NL2004128C - HEAVY DUTY TO MEASURE AND ITS MANUFACTURE. - Google Patents

Description

Title: Custom made heavy level crossing and its manufacture.

The invention relates to a railroad crossing (level crossing) for cars and its manufacture.

A level crossing is known that is made up of two or more prefabricated, reinforced concrete slabs (each max. 6 or 9 meters long) placed in line with each other with two grooves for receiving the rails. The concrete slabs are each lifted and placed separately with a crane in their place in the railroad 10, after which the rails are placed in the grooves and fixed therein and embedded in cast material. To set, each concrete slab is equipped with four leveling feet, one at each corner. Each adjusting foot comprises a membrane-like body protruding from the bottom side of the concrete slab, which during filling is filled with grout or concrete and stably supports the concrete slab after curing.

With a view to shortening the decommissioning time of the track, NL1030958 (Voestalpine Railpro bv) proposes to manufacture a level crossing of a prefabricated concrete slab cast in one piece with the above-mentioned leveling feet and those in the factory, i.e. to equip the set and embedded rails that protrude from the concrete slab on both sides prior to transport to the final destination and installation.

US 6,016,968A discloses placing partitions in a mold and collapsing prestressing wires running through those partitions and extending on one side outside the mold, the partitions being removed after hardening of the concrete, the partitions determined by the partitions 30 lengths of the prestressing wires are individually prestressed and during prestressing the concrete lengths determined by the partitions are stretched dry and flat against each other with the front ends, thereby sliding over the prestressing wires. The resulting composite concrete slab 35 is founded on sleepers. No mention is made of placing and embedding rails in the factory. Pre-tensioning the tension wires in steps along the length is cumbersome, time-consuming and susceptible to malfunction. The concrete slabs in the assembly can mutually shift vertically.

DE 1.930.541A discloses a prefabricated concrete slab with near-the-bottom tubes for tension cables and grooves in the top for rails and does not address the assembly of several concrete slabs, the setting and embedding of rails 5 and the foundation technique.

US 4,911,360A discloses the laying of prefabricated concrete slabs one after the other at the final destination in the work, after which the rails are placed in the molded grooves and embedded. The end faces facing each other have a groove for receiving a common rod with which the concrete slabs are coupled to each other. The foundation takes place through lower bolts.

DE 29.48.526A discloses the laying of prefabricated concrete slabs 15 one behind the other at the final destination in the work and the foundation of only the ends of the concrete slabs on embankment bodies.

NL 276.179A discloses a level crossing that is built up in the work from two or more separate concrete slabs with grooves for receiving rails. After the concrete slabs have been placed in line with each other in the work, the rails are placed in the aligned grooves. Vertical drillings in the concrete slab serve to inject sand under the concrete slab. After laying the concrete slab, these vertical bores are filled to prevent watering in. We speak of a large support surface and therefore a low soil load. It is also referred to as a reinforced substrate and that through the vertical drilling presses of sand under the concrete slab can be lifted by means of compressed air. Further details are not provided to make it clear to the person skilled in the art how the concrete slabs are founded.

The object of the invention is versatile and could primarily be aimed at offering a technically and commercially viable alternative to shorten the decommissioning time of the track. More in particular, the object of the invention could be to further shorten the decommissioning time of the track, starting from a prefabricated assembly of a concrete slab with preferably a length equal to the level crossing and integrated therein on the railroad rails to be connected which run past the concrete slab on both sides, which assembly is supplied in its entirety and is laid on its foundation on a foundation. The invention could also relate to another purpose.

Therefore, the invention is as defined in the accompanying one or more independent claim (s), while the dependent subclaiming claim (s) relate to advantageous further developments.

By making the concrete slabs in their own mold, the investment in tools can be kept low.

The invention offers the possibility of either pre-tensioning the tensioning elements, such as according to US 6,016,968A, or pre-tensioning them at once over their entire length, which latter option is preferred.

The invention thus relates to a method for making a railway crossing from prefabricated concrete slab, in which one or more of the following steps are followed: in a factory two or more concrete slabs of equal or different length and with the same width and thickness are separately a mold made by placing a reinforcement in each mold and pouring concrete in such a way that in each case a concrete slab with one or more of the following properties is formed: a reinforcement embedded in the concrete of the concrete slab of prestressed reinforcement elements running parallel to the rails , such as steel bars or wires, possibly in bundles, in the top of the concrete slab in operation 30 of the concrete slab, two parallel grooves for containing the two rails, near each corner a point of engagement for a hoist, two, three, four or more longitudinally and near the bottom side of the concrete slab in operation of the railway crossing, preferably r 35 mutually at the same level and with mutual spacing, hollow channels running in and embedded in the concrete and ending in both ends; on one or both end faces at a location at a distance from the top surface and the bottom surface, preferably at a distance above the hollow channels, a surface profiling, preferably of such placement and / or size, that of two in use condition with the end faces concrete slabs placed against each other the surface profiling coincides with each other, for example the surface profiling formed by one or more recesses and / or protrusions spaced above and / or next to each other, such as two or more spaced-apart spaces, spread in the width direction of the concrete slab arranged protrusions of concrete protruding in the direction of the length of the rails over a distance of at least 2 or 5 or 10 centimeters and on the other end face at a location corresponding to the protrusions, possibly in the width direction of the concrete slab, subdivided recess corresponding to the subdivision of the protrusions and having a shape compl is ementary to that of the protrusions and with a depth such that, in the case of two concrete slabs placed in line with each other, wherein the protrusions of one concrete slab are inserted to a maximum depth in the recess of the other concrete slab, a joint is added between the concrete slabs having a width preferably between about 10 or 20 millimeters and 30 or 50 millimeters, which protrusions are preferably made of concrete and integrated into the plate; wherein furthermore during the method one or more of the following operations are performed: in the mold at the ends of the concrete slab steel profiles are placed in width direction which protrude approximately halfway the thickness of the concrete slab with their ends sideways from the concrete slab around the engagement points to shape; after which at least two different concrete qualities 30 are successively poured into the mold in layers above each other to obtain a highly wear-resistant top layer; after curing, the concrete slabs are removed from the molds and inverted and placed in line with each other, with the possible protrusions on the end face of one concrete slab in the recess on the end face of the other concrete slab but not to the maximum insertion depth so that a joint remains between the concrete slabs which is preferably at least 5 millimeters and for example at most 5 millimeters wider (over-dimensioning) than the width of that joint in the finished product, so that the assembly of these concrete slabs has a length equal to the length of the finished product, apart from the excess length determined by the overdimensioning of the joint or joints, while ensuring that the grooves for the rails on the one hand and the hollow channels on the other are aligned with each other and preferably flexible clamping elements by the channels / sleeves are threaded which protrude beyond the end faces of the assembly of concrete slabs and which are raised in h leave the case stress-free; shrink-free pouring mortar is poured from above into the joints between the concrete slabs so that the joints, including any surface profiling, are completely filled with pouring mortar; while the pouring mortar is still sufficiently fluid, the tensioning elements are activated to keep the concrete slabs pressed against each other permanently, pressing out pouring mortar from the joints, whereby any protrusions located at the end face are pressed deeper into the recesses, so that the joint width decreases with substantially the over-dimensioning while the tensioning elements 20 are brought to their final tension; the pouring mortar is allowed to cure; at the top of the concrete slab in operation of the railway crossing, the cured casting mortar in the joint is covered with a material that adheres to the concrete and the mortar, remains flexible, initially form-free, hardening material, such as cork rubber, for permanently waterproofing the joints ; a one-piece rail is laid in each groove so that it protrudes sufficiently at both ends of the concrete slab assembly, e.g. over a minimum of 1 or 2 m, e.g. approx. 4 m, to facilitate connecting to the further rail, which rails are set and embedded; the prefabricated assembly of concrete slabs placed in line with each other with pre-tensioning elements placed therein and rails placed, placed and embedded in both grooves is hoisted on a truck and transported to its destination in the track and hoisted in the track.

Furthermore, one or more of the following 6 is preferably used: the hollow channels open at one end side to a level above the underside of the plate that is at least 1, 2 or 3 centimeters higher than the level at which the hollow channels meet the other end face, wherein preferably the end face with the higher level of the hollow channels is intended to be turned away from the other concrete slab in the assembly; the hollow channels follow a path through the concrete slab that is horizontal, continuously rising or consists of alternating horizontal and continuously rising parts; the hollow channels are filled over their entire length with shrink-free pouring mortar so that the clamping elements in the hollow channels are embedded over their entire length in shrink-free pouring mortar; the surface profiling on the front side consists exclusively of depressions made in the flat surface; the surface profiling comprises one or more grooves parallel to each other; the rails placed in the grooves hardly protrude, if at all, above the top of the plate, the top of the plate possibly being formed by a top layer which is subsequently applied to the top of the plate to form the road surface for cars and the like .

One or more of the following aspects are preferably applied: provisions are made for making leveling feet under the concrete slabs, for example one at each corner of a concrete slab; sufficient attention during making in the mold to ensure the required minimum galvanic resistance between the rails; in the track the product is placed on a temporary foundation in order to, based on that foundation, fill the support feet with grout via pipes integrated in the concrete slabs; the rails are connected to the 30 rails on either side of the level crossing; use of a concrete slab resp. mold of a first length, for example 6 meters and a concrete slab of a second length resp. mold, for example S meter; exclusively use of one or more concrete slabs resp. mold of a first length and one or more concrete slabs resp. mold 35 of a second length; use of at most two or three concrete slabs for making a prefabricated assembly.

It has thus been found possible to prefabricate a railway crossing 7 in a modular way.

It has been found that it can be advantageous if the tensioning cables are brought to the permanent final tension before the filling of the joint hardens or the filling is only at the early stage of hardening and has not yet been bound off. However, this is not always necessary for the invention.

It has further been found that it can be advantageous if the joint is first completely filled with casting mass and then, before the casting mass hardens or settles, the joint is permanently squeezed together, for instance over a minimum of 5 mm and optionally a maximum of 15 mm so that part of the filling is pressed out of the joint. It has been found that only tension cables at the bottom of the product would suffice.

Bottom bolting is not necessary for the invention, whereby a considerable gain in time is achieved during installation.

By applying the prestressing wires running through the sleeves, the transition can be hoisted in its entirety at a limited number of engagement points and there is no risk that the transition will become hollow or convex after installation.

A non-limiting example is as follows: Two concrete slabs with a length of 6 resp. 9 meters are manufactured in a factory in a shed by a 6 resp. 9 meters long mold reinforcement and pouring concrete. During curing, 25 m.b.v. e.g. vibrators sufficiently compacted the concrete. The substantially flat bottom of the mold is equipped with profiles that save the grooves for the rails in the concrete surface. In the mold, concrete of at least two qualities is deposited on top of each other in layers; first concrete is poured which provides a very durable surface. Also, before or during the making of the concrete slab, provisions are placed in the mold for integrating the support feet and the connected grout pipes in the concrete slab. Steel profiles, for example pieces of rail, with a length greater than the width of the concrete plate are also placed in the mold at the ends of the concrete slab. These profiles will protrude approximately halfway the thickness of the concrete slab with their ends sideways from the concrete slab 8 and form lifting points. And hollow tubes are placed in the longitudinal direction of the mold at a small distance, for example 25 centimeters, below the filling height of the mold.

It is ensured that two integral, identical protrusions form on an end face of the concrete slabs which, viewed from the side of the concrete slab, are truncated cone-shaped, with the truncated top of the concrete slab facing away and viewed one behind the other in the same view. Viewed from the top view of the concrete slab, each protrusion extends over about 1/3 of the width of the concrete slab, keeping a distance to the side edge of the concrete slab and keeping a wider distance with the other protrusion. On the other end face, each concrete slab has a recess into which the protrusion fits tightly, while maintaining a joint between the facing sides of the concrete slabs. When the projection of the other concrete slab is inserted into the recess of one concrete slab to a maximum depth, the concrete slabs only support via the protrusion resp. the recess against each other and the joint width is 20 millimeters.

After sufficient hardening, the concrete slab is removed from the mold and vice versa, so that the side facing downwards in the mold with the two grooves is facing upwards.

The two concrete slabs are placed end to end so that the grooves at the top and the hollow pipes at the bottom are aligned with each other. Clamping cables are inserted into the hollow tubes, the ends of which extend beyond the concrete slabs. At those ends there is a thread on which one can tighten tensioning screws, without tensioning the tensioning cables. Along the bottom and both sides of the joint between the concrete slabs, a formwork is applied after which the joint is poured from above with mortar that is as fluid as water. Immediately afterwards, the tensioning screws are tightened, so that they press directly or indirectly against the ends of the concrete slabs while tensioning the tensioning cables. As a result, the concrete slabs are pressed towards each other, as a result of which the joint width decreases, mortar is pressed out of the joint and the concrete slabs eventually come to rest against each other via the protrusions projecting into the recesses.

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As soon as the desired tension has been built up in the tensioning cables, the tensioning nuts are secured, after which the mortar is allowed to cure in the joint. After the mortar has hardened, the joint on the top of the product is scratched open to a certain depth, after which the space that is released is filled with an adhesive, hardening, flexible paste or sealant so that the joint is watertight from above.

The rails are then placed in the grooves, after which the remaining space in the groove is filled with an initially form-free embedding and bonding material. The rails are eight meters longer than the two concrete slabs together and protrude about the same end beyond the respective end of the two concrete slabs together on either side. After sufficient hardening of that embedding material, the product is placed on a truck and transported to the destination.

At the destination, the product is attached at its four corners and elsewhere along its length by the laterally protruding pieces of rail to the lifting hook of a crane and hoisted at its final destination. The product is set based on a temporary foundation, after which the support feet are filled with grout. After the grout has hardened sufficiently, the temporary foundation is removed and the specified concrete product rests on its support feet.

In an alternative, the transition is placed directly from the transport vehicle on a flattened sand bed at its final destination, whereby use of a temporary foundation, adjustment of the product and filling of the support feet are eliminated.

The accompanying drawing shows in Fig. 1 a perspective view of a part of a concrete slab according to an embodiment of the invention and Fig. 2 shows in a side view in section along the line II-II in Fig. 1 a part of two in Concrete slabs of Fig. 1 placed in line with each other for making a level crossing according to the invention.

Shown are the concrete slabs 1, the grooves 2 for the rails 3, the lifting points 4, the surface profiling 5 in the ends, the hollow sleeves 6 and the joint 7.

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In Fig. 1 the rails 3 are missing and in both figures the tension wires are missing in the sleeves 6. The sleeves 6 open below the profiling 5 and are located next to each other and run obliquely upwards from the joint 7 to the other end face (this applies 5 for both the plate 1 on one side and the other side of the joint 7). The profiling 5 consists of three grooves running horizontally one above the other. The rails 3 protrude outside the concrete slabs (Fig. 2).

Other embodiments also belong to the invention.

For example, where the protrusions and optionally also the matching recesses on the end face of each plate are missing, or wherein each end face of each plate contains both recesses and matching protrusions, or each end face of each plate contains only recesses. The concrete slabs 15 could furthermore be provided on their end faces on two or more levels with protrusions and / or matching recesses. It should be understood that projections on the end face of one plate are intended to fit into recesses on the end face of an adjacent plate.

The product can have, apart from the rails, a length that is created by assembling one, two or more pieces of 6 or 9 meters, so that a length of 6 meters plus 3 meters or a multiple of 3 meters, for example 18 or 27 meters.

Claims (18)

Method for making a prefabricated railway crossing with a length of at least ten meters from two or more prefabricated concrete slabs with a length of at least five meters each, wherein in a factory the two or more concrete slabs of equal width and thickness and with preferably together a length substantially equal to the level crossing is fabricated by placing for each in a separate or own mold reinforcement and at least two parallel hollow tubes (6) and pouring concrete such that in each mold concrete slabs, preferably on their are produced which, by curing in the mold, have the following properties: preferably close to the underside in use, the hollow sleeves (6) run side by side at preferably mutually equal level in the longitudinal direction of the transition and mouth at one or both ends of the concrete slab; two parallel grooves (2) run in the top in use for receiving the rails (3) sunk therein, the two or more hardened concrete slabs (1) being aligned in line with each other at the factory so that the grooves (2) and sleeves (6) are mutually aligned while maintaining or forming a joint (7) between two adjoining concrete slabs and in each tube (6) of one or all concrete slabs one or more tensioning elements, such as cables, are arranged so that each tensioning element extends through all concrete slabs, preferably over substantially the entire length of the transition, and the tensioning elements are brought to the desired final bias and the rails are placed in the grooves (2), set, fixed and fixed embedded, so that the transition thus prefabricated with the prestressing elements brought to final pre-tensioning and placed, set and embedded rails in both grooves from the factory s a whole is transported to its final destination and laid in the railway track and its rails (3) are connected to the rails of the railway track on either side of the level crossing. 2. Method as claimed in claim 1, wherein the one or more joints (7) are filled with an initially form-free filler so that after hardening of the filler, the concrete slabs are permanently fixed to each other by the filler. 3. Method as claimed in claim 1 or 2, wherein the tensioning elements are brought to the desired final bias by pulling on their one or both ends and then fixing. 4. Method as claimed in any of the claims 1-3, wherein the tensioning elements are brought to the desired final prestressing while the filler has not yet hardened, so that during the pretensioning of the tensioning elements the concrete slabs are preferably moved towards each other while reducing of the width of the joint, preferably about a minimum of about 5 millimeters, and a part of the filler is pressed out of the joint (7). 20 A method according to any one of claims 1-4, wherein it is ensured that the concrete slabs are formed on one or both end faces at a location at a distance from the top surface and the bottom surface, preferably at a distance above the hollow channels, when forming in the mold. Have a surface profiling (5), preferably consisting exclusively of depressions made in the flat surface, such as one or more grooves parallel to each other, which profiling (5) is preferably arranged and dimensioned in such a way that of two in use condition with the end faces of concrete slabs placed against each other, the surface profiling coincides with each other, and which surface profiling forms part of the joint (7) when the transition is assembled from the cask concrete slabs and, when filling the joint with filler, it is also preferably completely filled with filler being filled. 35 A method according to any one of claims 1-5, wherein it is ensured that for the concrete slabs when the molds are formed in the mold the tubes (6) open out at one end face at a level above the underside of the slab that is at least 1, 2 or Is 3 centimeters higher than the level at which the sleeves on the other end face follow, following a path that is continuously rising or alternately horizontal and continuously rising, and where during the assembly of a concrete slab the transition is made from the stripped concrete slabs the end face with the higher level of the tubes is placed away from the other concrete slab adjacent the common joint (7) in the assembly. 7. Method as claimed in any of the claims 1-6, wherein while assembling the transition from the cased concrete slabs the tubes (6) are filled over their preferably entire length with initially form-free filling material so that the tension elements in the tubes over their (entire ) length are embedded in cured filler material. 8. Method as claimed in any of the claims 1-7, wherein the rails that are placed in the grooves have such a length that, when placed and embedded in the grooves, they pass sufficiently far on one or both sides beyond the assembled concrete slabs, e.g. over a minimum of 1 or 2 m, eg approx. 4 m, to facilitate connection to the existing track and / or to ensure that the connection location with the existing track is at a distance of at least 1 meter from the concrete slab. 9. Method as claimed in any of the claims 1-8, wherein, preferably exclusively, use is made of a concrete slab 30 resp. mold of a first length, for example 6 meters and a concrete slab resp. mold, of a second length, for example 9 meters. 10. Method as claimed in any of the claims 1-9, wherein it is ensured that tensioning elements are used with such a length that one or both ends thereof project beyond the concrete slabs. A method according to any of claims 1-10, wherein four or more tubes (6) are placed in a mold and a tensioning element is placed in each tube. A method according to any of claims 1-11, wherein the tensioning elements are biased at once over their entire length. 13. Prefabricated railway crossing with a length of at least ten meters which is composed of two or more prefabricated concrete slabs, each with a length of at least five meters and of the same width and thickness and preferably together a length substantially equal to the railway crossing with at least two parallel hollow tubes (6) running parallel to each other in the longitudinal direction of the transition 15, near the in use underside at preferably mutually the same level and with in the top in use two parallel grooves (2) with the rails (3) recessed therein at both ends preferably protrude beyond the assembly of concrete slabs over a length of preferably at least 1 or 2 meters, such as approximately 4 meters, with one or more tensioning elements located on the final prestressing in each tube (6), so that each tensioning element extends through all concrete slabs over substantially the entire length of the transition, and with between the concrete slabs a joint (7) that is filled with an initially form-free filler with which the concrete slabs are permanently fixed to each other, so that the thus prefabricated transition with the prestressed elements brought into position and set, embedded in both grooves 30 in its entirety from the tracks can be transported from the factory to its final destination and placed in the railway track and its rails (3) can be connected to the rails of the railway track on either side of the level crossing. 35 Railroad crossing according to claim 13, wherein the joint (7) is bounded on both sides by a mutually coinciding surface profiling (5) in the end faces of the concrete slabs at a distance from the upper surface and the lower surface and above the hollow sleeves (6) , preferably consisting exclusively of depressions made in the flat surface, such as one or more grooves parallel to each other, completely filled with filler. 15. Railway crossing as claimed in claim 13 or 14, wherein the sleeves (6) open at one end face at a level above the bottom of the plate that is at least 1, 2 or 3 centimeters higher than the level at which the sleeves at the other end face, following a path that is continuously rising or alternately horizontal and continuously rising, and wherein the end face with the higher level of the sleeves is placed away from the other concrete slab adjoining the joint (7) adjacent the communities the assembly. 16. Railway crossing according to one of claims 13-15, wherein the sleeves (6) are filled over their entire length with initially form-free filling material, so that the tensioning elements in the sleeves are embedded over their entire length in cured filling material. 17. Railway crossing according to one of claims 13-16, wherein the tubes (6) open out on both sides of the concrete slab assembly. A railway crossing according to any of claims 13-17, wherein four or more tubes (6) are present in each concrete slab and each comprises a tensioning element.