POUTRE EN BETON ET PROCEDE DE PRODUCTION ASSOCIE

CONCRETE SLEEPER AND METHOD FOR THE PRODUCTION THEREOF

Abrégé français

L'invention concerne une poutre en béton pour des grandes charges dynamiques comprenant des portées à rails (2) et une partie base inférieure, comprenant du béton standard (4) à haute rigidité, recevant des forces de pression élevées, les portées à rails (2) et/ou la partie base inférieure comprenant un matériau résistant à l'usure, au frottement ou à la traction.

Abrégé anglais

Disclosed is a concrete sleeper for great dynamic loads with rail supporting
areas (2) and a lower base zone. Said concrete sleeper is made of a high-
strength standard concrete (4) that absorbs great pressure. The rail
supporting areas (2) and/or the lower base zone is/are made of a wear-
resistant, non-abrasive, or tension-proof material.

Revendications

6
Claims
1. Concrete sleeper for high dynamic loads having rail support surfaces (2)
and
a lower sole region, consisting of a high-strength standard concrete (4)
capable
of withstanding high compression forces, characterised in that the rail
support
faces (2) and/or the lower sole region consist(s) of a wear-resistant,
abrasion-
resistant or tension-resistant material.
2. Concrete sleeper according to claim 1, characterised in that the wear-
resistant, abrasion-resistant or tension-resistant material is a prefabricated
plate
or profile or a metal angle, in particular a steel angle (3).
3. Concrete sleeper according to claim 1 or 2, characterised in that the wear-
resistant, abrasion-resistant or tension-resistant material is a concrete
layer (3',
3"") bonded to the standard concrete (4) and/or is a special concrete (3",
3"').
4. Method of manufacturing a concrete sleeper for high dynamic loads,
consisting of a high-strength standard concrete (4) capable of withstanding
high
compression forces, having rail support surfaces (2) and a lower sole region,
characterised in that the rail support surfaces (2) and/or the lower sole
region
is/are manufactured from a wear-resistant, abrasion-resistant, or tension-
resistant material, which is inserted into a sleeper mould (1) below or on the
standard concrete (4) as a prefabricated plate or profile and bonds to the
standard concrete as this hardens.
5. Method of manufacturing a concrete sleeper according to claim 4,
characterised in that a metal angle, in particular a steel angle (3) is
inserted as
a wear-resistant, abrasion-resistant or tension-resistant material.
6. Method of manufacturing a concrete sleeper according to claim 4,
characterised in that the wear-resistant, abrasion-resistant or tension-
resistant
material as a first concrete layer (3', 3 "") and/or as special concrete (3",
3"') is

7
bonded to the standard concrete (4) wet-on-wet in a sleeper mould (1) and is
hardened.
7. Method of manufacturing a concrete sleeper according to claim 6,
characterised in that the different types of concrete are introduced one after
another into the sleeper mould (1) and are mixed in the border region by
shaking or vibrating in order to form a monolithic body.
8. Method of manufacturing a concrete sleeper according to claim 4,
characterised in that a preferably prefabricated plate of plastics material is
used.
9. Method of manufacturing a concrete sleeper according to claim 8,
characterised in that the plate is introduced into the sleeper mould (1) in
the
liquid or still-plastic form and in this state forms a bond with the concrete.

Description

CA 02589943 2007-05-30
1
Concrete sleeper and method for the production thereof
The invention relates to a concrete sleeper for high dynamic loads with rail
support surfaces and a lower rail region, consisting of a high-strength
standard
concrete capable of withstanding high compression forces.
In the case of high dynamic loads, the phenomena of wear and/or abrasion
frequently occur in the rail support regions and on the underside of the
concrete
sleepers. This wear is brought about by the compression of plastics layers
inserted between the rail and the concrete body of the concrete sleeper, or by
the shifting of grains in the ballast bed underneath the concrete sleeper.
Such
abrasion phenomena may also arise for example due to the braking of the
enormously long trains used in the USA and Australia, which may displace the
welded rails by a few millimetres, naturally leading to corresponding abrasion
action on the concrete sleepers.
In the case of pulsating vertical load, the plastics layers are also expanded
and
contracted in the horizontal direction and consequently rub against the
concrete
surface of the sleepers. On the underside of the concrete sleepers, again the
ballast grains rub against the concrete body. This results in the removal of
material at the rail support points and on the underside of the concrete
sleeper.
Consequently, the geometry and carrying capacity of the concrete sleepers is
sufficiently impaired over time that these are no longer fit as safe, stable
supporting elements.
The object of the invention is therefore to create a concrete sleeper of the
type
mentioned in the introduction which counteracts these properties of wear at
minimal cost.

CA 02589943 2007-05-30
2
To achieve this it is proposed according to the invention that rail support
surfaces and/or the lower sole region consist(s) of a wear-resistant, abrasion-
resistant or tension-resistant material.
In addition, the invention relates to a method of manufacturing a concrete
sleeper of the type described.
It may be provided according to the invention that the wear-resistant,
abrasion-
resistant or tension-resistant material is inserted as a prefabricated plate
or
profile into a sleeper mould below or on the standard concrete and bonds
therewith as this hardens.
The wear-resistant, abrasion-resistant or tension-resistant material may be an
inserted metal angle, for example.
According to an alternative embodiment of the invention it can be provided
that
the wear-resistant, abrasion-resistant or tension-resistant material is bonded
and hardened wet-on-wet with the standard concrete in a sleeper mould, in that
according to the type of placing in the sleeper, first the wear-resistant,
abrasion-
resistant or tension-resistant material is inserted into the sleeper mould as
a
special concrete material and then the standard concrete is poured in or
conversely the standard concrete is poured in first and then, to form the wear-
and abrasion-resistant sole, the special concrete material is introduced into
the
sleeper mould as the top layer.
According to the invention, in this method, by introducing the different
plastic
concrete materials directly one after another, wet on wet, the standard
concrete
and the special concrete material can be mixed together in their border region
by shaking or vibrating in such a manner that they form a monolithic body, but
one which has over its height the desired differing bending tensile strength
or
abrasion-resistance.

= CA 02589943 2007-05-30
3
Alternatively, in a development of the method according to the invention, it
can
be provided that a preferably prefabricated plate composed of plastics
material
is used, the plate preferably being inserted in the liquid or still-plastic
form into
the concrete mould and in this state forming a bond with the concrete.
Further advantages and details of the invention will appear from the following
description of some embodiments and from the drawings, which show:
Figures 1 and 2, a section through a sleeper mould for manufacturing a
concrete sleeper according to the invention having abrasion-resistant rail
support surfaces, different modifications being shown to the left and right,
Figures 3 and 4, a longitudinal section through a sleeper mould in two
different
stages of filling for the manufacture of a concrete sleeper according to the
invention with abrasion-resistant and/or wear-resistant material in the lower
sole
region of the concrete sleeper,
Figures 5 and 6, longitudinal sections through a sleeper mould in the
manufacture of a concrete sleeper according to the invention with high tensile
strength in the lower sole region, and
Figures 7 to 9, sections through a sleeper mould in the various stages of
manufacture of a concrete sleeper, which is exposed in the centre of the upper
face to high tensile stresses.
In Fig. 1, a sleeper mould 1 is shown which has the shaping regions for
forming
rail support surfaces 2. In order to achieve increased abrasion- and wear-
resistance in the region of these rail support surfaces 2 acting as supports
in the
case of high dynamic, possibly pulsating vertical loads, either, as is shown
to
the right in Fig. 1, steel angles 3 can be inserted before filling with the
sleeper
concrete, or a first concrete layer 3' consisting of an abrasion- and wear-
resistant material can be applied, as is shown to the left in Fig. 1. Then the

CA 02589943 2007-05-30
4
mould is filled with a standard sleeper concrete 4, as is shown in Fig. 2. In
this
case, a prefabricated component, in the present case the steel angle 3, is
bonded into the pressure-resistant standard concrete 4 or by shaking and
vibration, shown to the left, the two types of concrete are mingled in the
border
region, so that a monolithic body is formed, but one which has over its height
the desired different properties of abrasion- and wear-resistance.
In Figures 3 and 4, the method of manufacturing a sleeper with high abrasion-
and wear-resistance in the lower sole region is shown. To this end, first the
standard concrete 4 is introduced into the sleeper mould 1, leaving a slight
layer
thickness free at the top, and then still in the wet state of the standard
concrete
4, a layer of an abrasion-resistant and/or wear-resistant special concrete 3"
is
applied.
In the embodiment according to Figures 5 and 6, the manufacture of a sleeper
is shown for rail sections in which high tension forces occur in the lower
region
of the concrete sleepers. Into the sleeper mould 1, first, as before, the
standard
concrete 4 with a high pressure-resistance is introduced up to about half the
sleeper height, and then a special concrete 3"' with a high tensile strength
is
poured in, and again by compression and vibration, a monolithic bond of the
two
types of concrete is achieved in the border areas.
Finally, Figures 7 to 9 show an embodiment in which a concrete sleeper, as
manufactured in Figures 5 and 6, has been prepared for the case where it rests
in the centre, with the consequence that additional tensile stresses can occur
on
the upper face in the centre. To this end, first a tension-resistant concrete
layer
3"" is applied in the centre of the sleeper mould 1 as a first concrete layer,
and
then the normal standard concrete 4 is introduced into the sleeper mould 1,
and
then correspondingly to Figures 5 and 6, the tension-resistant special
concrete
3"' is poured in as a further concrete layer.

CA 02589943 2007-05-30
The invention is not limited to the embodiments shown. Due to the different
use
of abrasion-resistant or wear-resistant special types of concrete and tension-
resistant concrete in different regions of the sleeper, for example, the
modification which increases tensile strength according to Figures 5 to 9
could
be combined with the modification in which a high abrasion-resistance is
achieved, as is shown for example in Figures 1 to 4.

Dessin représentatif