METHOD FOR THE REHABILITATION OF RAILWAY SLEEVE TRAFFIC VEHICLES

Description

[0001] The present invention relates to a method for the rehabilitation of railway sleepers for rail vehicles according to the preamble of claim 1.

[0002] Railway sleepers are part of the track superstructure, which supports the rails for rail vehicles and transfers and distributes the forces generated under load to the track bed. This secures the rails in place. Concrete sleepers, which are machine-cast from concrete, are typically used.

[0003] Since the mid-1990s, ballastless track, also known as "slab track," has been available. This type of track superstructure replaces the ballast bed with a solid trackbed made of concrete or asphalt. For this, rigid concrete sleepers are pre-assembled into a pre-cast concrete trough or formwork, creating a grout cavity between the base and the wall of the trough (formwork). To prevent structure-borne noise, the trough is often lined with elastomeric foam. The sleepers are then moved into their final installation position, a very complex process requiring them to be supported and precisely adjusted. This adjustment is necessary to ensure that the subsequent track laying meets the required standards of accuracy.After the track bed has been precisely fixed in place, the cavity beneath the sleeper is filled with a suitable grout, and the sleeper is embedded to approximately half its height. Various systems exist for slab track construction, such as Rheda 2000, the Züblin system, the Bögel system, etc.

[0004] Slab track offers the advantage of improved track stability at high speeds, resulting in significantly lower maintenance costs. It is also more weather-resistant. However, slab track systems have the disadvantages of more complex installation and considerably higher investment costs compared to conventional track superstructures, as the position of the rail fastenings must be precisely measured during the pouring of the concrete bedding. This places high demands on the stability of the subgrade, since significant adjustments to the rail fastening system are no longer possible.

[0005] Traditional ballasted track superstructures cannot always withstand the forces generated by frequent train crossings, and over time, displacements of the superstructure often occur, ultimately leading to track misalignment. For safety reasons, these sections must therefore be traversed at low speeds.

[0006] Not only the classic ballasted track, but also the slab track is subjected to enormous stresses when a train passes over it. The sleepers oscillate as the train passes over them and yield when force is applied. The sleeper being traversed swings from top to bottom. Adjacent sleepers must absorb the load. The situation becomes problematic with sleepers where cavities have formed on the underside. Such cavities often contain air pockets. Over time, water penetrates these cavities, which freezes at temperatures below 0 °C, leading to damage to the sleeper. Furthermore, gaps can form between individual sleepers, which, after the concrete shrinks, allow small amounts of water to penetrate the concrete sleeper.Even with careful concreting of the space below the concrete sleepers, voids are often found because air below the sleeper is often difficult to escape during the concrete compaction process.

[0007] Damage caused by water penetrating through the joint or into the cavities necessitates the replacement of the sleeper for safety reasons. In the case of slab track, the reinforced concrete slab can also develop cracks, which can likewise allow water to penetrate the structure from above and thus into existing cavities beneath the sleeper. Affected sleepers therefore often exhibit spalling around the sleepers, as well as the aforementioned cavities beneath them, which can cause the firmly embedded sleepers to exhibit noticeable movement under load, i.e., when a train passes over them. In addition, there is damage to the concrete structure caused by wear and tear and environmental factors. Such damage patterns are either impossible to repair using conventional methods or can only be repaired with considerable effort.

[0008] EP 2 690 218 A2 describes such a method for repairing cracks in concrete sleepers by injecting a filler material, whereby the crack(s) are at least partially sealed with a sealant in the upper area of ​​the concrete sleeper. For this purpose, a crack analysis is carried out, and the crack is then sealed by applying the sealant in a strip along the crack. Subsequently, an open area is created to inject the filler material into the crack using a low-pressure pump.

[0009] A similar process is described in DE 10 2012 202 877 A1, in which a resin is introduced into the railway sleeper at a particularly low pressure of 0.1 to 2.6 bar, essentially without pressure. DE 10 2015 119 884 A1 describes a method for repairing concrete sleepers that have cracks or damage.

[0010] DE 102 48 037 B3 describes a method for the post-treatment of a railway track, in which fastening bolts are first removed, the rail support is drilled from the bottom of the fastening openings to the underside and then hardening flowable post-treatment material is introduced through the bore.

[0011] The methods mentioned are only suitable for the rehabilitation of concrete sleepers, but not for the repair of voids or air pockets around the sleepers. This is due, among other things, to the fact that the pressures used do not allow for the injection of the grout material.

[0012] DE 10 2012 009 284 A1 describes a method for the rehabilitation of railway sleepers for rail vehicles, comprising the steps of identifying cavities in a sleeper, creating inlet openings for the introduction of a filling material and outlet openings for air extraction in the joint area, injecting a pressurizable filling material into the inlet openings formed at the joint under pressure until it emerges at the outlet openings of the joint, sealing the outlet openings formed at the joint, and allowing the filling material to harden.

[0013] Against this background, the object of the present invention is to provide an alternative and improved method for the refurbishment of the aforementioned component areas for rail vehicles.

[0014] This problem is solved by a method with the features of claim 1. The method according to the invention comprises, in a first step, the identification of

[0015] Cavities or air bubbles in the component section to be treated. According to the invention, this is a railway sleeper. Such cavities occur particularly below the sleeper. Damaged sleepers are preferably identified by visual inspection, camera-based methods, or ultrasonic treatment.

[0016] In a further process step, a joint is pre-treated along the circumference of the threshold to be treated. The joint is thus prepared directly at the interface between the threshold and the underlying reinforced concrete slab. Preferably, the circumferential groove is created by grinding, needle drilling, blasting, or brushing. The joint is then preferably brushed clean.

[0017] In a further process step, inlet openings for introducing a filler material and outlet openings for air extraction are created in the joint area, and the joint is sealed with a sealing material. The sealing creates a kind of collar within the joint. The inlet openings are preferably positioned opposite the outlet openings on the longitudinal side of the railway sleeper. The spacing of the respective inlet and outlet openings, the width and height, and the shape of the sealing material depend on the specific sleeper type and the track construction. The inlet openings for the filler material and the outlet openings for air extraction are created either before or after the sealing material has been formed on the longitudinal sides of the sleeper.

[0018] The next step in the process is to expel the air from beneath the sleepers and fill the cavities with a filler material. The joint is completely sealed by the sealing process, remaining open only through the inlet openings. To expel the air and fill the cavities, a pressurized filler material is injected into these openings under pressure. Injecting the filler material displaces the air in the cavities and directs it to the outlet openings for venting. The venting of the cavities is complete when excess filler material emerges from the outlet openings. Once this occurs, it can be assumed that all cavities are sufficiently filled with filler material.

[0019] In the next step of the process, the outlet openings at the joint are sealed. Then, additional filler material is injected under high pressure through the inlet openings, causing the filler material to be compressed. The filler material is then allowed to harden. Preferably, the injection pressure is between 3 and 18 bar, more preferably between 8 and 16 bar, and preferably around 12 bar. The subsequent compression of the filler material is carried out at a compression pressure between 8 and 16 bar, preferably around 12 bar. Preferably, the filler material is injected using a high-pressure pump.

[0020] In a preferred embodiment, the inlet openings for the filling material and / or the outlet openings for air extraction are injection packers, angled packers, hose nozzles, or crimping nipples. The sealing material is preferably a plastic, a synthetic resin, a polymer-modified mortar, a reactive resin, or a polymer. Preferred polymers are silicone, polysulfide, acrylate, or PMMA, or even mortars based purely on minerals.

[0021] The filler material is preferably a reactive resin, synthetic resin, two-component adhesive, epoxy resin, polyurethane resin, polyester resin, silicone resin or another chemically curable adhesive or resin, or injection materials on a mineral basis.

[0022] The choice of sealing material, filling material, and the spacing of the inlet and outlet openings depend on the specific damage pattern and the type of track construction.

[0023] The method according to the invention is preferably used in the case of fixed roadways.

[0024] The invention is explained in more detail in the following drawing: In Fig.1Various views of a concrete sleeper 1 are shown, with a rail mounted on it and framed by spring elements 3. Preferably, the substrate is a reinforced concrete slab, as used in "fixed track" construction. The joint along the concrete sleeper is first pre-treated, preferably by grinding, pinning, blasting, or brushing. The joint is then cleaned. Subsequently, a seal is formed in the treated joint, and access points in the form of inlet and outlet openings are created in the seal. Suitable packers are provided for this purpose, enabling the injection of a synthetic resin. Preferably, injection packers 4 are used. The spacing of the injection packers depends on the type of damage and can be adjusted as needed.The sealing material preferably consists of a polymer-modified mortar, a synthetic resin, a reactive resin or sealants based on construction chemical polymers.

[0025] Once the sealant has cured, a filler material, such as a reactive resin, is injected at high pressure (approximately 12 bar) through inlet openings located along the length of the concrete sleeper. The injection of the filler material causes the air trapped in the cavities to escape through outlet openings on the opposite side of the sleeper. The injection continues until the resin flows out of the outlet openings. The injection packers are then closed to allow air to escape, and more filler material is injected through the inlet openings at a pressure of approximately 12 bar to compact the filler material within the sleeper's cavities. The entire injection process takes about 20 minutes. The filler material can be supplied via pipes or hoses, and hoses or pipes can also be used for air extraction.

Claims

1. A method for reconstructing railroad ties for railroad vehicles, comprising the steps of: a. identifying cavities or air bubbles in a tie, b. pre-treating a joint directly along the perimeter of the tie to be treated in the threshold area between the tie and the reinforced concrete slab below, c. attaching inlet openings for introducing a filling material and outlet openings for discharging air in the joint area and insulating the joint with an insulating material, d. venting the cavities by injecting a compressible filling material into the inlet openings formed at the joint under pressure, wherein the venting is completed until the filling material emerges at the outlet openings of the joint, e. sealing the outlet openings attached to the joint, f. grouting the filling material in the tie by further injecting filling material via the inlet openings under a pressure between 8 and 16 bar, g. allowing the filling material to harden.

2. The method for reconstructing railroad ties for railroad vehicles according to claim 1, characterized in that the insulation of the joint forms a circumferential collar.

3. The method for reconstructing railroad ties for railroad vehicles according to claim 1 or claim 2, characterized in that the inlet openings for the filling material and / or the outlet openings for air discharge are formed by injection packers, angle packers, hose nozzles or grouting nipples.

4. The method for reconstructing railroad ties for railroad vehicles according to one of the claims 1 to 3, characterized in that the insulating material is a plastic, a synthetic resin, a plastic-modified mortar, a reaction resin or a polymer.

5. The method for reconstructing railroad ties for railroad vehicles according to claim 4, characterized in that the polymer is a silicone, polysulfide, acrylate or PMMA or mortar materials on a purely mineral basis.

6. The method for reconstructing railroad ties for railroad vehicles according to one of the claims 1 to 5, characterized in that the injection of the filling material is carried out at a pressure between 3 and 18 bar, preferably between 8 and 16 bar, preferably at approximately 12 bar.

7. The method for reconstructing railroad ties for railroad vehicles according to one of the claims 1 to 6, characterized in that the filling material is a reaction resin, synthetic resin, two-component adhesive, epoxy resin, polyurethane resin, polyester resin, silicone resin or another chemically hardenable adhesive or resin, or also injection material on a mineral basis (e.g., cement suspension, cement paste, etc.).

8. The method for reconstructing railroad ties for railroad vehicles according to one of the claims 1 to 7, characterized in that the inlet openings for the filling material and the outlet openings for air discharge are arranged on opposite sides of the tie.

9. The method for reconstructing railroad ties for railroad vehicles according to claim 8, characterized in that the distances between the inlet openings for the filling material and / or the outlet openings for air discharge are selected according to the damage.

10. The method for reconstructing railroad ties for railroad vehicles according to one of the claims 1 to 9, characterized in that the circumferential joint is created by grinding, needling, blasting or brushing.

11. The method for reconstructing railroad ties for railroad vehicles according to one of the claims 1 to 10, characterized in that the filling material is injected by means of a highpressure pump.