Roadbed construction method and roadbed

Abstract

To suppress variations in quality of a roadbed by simplifying construction, and also to suppress variations in temperature in a surface direction of a roadbed surface.SOLUTION: A construction method of a roadbed 12 includes: a mixture forming step of forming a mixture by previously mixing aggregates 21 and a water pumping material 22 having an average particle diameter smaller than an average particle diameter of the aggregates 21; and a laying step of laying the mixture to form the roadbed 12. The water pumping material 22 exhibits a water pumping property by a capillary phenomenon between the aggregate 21 and the water pumping material 22 and between the water pumping materials 22 by filling a gap between the aggregates 21.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a roadbed construction method and a roadbed.

Background Art

[0002] Patent Document 1 discloses a pavement structure including a wet surface layer, a capillary water retention layer provided below the wet surface layer, a water pumping member provided inside the capillary water retention layer, and a water barrier member provided on at least one of the lower surface and side surfaces of the capillary water retention layer.

[0003] The wet surface layer forms the road surface and has water pumping and water permeability properties. The capillary water retention layer has water pumping and water permeability properties and is capable of retaining capillary water. As the capillary water retention layer, sand or a sand bag is disclosed.

[0004] The water pumping member is capable of supplying moisture to the wet surface layer by capillary action and has a higher water pumping speed than the capillary water retention layer. The water pumping member is installed substantially vertically inside the capillary water retention layer and is a member capable of pumping moisture upward by capillary action. As the water pumping member, a water-permeable sheet, a cylindrical member composed of a hollow portion extending substantially vertically and a water pumping wall formed around the hollow portion, is disclosed. As the cylindrical member, ceramics is disclosed, and a rod-shaped member having a high thermal conductivity such as copper or aluminum is also disclosed.

[0005] In such a pavement structure, during rainfall, rainwater penetrates and is retained in the capillary water retention layer through the wet surface layer. Also, during sunny days, it is possible to supply capillary water to the wet surface layer by the capillary water retention layer and the water pumping member due to capillary action.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the case of the paving structure disclosed in Patent Document 1, a roadbed that supports the wet surface layer from below is constituted by a capillary water retention layer and a pumping member. For this reason, due to the complexity of the construction, variations in the quality of the roadbed are likely to occur. In addition, variations in temperature in the surface direction of the roadbed surface are likely to occur.

Means for Solving the Problems

[0008] A roadbed construction method and each aspect of the roadbed for solving the above problems are described. [Aspect 1] A mixture forming step of previously mixing an aggregate and a pumping material having an average particle size smaller than the average particle size of the aggregate to form a mixture; A laying step of laying the mixture to form a roadbed, and The pumping material exhibits pumping property due to capillary action through the gaps between the aggregates by filling the gaps between the aggregates, between the aggregates and the pumping material, and between the pumping materials. A roadbed construction method.

[0009] According to the method, since the aggregates are dispersed throughout the roadbed, the supporting force of the roadbed can be ensured by the aggregates. In addition, by previously mixing the aggregates and the pumping material, the gaps between the aggregates are filled with the pumping material. As a result, the pumping material is dispersed throughout the roadbed. And, throughout the roadbed, the pumping property due to capillary action between the aggregates and the pumping material, and between the pumping materials is exhibited. Therefore, by simplifying the construction, variations in the quality of the roadbed can be suppressed. In addition, variations in temperature in the surface direction of the roadbed surface can be suppressed.

[0010] [Aspect 2] The pumping material is a porous body. The roadbed construction method according to Aspect 1.

[0011] According to the same method, since the water-lifting material is a porous body, the water-lifting material has water retention. As a result, the water retention of the roadbed is improved. [Aspect 3] An aggregate, a water-lifting material having an average particle size smaller than the average particle size of the aggregate and filling the space between the aggregates, and the water-lifting material exhibits water-lifting property by capillary action through the gaps between the aggregates and between the water-lifting materials by filling the gaps between the aggregates. Roadbed.

[0012] According to the same configuration, the same operational effects as those in Aspect 1 can be achieved. [Aspect 4] The water-lifting material is a porous body. The roadbed according to Aspect 3.

[0013] According to the same configuration, the same operational effects as those in Aspect 2 can be achieved.

Effects of the Invention

[0014] According to the present invention, the variation in the quality of the roadbed can be suppressed by simplifying the construction. In addition, the variation in temperature in the surface direction of the roadbed can be suppressed.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0016] Hereinafter, with reference to FIGS. 1 to 4, a roadbed construction method and an embodiment of the roadbed will be described. As shown in FIG. 1, the pavement structure 10 includes a wet surface layer 11, a roadbed 12 provided below the wet surface layer 11, and a sheet 30 covering the lower surface and side surfaces of the roadbed 12.

[0017] <Wet surface layer 11> As shown in FIG. 1, the wet surface layer 11 forms the road surface and has water repellency and moisture permeability.

[0018] As the wet surface layer 11, it is possible to penetrate rainwater downward through the wet surface layer 11 during rainfall, and it is possible to pump up moisture from the lower surface of the wet surface layer 11 during sunny days. As the wet surface layer 11, known paving materials can be used. As the base material of the wet surface layer 11, for example, paving blocks, porous asphalt, and porous concrete can be appropriately used.

[0019] <Roadbed 12> As shown in FIGS. 1 and 2, the roadbed 12 includes an aggregate 21 and a water pumping material 22. (Aggregate 21) The aggregate 21 is preferably graded crushed stone. The aggregate 21 of this embodiment is crushed stone (M-25) whose particle size is adjusted to 25 mm or less.

[0020] (Water pumping material 22) The water pumping material 22 has an average particle size smaller than the average particle size of the aggregate 21 and fills the space between the aggregates 21. The water pumping material 22 exhibits water pumping property due to capillary action through the gaps between the aggregates 21 by filling the gaps between the aggregates 21, between the aggregate 21 and the water pumping material 22, and between the water pumping materials 22.

[0021] The water pumping material 22 is preferably a porous body. The water pumping material 22 of this embodiment is porous α (registered trademark) whose particle size is adjusted to 3 mm or less. Note that porous α is a porous glass foam and is formed from waste glass and shells as raw materials.

[0022] <Sheet 30> As shown in FIG. 1, the sheet 30 is a known sheet having water shielding properties. Note that the sheet 30 may be a known civil engineering sheet with low water permeability. Also, the sheet 30 is not essential and can be omitted.

[0023] Next, a construction method of the roadbed 12 will be described. As shown in FIG. 3, the construction method of the roadbed 12 includes a mixture forming step and a laying step. (Mixture forming step) The mixture forming step is a step of previously mixing the aggregate 21 and the water pumping material 22 to form a mixture. In the mixture forming step of the present embodiment, the aggregate 21 and the water pumping material 22 are mixed using a mixer (not shown in the figure).

[0024] (Laying step) The laying step is a step of laying the mixture to form the roadbed 12. In the laying step of the present embodiment, the roadbed 12 is formed by previously laying the sheet 30 and laying the above mixture in the region surrounded by the sheet 30.

[0025] Next, the operation of the present embodiment will be described. As shown in FIG. 4(a), during rainfall, rainwater penetrates into the lower roadbed 12 through the wet surface layer 11.

[0026] As shown in FIG. 4(b), during sunny days, due to capillary action between the aggregate 21 and the water pumping material 22 and between the water pumping materials 22, the water held in the roadbed 12, that is, capillary water, is pumped up and supplied to the wet surface layer 11.

[0027] In this embodiment, since the aggregate 21 is dispersed throughout the roadbed 12, the aggregate 21 can ensure the supporting force of the roadbed 12. Further, by mixing the aggregate 21 and the water-lifting material 22 in advance, the gaps between the aggregates 21 are filled with the water-lifting material 22. Thereby, the water-lifting material 22 is dispersed throughout the roadbed 12. Then, in the entire roadbed 12, water-lifting property due to capillary action is exhibited between the aggregate 21 and the water-lifting material 22 and between the water-lifting materials 22.

[0028] Next, the effects of this embodiment will be described. (1) The construction method of the roadbed 12 includes a mixture formation step and a laying step. The water-lifting material 22 exhibits water-lifting property due to capillary action between the aggregate 21 and the water-lifting material 22 and between the water-lifting materials 22 by filling the gaps between the aggregates 21.

[0029] According to such a method, since the above actions are achieved, the construction becomes simple, so that variations in the quality of the roadbed 12 can be suppressed. Further, variations in temperature in the surface direction of the roadbed 12 can be suppressed.

[0030] (2) In the case of the structure disclosed in Patent Document 1, when constructing the roadbed, after arranging the water-lifting member so as to extend in a substantially vertical direction, a capillary water retention layer is laid. For this reason, there is a problem that the construction is laborious.

[0031] In this regard, according to the construction method of this embodiment, since the roadbed 12 is formed by laying a mixture in which the aggregate 21 and the water-lifting material 22 are mixed in advance, the roadbed 12 can be easily constructed.

[0032] (3) The roadbed 12 includes the aggregate 21 and the water-lifting material 22. According to such a configuration, the same operational effects as in (1) can be achieved. (4) The water-lifting material 22 is a porous body. Since the water-lifting material 22 is a porous body, the water-lifting material 22 has water retention property. Thereby, the water retention property of the roadbed 12 is improved.

[0033] <Modification Example> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0034] · The water - lifting material 22 may be a porous body other than porous α. As long as the water - lifting material 22 has an average particle size smaller than the average particle size of the aggregate 21, those with different particle size distributions such as the maximum particle size and the average particle size can be used.

[0035] · The water - lifting material 22 does not have to be a porous body. · The aggregate 21 may be crushed stone other than M - 25. Also, the aggregate 21 may be crusher run.

Explanation of Signs

[0036] 10…Pavement structure, 11…Wet surface layer, 12…Subgrade, 21…Aggregate, 22…Water - lifting material, 30…Sheet

Claims

1. A mixture forming step of pre-mixing an aggregate and a pumping material having an average particle size smaller than the average particle size of the aggregate to form a mixture; A laying step of laying the mixture to form a roadbed, wherein the pumping material exhibits water pumping property by capillary action through the gaps between the aggregates by filling the gaps between the aggregates, between the aggregates and the pumping material, and between the pumping materials; A method for constructing a roadbed.

2. The pumping material is a porous body. The method for constructing a roadbed according to Claim 1.

3. An aggregate, a pumping material having an average particle size smaller than the average particle size of the aggregate and filling the gaps between the aggregates, wherein the pumping material exhibits water pumping property by capillary action through the gaps between the aggregates, between the aggregates and the pumping material, and between the pumping materials by filling the gaps between the aggregates; A roadbed.

4. The pumping material is a porous body. The roadbed according to Claim 3.

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