SINGLE-BLOCK CROSS BEAM WITH AN INTERNAL CAVITY

Abstract

The invention relates to a concrete railway sleeper, the sleeper comprising a central portion (12) and two rail support portions (14) positioned on either side of the central portion (12), the sleeper having a longitudinal axis extending from one rail support portion to the other, the sleeper having at least one empty internal cavity (60) extending along the longitudinal axis in the central portion. Figure for the abbreviation: Fig. 2b

Description

Title of the invention: MONOBLOCK CROSSMEMBER WITH AN INTERNAL CAVITY Scope of the invention

[0001] 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. EARLIER ART

[0002] Railway tracks are generally formed by two rails along which trains travel. The rails are fixed to sleepers that extend perpendicularly to the rails and are anchored in a bed of ballast. The ballast is made up of a multitude of pebbles, also called ballast grains.

[0003] When traveling on railway tracks, trains generate significant vibrations and exert considerable forces on the rails, particularly lateral forces on curves. The sleepers then serve to maintain the rails parallel to each other and also to keep the sleeper / rail assembly firmly anchored in the ballast in a fixed position with good stability, despite the vibrations and forces exerted on the rails. For trains traveling at high speeds, the sleeper / rail assembly is subjected to even greater vibrations and forces.

[0004] Sleepers can be made of various materials such as wood, concrete, or, more recently, polymer or composite materials. However, wood, polymer, and composite materials are not sufficiently heavy and / or strong for use on railway tracks used by high-speed trains and / or tracks with long welded rails. Because such sleepers are lightweight, they are not sufficiently anchored in the ballast to ensure good stability of the sleeper / rail assembly. Concrete sleepers, with their high density, particularly between 2 and 2.5, and good strength, are therefore preferred, especially for railway tracks used by high-speed trains and / or tracks with long welded rails.

[0005] However, the manufacture of concrete sleepers involves the consumption of natural resources such as water, gravel, sand, and the constituents of cement (clay and limestone), and therefore results in a significant carbon footprint. For example, a sleeper conforming to the standard gauge used by the SNCF has It has a length of 2260 mm and a trapezoidal cross-section with a base of 300 mm and a height of 170 mm. Such a standard crossbeam weighs 290 kg and generates 46 kg of CO2 during its manufacture. Description of the invention

[0006] An objective of the invention is to reduce the amount of materials used in the manufacture of the concrete sleeper while maintaining, or even improving, its stability in functional position, and in particular its anchoring in the ballast.

[0007] For this purpose, the invention has as its first object a concrete railway sleeper, the sleeper comprising a central portion and two rail support portions positioned on either side of the central portion, the sleeper having a longitudinal axis extending from one rail support portion to the other, the sleeper having at least one empty internal cavity extending along the longitudinal axis in the central portion.

[0008] The sleeper thus contains less concrete compared to a prior art sleeper. The weight of the sleeper is therefore reduced, and the quantity of materials used to manufacture it, particularly water, cement, or sand, can be decreased. The sleeper therefore has a lower carbon footprint while maintaining the same stability as a prior art sleeper, since its external shape can be similar to prior art sleepers.

[0009] An internal cavity is understood to be a cavity formed between two lateral sides of the crossbeam and which does not open onto either of the lateral sides. In cross-section, the cavity may be closed in all radial directions and thus be completely surrounded by concrete, or it may be open on an upper or lower surface of the crossbeam, thus forming a longitudinal trench. The cavity may also be closed along one longitudinal portion and open along another longitudinal portion.

[0010] The concrete totally or partially surrounding the cavity then forms the solid part of the cross-section and the cross-section of the cavity is chosen so that there is enough concrete around it and the cross-section is sufficiently strong.

[0011] When terms such as "upper", "lower", "above" or "below" are used, they refer to a sleeper in the position of use on a ballast bed.

[0012] The longitudinal axis extends in the sleeper from one rail support section to the other, passing through the central section. When the sleeper is in its operating position on ballast, the longitudinal axis is substantially parallel to the ground.

[0013] The cross member may have a single cavity or, conversely, several cavities distributed within the cross member. When the cross member has several cavities, it may have several cavities along the longitudinal axis and / or several cavities along radial directions. The cavities can, for example, be positioned successively along the longitudinal axis, either staggered or aligned. The cavities can also be positioned successively in a radial direction, either staggered or aligned.

[0014] The cross member is preferably monobloc, meaning that it is manufactured in one piece and from the same material for its different parts. The cross member may nevertheless include additional internal or external elements such as, for example, reinforcing elements or fastening devices which are integrated during manufacturing or fixed to the cross member after its manufacture.

[0015] Preferably, the concrete sleeper should have dimensions corresponding to standard sleepers so that it can be handled and put in place according to the usual procedures.

[0016] According to particular embodiments of the invention which may be taken alone or in combination: - in cross-section, the cavity is closed in all radial directions; - in cross-section, the cavity is open on an upper or lower surface of the cross member; - the cavity is elongated along the longitudinal axis; the cavity can thus have a greater or lesser length without weakening the cross member; when the cross member has several cavities, at least some, or even all, of the cavities can be elongated along the longitudinal axis; - a section of the cavity can be, for example, round, oval, rectangular, triangular... - the cavity is profiled, preferably along the longitudinal axis; the surface area of ​​the cross section is then constant along the longitudinal axis, which avoids inducing areas of weakness in the cross member; - the cavity or at least one of the cavities also extends into at least one of the support portions; this allows the cavity to be lengthened and thus its volume increased without too much widening of the cross-section of the cavity so as not to weaken the sleeper; according to a possible variant, the cavity or at least one of the cavities extends into both rail support portions; - each rail support section terminates with an end face, the cavity opening onto at least one of the end faces; thus, the length of the cavity is optimized; moreover, the opening on at least one of the end faces can allow ballast grains to position themselves spontaneously in the cavity, thus contributing to stabilizing the sleeper; according to a possible variant, the cavity can open onto both end faces; - the cavity has a cross-section with a surface area between 1,000 mm2 and 10,000 mm2 inclusive; the cross-sectional area of ​​the cavity can be adapted to choose the volume of the cavity and obtain the desired lightness of the cross-section; - the cross-section is a first cross-section and the two rail support portions each have a second cross-section, an area of ​​the first cross-section is between 5% and 50% inclusive of the area of ​​the second cross-section; this reinforces the advantage that the cavity is surrounded by enough concrete for the sleeper to have sufficient strength; the cross-section of the sleeper is thus chosen according to the desired weight reduction and in such a way as to maintain a minimum strength of the sleeper; - Each of the two rail support sections has at least one external lateral recess; this recess allows ballast grains to be accommodated when the sleeper is installed in the operating position on a bed of ballast; the sleeper is thus firmly anchored in the ballast and is therefore more stabilized than a sleeper without a recess; indeed, the ballast grains which are arranged in the recess help to hold the sleeper which thus moves less easily under the effect of passing trains; moreover, points of contact between the ballast grains and also between each ballast grain and the sleeper create frictional forces which make the movement of the sleeper even more difficult;Furthermore, the presence of a recess reduces the amount of concrete used to manufacture the sleeper, thus reducing the amount of water and materials used to manufacture the sleeper, and also the amount of CO2 emitted during its manufacture; - the recess extends over at least 80% of the length of the rail support section; the recess thus has an optimized length allowing for more ballast grains to stabilize the sleeper; moreover, the recess extends even below the rail, and on both sides of the rail, when the sleeper is installed, which allows the sleeper to be stabilized as close as possible to the vibrations caused by passing trains; - the recess has a depth greater than or equal to 30 mm, the depth being measured in a horizontal plane; the recess thus has a depth greater than half of a possible dimension of the ballast grains which can classically range from 31.5 to 50 mm, which makes it possible to guarantee that at least some ballast grains have their center of gravity positioned in the recess and that their weight contributes to ballasting the sleeper by creating weight in the recess; - the central section comprises two lateral sides and anchoring elements projecting from the respective lateral sides; the anchoring elements improve the stability of the sleeper in the ballast bed, particularly due to the ballast grains which are positioned on either side of these anchoring elements when the crossbar is in a functional position; - the central portion has at least one ballast grain receiving housing, the housing being contiguous to the anchoring element or to at least one of the anchoring elements; the housing thus makes it possible to stabilize the sleeper by receiving ballast grains without adding weight to the sleeper; preferably the housing does not have a bottom face; - the housing is delimited by two of the anchoring elements or by the anchoring element and one of the support portions; the ballast grains are thus retained in the housing; when the housing is delimited by two anchoring elements, they extend over the same width; - the width of the central portion is less than the width of the rail support portions; the rail portions thus protrude from the central portion, preferably by a width equivalent to the width of the anchoring elements; - the anchoring element(s) extend from one of the side sides over a width greater than or equal to 30 mm; this width allows the ballast grains to have at least half of one of their dimensions inside the housing; and - the anchoring element(s) extend over at least 80% of a height of the sleeper; the housing is thus formed over at least 80% of this height, which allows several ballast grains to be stacked according to the height.

[0017] The invention has as its second object a railway track comprising at least one sleeper according to the first object.

[0018] The railway track is thus more stable than a railway track consisting solely of sleepers according to the prior art.

[0019] 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.

[0020] The invention has as its third object the use of a previously described sleeper in which the sleeper is installed on a railway track leaving the cavity empty.

[0021] The cavity is thus not used for any purpose other than to lighten the crossbeam. At most, when the cavity opens onto one or both end faces, a few grains of ballast may enter one or both of the opening ends of the cavity.

[0022] However, the introduction of the ballast grains is spontaneous and inevitable in this case and does not result from the intervention of an operator. Furthermore, the majority of the cavity remains empty. Brief description of the Figures

[0023] Other features and advantages of the invention will become apparent from the following description, given solely by way of example and with reference to the accompanying drawings, in which:

[0024] - Fig. 1a represents a schematic and perspective view of a cross member along a first embodiment of the invention; - Figure 1b represents a perspective and cross-sectional view of the cross member of figure 1a; - the figure represents a schematic top view of the cross member of figure la; - Figure Id represents a schematic side view of the cross member in Figure Ia; - Figure 2a represents a schematic top view of a cross member according to a variant of the first embodiment of the invention; - Figure 2b represents a schematic and perspective view of the crossbeam in Figure 2a; - [Fig.2c] represents a schematic and cross-sectional view of a variant of the cross member of [Fig.2a]; - Figure 3a represents a schematic perspective view of a cross member according to a second embodiment of the invention; - Figure 3b represents a schematic top view of the cross member in Figure 3a; - [Fig.3c] represents a schematic side view of the crossbeam of [Fig.3a]; and - [Fig.4] represents schematically in top view a railway track according to an embodiment of the invention. Detailed description of an example of implementation

[0025] With reference to figures 1a to 1d, a railway sleeper 10A according to a first embodiment of the invention comprises a central portion 12 and two rail support portions 14 (or support portions) positioned on either side of the central portion 12. The support portions 14 are more particularly positioned at each end of the sleeper 10. The sleeper 10A has a longitudinal axis extending from one support portion 14 to the other.

[0026] The crossbeam 10A has an empty internal cavity 60, visible in [Fig. 1b], extending along the longitudinal axis (X). The cavity 60 forms a hollow portion of the crossbeam 10A, and the concrete surrounding the cavity forms a solid portion 62 of the crossbeam. In this embodiment, the internal cavity is said to be "closed" because, in cross-section, it is completely surrounded by concrete. However, according to a possible variant, the internal cavity could be open on an upper 26 or lower surface of the crossbeam.

[0027] The sleeper 10A is in this case a single-piece concrete unit with an elongated shape and an overall square cross-section. The density of the solid part 62 of the sleeper is in this example at least 1.8, preferably at least 2, and for example 2.4. In this way, the sleeper is sufficiently heavy and stable when in its operating position and can thus be used for railway tracks on which high-speed trains run.

[0028] The central portion 12 preferably has a width L2 less than a width L3 of the rail support portions 14, the width being measured in a horizontal direction and perpendicular to the longitudinal axis X. The separation between each support portion 14 and the central portion 12 is made in a narrowing zone 13, the central portion 12 corresponding to the entire part of the sleeper which is located between the support portions 14 and which has a width L2.

[0029] The reduced width of the central portion 12 compared to the rail support portions 14 allows the sleeper 10A to be lighter than a sleeper with a width equal to that of the rail support portions along its entire length, while still being sufficiently anchored in the ballast. This sleeper shape thus reduces the amount of concrete used in its manufacture, thereby also limiting the amount of water and materials used, and the amount of CO2 emitted, during its production.

[0030] The cavity 60 is in this case elongated along its longitudinal axis, which allows the void to be distributed along the length of the sleeper. The length of the cavity can be adapted to the desired void volume inside the sleeper. The void volume is specifically chosen to find a compromise between a weight sufficiently reduced to limit the amount of material used in manufacturing the sleeper and a weight sufficient to ensure the sleeper's stability on the ballast bed.

[0031] In this embodiment, the cavity 60 has a round and closed cross-section, as illustrated in particular in [Fig.lb], but the section may have other shapes and be for example oval, square or rectangular, and possibly open on the upper or lower surface of the cross-section.

[0032] The cavity 60 is profiled and thus has a constant cross-section along its entire length. Preferably, the cavity 60 is concentric with the longitudinal axis X so that the amount of concrete surrounding the cavity 60 is uniform along its entire length. Therefore, the crossbeam does not have any weak points where the amount of concrete surrounding the cavity could be insufficient.

[0033] The invention is not limited to a single cavity, and the cross member may comprise several cavities. The cavities may then be aligned along the longitudinal axis and / or in radial directions. When the cross member comprises several cavities, they can all be open, all closed, or some cavities can be open and some cavities can be closed.

[0034] The cavity 60, or cavities if the sleeper has several, can also extend into at least one of the support portions 14, as is the case in [Fig. 2a], or even into both rail support portions 14. The range of possible lengths for the cavity is therefore large and allows for a wide choice of void volume in the sleeper. When a sleeper of standard length of 2260 mm has a single cavity, the latter can have a length between 1000 mm and 2260 mm inclusive. Generally speaking, the length of a cavity or the sum of the lengths of several cavities aligned along the longitudinal axis can be between 20% and 100% inclusive of a maximum length of 1 m of the sleeper.

[0035] Each rail support section 14 terminates in an end face 15 that extends substantially perpendicularly to the longitudinal axis. According to an alternative embodiment shown in Figures 2a and 2b, the cavity 60 can then open onto at least one of the end faces 15. When the sleeper 10A has several cavities aligned along the longitudinal axis, at least one of the sleeper's cavities can then open onto at least one of the end faces 15. The cavity, or one of the cavities, thus forms an opening 63 on the end face. This opening 63 allows ballast grains to naturally position themselves in the cavity 60 without operator intervention, thereby helping to stabilize the sleeper 10A when it is in its operating position.

[0036] According to another possible embodiment, the cavity 60 can also open onto each of the end faces 15 and thus be through-hole. When the cross member 10A has several cavities aligned along the longitudinal axis, one of the cavities can open onto one end face 15 and another cavity can open onto the other end face 15.

[0037] The cavity 60 has a first cross-section which can have a surface area between 1,000 mm² and 10,000 mm² inclusive. Such a cross-section ensures that the volume of the solid part 62 of the cross member 10A, which totally or partially surrounds the cavity 60, is sufficiently large to maintain the cross member's strength. The volume of the cavity can thus be chosen by determining the length of the cavity and the first cross-section, in order to obtain a compromise between reducing the cross member's weight and maintaining its strength.

[0038] When the cross member has several cavities in a radial direction, the sum of the areas of the first cross section of the different cavities can be between 1,000 mm2 and 10,000 mm2 inclusive.

[0039] The solid part of the cross member 10A totally or partially surrounding the cavity 60 or the cavities is then sufficiently thick to ensure the solidity of the cross member.

[0040] In this case, the support portions 14 have a second cross-section, and the area of ​​the first cross-section can have a value between 5% and 50% (inclusive) of the area of ​​the second cross-section. The second cross-section corresponds to the entire cross-section, which therefore includes the solid part and the first cross-section.

[0041] Furthermore, the central portion 12 has a third cross-section, and the area of ​​the first cross-section can have a value between 5% and 50% (inclusive) of the area of ​​the third cross-section. The third cross-section corresponds to the entire cross-section, which therefore includes the solid part and the first cross-section.

[0042] In addition, the sleeper 10A has two fastening devices 28 onto which iron rails can be conventionally fixed. In particular, one fastening device is positioned on the upper surface 26 of each rail support portion 14.

[0043] The sleeper 10A is intended to be anchored in a conventional manner in a ballast bed. When the sleeper 10A is in its operating position in the ballast, it rests on ballast grains and its lateral faces are surrounded by ballast grains. In this position, the upper surface 26 of the sleeper 10A emerges from the ballast grains.

[0044] According to an alternative embodiment shown in the cross-section of the cross member 10A illustrated in [Fig.2c], the cavity 60 can be opened on the upper face 26 of the cross member.

[0045] According to this embodiment, where the sleeper extends into one or both rail support sections, the cavity is interrupted or closed under the rail so as not to weaken the sleeper in the portion of the sleeper most subjected to the weight of trains and the vibrations associated with their passage. In particular, the cavity is interrupted at least between the two fastening devices 28, and preferably over a portion extending from 20% to 80% of the length of the rail support section(s) 14, this portion including the two fastening devices 28.

[0046] When the internal cavity 60 is open on the upper surface 26 of the cross member, it may include openings leading onto one or both end faces, one or both lateral sides, and / or the lower surface of the cross member. The cavity then has a bottom comprising portions sloping down to the openings. These openings are intended to drain any water that may be present in the internal cavity, in particular rainwater.

[0047] In the embodiment illustrated in figures 1a-d and 2a-c, the cross member 10A has two external lateral recesses 16a,b on the lateral sides of each support portion 14. Each recess allows ballast grains to be held. When the sleeper is installed in its operating position on a ballast bed, the presence of ballast grains in the external lateral recesses 16a,b adds weight to each recess, thus increasing the weight of the support sections 14. The recesses 16a,b, which hold the ballast grains, therefore increase the anchorage of the sleeper 10A in the ballast, particularly the anchorage of the sleeper section most likely to move during train passage. Ballasting the sleeper with ballast grains at this support section 14 thus optimizes the stability of the sleeper 10A in the ballast.

[0048] In addition, points of contact between the ballast grains and also between each ballast grain and the sleeper 10A create frictional forces which limit, or even prevent, any movement of the sleeper.

[0049] Each recess 16a,b is formed by a lateral flank 18a,b of the support portion 14 as well as by three faces 20a,b, 22a,b and 24a,b projecting from the lateral flank 18a,b.

[0050] Advantageously, the recess 16a,b is positioned at the level of the support portion 14 because it is the portion of the sleeper 10A on which the railway rails rest when the latter is in its position of use, and therefore the portion of the sleeper 10A which particularly needs to be stabilized.

[0051] Face 20a of the recess forms a bottom face, face 22a is an outer lateral face, and face 24a is an inner lateral face. In this embodiment, the three faces 20a, 22a, and 24a extend laterally over a distance L1 greater than or equal to 30 mm. Thus, the recess has a height and depth substantially equal to or greater than the largest dimension of a ballast grain. In this way, at least some ballast grains have the majority of their volume within the recess, and the weight of each ballast grain contributes to increasing the weight of the sleeper by exerting pressure on the bottom face 20a. The depth L1 corresponds to the distance between the lateral side 18a of the support portion 14 and a free edge 17a of the bottom face 20a.

[0052] Furthermore, the recess 16a has an average height He defined as the average vertical distance between the upper surface 26 of the cross member and an upper surface of the free edge 17a of the bottom face 20a. The height He is also greater than or equal to 30 mm, and preferably between 120 and 200 mm inclusive.

[0053] The bottom face 20a, in particular its upper surface, forms an angle with the lateral side 18a having a value of 120°. Advantageously, the inclination of the bottom face 20a is a compromise between an inclination shallow enough to allow the ballast grains to remain in place in the recess 18a and an inclination sufficient to reinforce the bottom face 20a and prevent it from breaking under the effect of the ballast grains or during handling. Furthermore, the inclination of the The bottom face 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 strength.

[0054] According to possible embodiments, the inclination of the bottom face 20a can have a value between 95° and 150° inclusive, preferably between 100° and 135° inclusive, with respect to a vertical plane.

[0055] Each rail support section 14a has a length 11, and the bottom face, in particular the free edge 17a,b of the bottom face 20a, extends over a length 12 at least equal to 80% of the length 11. The length of the recess 16a,b is thus optimized so as to increase the weight of the sleeper over a large part of the rail support section 14a, which is the portion most subject to movement due to the passage of trains. In particular, the recess 16a,b even extends under the rail when the sleeper is in its operational position to form a railway track.

[0056] In this embodiment, the central portion 12 has two lateral sides 32a and 32b which are flat.

[0057] We will now present a second embodiment. Only the features differing from those of the first embodiment will be described.

[0058] In the second embodiment shown in Figures 3a, 3b and 3c, a sleeper 10B differs from the sleeper 10A in that it has two anchoring elements 40a,b which project from the lateral sides 32a,b of the central portion in a transverse direction. When the sleeper 10B is in its operating position on the ballast grains, ballast grains are arranged on either side of the anchoring elements 40a,b, thereby improving the stability of the sleeper.

[0059] The central portion 12 then has a width L2 which is measured between the anchoring elements 40a,b and which corresponds to the distance separating the two lateral sides 32a and 32b.

[0060] Sometimes, in the continuation of the description of this second embodiment, only the elements of one of the lateral faces of the cross member 10A will be described (elements indexed "a") but the description also applies to the other lateral face which is identical (elements indexed "b").

[0061] The two anchoring elements 40a allow three housings to be formed along the face of the lateral side 32a and 32b. A first housing 44a is formed between the two anchoring elements 40a and two housings 42a are formed between each anchoring element 40a and the support portion 14 which is juxtaposed to them.

[0062] In the case where the cross member 10B has a single anchoring element 40a, two housings are formed between the anchoring element 40a and each of the support portions 14 which is juxtaposed to it.

[0063] The recesses 42a,b and 44a,b formed along each lateral side 32a,b accommodate ballast grains and thus further improve the stability of the sleeper 10B when in use. Indeed, the points of contact between the ballast grains, and also between each ballast grain and the sleeper, create frictional forces that make it more difficult for the sleeper 10B to move when trains pass.

[0064] In this embodiment, a distance D2 between two anchoring elements 40a,b is greater than the distance DI between an anchoring element and the inner face 24a. However, the anchoring elements can be distributed differently.

[0065] The sleeper 10B has an average height H ranging from a maximum height Hm at the end of the sleeper to a minimum height in the middle of the sleeper, the minimum height being slightly less than the maximum height. The anchoring elements 40a,b extend over at least 80% of the height H of the sleeper 10A, the height being considered at the location of each anchoring element 40a,b. In this way, the contact surface between the anchoring elements 40a,b and the ballast grains positioned in the recesses 42a,b and 44a,b is optimized.

[0066] The anchoring elements 40a,b have a triangular shape in top view and extend over at least 80% of the height of the cross member 10B. However, the anchoring elements may have other shapes and be for example square, rectangular or semi-circular in section.

[0067] Furthermore, the anchoring elements 40a emerge from the lateral side 32a by a distance L4 which is greater than or equal to 30 mm. The housings 42a and 44a thus have a lateral depth sufficient to accommodate at least half the volume of the ballast grains so that the latter contribute to stabilizing the sleeper.

[0068] The cross member 10B is symmetrical on both sides of the longitudinal axis X. Thus, each anchoring element 40a of the first lateral flank 32a is aligned with an anchoring element 40b of the second lateral flank 32b. In other words, the anchoring elements of the two lateral flanks 32a,b are aligned in pairs. The cross member 10B is therefore stabilized identically on each of its lateral flanks 32a,b.

[0069] According to another possible embodiment not shown, the cross member may have one or more anchoring elements on each lateral side of the central portion and may not have recesses in the rail support portions.

[0070] With reference to [Fig.4], a railway track 50 according to one embodiment of the invention comprises a plurality of sleepers 10 as described according to the first or second embodiment and two rails 52 fixed to the fastening devices 28 of each of the sleepers 10.

[0071] The railway track is thus more stable than a railway track consisting solely of sleepers according to the prior art and allows the circulation of high-speed trains.

[0072] During use, the sleeper A or B is placed on the ballast bed and partially embedded in the ballast bed, then the rails are fixed onto the support portions. The cavity is then left empty.

[0073] When the cavity opens onto one or both end faces, ballast grains may occupy the opening end of the cavity, but the cavity is not intended to accommodate other elements.

Claims

Demands

1. Railway sleeper (10A, 10B) made of concrete, the sleeper 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) having at least one external lateral recess (16a,b), each external lateral recess being configured to accommodate ballast grains so as to weight the rail portions, the sleeper having a longitudinal axis extending from one rail support portion to the other, the sleeper (10A, 10B) having at least one empty internal cavity (60) extending along the longitudinal axis (X) in the central portion (12).

2. Railway sleeper (10A, 10B) according to claim 1, wherein, in cross-section, the cavity (60) is closed in all radial directions.

3. Railway sleeper (10A, 10B) according to claim 1, wherein, in cross-section, the cavity (60) is open on an upper (26) or lower surface of the sleeper (10A, 10B).

4. Cross member (10A, 10B) according to any one of the preceding claims, wherein the cavity (60) is elongated along the longitudinal axis (X).

5. Cross member (10A, 10B) according to any one of the preceding claims, wherein the cavity (60) is profiled.

6. Cross member (10A, 10B) according to any one of the preceding claims, wherein the cavity (60) or at least one of the cavities (60) also extends into at least one of the rail support portions (14).

7. Cross member (10A, 10B) according to any one of the preceding claims, wherein each rail support portion (14) terminates with an end face (15), the cavity (60) opening onto at least one of the end faces (15).

8. Cross member (10A, 10B) according to any one of the preceding claims, wherein the cavity (60) has a cross section having an area between 1,000 mm2 and 10,000 mm2 inclusive.

9. Cross member (10A, 10B) according to the preceding claim, the cross section being a first cross section, the two portions

10.

11.

12.

13.

14.

15.

16.

17.

18. of rail support (14) each have a second cross-section, an area of ​​the first cross-section is between 5% and 50% inclusive of the area of ​​the second cross-section. Cross member (10A, 10B) according to any one of the preceding claims, wherein the recess (16a,b) extends over at least 80% of a length (11) of the rail support portion (14). Cross member (10A, 10B) according to any one of the preceding claims, wherein the recess (16a,b) has a depth greater than or equal to 30 mm, the depth being measured in a horizontal plane. Cross member (10A, 10B) according to any one of the preceding claims, wherein the central portion (12) comprises two lateral flanks (32a,b) and anchoring elements (40a,b) projecting from the respective lateral flanks (32a,b). Crossbeam (10A, 10B) according to the preceding claim, wherein the central portion (12) has at least one ballast grain receiving housing, the housing being contiguous to the anchoring element (40a,b) or to at least one of the anchoring elements (40a,b). Cross member (10A, 10B) according to claim 13, wherein the housing is delimited by two of the anchoring elements (40a,b) or by the anchoring element (40a,b) and one of the support portions (14). Cross member (10A, 10B) according to claim 13 or 14, wherein the anchoring element or each anchoring element (40a,b) extends from one of the lateral sides (32a,b) over a width (L4) greater than or equal to 30 mm. Cross member (10A, 10B) according to any one of claims 12 to 15, wherein the anchoring element or each anchoring element (40a,b) extends over at least 80% of a height H of the cross member (10A). Railway track comprising at least one sleeper (10A, 10B) according to any one of claims 1 to 16. Use of the sleeper (10A, 10B) according to any one of claims 1 to 16, wherein the sleeper (10A, 10B) is installed on a railway track leaving the cavity empty.

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