Self-weathering concrete and steel bridge requiring no heavy maintenance

Abstract

A bridge (2) comprising a support slab (20) having an upper face arranged to support a traffic lane (1) and a lower face opposite the upper face, said bridge (2) further comprising a plurality of reinforcing members (21) attached at least to the lower face of the support slab (20) so as to improve its mechanical resistance, said support slab (20) being at least partially made of concrete and the plurality of reinforcing members (21) being at least partially made of weathering steel, said support slab (20) at least partially encasing said reinforcing members (21). Figure 1

Description

Title of the invention: Self-skidding concrete and steel bridge requiring no heavy maintenance. Technical field

[0001] The present invention relates to the field of bridges, in particular railway bridges.

[0002] A railway track comprises, in a known manner, two parallel longitudinal rails fixed to a plurality of sleepers arranged perpendicular to the rails. The sleepers themselves rest on a rigid support or on ballast supporting the railway track.

[0003] In order to ensure the continuity of the railway line over obstacles, such as, for example, gaps, roads, railway lines or watercourses, it is known to provide railway bridges at these locations to support the track. Such bridges can be made of metal and / or concrete.

[0004] A railway bridge most commonly comprises, in a known manner, a concrete support slab configured to support a section of railway track. The support slab is configured to receive and support the plurality of sleepers or the ballast on which the plurality of sleepers rests. The assembly comprising the support slab, the section of railway track, the plurality of sleepers and / or the ballast forms the deck of the railway bridge.

[0005] Railway bridges are generally designed with significant dimensions, particularly the deck thickness, which determines their resistance to the passage of a vehicle such as a train. The available height around the track for designing the deck is a key criterion for choosing the type of bridge to be used.

[0006] Over time, railway bridges require significant maintenance. In particular, the paint deteriorates and necessitates extensive and regular repainting. Furthermore, water can stagnate on the concrete supporting the ballast or directly on the sleepers, which can cause concrete deterioration. To remedy this waterproofing problem, it is necessary to remove all the track from the bridge, reseal it, and then reinstall the track. Such maintenance is time-consuming, expensive, disruptive, and halts train traffic on the track for the duration of the work.

[0007] Furthermore, it is known that the deck of the railway bridge is placed on bearing devices generally containing rubber or an elastomer so as to support and dampen the forces transmitted by the deck.

[0008] However, these support devices wear out over time and require maintenance and replacement when they show excessive wear. The replacement of The maintenance of the bridge deck requires lifting the bridge, replacing worn bridge deck supports with new ones, and reinstalling the deck. Such maintenance is time-consuming, expensive, disruptive, and halts traffic on the track for the duration of the work.

[0009] The invention thus aims to eliminate at least some of these drawbacks, in particular to reduce the heavy maintenance operations required for bridges. PRESENTATION OF THE INVENTION

[0010] The invention relates to a bridge comprising a support slab. The support slab has an upper face arranged to support a traffic lane and a lower face opposite the upper face. The bridge further comprises a plurality of reinforcing elements attached at least to the lower face of the slab so as to improve its mechanical resistance. The slab is at least partially made of concrete and the plurality of reinforcing elements are at least partially made of weathering steel. The slab at least partially encases the reinforcing elements.

[0011] Weathering steel advantageously eliminates the need for painting reinforcing elements exposed to external conditions, thereby reducing maintenance. The support slab, at least partially made of concrete and at least partially encasing the reinforcing elements, which are at least partially made of weathering steel, improves the bridge's mechanical strength. In particular, the combination of concrete and weathering steel increases the bond between the support slab and the reinforcing element, thereby strengthening the bridge structure.

[0012] Advantageously, the support slab comprises a proportion of ultra-high-performance fiber-reinforced concrete.

[0013] Ultra-high-performance concrete (UHPFRC) has a high binder content, resulting in the absence of capillary porosity in the support slab. Thus, UHPFRC prevents water infiltration and stagnation into the support slab. This increases the lifespan of the bridge's waterproofing, at least twice that of a conventional bridge. Ultra-high-performance concrete (UHPFRC) includes internal reinforcements that advantageously transmit mechanical forces to reinforcing elements, at least partially made of weathering steel. This improves the transfer of mechanical forces between the reinforcing elements and the internal reinforcements.

[0014] Advantageously, the support slab comprises a slab body and a waterproofing layer, the waterproofing layer covering the slab body and being interposed between the latter and said traffic lane, said waterproofing layer forming the proportion of ultra-high performance fiber-reinforced concrete of the support slab.

[0015] The ultra-high-performance fiber-reinforced concrete waterproofing layer protects the concrete slab, particularly from water ingress and stagnation. This increases the lifespan of the bridge's waterproofing, at least twice that of a conventional bridge. Furthermore, the waterproofing layer eliminates the need for maintenance and replacement of bridge waterproofing, namely removing the entire track, re-sealing, and reinstalling the track.

[0016] Advantageously, the sealing layer has a thickness of between 3cm and 5cm.

[0017] According to one variant, the support slab is entirely made of ultra-high performance fiber-reinforced concrete.

[0018] Advantageously, the bridge further comprises at least one support member of said bridge, said plurality of reinforcing members being embedded at least partially in said support member.

[0019] Advantageously still, the said plurality of reinforcing members is entirely embedded in the said support member.

[0020] The at least partial embedding of the plurality of reinforcing elements within the bearing eliminates the need for bearings made at least partially of rubber, and therefore their upkeep and maintenance. In particular, replacing said bearings requires lifting the deck to replace the bearing with a new one, which results in the suspension of traffic on the bridge.

[0021] According to a first embodiment, each reinforcement member comprises at least two self-weathering steel support beams, said support beams each being at least partially encased by the support slab.

[0022] According to a second embodiment, each reinforcement member comprises at least two support beams and a plurality of self-weathering steel fastening systems, the plurality of fastening systems protruding from each support beam, said fastening systems being encased by the support slab.

[0023] Advantageously, the bridge further comprises at least one reinforcement plate extending between the support beams and the underside of the support slab, the plurality of attachment systems projecting from said reinforcement plate.

[0024] Advantageously still, the plurality of fastening systems is derived from the material of the reinforcement plate.

[0025] Other features and advantages of the invention will become apparent from the following description, made with regard to the accompanying figures given by way of non-limiting examples and in which identical references are given to similar objects. PRESENTATION OF THE FIGURES

[0026] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0027] Fig. 1 is a front and cross-sectional view of a bridge according to a first embodiment of the invention, comprising a support slab attached to a plurality of reinforcing members, said plurality of reinforcing members being directly embedded in a support member;

[0028] Fig. 2 is an exploded perspective view of a variant of the bridge in Fig. 1, in which the plurality of reinforcing members is connected to bearing devices, themselves connected to the bearing member;

[0029] The [Fig.3] is an exploded perspective view of a variant of the bridge of the [Fig.1], in which the plurality of reinforcing members is entirely embedded in the support member;

[0030] Fig. 4 is a front and cross-sectional view of a bridge according to a second embodiment of the invention, in which the reinforcement member comprises a plurality of support beams partially encased by the support slab, the plurality of reinforcement members being connected to bearing devices, themselves connected to the bearing member;

[0031] [Fig.5] is a view similar to that of [Fig.4], in which the plurality of support beams is completely encased by the support slab;

[0032] Figure 6 is an exploded perspective view of the bridge in Figure 5; and

[0033] Fig. 7 is an exploded perspective view of a variant of the bridge in Fig. 4. in which the plurality of reinforcing members is entirely embedded in the supporting member.

[0034] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0035] The invention relates to a bridge 2, in particular a railway bridge, allowing the support of a traffic track 1, in particular a railway track, allowing the circulation of vehicles, in particular railway vehicles.

[0036] It goes without saying that the invention is not limited to the railway field but applies to any type of bridge intended to accommodate a traffic lane, road or pedestrian for example.

[0037] As illustrated in figures 1 and 2, the traffic track 1 comprises two parallel longitudinal rails 3 fixed on a plurality of sleepers 4 arranged perpendicular to the rails 3.

[0038] The sleepers 4 rest on ballast (not shown) which supports and stabilizes the traffic track 1. Of course, the sleepers 4 can rest directly on the bridge 2, as illustrated in the figures.

[0039] Bridge 2 includes a support slab 20.

[0040] The support slab 20 comprises an upper face and a lower face. The upper face is arranged to support a portion of the traffic lane 1, and the lower face is opposite the upper face. For example, the support slab 20 may have a length of 15 m, a width of 3.5 m, and a thickness of 15 cm.

[0041] According to the invention, the support slab 20 is at least partially made of concrete.

[0042] Thus, the support slab 20 may contain a proportion of concrete, and in particular a proportion of ultra-high-performance fiber-reinforced concrete (UHPFRC). UHPFRC is known to have a compressive strength of 130 to 250 MPa and a flexural strength of 20 to 50 MPa. Furthermore, UHPFRC has a high binder content, which results in the absence of capillary porosity.

[0043] As illustrated in figures 1 to 7, the support slab 20 can comprise a slab body 200 and a sealing layer 201.

[0044] The waterproofing layer 201 covers the slab body 200 and is interposed between said slab body 200 and the traffic lane 1. The waterproofing layer 201 is made of ultra-high performance fiber-reinforced concrete and forms the proportion of ultra-high performance fiber-reinforced concrete of the support slab 20.

[0045] The sealing layer 201 has a thickness of between 3cm and 5cm.

[0046] Such a thickness ensures proper implementation of the sealing layer 201 while limiting the risks of cracking and costs, in particular the costs related to the manufacture of said sealing layer 201.

[0047] The ultra-high-performance fiber-reinforced concrete waterproofing layer 201 protects the concrete slab body 200, for example, from water ingress and stagnation. The waterproofing layer 201 thus increases the service life of the bridge 2's waterproofing, making it at least twice as long as that of a conventional bridge.

[0048] The 201 sealing layer makes it possible to avoid the work involved in the maintenance and replacement of the waterproofing of bridges, namely removing all the track present on the bridge, redoing the waterproofing and reinstalling the track on the bridge.

[0049] Alternatively, the support slab 20 can be made entirely of concrete, in particular, of ultra-high performance concrete.

[0050] The ultra-high-performance fiber-reinforced concrete (UHPFRC) support slab 20 prevents water infiltration and stagnation. The UHPFRC thus increases the service life of the bridge 2's waterproofing, making it at least twice as long as that of a conventional bridge.

[0051] The UHPC support slab 20 eliminates the need for work caused by the maintenance and replacement of bridge waterproofing, namely removing all the track present on the bridge, redoing the waterproofing and reinstalling the track on the bridge.

[0052] It goes without saying that the support slab 20 could be made of a concrete mixture comprising, for example, UHPC and ordinary concrete.

[0053] Bridge 2 further includes a plurality of reinforcing elements 21.

[0054] The plurality of reinforcing members 21 is at least partially made of self-weathering steel.

[0055] In particular, the plurality of reinforcing members 21 may have a proportion of weathering steel, or be entirely of weathering steel. Weathering steel is available, for example, under the commercial name CORTEN.

[0056] The self-weathering steel of the plurality of reinforcing members 21 has the advantage of not requiring the application of a corrosion protection system, such as paint, to the reinforcing members 21.

[0057] Self-weathering steel eliminates the need for maintenance of paint or other corrosion protection systems to be applied to the reinforcing components 21.

[0058] In addition, each reinforcing member 21 comprises at least two support beams 23. Each support beam 23 can be a so-called PRS beam, i.e. a Welded Reconstituted Beam, or a so-called HEB or HEA rolled beam, i.e. an H or I beam with wide flanges, IPN, i.e. an I beam with a normal profile, or a so-called IPE beam, i.e. an I beam with a European profile, for example.

[0059] In other words, each support beam 23 comprises a first portion extending between the support on which the bridge 2 rests and the support slab 20, a second portion extending orthogonally to the first portion, between the latter and the support slab 20 and a third portion extending orthogonally to the first portion, between the latter and the support on which the bridge 2 rests.

[0060] As illustrated in figures 1 to 7, the support slab 20 at least partially encases the reinforcing members 21, so as to improve their mechanical resistance.

[0061] According to a first embodiment of the invention illustrated in figures 1 to 3, the plurality of reinforcing members 21 are attached to the underside of the support slab 20 so as to improve its mechanical resistance.

[0062] In particular, each reinforcing member 21 comprises at least two support beams 23. As illustrated in Figures 1 and 2, for example, the reinforcing member 21 comprises four support beams 23, juxtaposed to each other, according to the width of the support slab 20.

[0063] In addition, the reinforcing member 21 includes a plurality of attachment systems 24. These attachment systems 24 project from the second portion of each support beam 23, towards the support slab 20 and are embedded in the latter.

[0064] The 24 fastening systems are made of self-weathering steel.

[0065] Thus, the anchoring systems 24 are embedded at least partially in the concrete support slab 20. The contact between the concrete of the support slab 20 and the weathering steel of the anchoring systems 24 increases the adhesion between the support slab 20 and the reinforcing element(s) 21. This improved adhesion further enhances the mechanical strength of the slab and strengthens the bridge structure 2.

[0066] As illustrated in Figures 1 to 3, the bridge 2 may further comprise at least one reinforcing plate 25. This reinforcing plate 25 extends between the support beams 23 and the underside of the support slab 20. In particular, the reinforcing plate 25 extends between the second portion of each of the support beams 23 and the underside of the support slab 20. In this case, the plurality of attachment systems 24 protrude from the reinforcing plate 25, rather than from the second portion of the support beams 23.

[0067] The reinforcement plate 25 can for example be made of steel, in particular of self-weathering steel.

[0068] The fastening systems 24 can be fixed to the reinforcement plate 25 or made of material with the reinforcement plate 25.

[0069] Just like the fastening systems 24, the reinforcement plate 25 can be embedded in the support slab 20.

[0070] Thus, the reinforcing elements 21 constitute a tie rod, increasing the resistance capacity of the bridge structure 2 with respect to bending forces. The second portion of the support beams 23, the reinforcing plate 25, and / or the attachment systems 24 have a mechanical role in resisting most of the tensile forces due to the bending of the support slab 20 and allow for better control of the fatigue behavior of the structure due to variable stresses on the traffic lane 1, thereby giving it high durability.

[0071] According to a second embodiment illustrated in figures 4 to 7, the plurality of reinforcing members 21 is attached to the support slab 20 so as to improve its mechanical resistance.

[0072] In particular, and as shown in [Fig. 4], the plurality of reinforcing members 21 is partially encased by the support slab 20. Here, each support beam 23 and more particularly the second portion and part of the first portion of each support beam 23 is embedded in the support slab 20.

[0073] Each reinforcing member 21 comprises at least two support beams 23. As illustrated in [Fig.4], the reinforcing member 21 comprises eighteen support beams 23, juxtaposed to one another, according to the width of the support slab 20.

[0074] Each of the support beams 23 is made of weathering steel.

[0075] Thus, the support beams 23 are partially embedded in the support slab 20, which is at least partially made of concrete. The contact between the concrete of the support slab 20 and the weathering steel of the support beams 23 increases the bond between the support slab 20 and the reinforcing element(s) 21. This improved bond further enhances the mechanical strength of the slab and strengthens the structure of the bridge 2.

[0076] According to a variant shown in [Fig.5], the plurality of reinforcing members 21 is completely encased by the support slab 20. Here, each support beam 23 is completely encased in the support slab 20.

[0077] The support beams 23 are here also juxtaposed to each other, according to the width of the support slab 20 and are made of weathering steel.

[0078] The complete embedding of the support beams 23 in the support slab 20 increases the contact area between the concrete of the support slab 20 and the weathering steel of the support beams 23, and thus further increases the bond between the support slab 20 and the reinforcing element 21 or reinforcing elements 21. Better bonding further improves the mechanical strength of the slab and strengthens the structure of the bridge 2.

[0079] The reinforcing members 21 of this second embodiment, like those of the first embodiment, act as a tie rod, increasing the resistance capacity of the bridge structure 2 to bending forces. The support beams 23 have a mechanical role in resisting most of the tensile forces due to the bending of the support slab 20 and allow for better control of the structure's fatigue behavior under varying loads on the traffic lane 1, thus ensuring high durability.

[0080] The bridge 2 according to the invention further comprises at least one support member 22 of the bridge 2 on its support.

[0081] The support member 22 is for example made of reinforced concrete.

[0082] As illustrated in Figures 2 and 4 to 6, the bridge 2 may further include support devices 5, interposed between the plurality of reinforcing members 21 and the support member 22.

[0083] The support devices 5 comprise rubber or any other elastomer and allow the forces transmitted by the plurality of reinforcing members 21 to the support member 22 to be dampened.

[0084] According to a variant illustrated in figures 1, 3 and 7, the plurality of reinforcing members 21 is embedded at least partially in the support member 22. This variant is the preferred mode of the invention.

[0085] In other words, the plurality of reinforcing members 21 is partly embedded in the support member 22, or entirely embedded in the support member 22.

[0086] According to the first embodiment of the invention and with reference to [Fig.1], the third portion of each support beam 23 is embedded at least partially and connected in the support member 22 by plugging.

[0087] With reference to [Fig.3], each support beam 23 is fully embedded in the support member 22, only the fastening systems 24 are not encased by said support member 22.

[0088] According to the second embodiment of the invention and with reference to [Fig.7], each support beam 23 is fully embedded in the support member 22. Furthermore, the connection between the support slab 20 and the support beams 23 is made by means of an anchoring system comprising a plurality of reinforcements, in particular made of steel, which extend from the support slab 20 and in the direction of said support beams 23. Said reinforcements pass through the support beams 23 via holes provided in said support beams 23.

[0089] The integration of the plurality of reinforcing members 21 into the support member 22 eliminates the need for bearings 5 ​​and therefore their upkeep and maintenance. In particular, replacing the bearings 5 ​​requires lifting the deck to replace the bearing to be changed with a new one, which results in the suspension of traffic on bridge 2.

[0090] Thus, the bridge 2 according to the invention requires little maintenance operations, in particular concerning the sealing of the support slab 20, the corrosion of the reinforcing elements 21 and the use of the bearing devices 5, while allowing the mechanical resistance of the support slab 20 to be improved and the structure of the bridge 2 to be reinforced.

Claims

Demands

1. Bridge (2) comprising a support slab (20) having an upper face arranged to support a traffic lane (1) and a lower face opposite the upper face, said bridge (2) further comprising a plurality of reinforcing members (21) secured at least to the lower face of the support slab (20) so as to improve its mechanical resistance, said support slab (20) comprising a proportion of ultra-high performance fiber-reinforced concrete and the plurality of reinforcing members (21) being at least partially made of weathering steel, said support slab (20) at least partially encasing said reinforcing members (21).

2. Bridge (2) according to claim 1, wherein the support slab (20) comprises a slab body (200) and a waterproofing layer (201), the waterproofing layer (201) covering the slab body (200) and being interposed between the latter and said traffic lane (1), said waterproofing layer (201) forming the proportion of ultra-high performance fiber-reinforced concrete of the support slab (20).

3. Bridge (2) according to claim 2, wherein the sealing layer (201) has a thickness between 3 cm and 5 cm.

4. Bridge (2) according to any one of claims 1 to 3, wherein the support slab (20) is entirely made of ultra-high performance fiber-reinforced concrete.

5. Bridge (2) according to any one of claims 1 to 4, further comprising at least one support member (22) of said bridge (2), said plurality of reinforcing members (21) being embedded at least partially in said support member (22).

6. Bridge (2) according to claim 5, wherein said plurality of reinforcing members (21) is fully embedded in said support member (22).

7. Bridge (2) according to any one of claims 1 to 6, wherein each reinforcing member (21) comprises at least two support beams (23) of weathering steel, said support beams (23) each being at least partially encased by the support slab (20).

8. Bridge (2) according to any one of claims 1 to 6, wherein each reinforcing member (21) comprises at least two support beams (23) and a plurality of weathering steel attachment systems (24), the plurality of attachment systems (24) projecting from

9. each support beam (23), said attachment systems (24) being encased by the support slab (20). Bridge (2) according to claim 8, further comprising at least one reinforcement plate (25) extending between the support beams (23) and the underside of the support slab (20), the plurality of attachment systems (24) projecting from said reinforcement plate (25).

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