Double-gradient prefabricated track plate for ballastless track

Abstract

The invention relates to the technical field of railway tracks, in particular to a double-gradient prefabricated track slab for a ballastless track, which comprises a phase change material gradient distribution area and a magnetic emulsion gradient distribution area, the content of the phase-change material in the phase-change material gradient distribution area is in gradient distribution from more to less from the upper surface to the bottom surface of the prefabricated track slab, and the content of the magnetic emulsion in the magnetic emulsion gradient distribution area is in gradient distribution from more to less from the bottom surface to the upper surface of the prefabricated track slab. The two gradient distribution areas avoid the situation that a performance mutation interface exists at the junction of two materials in the prefabricated track slab. The phase change material reduces the temperature gradient of the track plate structure, the magnetic emulsion can enhance bonding between the prefabricated track plate and the self-compacting concrete layer, and the prefabricated track plate and the self-compacting concrete layer directly or indirectly relieve the key problem of damage between track layers.

Description

Technical Field

[0001] This application relates to the technical field of railway tracks, and particularly to a double-gradient precast track slab for ballastless tracks. Background Art

[0002] CRTS III-type slab ballastless tracks have become one of the most widely used and most promising high-speed railway ballastless track types in China. This track mainly includes a precast track slab, a self-compacting concrete filling layer, and a base slab that are stacked in sequence from top to bottom. Among them, the precast track slab directly bears the train load and is the core component that mainly bears the load and impact force in the ballastless track, which is directly related to the safe and stable operation of the train.

[0003] The problem of interlayer debonding of precast track slabs has attracted much attention. These problems not only reduce the safety and durability of the track but also affect the running smoothness of the train and the riding comfort. Summary of the Invention

[0004] The purpose of this application is to provide a double-gradient precast track slab for ballastless tracks to solve the problem of interlayer debonding of precast track slabs in the prior art.

[0005] To achieve the above purpose, a precast track slab for ballastless tracks provided by this application includes a phase change material gradient distribution area and a magnetic emulsion gradient distribution area.

[0006] The content of the phase change material in the phase change material gradient distribution area shows a gradient distribution from more to less in the direction from the upper surface to the bottom surface of the precast track slab.

[0007] The content of the magnetic emulsion in the magnetic emulsion gradient distribution area shows a gradient distribution from more to less in the direction from the bottom surface to the upper surface of the precast track slab.

[0008] Compared with the prior art, this application at least includes the following beneficial effects:

[0009] 1. The phase change material gradient distribution area can effectively alleviate the problem of too rapid temperature change inside the track slab, reduce the stress between different structural layers, and thus reduce the deformation difference between different layers.

[0010] 2. The magnetic emulsion gradient distribution area can specifically improve the bondability of the interface. Thus, when arranging the precast track slab, the magnetic emulsion gradient distribution area is connected to the self-compacting concrete layer, thereby reducing the debonding problem between the precast track slab and the self-compacting concrete.

[0011] 3. Compared with the technical solution of adding emulsions or phase change materials to the entire precast track slab, by setting two gradient distribution regions inside the precast track slab, on the one hand, only a small amount of additive materials are used, ensuring the overall strength of the precast track slab while being more economical. On the other hand, the gradient distribution enables the gradual change of the material properties inside the precast track slab, avoiding deformation differences caused by stress changes. Description of the Drawings

[0012] Figure 1 Shows a cross-sectional schematic view of a CRTS III ballastless track according to an embodiment of the present application.

[0013] Figure 2 Shows a cross-sectional schematic view of a track support and a precast track slab according to an embodiment of the present application.

[0014] Figure 3 Shows a flow chart of the construction process of a track support and a precast track slab according to an embodiment of the present application.

[0015] Reference numerals in the drawings:

[0016] 1. Track support; 2. Precast track slab; 3. Self-compacting concrete; 4. Base slab; 5. First concrete layer; 6. Second concrete layer; 7. Phase change material enrichment side; 8. Magnetic emulsion enrichment side; 9. Phase change material gradient distribution region; 10. Magnetic emulsion gradient distribution region. Detailed Embodiments

[0017] The technical solution of the present application will be further described below in conjunction with the drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application. Additionally, it should be noted that for the convenience of description, only parts related to the present application are shown in the drawings, rather than all of them.

[0018] Some orientation terms are defined in the present application. Without contrary explanations, the orientation terms such as "upper", "lower", "left", "right", "inner", and "outer" are used for the convenience of understanding, and thus do not constitute a limitation to the protection scope of the present application.

[0019] In this application, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include indirect contact between the first and second features through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.

[0020] In the description of this application, unless otherwise clearly specified or limited, the terms "connected", "joined" and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0021] As Figure 1 shown, the embodiment of this application relates to a ballastless track, which includes a track support table 1, a precast track slab 2, self-compacting concrete 3 and a base slab 4 arranged in sequence from top to bottom. There are two track support tables 1, and the two track support tables 1 are distributed left and right and arranged on the upper surface of the precast track slab 2. The bottom surface (i.e., the lower surface) of the precast track slab 2 is in direct contact with the upper surface of the self-compacting concrete 3. The lower surface of the self-compacting concrete 3 is in direct contact with the upper surface of the base slab 4.

[0022] The term "upper surface of the precast track slab 2" refers to the side of the precast track slab 2 where the track support table 1 is located.

[0023] The term "bottom surface of the precast track slab 2" refers to the surface opposite to the upper surface of the precast track slab 2, that is, the surface of the precast track slab 2 far from the track support table 1.

[0024] As Figure 2 shown, the precast track slab 2 according to the embodiment of this application includes a concrete main body, steel bars arranged in the concrete main body, and a phase change material and a magnetic emulsion doped in the concrete main body.

[0025] The phase change material forms a phase change material gradient distribution region 9 in the precast track slab 2. The content of the phase change material in the phase change material gradient distribution region 9 shows a gradient distribution from more to less in the direction from the upper surface to the bottom surface of the precast track slab 2.

[0026] The gradient distribution region 9 of the phase change material can effectively alleviate the problem of too rapid temperature change, reduce the stress between different structural layers, and thus reduce the deformation difference between different layers.

[0027] The magnetic emulsion forms a magnetic emulsion gradient distribution region 10 in the precast track slab 2. The content of the magnetic emulsion in the magnetic emulsion gradient distribution region 10 shows a gradient distribution from more to less in the direction from the bottom surface to the upper surface of the precast track slab 2.

[0028] The magnetic emulsion gradient distribution region 10 can specifically improve the adhesiveness of the surface. Thus, when arranging the precast track slab 2, the magnetic emulsion gradient distribution region 10 is in contact with the self-compacting concrete layer, thereby reducing the debonding problem between the precast track slab 2 and the self-compacting concrete 3.

[0029] The two gradient distribution regions avoid the existence of a performance mutation interface at the junction of the two materials inside the precast track slab 2. Both directly or indirectly alleviate the key problem of interlayer damage of the track.

[0030] Compared with the technical solution of adding emulsion or phase change material to the entire precast track slab 2, by setting two gradient distribution regions inside the precast track slab 2, on the one hand, only less additive materials are used, ensuring the overall strength of the precast track slab 2 while being more economical. On the other hand, the gradient distribution makes the materials inside the precast track slab 2 change slowly, avoiding the deformation difference caused by stress change.

[0031] As Figure 2 shown, the gradient distribution region 9 of the phase change material includes a phase change material enrichment side 7 and a phase change material sparse side. The phase change material enrichment side 7 is located on the upper surface of the precast track slab 2, and the phase change material sparse side is located below the phase change material enrichment side 7 and above the magnetic emulsion gradient distribution region 10.

[0032] As Figure 2 shown, the magnetic emulsion gradient distribution region 10 includes a magnetic emulsion enrichment side 8 and a magnetic emulsion sparse side. The magnetic emulsion enrichment side 8 is located on the bottom surface of the precast track slab 2, and the magnetic emulsion sparse side is located above the magnetic emulsion enrichment side 8 and below the gradient distribution region 9 of the phase change material.

[0033] It can be seen that the gradient distribution region 9 of the phase change material and the magnetic emulsion gradient distribution region 10 do not cross. For example, in Figure 2 , the gradient distribution region 9 of the phase change material is entirely located above the magnetic emulsion gradient distribution region 10.

[0034] The phase change material has an electrical response. When an electric field is applied to the phase change material, the phase change material will move directionally according to the voltage level.

[0035] Further, the phase change material gradient distribution region 9 is formed by applying an electric field to the unfrozen concrete. The steps of forming the phase change material gradient distribution region 9 will be described later.

[0036] Exemplarily, the phase change material is a phase change microcapsule with an electric response. It should be noted that such a phase change material is known in the prior art. Specifically, the above-mentioned phase change material can be synthesized by polymerizing a monomer with an electric response and a phase change microcapsule under certain conditions.

[0037] Exemplarily, the monomer with an electric response is selected from acrylamide and methylene bisacrylamide. Acrylamide or methylene bisacrylamide can move in response to an electric field.

[0038] The magnetic emulsion has a magnetic response. When a magnetic field is applied to the magnetic emulsion, the magnetic emulsion will move directionally according to the direction of the magnetic field.

[0039] The magnetic emulsion gradient distribution region 10 in the precast track slab 2 is formed by magnetic response. Further, the magnetic emulsion gradient distribution region 10 is formed by applying a magnetic field to the unfrozen concrete. The steps of forming the magnetic emulsion gradient distribution region 10 will be described later.

[0040] Exemplarily, the magnetic emulsion is an emulsion with a magnetic response. It should be noted that such a magnetic emulsion is known in the prior art. Specifically, it can be a magnetic emulsion synthesized by mixing iron oxide particles and an emulsion under certain conditions.

[0041] Exemplarily, the emulsion is selected from styrene-acrylic emulsion, acrylate emulsion, and polyurethane emulsion. The iron oxide particles can move in response to a magnetic field.

[0042] As Figure 3 shown, in this embodiment, the precast track slab 2 can be manufactured by the following method:

[0043] a. Pour the track support 1;

[0044] b. Pour the first concrete layer 5 with concrete A; wherein, a phase change material with an electric response effect is incorporated into the concrete A and stirred evenly; wherein, the dosage of the phase change material is 5% - 15% of the concrete A;

[0045] c. Apply an electric field to the first concrete layer 5, and the phase change material gradually moves towards the lower surface of the first concrete layer 5 to form the phase change material gradient distribution region 9;

[0046] d. Pour the second concrete layer 6 on the upper surface of the first concrete layer 5 with concrete B; wherein, a magnetic emulsion is incorporated into the concrete B and stirred evenly; wherein, the dosage of the magnetic emulsion is 5% - 15% of the concrete B;

[0047] e. Apply a magnetic field on the upper surface of the second concrete layer 6, and the magnetic emulsion moves towards the upper surface of the second concrete layer 6 to form a magnetic emulsion gradient distribution region 10.

[0048] After Figure 3 inverting the precast track slab 2 obtained Figure 2 the precast track slab 2 in

[0049] As an example, the magnetic field can be generated by N52 magnets.

[0050] As an example, the electric field can be generated using civil electricity.

[0051] The time for applying the electric field and the magnetic field is about half an hour, generally not exceeding 45 minutes. After the concrete starts to set initially, it is not conducive to the movement of the magnetic emulsion and the phase change material inside the concrete.

[0052] In addition, it should be noted that in order to ensure the bonding performance between the two layers of concrete, the interval between pourings should be as small as possible.

[0053] It should be noted that although in this embodiment, the phase change material gradient distribution region 9 and the magnetic emulsion gradient distribution region 10 are formed successively, however, in an embodiment not shown, the second concrete layer 6 can be poured on the lower surface of the first concrete layer 5 before forming the phase change material gradient distribution region 9 in the first concrete layer 5, and then a magnetic field is applied on the lower surface of the second concrete layer 6 while an electric field is applied on the upper surface of the first concrete layer 5, so that the phase change material gradient distribution region 9 and the magnetic emulsion gradient distribution region 10 are formed simultaneously.

[0054] In summary, the precast track slab 2 of the embodiment of the present application enables the magnetic emulsion and the phase change material to work together through the design of two gradient distributions, forming a more ideal composite structure.

[0055] The term "gradient distribution" refers to a heterogeneous composite structure composed of two or more materials, whose internal properties change gradually along one or more directions. The design of gradient distribution retains the advantages of the base materials, while being compatible with multiple properties, and effectively reduces the interfacial stress between different material layers through a smooth transition.

[0056] According to the requirements of different application environments, the gradient distribution can flexibly adjust its performance changes, thereby achieving multi-faceted structural optimization. Such a design concept makes it possible to combine performances that cannot be achieved by traditional homogeneous material structures. Therefore, the double-gradient distribution structure of the precast track slab improves the overall performance and durability of the entire track.

[0057] Magnetic emulsion and phase change material can exist stably in concrete. After being added to concrete in the form of internal admixture, they are enriched to the upper and lower surfaces respectively by physical field, which uses less materials than uniformly modified concrete and effectively controls costs. The upper and lower surfaces of the prefabricated track slab have dense layers of phase change material and magnetic emulsion respectively, which take into account the overall strength of the prefabricated track slab, reduce interface stress, reduce structural temperature gradient, and improve surface waterproof performance. Magnetic emulsion and phase change material are added in the form of internal admixture, and their improvement effect will not fail with the increase of service life.

[0058] The precast track slab is a prefabricated structure with two gradient distribution areas cast in layers, flexible application of physical fields and easy construction.

[0059] Although the present application has been described in detail above by means of general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed in the present application.

Claims

1. A double-gradient prefabricated track slab for ballastless track, characterized in that: Including phase change material gradient distribution area and magnetic emulsion gradient distribution area, The content of the phase change material in the phase change material gradient distribution area presents a gradient distribution from more to less in the direction from the upper surface to the bottom surface of the prefabricated track slab. The content of the magnetic emulsion in the magnetic emulsion gradient distribution area presents a gradient distribution from more to less in a direction from the bottom surface to the upper surface of the prefabricated track slab.

2. The double-gradient prefabricated track slab according to claim 1, characterized in that: The phase change material gradient distribution area includes a phase change material rich side and a phase change material sparse side, the phase change material rich side is located on the upper surface of the prefabricated track plate, and the phase change material sparse side is located below the phase change material rich side and above the magnetic emulsion gradient distribution area.

3. The double-gradient prefabricated track slab according to claim 1, characterized in that: The magnetic emulsion gradient distribution area includes a magnetic emulsion enriched side and a magnetic emulsion sparse side, the magnetic emulsion enriched side is located on the bottom surface of the prefabricated track plate, and the magnetic emulsion sparse side is located above the magnetic emulsion enriched side and below the phase change material gradient distribution area.

4. The double-gradient prefabricated track slab according to any one of claims 1 to 3, characterized in that: The phase change material is a phase change microcapsule with electrical response, and the phase change material can move in a directional manner under the action of an electric field.

5. The double-gradient prefabricated track slab according to any one of claims 1 to 3, characterized in that: The magnetic emulsion is an emulsion with magnetic response, and the magnetic emulsion can move in a directional manner under the action of a magnetic field.

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