The invention concerns a rail slab with an elastic mat for a floating railway, whereby a top side of the rail slab is provided for fixing rails of a railway to, whereby the elastic mat contains a base mat that fits against a bottom side of the rail slab and on which said rail slab rests, whereby the elastic mat contains two opposed standing lateral mat parts which each fit against a lateral side of the rail slab.
According to the present state of the art, floating railway tracks are made by placing a vibration-absorbing elastic mat between the rail slab and the substructure on which it rests. Further, lateral elastic mats are also placed on the sides of the rail slab between the slab and the adjacent fixed superstructure.
German patent application No.
Due to shear stresses, these lateral mats can be a limiting factor for obtaining sufficient vibration damping.
Furthermore, after a period of time, there occurs a loss of the vibration-absorbing qualities of this system as a result of a constant load of the elastic mat, which is usually made of an elastomer such as for example recycled resin-bonded rubber, vulcanised rubber, polyurethane (PU). For the current systems of floating rail tracks, a loss of performance is observed per time decade of about 1dB, which corresponds to a loss of 3dB to 4dB over a period of 20 years.
The invention aims to remedy these disadvantages by means of a floating railway slab with an elastic mat and a method for manufacturing a floating railway track, as in the claims appended hereto, whereby they make it possible to obtain sufficient vibration damping in a simple manner without the aforesaid disadvantages.
To this aim, the standing lateral mat parts have a cross section which widens as of the bottom of the rail slab to the upper side of the rail slab. As a result, the lateral mat parts will be relieved when the base mat is being pressed down, for example due to a load on the rail slab caused by a railway vehicle.
Practically, the cross section of the rail slab further preferably narrows from the bottom to the top side.
In particular, the lateral elastic mat parts are placed opposite each other with inner sides that incline towards each other, so that when the base mat is being pressed down, for example due to a load on the rail slab by a railway vehicle, the lateral mat parts will be relieved as the stress on these parts is reduced.
Other particularities and advantages of the invention will become clear from the following description of practical embodiments of the invention and the method according to the invention; this description is given as an example only and does not limit the scope of the claimed protection in any way; the following figures of reference refer to the accompanying drawings.
In the different drawings, identical reference figures refer to analogous elements.
The invention generally concerns a rail slab with an elastic mat for a floating railway track whereby performance losses of the vibration-absorbing qualities are compensated. The top side of the rail slab is hereby provided to fix rails of a railway to, and the rails are preferably continuously supported by the rail slab. The rail slab further rests with a bottom side on an elastic mat. The specific construction of the floating railway slab with the elastic mat according to the invention ensures an at least partial compensation of a reduced vibration damping which is due, for example, to the rigidity of the lateral mat parts.
Said lateral elastic mat parts are squeezed between the rail slab and the adjacent building material. As the inner sides of the mat parts extending opposite one another incline towards each other, the tension on the lateral mat parts will be reduced when the base mat is pressed due to a vertical load of the rail slab. Moreover, the mat parts will be preferably relieved more on the top side than on the bottom side, as these mat parts widen from the bottom side of the rail slab to the top side of the rail slab. By relieving the lateral mat parts, the tension on these mat parts is reduced, which results in a lower resonant frequency of the floating railway system as a whole and thus also in a better damping of vibrations.
Also, due to a continuous load on the base mat, a commonly called 'creep' of the base mat takes place, and the rail slab sinks in the floating railway track. Due to an oblique shape of the lateral mat parts and the rail slab, the outer sides of the lateral mat parts may hereby come off the lateral walls. As a result, the lateral mat parts are relieved, which enhances the lateral flexibility.
A first embodiment of a floating railway according to the invention is represented in
The standing lateral mat parts 2 thus have a thickness A on the top side 2" which is larger than the thickness B of these mats 2 on the bottom side 2'. According to this first embodiment, the thickness B on the bottom side 2' of the mat 2 is about 66 % of the thickness A on the top side 2" of the mat 2. More specifically, the thickness B amounts to for example 20 mm, whereas the thickness A amounts to for example 30 mm.
According to a method of the invention, a floating railway track as in the above-described first embodiment of the invention is manufactured in a concrete case. This concrete case is formed of a fixed concrete bottom or substructure 11 with two opposite standing concrete walls 12. These standing walls 12, according to this method, stand perpendicular to the substructure 11 and extend in the longitudinal direction of the railway. In the concrete case, an elastic base mat 3 is put on the substructure 11 between the walls 12. Against the opposite standing walls 12 are placed standing lateral elastic mat parts 2, with the outer sides 8 of the lateral mat parts 2 connecting to the walls 12. Preferably, these mat parts 2 are placed loosely against the walls 12. The inner sides 9 of the opposed standing lateral mat parts 2 hereby incline towards each other. The bottom side 2' of the lateral mat parts 2 hereby abuts on the edge of the base mat 3. Thus, the entire inner side of the concrete case is lined with the elastic mat formed of the base mat 3 and the lateral mat parts 2. Since the lateral mat parts 2 have a cross section which widens as of the bottom side 2' up to the opposite top side 2" of the lateral mat parts 2, there will be a free space between said mat parts 2 having a trapezoidal cross section and which narrows as of the base mat 3 to the top side 2" of the lateral mat parts 2. This free space is filled with a curing building material such as concrete. To this end, said building material is cast on the base mat 3, between the opposed extending mat parts 2. The curing building material can be cast in one or several layers. After it has cured, the material thus forms a rail slab 1 which rests on the base mat 3. Consequently, the rail slab 1 is surrounded by an elastic mat, as a result of which there is no direct contact between the rail slab 1 and the concrete case.
On the top side 4 of the rail slab 1, according to this method, rails 5 which are preferably provided with an elastic jacket are embedded in the curing building material, such that these rails are fixed in a groove in the rail slab. This can be obtained with a "top-down" method known as such which is applied for railways with embedded rails.
According to a specific variant of this method, the outer sides 8 of the lateral mat parts 2 are provided with a relief, as a result of which the contact surface between the standing walls 12 and the lateral mat parts 2 is reduced. This relief is an unevenness of the surface of the outer side 8 of the lateral mat parts 2 and it may consist of indentations and/or standing elements. In contrast, the walls 12 are preferably flat. Thus, open spaces are created between the mat parts 2 and the walls 12. Such a relief is advantageous in that, when the rail slab 1 is loaded as a railway vehicle runs over the railway, the lateral mat parts 2 will easily come off the standing walls 12, such that these mat parts 2 affect the vertical rigidity of the floating railway track only to a minimal extent.
According to another variant of this method, the concrete standing walls 12 consist of a temporary formwork. This formwork is removed after the rail slab 1 has been made or after the curing building material of the rail slab 1 has cured. A permanent surrounding material, such as for example crushed stone or concrete, is then put all around the rail slab 1 against the outer side 8 of the lateral mat parts 2.
According to a further variant of this method, the rails 5 are fixed on top of the rail slab 1 instead of in the above-described grooves.
According to an alternative method, the base mat 3 is placed on a fixed substructure 11 on which the rail slab 1 is subsequently placed. The lateral mat parts 2 are then placed against the lateral sides of the rail slab 1, after which a curing building material is applied to the mat parts 2.
A second embodiment according to the invention is represented in
The upper part of the lateral side 7 has a height which is for example 25% to 50% of the total height of the lateral side 7 or also of the height of the rail slab 1.
According to a possible method of the invention, the rail slab 1 of the second embodiment is cast in three different layers, whereby these layers are formed of a building material such as for example concrete. Thus, the first lower concrete layer 1' has a thickness D which amounts to for example 150 mm to 300 mm, and the second, connecting concrete layer 1" has a thickness E which amounts to for example 150 mm to 250 mm, and a third top concrete layer 1"' has a thickness F which amounts to for example 150 mm to 200 mm. This top layer 1"' can also be made, just as the other layers, of another road surfacing material.
The lateral sides of the first concrete layer 1' and the second concrete layer 1" are situated in line with each other, in contrast to the lateral side of the top concrete layer 1"'. Consequently, the lateral side 7 of the rail slab 1 exhibits a dent between the third and the second concrete layer 1"' and 1" respectively, as a result of which the latter has a non-linear profile in the vertical direction.
The outer sides 8 of the lateral mat parts 2 in this embodiment preferably have a relief 15 at the third and second concrete layer 1'" and 1" respectively. This relief 15 is an uneven surface which may consist for example of a corrugated surface or of standing studs.
A third embodiment according to the invention is represented in
Naturally, the invention is not restricted to the above-described method and device, but defined by the appended claims
Thus, according to the invention, the elastic mat may consist of a base mat and two standing lateral sides which form a whole and are made of a single piece of elastomer material. Thus, the elastic mat may also consist of several parts that are glued together.
Thus, the elastic mat can be made of recycled rubber or other elastomers known to a person skilled in the art.
Thus, the cross section of the lateral mat parts may have various forms whereby it widens at least partly from the bottom side to the top side.
Thus, the standing walls of the concrete case and/or the rail slab can also be provided with an unevenness such as for example vertical ribs.
Thus, the opposing standing walls of the concrete case may also be inclined away from one another, so that the cross section of the space in the concrete case widens from the bottom side to the top side.
Thus, the rail slab can be built out of concrete but also of other materials that a person skilled in the art deems suitable, or combinations thereof, such as for example asphalt. Thus, the above-described concrete case can also be made of other suitable building materials.
Thus, the outer side and/or the inner side of the lateral mat parts may feature a relief that is at least partially uneven, as a result of which the contact surface with the standing walls and/or the lateral sides of the rail slab is reduced.
Thus, the different qualities of the above-described embodiments can be mutually combined.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.