JP2008088714A - Ground surface cooling structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground surface cooling structure which is constructed almost in the same manner as a conventional manner of the construction of a pavement structure by means of general interlocking blocks or the like or the construction of a road surface structure having turf planted therein, and hardly generates unevenness in the pavement structure and is excellent in cooling effect. <P>SOLUTION: A water storage layer 4 having a predetermined thickness is formed on a roadbed 1. The water storage layer 4 has a water-permeable ceiling plate having a number of water-permeable pores formed thereat, and is formed by planarly arranging resin water storage members 4a which bear an upper load and secure storage spaces therein. Then a water conveying sheet 5 for penetrating and dispersing moisture from the water storage layer 4 in an in-lane direction is laid on the water storage layer 4, and blocks 7 are laid side by side on the water conveying sheet 5 via an upper sand cushion layer 6, joint sand 8 is filled in a joint between the blocks 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ground surface cooling structure that allows frequent evaporation of moisture from the ground surface, such as a pavement surface, and suppresses the temperature rise of the ground surface during fine weather.

  In recent years, an abnormal temperature rise in urban areas due to the heat island phenomenon has become a problem, and various studies have been made to suppress this abnormal temperature rise. One example is water-retaining pavement.

  The main idea of water-retaining pavement is that `` pavement material containing water-retaining material is laid on the pavement surface, and the water retained in this pavement material by rain, etc. The heat of vaporization generated by evaporation takes heat of the pavement surface, and the temperature rise is suppressed by suppressing the temperature rise of the pavement surface. " Various practical methods based on this concept have been studied.

  In addition, planting vegetation plants such as turf (greening) is also effective as a method of suppressing this abnormal temperature rise.

  As an example of a water-retaining pavement structure, for example, Patent Document 1 discloses a combination of a water-impermeable impermeable layer laid on a roadbed, a hard resin foam water storage block laid on the upper surface, and a water-repellent member. A water storage layer having an inner space, a water diffusion layer made of a fiber material laid on the upper surface, and a water retention block (permeable water retaining type interlocking block) laid on the upper surface of the water diffusion layer And a water retention type pavement structure provided with a water pumping member made of a fiber material connecting the water storage layer and the water diffusion layer.

  In addition, Patent Document 2 is a water conveyance sheet that is laid on a sand cushion layer on a roadbed as a water conveyance sheet used for a water retention pavement structure, and on which a water retention block is laid, Described are those equipped with a water-conducting layer, a water-absorbing layer, a water-stopping layer, etc., and those in which the surface level when the water-absorbing layer absorbs water and expands in volume is positioned above the surface level of the water-conducting layer ing.

JP 2003-268712 A Japanese Patent Laid-Open No. 2004-225311 JP 2003-105932 A JP 2003-286703 A

  The water-retaining pavement structure described in Patent Document 1 stores rainwater in a water reservoir formed in the pavement structure itself without providing a water supply facility, etc. However, unlike a general interlocking block pavement structure, there is no sand cushion layer between the water diffusion layer and the pavement material, and it is difficult to adjust the unevenness of the pavement material. . In addition, structurally, there is a problem that the provision of the water reservoir will cause unevenness. Furthermore, on the construction side, a process different from the construction of a conventional general pavement structure is necessary, which requires a lot of construction work and results in costly construction.

  In patent document 2, although the water conveyance sheet | seat which consists of a water stop layer and a water conveyance layer is provided directly under the water absorption type water retention block, since it is a structure where water storage performance is almost dependent on a water conveyance sheet | seat, water storage is carried out. In addition to being insufficient, the water guide sheet may be damaged on the road surface such as a road by mechanical force due to vehicle traffic.

  The present invention devises the structure of the water reservoir and the arrangement relationship with the water guide sheet, etc., regarding the cooling structure of the ground surface provided with the water reservoir and the water guide sheet for infiltrating and diffusing moisture from the water reservoir in the in-plane direction. Therefore, it is possible to perform construction that is almost the same as the conventional general pavement structure or soil greening structure planted with turf, etc., the durability of the water reservoir is high, the road surface is not prone to unevenness, and sustainable The object is to provide a ground surface cooling structure with excellent cooling effect.

The ground surface cooling structure according to claim 1 of the present application is a ground surface cooling structure that takes heat away from the heat of vaporization when moisture evaporates and lowers the temperature of the ground surface,
a. Resin water storage members having a water permeable ceiling plate with a large number of water permeable holes and capable of forming a water storage space inside while supporting an overload are arranged one or more in a row in a plane. A reservoir of a predetermined thickness,
b. A water guide sheet laid on the reservoir and capable of infiltrating and diffusing moisture from the reservoir in an in-plane direction;
c. An earth and sand layer laid on the water guide sheet and having water permeability and water retention and also having a function of complementing the function of the surface covering material;
d. A surface covering material laid on the earth and sand layer;
It is characterized by having.

  The overload is a load applied from its own weight, a sediment layer, a surface covering material, and a road surface when a pedestrian, a vehicle, or the like passes on the ground surface.

  The reservoir functions to store rainwater that has penetrated underground when it rains, and to supply water toward the ground surface during clear weather or when the temperature rises. In the present invention, the water storage layer is formed of a resin water storage member having a permeable ceiling plate and capable of forming a water storage space inside while supporting an overload, so that the water storage layer does not cause unevenness. In addition, it is possible to evenly and evenly support surface covering materials such as a water conveyance sheet laid on the top and a sand layer and a block (such as an interlocking block) such as a sand cushion layer on the top. Moreover, since it becomes durable by forming with the water storage member made from resin with a water-permeable ceiling board, the use under the road surface with much traffic volume is also attained.

  The water guide sheet is made of nonwoven fabric, woven fabric, tricot, or the like, and has a sheet thickness of about 5 mm or less. The filter functions to prevent dirt and sand from entering the resin water storage member by laying on the water permeable ceiling plate (on the water storage layer) having a large number of water permeable holes above the resin water storage member. Have.

  In addition, the structure which consists of a water reservoir and a water conveyance sheet | seat of this invention is applicable not only to a pavement structure but in the case of the soil etc. where the ground surface vegetated turf.

  Resin water storage members can be made of, for example, polyethylene or polypropylene, but those that are commercially available as members for assembling rainwater infiltration facilities (for example, the product name “System Panel” of Ebata Corporation) are diverted. May be. The thickness of the resin water storage member only needs to be able to withstand the overload because the required thickness varies depending on the structure of the water storage layer. The shape of the resin water storage member in the vertical direction is not particularly limited as long as the water storage space can be formed inside while supporting the loading load.

  Usually, if the height of the reservoir space is at least several tens to 100 mm, the effect can be expected. On the other hand, if the height of the reservoir space is too high, it is difficult to stably support the loading load. When the air portion of the water storage space increases, it is disadvantageous to suck up water. Therefore, it is desirable to stack one or two resin water storage members having a water storage space height of about several tens of millimeters.

  Therefore, the predetermined thickness of the water reservoir referred to in the present invention refers to a water reservoir comprising a resin water reservoir that can store sufficient water in the water storage space, can secure a height at which the water is sucked up, and can stably support the loading load. The thickness of the entire tank. The specific thickness of the specific water reservoir is desirably about 30 mm to 200 mm. More preferably, it is about 40 to 100 mm.

  In addition, although it can be considered that the low height is stacked in multiple stages, doing so will increase the cost and increase the construction work. Naturally, each stacked stage is a water storage space that communicates.

  The ceiling plate having a large number of water-permeable holes supports the earth and sand layer and does not drop the earth and sand into the water storage layer, and the shape of the water-permeable holes is not limited, but is formed in many shapes such as a circle, a polygon, etc. It is desirable. This water-permeable ceiling board may be provided not only at the uppermost stage but also between the respective stages as required. As a result, the strength of the reservoir can be improved.

  Reservoir water usually needs to be stored during rainy weather, but if drought due to clear weather lasts for a long period of time, water can be sprayed and infiltrated into the reservoir, automatic irrigation, or from rivers and ponds. Direct supply to the reservoir may be considered.

  In order to store water in the water storage layer, a water shielding sheet may be laid in the lower layer of the water storage layer, or a floor plate without a hole may be provided on the lowermost surface of the resin water storage member.

  When the ground surface dries out during drought, the water in the reservoir is infiltrated and diffused in the horizontal plane by the water supply means and the water guide sheet laid on the top surface of the reservoir, and the sand laid on the top surface of the water guide sheet. Moisture is supplied to the surface covering material such as blocks and vegetation plants in the form of soaking on the soil layer such as cushion layer or vegetation soil layer, and evapotranspiration of water from the ground surface frequently occurs through these surface covering materials. Can be.

  Thereby, the cooling effect by the heat of vaporization is obtained with respect to the temperature rise of the ground surface, and the suppressing effect such as the heat island phenomenon is obtained.

  The earth and sand layer has water permeability and water retention and also complements the function of the surface covering material. The surface covering material is a vegetation plant such as a block or turf, a water-permeable pavement, or gravel.

  In addition, a block will not be specifically limited if a water | moisture content evaporates from the surface, However, What satisfy | fills the specification of the water retention block of interlocking pavement technology association is preferable.

  Claim 2 is the ground surface cooling structure according to claim 1, in order to efficiently supply water from the water reservoir to the water guide sheet, the water supply for sucking up the water accumulated in the water storage space and guiding it to the water guide sheet The case where the means is provided is limited.

  Examples of the water supply means include capillary action and use of siphon.

  Further, according to a third aspect of the present invention, in the ground surface cooling structure according to the second aspect, the water supply means is of the same quality as the water conveyance sheet, suspended from the water conveyance sheet through the hole of the water permeable ceiling plate and into the water storage space. The case where it is a water supply sheet piece, a resin hollow string, or a resin nonwoven fabric piece is limited.

  These are intended to supply water in the water storage space to the water guide sheet mainly by capillary action, and to smoothly supply water from the water guide sheet to the earth and sand layer and the surface covering material as described above. These water supply sheet pieces and the like do not need to be hung in all of the holes. Although arrangement | positioning is not specifically limited, The grade which fully spread | diffuses in the surface of a water guide sheet | seat may be sufficient.

  Claim 4 limited to the ground surface cooling structure according to claim 1, 2 or 3, wherein the water guide sheet is a water guide sheet having a pumping distance of 20 cm or more measured by the JIS L 1907 birec method for 10 minutes. It is a thing.

  When a sand and sand layer such as a sand cushion layer is formed on the reservoir layer, there is a water guide sheet with a pumping distance of 10 cm or more between the reservoir layer and the earth and sand layer. Smooth infiltration and diffusion in the inward direction.

  The pumping distance can be measured by the JIS L 1907 birec method or a method based on this method (measuring the height of water that has risen by immersing water in a test piece of length 200 × width 25 mm). If the pumping distance is less than 20 cm in 10 minutes, there may be a case where the infiltration and diffusion of water supplied from the reservoir in the in-plane direction cannot be performed smoothly.

  In addition, when it was examined whether or not water could be pumped up to a surface covering material such as a block using a water conveyance sheet having a different pumping distance for 10 minutes, a water conveyance distance of 14 cm with a water conveyance sheet made of nylon (water conveyance sheet A), made of polyethylene terephthalate A pumping distance of 20 cm or more was measured with the water guide sheet (water guide sheet B).

  In the test shown in Table 1 to be described later, the test was conducted with the water guide sheet B based on this result.

  5. The ground surface cooling structure according to claim 1, wherein the ground surface is a road surface, the earth and sand layer is a sand cushion layer, and the surface covering material is a block. It is.

  This combination corresponds to the case of a pavement structure that is the main subject of the present invention.

  The sand cushion layer allows rainwater to pass through the reservoir during rain, supplies water during fine weather, and has a water retention function in the voids of the sand particles.

  Moreover, it has the function which complements the function of a road surface block, such as adjusting the unevenness of a road surface block as an original function, and maintaining the level of the road surface block upper surface. The sand of the sand cushion layer may be sand used for normal construction and is not particularly limited.

  In order to improve the water retention of the sand cushion layer, it is preferable to add a water retention material such as paper sludge incineration ash, lightweight aggregate, pumice, diatomaceous earth.

  Examples of the block include a water-retaining concrete block, a water-permeable concrete block, a ceramic block, a wooden block, an earth block, an elastic block, and a normal interlocking block. It is preferable to use a water-retaining block. It is also possible to use a plurality of types of blocks together.

The specifications of the water-retaining block of the Interlocking Pavement Technology Association have a water-retaining amount of 0.15 g / cm ³ or more and a wicking height of 70% or more, and the water-retaining block used in the present invention preferably satisfies these. More preferably, the water retention amount is 0.20 g / cm ³ or more and the suction height is 80% or more.

The cooling effect is further improved by using this water retaining block in the cooling structure of the present invention. Claim 6 is the ground surface cooling structure according to claim 5, wherein joint sand is provided between the blocks (joint portion). The case where it is filled is limited.

  In the case of a block, a material with low water permeability may be used for the surface layer from the viewpoint of the surface performance and design of the block, but if the joint is filled with joint sand, the permeability and water retention of that part In addition to being able to use this, it is easy to deal with non-landscapes caused by some cause. Although the kind of joint sand is not limited, the particle size structure which becomes favorable water permeability and water retention property is preferable.

  Claim 7 is the ground surface cooling structure according to claims 1 to 4, wherein the ground surface is a vegetation surface, the earth and sand layer is a vegetation soil layer, and the surface covering material is a vegetation plant such as turf. The case is limited.

  This is a structure that is not a pavement structure but a cooling effect due to vegetated soil etc., and a structure that has a greater cooling effect when cooling in places where pavement is not particularly required for use. . For example, a park, a rooftop of a building, etc.

  The vegetation soil layer supports vegetation plants, allows rainwater to pass through the reservoir during rain, supplies water during fine weather, and has a water retention function in the voids of the soil particles. The vegetation plant is turf or the like. In the case of this structure, a cooling effect is obtained by the water retention performance, evapotranspiration performance, heat shielding performance, etc. of the vegetation plant.

  According to the present invention, a resin water storage member having a water permeable ceiling plate having a large number of water permeable holes on the roadbed and capable of forming a water storage space inside while supporting an upper load is disposed. When a water reservoir of a certain thickness is formed and drought continues, moisture from the water reservoir permeates and diffuses in the in-plane direction by the water-conducting sheet laid on the reservoir, and further, a sand cushion layer or a vegetation soil layer Through the earth and sand layer, the water content of the reservoir can be efficiently supplied to the surface covering material such as blocks and vegetation plants, and the temperature rise of the ground surface can be suppressed by the heat of vaporization, which can be used as a solution to the heat island problem.

  Since the reservoir has a structure with sufficient rigidity, unevenness of the road surface does not become a problem, and even if it is disposed under a road surface with a large amount of traffic, it is not easily damaged. In addition, the construction itself is basically the same as the conventional construction except for the process of assembling and installing the resin water storage members that make up the water reservoir, and laying the water guide sheet on top of it. However, it is more advantageous than the conventional special cooling structure.

  A test for confirming the effect of the ground surface cooling structure of the present invention was conducted.

  FIG. 1 is a cross-sectional view of a pavement structure as a test body used in this test. In the test body corresponding to the best mode of the present invention, a pavement structure based on the design of an actual pavement structure was created in a section of 1000 mm × 1000 mm in which the upper and outer peripheries of the roadbed 1 were partitioned by a water shielding sheet 3. Is.

  The thickness of the roadbed 1 made of crushed stone is set to 100 mm, and the lower sand cushion layer 2 having a thickness of 30 mm for taking the horizontal of the water storage layer 4 is formed thereon, and the above-described water shielding sheet 3 is interposed thereon. A water storage layer 4 (thickness: about 60 mm) having a water storage space consisting of a resin water storage member 4a having a height of 50 mm is provided, a water guide sheet 5 is laid on the water storage layer 4, and a thickness of 30 mm is further provided on the water guide sheet 5. The upper sand cushion layer 6 was formed, and a block 7 having a thickness of 60 mm was spread thereon. Further, joint sand 8 was filled in the gaps between the blocks 7.

  As the water supply means, as will be described later, the water guide sheet 5 (trade name “water guide sheet # 5378” manufactured by Toray Industries, Inc., from the water-permeable hole in the water-permeable ceiling plate portion of the resin water storage member 4a, A water supply sheet piece 9 of the same quality as the water guide sheet B) was hung inside the water reservoir 4.

For the lower sand cushion layer 2 and the upper sand cushion layer 6, sand having a surface dry density of 2.55 g / cm ³ and a coarse particle ratio of 2.71 was used. The sand cushion layer in claim 5 is the upper sand cushion layer 6 here.

  FIG. 2 is a plan view of the resin water storage member 4a constituting the water storage layer, and FIG. 3 is a vertical sectional view. In addition, FIG. 2 shows a plane shape having a plane shape of 1000 mm × 1000 mm by combining four resin water storage members 4a having an uneven surface for connection on the outer peripheral portion of 500 mm × 500 mm and a height of the water storage space of 50 mm in the in-plane direction. A water storage layer having a water storage space height of 50 mm is constructed. Actually, a large number of resin water storage members 4a are connected and used according to the width of the road surface on which pavement or lawn is vegetated in the present invention or the distance in the continuous direction.

  The resin water storage member 4a has a water permeable ceiling plate 4b having a large number of water permeable holes 4d in an upper portion thereof, and has a structure in which a water storage space is formed inside while supporting an upper load. In this example, the lower surface of the resin water storage member 4 is open. However, rainwater penetrating from the ground surface is stored in the internal space of the resin water storage member 4 by laying the water shielding sheet 3. , Forming a reservoir.

  In addition, the resin water storage member 4 used for the test body is a thin type made of polypropylene (commercial name “system panel” manufactured by Ebata Co., Ltd.) among those commercially available as members for assembling the rainwater storage and penetration facility. It has a strength that can withstand the weight and traffic load of the upper part of the pavement when it is buried under the ground surface.

  In the water permeable ceiling plate 4b portion of the resin water storage member, a large number of water permeable holes 4d having a diameter of 20 mm are formed at a center distance of 50 mm, and one of the 1000 mm × 1000 mm specimens is formed from 16 water permeable holes 4d. A water supply sheet piece 9 of the same quality as the water guide sheet 5 (made by Toray Industries, Inc., trade name “water guide sheet # 5378”) is hung inside the water reservoir 4, and the water stored in the water reservoir 4 is in a dry condition where the weather is clear. Can be efficiently replenished to the block 7 or the surface soil.

  In addition, as a test body in the case where the upper surface is not paved with the block 7 or the like and used as a lawn, a vegetation soil layer was formed on the water guide sheet 5 of FIG. 1 and the lawn was planted thereon.

  As shown in FIG. 4, when measuring the temperature of the pavement surface when using the block 7, a hole 7c having a diameter of about 10 mm is opened on the lower surface of the block 7 to a position 10 mm from the surface of the block 7, and the thermocouple 10 is inserted. Three mortar-filled pieces were laid and recorded using a data logger. When the lawn was used, the temperature of the lawn surface was recorded by inserting a thermocouple 10 at a position 10 mm from the soil surface and using a data logger.

  FIG. 5 shows a cross-sectional view of a general pavement structure without a water reservoir as a comparative example. An upper sand cushion layer 6 having a thickness of 30 mm is formed on the road bed 1, and a block 7 Between them, joint sand 8 was packed.

  Table 1 shows a list of types of blocks used in the test specimens, presence / absence of a reservoir, block water retention amount, block suction height, surface temperature measurement results, examples, and comparative examples. No.1 and No.2 are concrete water retaining blocks (water retaining block A), No.3 and No.9 are conventional ordinary interlocking blocks, No.4 and No.5 are No.1 No.2 is a concrete water-retaining block (water-retaining block B) with a different composition, and No. 6 is a commercially available ceramic water-retaining block (water-retaining block C: trade name “Pacio II” manufactured by Tsurumi Techno Co., Ltd.). .

Here, as for the water retention block, the water retention amount of 0.15 g / cm ³ or more and the suction height of 70% or more, which are the standards of the water retention block of the Interlocking Pavement Technology Association, are all satisfied.

  The temperature measurement of the pavement surface was performed when the total rainfall for 24 hours was 47.7 mm 3 days before the outside air temperature was 27.7 ° C. The measurement results are shown in Table 2. The data were average values of 3 pieces each.

  From the comparison of No.2 and No.3 in Table 1 and No.3 and No.5, it can be seen that by using the water retaining block, the temperature of the pavement surface could be reduced by about 4 ° C. compared to the ordinary interlocking block. The same temperature reduction effect was seen even if different water retention blocks were used.

  Furthermore, by providing a reservoir, the temperature of the pavement surface was further reduced by about 4 ° C (No.1, No.4, No.6). When this water reservoir and water retention block were used in combination, the temperature was the same as in the case of No. 8 turf (no water reservoir).

  In the case of No.7, which used both No.8 turf and reservoir and conducted water from the reservoir to the soil layer, the temperature reduction effect was even greater. Moreover, even if it does not necessarily use a water retention block like No. 9, if it is set as the cooling structure of this invention, the temperature reduction effect will be acquired.

  Thus, if it is set as the cooling structure of this invention, the temperature rise of the ground surface can be suppressed effectively.

It is sectional drawing of the pavement structure as a test body. It is a top view of the resin water storage member which comprises a water storage layer. It is a vertical sectional view of a resin water storage member alone. It is a top view of the resin water storage member which comprises a water storage layer. It is sectional drawing of the general pavement structure without a water reservoir as a comparative example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Road bed, 2 ... Lower sand cushion layer, 3 ... Water shielding sheet, 4 ... Water storage layer, 4a ... Resin water storage member, 4b ... Water-permeable ceiling board, 4c ... Vertical rib, 4d ... Water-permeable hole, 5 ... Water conveyance Sheet, 6 ... upper sand cushion layer, 7 ... water retention block, 7a ... block base layer, 7b ... block surface layer, 7c ... hole, 8 ... joint sand, 9 ... water supply sheet piece, 10 ... thermocouple, 11 ... parting material.

Claims (7)

A cooling structure for the ground surface that takes heat away from the heat of vaporization when water evaporates and lowers the temperature of the ground surface, at least,
a. Resin water storage members having a water permeable ceiling plate with a large number of water permeable holes and capable of forming a water storage space inside while supporting an overload are arranged one or more in a row in a plane. A reservoir of a predetermined thickness,
b. A water guide sheet laid on the reservoir and capable of infiltrating and diffusing moisture from the reservoir in an in-plane direction;
c. An earth and sand layer laid on the water guide sheet and having water permeability and water retention and also having a function of complementing the function of the surface covering material;
d. A surface covering material laid on the earth and sand layer;
The ground surface cooling structure.   The ground surface cooling structure according to claim 1, wherein water supply means is provided for sucking up water accumulated in the water storage space and guiding it to the water guide sheet.   The water supply means is a water supply sheet piece of the same quality as the water transfer sheet, or a resin hollow string or a resin nonwoven fabric piece, which is hung from the water transfer sheet through the hole of the water-permeable ceiling plate to the water storage space. The ground surface cooling structure described.   The ground surface cooling structure according to claim 1, 2 or 3, wherein the water guide sheet is a water guide sheet having a pumping distance of 10 minutes or more measured by a JIS L 1907 birec method.   The ground surface cooling structure according to any one of claims 1 to 4, wherein the ground surface is a road surface, the earth and sand layer is a sand cushion layer, and the surface covering material is a block.   The ground surface cooling structure according to claim 5, wherein joint sand is filled between the blocks. The ground surface cooling structure according to any one of claims 1 to 4, wherein the ground surface is a vegetation surface, the earth and sand layer is a vegetation soil layer, and the surface covering material is a vegetation plant such as turf.

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