Note: Descriptions are shown in the official language in which they were submitted.
CA 02501351 2005-04-11
Description
The application relates to noise protection, such as a noise barrier for
positioning
next to a road or railway and to a method for producing said barrier.
Technical Field
The invention relates primarily to noise protection means of a kind that are
intended
for use on railways and roads where the environmental requirements stipulate a
lower noise
level than that which previously disclosed constructions were able to achieve,
and without
these affecting the surrounding environment and aesthetic considerations, in
addition to
which the construction itself shall withstand the effects of the weather in
variable climatic
zones. The noise protection comprises a sound-absorbent material produced from
rubber
granulate that is bonded together with the help of a bonding agent.
Description of the Prior Art
Previously disclosed are a variety of ways of compressing or moulding rubber
waste, either alone or in conjunction with other products, to form porous
material for
1 S acoustical and vibration damping or insulating purposes.
The noise protection in accordance with the present application is a further
development of the product in accordance with the Swedish Patent Application
with
reference number 9700799-1 and with publication number SE, C2, 513102. This
describes a
noise barrier made of rubber waste mixed with a bonding agent, which bonding
agent
remains soft even after cold curing. The document does not describe any
special
arrangements or constructions for adaptation in accordance with climatic and
environmental
conditions.
Description of the Present Invention
An aim of the invention is to provide a reliable means of attachment of a
sound-
absorbing unit in a framework.
In a first embodiment of the present invention, the noise protection comprises
a
sound absorbent that is produced from a rubber granulate which is bonded
together with the
help of a bonding agent and a framework that is produced from a material that
is harder than
the material in the sound absorbent. The framework is fully or partially
covered with the
sound absorbent on the side that is intended to face towards the source of the
sound.
Specifically the framework is made of concrete and constitutes part of a free-
standing
element which exhibits a sole for placing on the ground or equivalent, from
which there
extends a portion projecting upwards in relation to the sole, and the sound
absorbent is
arranged at least on the upward-projecting portion. The upward-projecting
portion is inclined
in relation to the sole, and the sound absorbent is arranged between the sole
and the under
side of the inclined portion. The upward-projecting portion exhibits an upper
portion which
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extends in parallel with the sole, and the sound absorbent is arranged on the
under side of
the upper portion. The noise protection is intended for positioning next to a
road or railway.
The rubber protection comprises a sound-reflecting framework and a sound
absorbent produced from rubber granulate, e.g. vehicle tyre granulate mixed
with a bonding
agent, whereby the framework comprises an upper portion, a sole portion and a
back portion
to which the sound absorbent is applied so that the sound absorbent is
enclosed by the
upper portion, the back portion and the sole portion and has one side intended
to face
towards the source of the sound on the road or the railway. The noise
protection can
preferably have a sole portion with an upper surface which, when the sole
portion is standing
on a horizontal surface, exhibits an inclination away from the back portion in
the direction of
the road or the railway in order to permit any liquid to drain away. For
example, the upper
portion has an upper surface that is convexly rounded to prevent the
accumulation of liquid
and dirt.
Brief Description of the Figures
From this point onwards in the running text, reference is made to the
accompanying
Figures for a better understanding of the embodiment and the given examples,
in conjunction
with which:
Figure 1 shows a cross-section of a noise barrier with a screen for
advertising or
similar and mesh protection.
Figure 2 shows a cross-section of an embodiment of a noise barrier in
accordance
with the present invention.
Figure 3 shows a cross-section of an embodiment of a noise barrier in
accordance
with the present invention placed on a finer macadam on a roadbed of coarse
macadam.
Detailed Description of the Present Invention
The invention relates to a noise barrier, a development thereof, whereby
disturbing
sound levels shall effectively be reduced at points where the technology can
best be
adapted.
The invention also relates to a method for the production of a noise barrier.
The noise protection in accordance with the invention includes a sound
absorbent
made of rubber granulate from vehicle tyres, which is bonded together using a
bonding
agent, which mixture can be moulded into and enclosed by a supporting
framework made of
concrete, for example. The characteristic features of the invention can be
appreciated from
the accompanying Patent Claims. It is noted that the sound absorbent is made
from rubber
granulate in pieces of 0-15 cm in size.
In a suitable method, the rubber mass is poured onto a plate with means for
securing the rubber to the plate. Before pouring the rubber, a mesh is placed
on the mould
plate. This mesh projects outwards by approximately 50 mm on the long sides.
The solidified
CA 02501351 2005-04-11
rubber mass, which forms the sound-absorbent unit, is placed together with the
mesh in the
concrete. In this way, the concrete penetrates partially into the sound-
absorbent unit.
Reinforcement is preferably provided in the concrete. The mould is closed and
filled with self-
compacting concrete. The projecting mesh is moulded securely in its upper and
lower edges
to the upper portion and the sole portion, respectively, of the framework in
this way and as
such provides a dependable assurance that the rubber will remain in the block.
The production method provides very effective attachment of the rubber. A very
uneven rear side is also obtained, which further improves the acoustic
properties of the
block. There is no smooth surface against which the sound can rebound.
The invention is described in greater detail with reference to, for example,
Figure 1,
which illustrates the principles of a noise barrier intended for use along
railways and roads.
A framework 10 is made of concrete and/or some other heavy material and
partially
encloses a sound absorbent 20 produced from rubber granulate. The sound-
absorbing unit is
moulded into the concrete mass 10. The framework 10 comprises a sole 11, from
which an
1 S upward-projecting portion 12 extends at an angle to the sole 11, and at
the upper portion of
which an upper portion 13 extends parallel with the sole 11. The sound
absorbent 20 is
arranged on the under side of the inclined portion 12 and the upper portion 13
and extends
along the top side of the sole 11.
The back portion 10 can be provided with advertisements and information signs,
or
alternatively a reflecting screen in the form of a receiver, onto which a
transmitter positioned
a short distance from the block can transmit a still or moving image about the
advertisement
or information. Also illustrated in Figure 1 is the screen 33, which is
described above and can
consist of a transparent material, homogeneous material or different types of
mesh. The
screen can be supplemented with barbed wire in order to make access to the
other side
difficult. The screen can be provided with advertisements, information signs
or alternatively a
reflecting screen in the form of a receiver, onto which a transmitter
positioned a short
distance from the block can transmit a still or moving image 33 for
advertising and
information. The framework 10 can also be formed with a drainage lip 37.
The side of the framework which is intended to face the noise source has
attached
to it a projecting mesh 36, which is moulded in place at its upper and lower
edges to the
upper and sole portions to form a secure attachment so that the rubber is
caused to remain
in the block and is not able to work loose towards the noise source. Several
noise barriers
are intended to be placed side by side along the road or railroad. A sealing
strip 38, e.g.
made of rubber or a rubber like material, can then be arranged between two
adjacent noise
barriers. The sealing strip 38 is rectangular in Figure 1 and extends from the
sole portion 11
to the upper portion 13.
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Figure 2 shows a cross-section of an embodiment of the present invention, in
which
the sole portion 11 exhibits an inclination so that water can drain away and
does not
therefore accumulate.
The sound absorbent 20, which has been moulded into the framework 12, exhibits
a
cavity which permits a certain amount of water to run through. The upper
surface 14 of the
sole portion 11 has an inclination away from the upward-projecting portion,
the back portion
12, so that, when the lower surface 15 of the sole portion bears flat and
horizontally on a
base, natural drainage of any water is obtained in a direction from the back
portion 12
towards the noise source, e.g. in the direction of the railway
track/carriageway. Ice formation
is prevented by the running water, and at the same time a certain self-
cleaning effect is
achieved because rain water carries dirt with it and runs off the sole
portion. The upper
portion 13 has an upper surface 16 which is convexly rounded and prevents the
accumulation of water and dirt on the upper portion. This is also an advantage
when the
noise protection is washed down during cleaning because the water runs off
both the sole
portion and the upper portion without requiring to be scraped or wiped off.
A mesh 36 is moulded into the upper portion 13 and the sole portion 11
adjacent the
sound absorbent in front of the side intended to face the road or railroad.
Figure 3 shows an arrangement for an embodiment of the present invention
adapted
for noise damping next to a railway. Railways normally have a roadbed of
coarse macadam
30, on which the rails are placed. In conjunction with the use of noise
screens, which are
stood directly on this coarse macadam, noise can leak through the macadam
under the noise
screen. In order to counteract this noise leakage, the noise screen can be
supplemented with
a bed of finer gravel or crushed macadam 32. The macadam under the noise
protection is
excavated to form a small trench, in which is laid a mat 31, for example made
of geotextile,
after which the trench is filled with a finer gravel 32. The noise screen is
then placed on the
gravel. Other water-permeable materials can also be used as a barrier between
the coarser
and the finer macadam. Figure 3 shows an arrangement for a noise barrier 10
next to a
railway comprising a noise screen, with a framework 12 and a sound absorbent
20, which
stands on a base of finer crushed macadam 32 segregated from the coarser
macadam 30 of
the roadbed by means of a mat 31. The mat prevents the finer gravel 32 from
sinking down
through the coarser gravel 30. By using a finer gravel, greater damping and
absorption of
noise under the noise screen is achieved. The mat allows water to pass through
in the event
of rain and during cleaning operations, but prevents the finer gravel from
being washed away
or from permeating down into the coarser macadam. In this way, the finer
gravel or sand is
prevented from permeating down into the roadbed and retaining water, which, as
the water
freezes, is associated with the risk of subsidence in the roadbed and track
dislocations. A
mesh 36 is partly moulded into an upper portion 13 and a sole portion 11.
CA 02501351 2005-04-11
Above the framework 10 can be raised a screen consisting of transparent
material,
homogeneous material or different types of mesh. The raised screen can be
supplemented
with barbed wire in order to make access to the other side difficult. The
screen can also be
provided with advertising, information signs or alternatively a reflecting
screen in the form of
S a receiver, onto which a transmitter positioned a short distance from the
block can transmit a
still or moving image for advertising or information.
In accordance with the present invention, a method for producing a noise
barrier
intended for placing next to a road or a railway next to the noise protection,
involves first
pouring a rubber mass onto a plate with means for securing the rubber to the
plate. A mesh
is placed on the mould plate before pouring the rubber. This projects by
approximately 50
mm on the long sides. A plate and rubber are placed in the concrete mould.
Reinforcement is
installed in the mould. The mould is closed and self-compacting concrete is
poured in. The
characterizing feature is that the sound absorbent is partially moulded into
the framework in
this way. The technical dimensions can, for example, be as listed below.
Technical Data
Length 3,500 mm
Height 1,000 mm
Width (bottom) 700 mm
alternatively 1,300 mm if supplemented with a screen over 1,000 mm Plexiglas
15 mm).
Weight including adhesive and tyre granulate approximately 2,425 kg (bottom
700 mm)
alternatively 3,100 kg (bottom 1,300 mm).
Concrete K 40. Watertight and frost resistant
Rubber Ground vehicle tyres (approximately 400 kg)
Adhesive Special single-component (40-50 kg/block)
