WO2024141745A1

WO2024141745A1 - One-piece tie having recesses

Info

Publication number: WO2024141745A1
Application number: PCT/FR2023/052131
Authority: WO
Inventors: Nicolas Bredy; Gilles Aubriet; Arnaud Loaec
Original assignee: Sateba France
Priority date: 2022-12-29
Filing date: 2023-12-28
Publication date: 2024-07-04

Abstract

The invention relates to a one-piece concrete railroad tie (10A, 10B, 10C) intended to be anchored in the ballast and to support railroad rails (52), the tie (10A, 10B, 10C) comprising a central portion (12) and two rail support portions (14) positioned on either side of the central portion (12), each of the two rail support portions (14) comprising at least one recess (16a, b), the recess being formed by a lateral flank (18a, b) of the rail support (14) and by three walls (20a, b, 22a, b, 24a, b) emerging from the lateral flank (18a, b), and being configured to be able to receive ballast grains when the tie (10A, 10B, 10C) is in a functional position on the ballast of the railroad.

Description

MONOBLOCK CROSS-MISSING WITH RECESSES

DESCRIPTION

FIELD OF INVENTION

The present invention relates to a one-piece concrete railway sleeper intended to be anchored in ballast and to support railway rails. The invention also relates to a railway track comprising such a sleeper.

TECHNOLOGICAL BACKGROUND

Railway tracks are generally formed by two rails along which trains move. The rails are attached to ties which extend in a direction perpendicular to the rails and which are anchored in a bed of ballast. Ballast is made up of a multitude of pebbles, also called ballast grains.

When traveling on railway tracks, trains generate a lot of vibration and exert significant forces on the rails, particularly lateral forces on curves. The sleepers then have the function of keeping the rails parallel to each other and also of keeping the sleeper/rail assembly solidly anchored in the ballast in a fixed position and with good stability, despite the vibrations and forces exerted on the rails. . For trains traveling at high speed, the sleeper/rail assembly is subject to even greater vibrations and forces.

The sleepers can be made of different materials such as wood, concrete or more recently polymer or composite materials. However, wood, polymer materials and composite materials are not sufficiently heavy and/or strong to be used for railway tracks on which high-speed trains run and/or tracks with long welded rails. . Indeed, the sleepers being light, they are not sufficiently anchored in the ballast to ensure good stability of the sleeper/rail assembly. Concrete sleepers having a high density, in particular between 2 and 2.5, and good solidity, are thus preferred, in particular for railway tracks on which high-speed trains run and/or tracks with long welded rails.

In order to further improve the anchoring of concrete sleepers in the ballast as well as their stability, sleepers comprising reliefs on their underside, intended to be in contact with the ballast, have been developed. Such sleepers shown in the figure 1, comprise a central portion 2, two end portions 3 and two rail support portions 4 each positioned between the central portion 2 and one of the end portions 3. The support portions 4 each comprise a fastening device of rail 5 and are widened in relation to the rest of the sleeper 1 because it is at the level of the rails that the forces, particularly lateral, exerted by the train, are the greatest.

The sleeper 1 also includes a lower face 6 comprising an alternation of furrows 7 and ribs 7' extending in a direction transverse to the sleeper and making it possible to improve the anchoring of the sleeper 1 in the ballast and therefore its stability.

However, the manufacture of concrete sleepers involves the consumption of natural resources such as water, gravel, sand as well as the constituents of cement (clay and limestone) and therefore results in a significant carbon footprint. For example, a sleeper meeting the standard template used by the SNCF has a length of 2260 mm and a trapezoid-shaped section with a base of 300 mm and a height of 170 mm. Such a standard sleeper weighs 290 kg and its manufacture typically generates a quantity of CO2 of 46 kg.

STATEMENT OF THE INVENTION

An objective of the invention is to reduce the quantity of materials used in the manufacture of the concrete sleeper by maintaining, or even improving, the stability of said sleeper in the functional position, and in particular its anchoring in the ballast.

Preferably, the concrete sleeper should have dimensions corresponding to standard sleepers so that it can be handled and installed using the usual methods.

To this end, the invention has as its first object a one-piece concrete railway sleeper intended to be anchored in the ballast and to support railway rails, said sleeper comprising a central portion and two support portions of rail positioned on either side of the central portion, each of the two rail support portions comprising at least one recess, said recess being formed by a lateral flank of the rail support portion and by three walls emerging from said lateral flank and being configured to accommodate grains of ballast when the sleeper is in the functional position on the ballast of the railway, each portion of rail support has a length 11 and the bottom wall extends over at least 80% of the length 11. The sleeper is thus solidly anchored in the ballast and is therefore more stable than sleepers of the prior art. In fact, the grains of ballast which are placed in the recess make it possible to weigh down the sleeper which thus moves less easily under the effect of the passage of trains. Furthermore, points of contact between the ballast grains and also between each ballast grain and the sleeper create friction forces which make it even more difficult to move the sleeper.

In addition, the presence of a recess makes it possible to reduce the quantity of concrete used for the manufacture of the sleeper which therefore reduces the quantity of water and materials used to manufacture the sleeper, and also the quantity of CO2 emitted for said manufacturing.

Advantageously, the recess is positioned at the level of the support portion because it is the portion of the sleeper on which the railway rails rest when the latter is in its functional position and therefore the portion of the sleeper which is the more likely to move when trains pass. Ballasting the sleeper using ballast grains and at this rail support portion thus optimizes the stability of the sleeper.

Furthermore, the length of the recess is optimized so as to make the crosspiece heavier over a large part of the rail support portion, even under the rail. Preferably, the recess extends over the entire length of the rail support portion.

According to a preferred embodiment, each rail support portion has two recesses, one being provided against a side of the support portion and the other being provided against an opposite side of said support portion.

According to particular embodiments of the invention which can be taken alone or in combination:

- the three walls are connected together to form a “U”;

- at least one of the three walls of said at least one recess extends laterally over a distance L1 greater than or equal to 30 mm; thus the recess has a depth greater than half of a possible dimension of the ballast grains which can conventionally range from 31.5 to 50 mm, which makes it possible to guarantee that at least certain ballast grains have their center of gravity positioned in the recess and their weight contributes to ballast the crosspiece by creating weight in the recess;

- the three walls are a bottom wall and two side walls, the bottom wall forming an angle with the side flank of the rail support portion of a value ranging from 95° to 150°, preferably ranging from 100° at 135°; the bottom wall thus has a sufficiently low inclination so that the ballast grains can remain in place in the recess but sufficient to reinforce the bottom wall and prevent it from breaking under the effect of ballast grains or when handling the latter; the central portion has two side walls and at least one anchoring element emerges from each of the two side walls, said at least one anchoring element extending in a direction perpendicular to the plane of the side walls; the anchoring element or elements make it possible to improve the stability of the sleeper in the ballast grains, in particular due to the ballast grains which are positioned on either side of these anchoring elements when the crosspiece is in the functional position;

- each anchoring element extends from the lateral side of the central portion over a length L4 greater than or equal to 30 mm; thus the anchoring element has a length greater than a possible dimension of a grain of ballast, which allows at least certain grains of ballast to be largely positioned between the lateral side of the central portion and a free end of the anchoring element so as to stabilize the crosspiece in an optimized manner; one of the side walls is an internal wall positioned between the lateral side of the rail support portion and the side side of the central portion and a housing is formed between said at least one anchoring element and the internal wall, said housing being configured to accommodate ballast grains; the housing thus makes it possible to stabilize the sleeper by accommodating grains of ballast without making the sleeper heavier; preferably, the crosspiece does not have a bottom wall between the internal wall and the anchoring element; preferably, the internal wall and the anchoring element emerge from the lateral side of the central portion by a distance of at least 30 mm;

- said at least one anchoring element emerging from a side flank and said at least one anchoring element emerging from the opposite side flank are aligned two by two; the crosspiece is thus stabilized in the same way on each of its lateral sides;

- the crosspiece has a density greater than or equal to 1.8; this density allows the crosspiece to be sufficiently heavy and therefore stable when it is in its functional position; And

- each support portion includes a railway rail attachment device.

The second object of the invention is a railway track comprising at least one sleeper according to the first object.

The railway track is thus more stable than a railway track comprising only sleepers according to the prior art. Preferably, the railway track comprises a plurality of sleepers such as those previously described, and even more preferably, only sleepers such as those previously described.

BRIEF DESCRIPTION OF THE FIGURES

Other characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of example and made with reference to the appended drawings, in which:

- Figure 1 represents a schematic perspective view of a sleeper of the prior art; Figure 2a represents a schematic perspective view of a crosspiece according to a first embodiment of the invention;

- Figure 2b shows a schematic top view of the crosspiece of Figure 2a;

- Figure 2c represents a schematic side view of the crosspiece of Figure 2a; Figure 3a represents a schematic perspective view of a crosspiece according to a second embodiment of the invention;

- Figure 3b shows a schematic top view of the crosspiece of Figure 3a;

- Figure 3c represents a schematic side view of the crosspiece of Figure 3a;

- Figure 4 represents a schematic perspective view of a crosspiece according to a variant of the second embodiment; Figure 5 schematically represents a top view of a railway track according to one embodiment of the invention;

- Figure 6 represents a schematic view of a sleeper of the prior art;

- Figure 7 represents a schematic view of a sample of railway track according to one embodiment of the invention in ballast; And

- Figure 8 represents a graph illustrating the test results carried out on the samples of Figure 7.

DETAILED DESCRIPTION OF AN EXAMPLE OF WORK With reference to Figures 2a to 2c, a railway sleeper 10À according to a first embodiment of the invention comprises a central portion 12 as well as two rail support portions 14 (or support portion) positioned on either side other of the central portion 12. The support portions 14 are more particularly positioned at each of the ends of the crosspiece 10.

The 10À crosspiece is a one-piece concrete piece with an elongated shape and a substantially square section. The density of the sleeper is at least 1.8, preferably at least 2, so that the sleeper is sufficiently heavy and stable when it is in the functional position and that it can thus be used for tracks railways on which high-speed trains run.

Each support portion 14a, b has two recesses 16a and 16b formed in each of the two side walls of the support portion 14. Each recess 16a, b is formed by a lateral flank 18a, b of the support portion 14 as well as by three walls 20a, b, 22a, b and 24a, b which emerge from the lateral side 18a, b.

The 10À crosspiece is intended to be anchored in a conventional manner in a ballast bed. When the sleeper 10À is in its functional position in the ballast, it rests on ballast grains and its side walls are surrounded by ballast grains. In this position, only an upper surface 26 emerges from the ballast grains.

In side view of the sleeper, the three walls are connected together to form a U, with the open end of the U pointing towards the upper surface of the sleeper.

Furthermore, the crosspiece 10À comprises two attachment devices 28 on which iron rails can be conventionally fixed. In particular, a fastening device is positioned on the upper surface 26 at each rail support portion 14.

Thus, when the sleeper 10A is in its functional position, that is to say anchored in a ballast bed and with a rail fixed on each rail support portion 14, the recesses 16a, b are filled with ballast grains . The sleeper 10A is thus weighed down, particularly at the level of the rail support portions 14a, b, which optimizes its anchoring in the ballast so that it remains in a stable position despite the passage of trains. Furthermore, the ballast grains positioned in the recesses are in contact with each other and are also in contact with the walls and side of the crosspiece 10A. These contacts create friction forces which increase the anchoring of the sleeper in the ballast and therefore its resistance to movements induced by the passage of trains.

In addition, the presence of a recess makes it possible to reduce the quantity of concrete used for the manufacture of the sleeper compared to a sleeper of equivalent dimensions and whose recesses would be filled with concrete. The amount of water and materials used to manufacture the crosspiece 10A is thus reduced, as is also the quantity of CO2 emitted for this manufacture.

Advantageously, the recess is positioned at the level of the support portion because it is the portion of the sleeper on which the railway rails rest when the latter is in its functional position and therefore the portion of the sleeper which is the more likely to move when trains pass. Ballasting the sleeper, using ballast grains, at this support portion, and even under the rails, thus makes it possible to optimize the stability of the sleeper.

Sometimes, in the remainder of the description of this first embodiment, only the elements of one of the side walls of the crosspiece 10A will be described (elements indexed "a") but the description also applies to the other side wall which is identical (elements indexed “b”).

Wall 20a of the recess forms a bottom wall, wall 22a is an outer side wall and wall 24a is an inner side wall. In this embodiment, the three walls 20a, 22a and 24a extend laterally over a distance L1 greater than or equal to 30 mm. The recess 16a thus has a depth allowing a plurality of ballast grains to be positioned in such a way that almost all of their volume is in the recess 16a and thus exert pressure in a vertical direction towards the wall. background 20a. The depth corresponds to the distance L1, that is to say the distance between the side flank 18a of the support portion 14 and a free edge 17a of the bottom wall 20a.

In addition, the recess 18a has a height He defined as being the vertical distance between the upper surface 26 of the crosspiece and an upper surface of the free edge 17a of the bottom wall 20a. The distance He of the recess 18a is also greater than or equal to 30 mm, and preferably between 120 and 200 mm.

According to a possible alternative embodiment, only the bottom wall 20a extends over the distance L1 and the side walls extend diagonally from the upper surface 26 towards a free edge of the bottom wall.

The bottom wall 20a, in particular its upper surface, forms an angle with the side flank 18a having a value of 120°. Advantageously, the inclination of the bottom wall 20a is a compromise between an inclination sufficiently low so that the ballast grains can remain in place in the recess 18a and an inclination sufficient to reinforce the bottom wall and prevent it from breaks under the effect of ballast grains or when handling the latter. In particular, the crosspiece 10À has a lower surface 30 that is flat and parallel to the upper surface 26. Thus, the inclination of the bottom wall 20a allows the latter to be thicker in its part positioned against the lateral side 18a than 'at its free edge 17a, which reinforces its solidity.

According to possible alternative embodiments, the inclination of the bottom wall 20a can have a value ranging from 95° to 150°, preferably from 100° to 135°.

Each rail support portion 14a has a length 11 and the bottom wall, in particular the free edge 17a, b of the bottom wall 20a, extends over a length 12 at least equal to 80% of the length 11. The length of the recess is thus optimized so as to make the crosspiece heavier over a large part of the rail support portion 14a which is the portion most subject to movements due to the passage of trains.

According to this embodiment, the central portion 12 has a first side flank 32a and a second side flank 32b which are smooth. These side walls 32a and 32b are parallel to each other and spaced apart by a width L2 which is the width of the central portion 12. The width L2 of the central portion 12 is smaller than a width L3 of the support portions 14a, b . Thus, the internal side walls 24a and the side flank 32a, on the one hand, and the internal side walls 24b and the side flank 32b, on the other hand, form two housings capable of accommodating ballast grains and reinforcing the anchoring of crosspiece 10A in the ballast.

A second embodiment is described with reference to Figures 3a to 3c. In this second embodiment, the crosspiece 10B differs from the crosspiece of the first embodiment essentially by the addition of anchoring elements which are described below. The other characteristics of the crosspiece are identical to those described in the first embodiment.

In this second embodiment, the crosspiece 10B comprises two anchoring elements 40a which emerge from the first sidewall 32a and two anchoring elements which emerge from the second sidewall 32b. The anchoring elements 40a, b extend in a direction perpendicular to the plane of the side walls 32a, b.

The anchoring elements 40a, b make it possible to further improve the stability of the crosspiece 10B in the ballast, in particular thanks to the ballast grains which are positioned on either side of these anchoring elements when the crosspiece 10B is in position. functional position.

Sometimes, in the remainder of the description of this second embodiment, only the elements of one of the side walls of the crosspiece 10B will be described (elements indexed “a”) but the description also applies to the other side wall which is identical (elements indexed “b”).

The anchoring elements 40a, b make it possible in particular to form housings capable of accommodating the ballast grains along each of the lateral blanks 32a, b. Two housings 42a are formed between each anchoring element 40a and each internal side wall 24a and a third housing 44a is formed between the two anchoring elements.

The housings 42a, b and 44a, b make it possible to accommodate ballast grains and thus increase the contact surface between the crosspiece 10B and the ballast grains. Furthermore, the plurality of ballast grains positioned in the housings and making contacts between them increases the resistance of the ballast on the sleeper 10B and therefore improves the stability of the sleeper.

Each anchoring element 40a, b emerges from the lateral flanks of the central portion by a distance L4 of at least 30 mm which is thus equivalent to or significantly less than the distance L1.

The 10À crosspiece has an average height H which goes from a maximum height Hm at the end of the crosspiece to a minimum height in the middle of the crosspiece and which is slightly lower than the maximum height. The anchoring elements 40a, b extend over at least 80% of the height H of the crosspiece 10À, said height being considered at the location where each anchoring element 40a, b is located. In this way, the contact surface between the anchoring elements 40a, b and the ballast grains positioned in the housings 42a, b and 44a, b is thus optimized.

The anchoring elements 40a, b have a triangle shape in top view (or in cross section) and which extends over the entire height of the crosspiece 10B. However, the anchoring elements can have other shapes and for example be of square, rectangular or semi-circular section.

The crosspiece 10B is symmetrical on either side of a longitudinal axis. Thus, each anchoring element 40a of the first sidewall 32a is aligned with an anchoring element 40b of the second sidewall 32b. In other words, the anchoring elements of the two opposite side walls 32a and 32b are aligned two by two along an axis perpendicular to the longitudinal axis of the crosspiece. The crosspiece 10B is thus stabilized in an identical manner on each of its lateral sides.

The anchoring elements 40a are spaced apart by a distance D1 with the internal side wall 24a and the two anchoring elements 40a are spaced apart by a distance D2, the distance D2 being greater than the distance D1. The distances D1 and D2 are measured between the axes of vertical symmetry of the anchoring elements 40a and the internal side walls 24a.

According to possible embodiment variants, the distances D1 and D2 may be equal or the distance D1 may be greater than the distance D2. Furthermore, according to other possible variants, the crosspiece can comprise a single anchoring element on each of the lateral sides 32a and 32b like the crosspiece 10C illustrated in Figure 5, or comprise three or four anchoring elements on each of the lateral flanks 32a and 32b.

With reference to Figure 4, a crosspiece 10C according to a variant of the second embodiment can comprise a single anchoring element 40a, b positioned in the middle of the lateral side 32a, b, the other elements of the crosspiece being identical to the crosspiece 10B.

With reference to Figure 5, a railway track 50 according to one embodiment comprises a plurality of sleepers 10B such as those described according to the first or second embodiment as well as two rails 52 fixed to the attachment devices 28 of each of the sleepers.

The railway track is thus more stable than a railway track comprising only sleepers according to the prior art and can allow high-speed train traffic.

EXAMPLES

Tests were carried out in the laboratory to assess the strength of the anchoring of the sleepers in ballast.

The tests were carried out on 10À-C sleepers according to the invention and on a TC sleeper of the prior art. All sleepers are made of concrete and have a density greater than 1.8. The dimensions of the different sleepers tested are detailed below.

- Crossbar 10A

• Maximum height (Hm) = 200 mm

• Maximum length (Im) = 2260 mm

• Maximum width (L3) = 300 mm

• Length of the support portion (11) = 661 mm

• Length of recess 16a, b (12) = 497 mm

• Height of the recess (He) = 136 mm

• Depth of the recess (L1) = 63 mm

• Distance between two internal side walls 24a, b (13) = 972 mm

• Weight = 205 kg - Crossbar 10B

• Maximum height (Hm) = 200 mm

• Maximum length (Im) = 2260 mm

• Maximum width (L3) = 300 mm

• Length of the support portion (11) = 661 mm

• Length of recess 16a, b (12) = 497 mm

• Height of the recess (He) = 136 mm

• Depth of the recess (L1) = 63 mm

• Length of anchoring elements 40a, b (L4) = 53 mm

• Distance between two anchoring elements 40a, b (D2) = 481 mm

• Distance between two internal side walls 24a, b (13) = 972 mm

• Distance between a side wall 24a, b and an anchoring element 40a, b (D1) = 255 mm

• Weight = 220 kg

- Following 10C sleepers:

• Maximum height (Hm) = 200 mm

• Maximum length (Im) = 2260 mm

• Maximum width (L3) = 300 mm

• Length of the support portion (11) = 661 mm

• Length of recess 16a, b (12) = 497 mm

• Height of the recess (He) = 136 mm

• Depth of the recess (L1) = 63 mm

• Length of anchoring elements 40a, b (L4) = 53 mm

• Distance between two internal side walls 24a, b (13) = 972 mm

• Distance between a side wall 24a, b and an anchoring element 40a, b (D1) = 486 mm

• Weight = 215 kg

- TC crossbar

• Maximum height (Hm) = 200 mm

• Maximum length (Im) = 2260 mm

• Maximum width (L3) = 300 mm

• Weight = 290 kg

Test protocol: With reference to Figure 7, a ballast bed 60 with a volume of approximately 2.5 to 3 m ³ is formed in a tank 62 with a length of 4 m, a width of 1.5 m and with a height of 0.4 m.

The sample 70 tested corresponds to two sleepers 10 spaced at a distance of 600 mm and to which two portions of rail 64 are fixed, each portion of rail 64 having a length of 1250 mm. The sleepers 10 are anchored in the ballast so that the ballast surrounds the side walls of the sleepers and only the surface 26 of the sleeper emerges from the ballast. A layer of ballast with a height of 350 mm is then present under the sleepers.

A force is then applied to one of the rails 64 by means of a hydraulic cylinder 68 in a horizontal direction and perpendicular to the longitudinal axis of the rail 64. The force presents a load increase of 6 kilonewton/minute or 6kN/min .

A device 66 makes it possible to measure the movement of the sample in the direction of the applied force. Several tests are carried out for each sample.

The graph in Figure 8 represents the average force applied to the different samples so that they move 2 mm and 4 mm, the unit kN/TB meaning kilonewton per concrete sleeper.

The graph in Figure 8 represents the values obtained for four samples, the first comprising two TC sleepers (sample 70TC), the second comprising two 10À sleepers (sample 70À), the third comprising two 10B sleepers (sample 70B) and the fourth comprising two 10C sleepers (sample 70C).

We can see that the force to be applied for the 70À sample is similar to that applied for the 70TC sample, which means that the anchoring of these two samples is similar. Indeed, for samples 70TC and 70À, a force of 3.90 kN/TB and 3.75 kN/TB respectively must be applied for the sample to move by 2 mm, and a force of 4.40 kN/ TB and 4.20 kN/TB respectively must be applied for the sample to move 4 mm. The recesses allowing ballast grains to be accommodated therefore make it possible to compensate for the lightening of the crosspiece since the anchoring of the sample 70À comprising two crosspieces of 205 kg is equivalent to the anchoring of the sample 70TC comprising two crosspieces of 290 kg.

These tests also show that the force to be applied for samples 70B and 70C comprising sleepers having anchoring elements must be greater than for samples 70TC and 70À not having anchoring elements. Indeed, for samples 70B and 70C, a force of 5.20 kN/TB and 5.10 kN/TB respectively must be applied for the sample to move by 2 mm, and a force of 5.40 kN/ TB must be applied so that the sample moves 4 mm. The anchoring elements therefore make it possible to significantly improve anchoring while reducing the weight of the sleepers used, and therefore limiting the quantity of raw material used during manufacturing and the carbon footprint linked to manufacturing.

Claims

1. One-piece concrete railway sleeper (10A, 10B, 10C) intended to be anchored in the ballast and to support railway rails (52), said sleeper (10A, 10B, 10C) comprising a portion central portion (12) and two rail support portions (14) positioned on either side of the central portion (12), each of the two rail support portions (14) comprising at least one recess (16a, b) , said recess being formed by a lateral flank (18a, b) of rail support (14) and by three walls (20a, b, 22a, b, 24a, b) emerging from said lateral flank (18a, b) and being configured to accommodate grains of ballast when the sleeper (10A, 10B, 10C) is in the functional position on the ballast of the railway, in which each portion of rail support (14) has a length 11 and the bottom wall ( 20a, b) extends over at least 80% of the length 11.

2. Crossbar (10A, 10B, 10C) according to claim 1, in which the three walls are connected together so as to form a “U”.

3. Crossbar (10A, 10B, 10C) according to claim 1 or 2, in which at least one of the three walls (20a, b, 22a, b, 24a, b) of said at least one recess (16a, b) is extends laterally over a distance L1 greater than or equal to 30 mm.

4. Crossbar (10A, 10B, 10C) according to any one of claims 1 to 3, in which the three walls are a bottom wall (20a, b) and two side walls (22a, b, 24a, b), the bottom wall (20a, b) forming an angle with the lateral flank (18a, b) of the rail support portion (14) of a value ranging from 90° to 150°, preferably ranging from 100° to 135°.

5. Crossbar (10A, 10B, 10C) according to any one of claims 1 to 4, in which the central portion (12) comprises two side walls (32a, b) and in which at least one anchoring element (40a , b) emerges from each of the two lateral flanks (32a, b), said at least one anchoring element (40a, b) extending in a direction perpendicular to the plane of the lateral flanks (32a, b).

6. Crossbar (10À, 10B, 1OC) according to claim 5, in which each anchoring element (40a, b) extends from a lateral flank (32a, b) of the central portion (12) on a length L4 greater than or equal to 30 mm.

7. Crossbar (10À, 10B, 10C) according to claim 5 or 6, in which one of the side walls is an internal wall (24a, b) positioned between the lateral flank (18a, b) of the rail support portion ( 14) and the lateral side (32a, b) of the central portion (12) and in which a housing (42a, b) is formed between said at least one anchoring element (40a, b) and the internal wall (24a , b), said housing (42a, b) being configured to accommodate ballast grains.

8. Crosspiece (10À, 10B, 10C) according to any one of claims 5 to 7, in which said at least one anchoring element (40a) emerging from a lateral side (32a) and said at least one element d The anchor (40b) emerging from the opposite side flank (32b) are aligned two by two.

9. Crossbar (10À, 10B, 10C) according to any one of claims 1 to 8, having a density greater than or equal to 1.8.

10. Railway track comprising at least one sleeper (10À, 10B, 10C) according to any one of claims 1 to 9.