Method for reinforcing concrete slabs on which ballast tracks are laid.

Abstract

The objective is to provide a method for reinforcing a concrete floor slab on which a ballast track is placed, by enabling the reinforcement of the concrete floor slab without removing the ballast track, particularly the ballast itself. [Solution] A method for reinforcing a concrete floor slab 2 on which a ballast track 1 is laid, comprising: a pre-watering step of sprinkling water on the ballast track 1 to wet the silt surface of the silt layer 3 and / or the ballast surface of the ballast layer 4; and an impregnating repair material sprinkling step of sprinkling an impregnating repair material on the ballast track 1 and supplying it to the surface of the concrete floor slab 2.

Description

Technical Field

[0001] The present invention relates to a method for reinforcing a concrete floor slab on which a ballast track is laid.

Background Art

[0002] Conventionally, a structure is known in which a concrete floor slab is constructed on a viaduct, a river-crossing bridge, a tunnel, etc., and a ballast track is laid thereon. Although such a concrete floor slab has a ballast track laid thereon and is covered with ballast, etc., rainwater, etc. passes through the ballast, etc. and reaches the concrete floor slab, so the concrete gradually deteriorates. It is necessary to reinforce the deteriorated concrete floor slab to maintain a state in which the ballast track can be safely supported over a long period of time. In addition, as a reinforcing material for reinforcing deteriorated concrete, an impregnating repair material that impregnates from the concrete surface and cures the vicinity of the concrete surface is known (Patent Documents 1 and 2), and a method of applying or spraying such an impregnating repair material to the concrete surface to reinforce the concrete has been implemented.

[0003] However, since the surface of a concrete floor slab on which a ballast track is laid is covered by the ballast track, in order to perform the reinforcement work, it is necessary to remove the ballast track, at least the ballast, to expose the concrete floor slab, which requires a great deal of labor, cost, and time. Furthermore, night work and line closure are also necessary, and the implementation of the reinforcement work was extremely difficult.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As mentioned above, reinforcing concrete slabs that have deteriorated due to rainwater and other factors is extremely difficult. However, if the deterioration of the concrete slabs is left unattended and damage occurs to the ballast track, it can cause significant disruption to railway operations and even lead to railway accidents such as derailments. Therefore, the objective is to provide a method for reinforcing a concrete floor slab on which a ballast track is laid, by enabling the reinforcement of the concrete floor slab without removing the ballast track, particularly the ballast itself. [Means for solving the problem]

[0006] To solve the aforementioned problems, the present invention has the following configuration. A method for reinforcing a concrete slab on which a ballast track is laid, A pre-watering step involves spraying water onto the ballast track to wet the silt surface of the silt layer and / or the ballast surface of the ballast layer, A method for reinforcing a concrete floor slab on which a ballast track is laid, comprising: an impregnation repair material application step of applying an impregnation repair material to the ballast track and supplying it to the surface of the concrete floor slab. [Effects of the Invention]

[0007] The present invention provides a method for reinforcing a concrete floor slab on which ballast tracks are laid, which allows for the reinforcement of the concrete floor slab without removing the ballast tracks from the concrete floor slab on which the ballast tracks are laid. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a concrete slab on which a ballast track according to an embodiment of the present invention is laid. [Modes for carrying out the invention]

[0009] [Embodiment] Hereinafter, with reference to the drawings, a method for reinforcing a concrete slab on which a ballast track is laid according to an embodiment of the present invention will be described.

[0010] [Concrete slab with ballast track laid on it] Generally, a ballast track consists of a ballast layer (crushed stone) laid on the roadbed, sleepers placed on top of the ballast layer, and rails fixed to the sleepers. Furthermore, the ballast is broken down by the weight and vibrations of trains running on the rails, generating fine particles (silt), which accumulate beneath the ballast layer to form a silt layer. Then, after a predetermined period of time has elapsed, the ballast track 1, as shown in Figure 1, is laid on a concrete base plate 2 serving as the roadbed and has a silt layer 3, a ballast layer 4, sleepers 5, and rails 6. The silt layer 3 is stacked on the concrete base plate 2, the ballast layer 4 is stacked on the silt layer 3, sleepers 5 are installed on the upper surface of the ballast layer 4, and rails 6 are fixed to the upper surface of the sleepers 5.

[0011] The ballast that makes up ballast layer 4 is made of hard, tough stones such as granite, crushed to a size of about 10 to 80 mm. Ballast layer 4 has many voids between the ballast particles, which securely fixes the sleepers 5 and absorbs vibrations of the sleepers 5 and rails 6 caused by the movement of trains. Although ballast layer 4 is said to have high water permeability because the ballast particles are large and there are relatively large voids between them, the water and impregnating repair materials that are sprayed tend to adhere to and be adsorbed on the ballast surface as they fill the voids between the ballast particles, resulting in a tendency for a large amount of water and impregnating repair materials to remain on the ballast surface. Silt layer 3 is formed when silt, which has been pulverized by crushing and abrasion of ballast, settles and accumulates below ballast layer 4. As a result, there are few voids between the silt particles, and the surface area of ​​the silt is large. Therefore, water and impregnating repair materials sprayed onto silt layer 3 adhere to and are adsorbed onto the surface of the silt, or remain in the voids between the silt particles, which reduces the amount of water and impregnating repair materials that permeate downwards. Even if an impregnating repair material is sprayed from above the ballast track 1 in an attempt to reinforce the concrete floor slab 2 without removing the ballast track 1, a large amount of the impregnating repair material stays in the silt layer 3 and the ballast layer 4, particularly in the silt layer 3, resulting in less impregnating repair material reaching the surface of the concrete floor slab 2. Therefore, it is necessary to spray a much larger amount of the impregnating repair material than the amount required for reinforcing the concrete floor slab 2, which causes a problem of increasing the cost of the reinforcement work for the concrete floor slab 2.

[0012] [Reinforcement of Concrete Floor Slab] In this embodiment, the reinforcement work for the concrete floor slab includes a pre-water spraying step, an impregnating repair material spraying step, and a post-water spraying step.

[0013] [Pre-Water Spraying Step] The pre-water spraying step is a step of spraying water on the ballast track 1 before spraying the impregnating repair material. The pre-water spraying step supplies water to the silt layer 3 and the ballast layer 4 to moisten the surfaces of the silt and the ballast, and suppresses the adhesion and adsorption of the subsequently sprayed impregnating repair material to the surfaces of the silt and the ballast, so as to increase the amount of the impregnating repair material that penetrates through the silt layer 3 and the ballast layer 4 and reaches the surface of the underlying concrete floor slab 2. When the voids in the silt layer 3 and the ballast layer 4 are filled with the sprayed water, it becomes a factor that hinders the downward penetration of the impregnating repair material. Therefore, the amount of water to be sprayed is limited to the amount necessary to moisten the surfaces of the silt and the ballast. The actual spraying amount in the pre-water spraying step is determined by the amounts of the silt and the ballast in the silt layer 3 and the ballast layer 4, the water absorption state of the silt layer 3 and the ballast layer 4, etc. However, as a rough guide, it is about 8 - 12 L / m

[0013] , , , <00​​​​​​"Impregnation-based repair material spraying process" The impregnation-based repair material spraying process is a process of spraying an impregnation-based repair material onto the ballast track 1. The impregnation-based repair material is a process of supplying the impregnation-based repair material to the surface of the concrete floor slab 2 by permeating through the silt layer 3 and the ballast layer 4. As the impregnation-based repair material, silicate-based impregnating materials, silane-based impregnating materials, etc. are used. As the silicate-based impregnating material, for example, TS Sealer (Sixon Co., Ltd.), RC Guard (registered trademark: ABC Shokai Co., Ltd.), Super Shield (Super Shield Co., Ltd.), etc. are used. As the silane-based impregnating material, for example, Magic Repeller (registered trademark: Kajima Corporation), New Spangard (Sho Bond Construction Co., Ltd.), Aqua Seal 1400 (Daito Paint Co., Ltd.), etc. can be used. In addition to silicate-based impregnating materials and silane-based impregnating materials, other known impregnation-based repair materials can also be used as the impregnation-based repair material. Due to the pre-water spraying process, the surfaces of the silt and ballast are wet. Therefore, although the adhesion and adsorption of the impregnation-based repair material to the surfaces of the silt and ballast are suppressed, it does not completely penetrate the silt layer 3 and the ballast layer 4. So, the spraying amount of the impregnation-based repair material needs to be more than the amount directly sprayed or applied to the concrete surface. It varies depending on the type of impregnation-based repair material, the dilution degree of the impregnation-based repair material, the amount and wet state of the silt and ballast in the silt layer 3 and the ballast layer 4. For example, when using TS Sealer (Sixon Co., Ltd.) diluted at 1:2, with the diluted solution, 2 - 4 L / m 2 (stock solution: 0.67 - 1.33 L / m 2 , main component amount: 128 - 256 g / m 2 : about 3.2 - 6.4 times that of directly supplying to the concrete surface).

[0015] [Post-water spraying process] The post-water spraying process is a process of spraying water onto the ballast track 1 after spraying the impregnation-based repair material. The post-water spraying process is a process to reduce the loss of impregnating repair material by moving the impregnating repair material that has been sprayed onto the ballast track 1 in the impregnating repair material spraying process and remains in the silt layer 3 and ballast layer 4 downwards to reach the surface of the concrete floor slab 2. The actual amount of water sprayed in the post-watering process is determined by factors such as the amount of silt and ballast in silt layer 3 and ballast layer 4, and the amount of impregnating repair material sprayed in the impregnating repair material spraying process. However, a rough guideline is 1-2 L / m 2 It is to that extent. The post-watering step reduces the loss of the impregnating repair material mentioned above, and also contributes to the uniformity of the impregnating repair material reaching the surface of the concrete floor slab 2. The post-watering step is not an essential step in the reinforcement work of the concrete floor slab 2, but as mentioned above, it is effective as an auxiliary step and is preferably performed as one of the steps in the reinforcement work of the concrete floor slab 2.

[0016] As described above, when impregnating repair materials are scattered on the ballast track 1 and reach the surface of the concrete slab 2, they react with calcium hydroxide (Ca(OH)2) in the concrete slab 2 to form a CSH (calcium silicate hydrate) layer, similar to conventional concrete surface reinforcement. This densifies the surface of the concrete slab 2, improving hardness and suppressing water absorption. In the case of silane-based impregnating materials, they react with moisture on the surface of the concrete slab 2 to form a siloxane network (Si-O-Si), suppressing water absorption and salt penetration.

[0017] In this embodiment, as described above, the pre-watering step wets the surfaces of the silt and ballast, then the impregnating repair material application step allows the impregnating repair material to permeate the silt layer 3 and ballast layer 4 and be supplied to the surface of the concrete floor slab 2, and the post-watering step moves the impregnating repair material remaining in the silt layer 3 and ballast layer 4 downwards and supplies it to the surface of the concrete floor slab 2. This allows the impregnating repair material to be supplied to the surface of the concrete floor slab 2 without removing the ballast track 1. Furthermore, the pre-watering step and post-watering step allow the impregnating repair material to be efficiently supplied to the surface of the concrete floor slab 2, so that reinforcement work on the surface of the concrete floor slab 2 beneath the ballast track 1 can be carried out without requiring a great deal of labor, expense, or time.

[0018] The method for reinforcing a concrete slab beneath a ballast track according to an embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to the embodiment, and any design changes, etc., that do not depart from the gist of the present invention are also included. [Explanation of symbols]

[0019] 1. Ballast track 2. Concrete floor slab 3. Silt layer 4. Ballast layer 5 Railway sleepers 6 rails

Claims

1. A method for reinforcing a concrete slab on which a ballast track is laid, A pre-watering step involves spraying water onto the ballast track to wet the silt surface of the silt layer and / or the ballast surface of the ballast layer, A method for reinforcing a concrete floor slab on which a ballast track is laid, comprising: an impregnation repair material application step of applying an impregnation repair material to the ballast track and supplying it to the surface of the concrete floor slab.

2. A method for reinforcing a concrete floor slab on which a ballast track is laid, characterized in that it includes a post-watering step of spraying water onto the ballast track to move the impregnating repair material supplied by the impregnating repair material spraying step and remaining on the silt layer and / or ballast layer to the surface of the concrete floor slab, as described in claim 1.

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