressed in order to serve as a foundation of the court. If the
stones used are too coarse the surface gaps should be filled with
smaller gravel in order to ensure correct levelness and to avoid the
fine elements of the surface material migrating to the lower level.
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The role of the intermediary layer
is that of preserving the humidity essential to clay courts. Stocked
water is returned to the surface layer by capillarity. This is 6 to
10 cm layer of cinders or sometimes specific volcanic rock (pouzzolane),
must have a finer grained upper layer to enable water to rise to the
surface.
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Crushed limestone is used to make
the coating. The material selected must correspond to technical criteria
in term of granulometry (measurement of the elements of which it consists),
friability (erosion resistance capacity), water retention capacity
and permeability. 60 to 70 tons of material are necessary to make
a coating 4 to 5 cm deep after compression.
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The coloring layer has three functions-
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-to avoid players being disturbed
by light reverberating on the limestone.
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-to ensure sufficient contrast
between the ground and the ball.
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-to reconcile sliding and pushing
off.
It must therefore fulfill both colorimetric and granulometric demands.
Two tons of crushed brick, which integrate with the surface of the
limestone coating, are sufficient to color the court. The construction
of a traditional clay court implies respecting this norm which corresponds
to the technical recommendations.
Annual Resurfacing
The limestone used in clay
courts is sensitive to extreme cold. At the end of autumn, the courts
are swept in order to remove all the elements, which are not part of the
surface (vegetable matter, small stones, and excess crushed brick). The
painted lines are removed as soon as they separate from the coatings so
that they will not become mixed with the limestone. Once the court has
been cleaned new limestone is added to the place where the soil has been
eroded, mainly behind the baseline.
In spring, as soon as the
weather allows it, the coating is turned over and its total thickness
decompacted as far down as the layer of cinders. The difficulty of this
job lies in homogeneously turning over the whole coating without altering
the levelness or homogeneity of the intermediary layer of cinders. This
can be done by alternative movement machines, which can attain the exact
depth required. It is essential that no hard slab remains after turning
over the limestone, in order that the flow of water between the layers
remains unaltered.
After allowing the court
to “breathe” for a few days it is advisable to reconstitute
a flat, unified and compact surface. The ground is then leveled and rollered.
During this series of operations the limestone must be damp but not sticky.
Little by little the court hardens. At the end of the cycle the coating,
which has hardened, is then colored with crush brick, and rollered again
with a large roller. After applying a layer of linseed oil the lines should
be painted on. Plastic lines should be repositioned before blocking the
limestone. The least used sections will be placed at the back of the court.
Both supple and hard, the
court will preserve its initial properties. It is properly maintained,
throughout the season, by the members of the club and maintenance personnel.
Standard
Maintenance
In order for the court
to keep its original characteristics throughout the season, maintenance
operations should be undertaken.
Watering the court each
evening in order to correctly dampen it is imperative. The court is commonly
drenched (while avoiding puddles) for about 30 minutes, hose in hand.
Passing the dragging net
after each game enables a perfect distribution of the crushed brick and
the limestone which has come loose from the coating. This limits the risk
of false-rebounds.
During the season, bits
of limestone get separated from the coating and mixes with the crushed
brick. This sand, which is impossible to block, causes many false-rebounds.
Sweeping the court during the season is therefore is essential. A birch
broom is the perfect implement for this job.
Note:
Based on French Clay Court
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