JP2016069880A - Water retentive pavement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water retentive pavement structure which can suppress a rise in temperature of a road surface for an extended period even when the road surface is overheated as an interlocking block holds water stored on a base course with a simple structure.SOLUTION: A water retentive pavement structure comprises a waterproof base course 120 formed on a roadbed, a water retention body formed by a water retentive paving sand layer 150 installed on the base course 120 and a water retentive interlocking block 170 laid on the paving sand layer 150 and constituting a road surface, and a gutter 180 installed in contact with the side face of the water retention body and having a drain hole 185a of which the bottom edge is formed at the position of 1 mm or higher from the surface of the base course 120.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water-retaining pavement structure including a floor sand layer having water retention and an interlocking block.

  In recent years, there has been a problem of a heat island phenomenon in which the temperature in urban areas is higher than that in the surrounding suburbs. Such high temperatures are mainly caused by the reflection of direct sunlight from the building and the temperature of pavements such as asphalt and concrete.

  In order to prevent a high temperature due to the heat island phenomenon, pavement is known to have a cooling function due to water retention. For example, Patent Document 1 discloses a pavement below the pavement to further improve the cooling performance. There has been proposed a pavement in which water reservoirs to be stacked are provided and a part of the water in the lateral groove is sucked into the water reservoir by the water guide member. And by such a structure, it is going to maintain surface cooling over a long period of time.

JP 2003-160906 A

  However, the above structure is complicated and unsuitable for wide application. Moreover, the drainage mechanism to the side groove is obliged by the standard of the interlocking block pavement technology association, and if the drainage mechanism is simply provided in accordance with the standard, the water in the reservoir flows as it is to the side groove.

  The present invention has been made in view of such circumstances, and the temperature of the road surface is maintained even when the road surface is overheated by the interlocking block holding the water accumulated on the roadbed with a simple structure. It aims at providing the water retention pavement structure which can suppress a raise over a long time.

  (1) In order to achieve the above object, the water-retaining pavement structure of the present invention includes a waterproof roadbed formed on a roadbed, a floor sand layer provided on the roadbed and having water retention, and the floor sand layer A water retaining body formed of a water retaining interlocking block laid on the road surface and a side surface of the water retaining body, and a lower end of the opening is formed at a position of 1 mm or more from the surface of the road base And a side groove having a drainage hole.

  Thereby, even when the road surface is overheated, the temperature rise of the road surface can be suppressed for a long time by holding the interlocking block with water stored on the roadbed with a simple structure.

  (2) Moreover, the water-retaining pavement structure of the present invention is characterized in that the spread sand layer is made of spread sand having a coarse particle ratio of 1.5 or more and 3.5 or less. Thereby, the floor sand layer can suck up and hold the water accumulated on the roadbed, and the interlocking block can also retain the water for a sufficient time.

  (3) Moreover, the water retention pavement structure of this invention is characterized by the lower end of the opening part being formed in the position where the said drain hole is 10 mm or more from the surface of the said roadbed. Thereby, it becomes easy for water to collect in a floor sand layer, and the water retention of a floor sand layer and an interlocking block can be improved.

  (4) Moreover, the water-retaining pavement structure of the present invention is characterized in that the road surface formed by the interlocking block is used as a sidewalk. Thereby, since the load concerning a road surface becomes small, malfunctions, such as an interlocking block tilting, can be avoided because a floor sand layer becomes loose.

  (5) Moreover, the water retention pavement structure of this invention is characterized by the said roadbed having the roadbed main body which consists of a water-permeable material, and the waterproof sheet provided in the surface of the said roadbed main body. In this way, it is possible to easily collect water on the roadbed by laying a waterproof sheet on the roadbed for a conventional sidewalk without water-blocking to make a new roadbed.

  (6) Moreover, the water-retaining pavement structure of the present invention is characterized in that the side groove has a groove part and a grating fitted in the groove part, and the drainage hole is formed in the grating. . Thereby, water retention can be adjusted at the time of design of a grating by the position of the drain hole provided in the grating. Moreover, the water drainage hole which can adjust a magnitude | size can also be provided and water retention can be adjusted on-site.

  According to the present invention, the water accumulated on the roadbed is held by the interlocking block with a simple structure, so that the temperature rise of the road surface can be suppressed for a long time even when the road surface is overheated.

It is sectional drawing which shows the water retention pavement structure of 1st Embodiment. It is sectional drawing which shows the water retention pavement structure of 2nd Embodiment. It is sectional drawing which shows the water retention pavement structure of 3rd Embodiment. It is sectional drawing which shows the water retention pavement structure of 4th Embodiment. It is a table | surface which shows the conditions of a test. (A), (b) is the front sectional drawing and side sectional drawing of a test body, respectively. It is a table | surface which shows the data of a test result. It is a graph which shows the surface temperature of a block with respect to measurement time.

  Next, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are given to the same components in the respective drawings, and duplicate descriptions are omitted.

[Water retentive pavement structure]
(First embodiment)
FIG. 1 is a cross-sectional view showing a water retention pavement structure 100. The water-retaining pavement structure 100 includes a roadbed 120, a laying sand layer 150, a joint sand 160, an interlocking block 170 (“IL block” in the figure, the same applies hereinafter) and a side groove 180 on the roadbed 110. The road bed 110 is a portion of the ground that has been ground and ground when the pavement is formed, and is formed of substantially uniform soil on the lower surface of the pavement.

  The roadbed 120 is formed by the lower layer roadbed 121 and the upper layer roadbed 122 on the roadbed 110. The lower layer roadbed 121 is made of crusher orchid, steel slag, and sand. The upper layer roadbed 122 is an asphalt stable treatment roadbed and impermeable.

  The ground sand layer 150 is provided on the roadbed 120 and has water retention. The bed sand layer 150 is preferably made of bed sand having a coarse particle ratio of 1.5 or more and 3.5 or less (JIS A 1102: 2006). Thereby, the floor sand layer can suck up and hold the water accumulated on the roadbed, and the interlocking block can also retain the water for a sufficient time. In addition, although it is preferable that the bed sand layer 150 is formed with the thickness of about 20 mm-30 mm, it is not necessarily limited to this.

  The joint sand 160 is filled between the interlocking blocks 170, strengthens their engagement, and transmits a load. Due to the shape of the joint keep provided in the interlocking block 170, an appropriate filling amount of the joint sand 160 is maintained.

  The interlocking block 170 is a concrete block and is laid on the laid sand layer 150 to form a road surface. The interlocking block 170 is formed to be porous and has water retention. Then, the joints are kept on the side surfaces, and joints between adjacent blocks are held when laid in a predetermined pattern. The held joints prevent the interlocking block 170 from competing and prevent corner chipping, and secure a space for filling joint sand. The bed sand layer 150 and the interlocking block 170 configured as described above form a water retaining body.

  The side groove 180 is provided in contact with the side surface of the water retaining body and collects water flowing on the roadbed 120 or the road surface into the groove and appropriately discharges it. The side groove 180 has a groove part 183 and a grating 185 fitted in the groove part 183. The grating 185 is made of metal and guides water flowing from above into the concave shape of the groove portion 183 through a lattice hole communicating in the vertical direction. The grating 185 has a drain hole 185a in which the lower end of the opening is formed at a position 1 mm vertically upward from the surface of the roadbed 120.

  The lower end of the opening of the drain hole 185a is at least 1 mm from the surface of the roadbed 120. Thereby, the interlocking block 170 holds the water accumulated on the roadbed 120 with a simple structure, so that the temperature rise of the road surface can be suppressed for a long time even when the road surface is overheated. The drain hole 185a preferably has a circular cross section from the viewpoint of ease of processing, but is not necessarily limited thereto, and may have a rectangular cross section. Moreover, it is preferable to provide a filter part such as a nonwoven fabric or a net in the opening or inside of the drain hole 185a so as not to allow the sand to flow out.

  Further, the water retention capacity can be adjusted when the grating 185 is designed by the position of the drain hole 185 a provided in the grating 185. Further, for example, a drainage hole 185a whose size can be adjusted by a slide mechanism can be provided so that water retention can be adjusted on site. The drain hole 185a is provided so as to be inclined downward from the side of the laid sand layer 150 toward the groove 183, and is formed so that water accumulated in the laid sand layer 150 can be drained to the groove 183.

(Second Embodiment)
In the above embodiment, the drainage hole 185a is formed so that the lower end is at a position of 1 mm or more from the surface of the roadbed 120, but the drainage hole may be provided at a position further vertically upward from the surface. FIG. 2 is a cross-sectional view showing a water-retaining pavement structure 200 in which the position of the drain hole is vertically upward. The water retentive pavement structure 200 has the same configuration as the water retentive pavement structure 100 except for the side grooves 280. The side groove 280 has a groove portion 183 and a grating 285 fitted in the groove portion 183, and the grating 285 has a drain hole 285a.

  It is preferable that the drain hole 285a has a lower end of the opening at a position of 10 mm or more from the surface of the roadbed 120. Thereby, water becomes easy to accumulate in the bed sand layer 150, and the water retention of the bed sand layer 150 and the interlocking block 170 can be improved. In addition, if the lower end of the opening part of the drain hole 285a is provided 20 mm or more from the surface of the roadbed 120, the water retention can be further increased. You may design so that the lower end of the opening part of the drain hole 285a may match with the upper end of the bed sand layer 150.

(Third embodiment)
In the above embodiment, the drain hole is provided in the grating, but the drain hole may be provided in the wall of the groove. FIG. 3 is a cross-sectional view showing a water-retaining pavement structure 300 in which drainage holes are provided in the groove. The water retentive pavement structure 300 has the same configuration as the water retentive pavement structure 100 except for the side grooves 380. The side groove 380 has a groove portion 383 and a grating 385 fitted in the groove portion 383, and the groove portion 383 has a drain hole 383a. In this case, the drainage hole 383a is opened at a predetermined position of the groove 383 by using a drill or the like at the site. The drain hole 383a preferably has a circular cross section for ease of processing, but is not necessarily limited thereto.

(Fourth embodiment)
In the above embodiment, the upper layer roadbed is formed of an impermeable material, but a waterproof sheet may be provided on the water permeable upper layer roadbed. FIG. 4 is a cross-sectional view showing a water-retaining pavement structure 400 provided with a waterproof sheet. The water retention pavement structure 400 has the same configuration as the water retention pavement structure 300 except for the roadbed 420.

  A roadbed 420 of the water retention pavement structure 400 is formed of a lower layer roadbed 121, an upper layer roadbed 422, and a waterproof sheet 423. The lower layer roadbed 121 and the upper layer roadbed 422 constitute a roadbed body. When the road surface formed by the interlocking block 170 is a sidewalk, a granular roadbed made of particle size-adjusted crushed stone, steel slag, or the like is generally used as the upper layer roadbed 422 instead of an asphalt stabilization treatment roadbed.

  The road base body is made of a water-permeable material and has a waterproof sheet 423 provided on the surface of the road base body. In this way, by placing the waterproof sheet 423 on a conventional sidewalk roadbed without water-blocking to make a new roadbed 420, water can be easily stored on the roadbed 420. In this case, the roadbed body is preferably formed with a continuous particle size so that it can be easily tightened. In addition, a waterproof sheet is unnecessary if the road base is not limited to the asphalt stabilization processing road base, and the road base is a material that hardly permeates.

  Further, the road surface formed by the interlocking block 170 is used for both a roadway and a sidewalk, but is preferably used as a sidewalk. When water is accumulated on the roadbed, there is a high possibility that problems such as slack in the sand layer and tilting of the interlocking block 170 may occur. However, in the case of a sidewalk, the load applied to the road surface is small, and such a problem hardly occurs.

[Example]
(Test conditions)
In order to confirm the function of the water-retaining pavement structure as described above, a test body was prepared and tested. First, test conditions will be described. FIG. 5 is a table showing test conditions. As shown in FIG. 5, a straight type water-retaining interlocking block having dimensions of 200 mm in length, 100 mm in width, and 80 mm in height was used as the interlocking block, and tap water was used as the water.

Interlocking blocks that meet the water retention performance quality standards defined in the “Interlocking Block Pavement Design and Construction Guidelines” of the Interlocking Block Pavement Technology Association were used. Specifically, the water retention amount is 0.15 × 10 ³ kg / m ³ or more and the suction height is 70% or more. Mountain sand from Kakegawa City, Shizuoka Prefecture was used for the sand. The surface dry density of the mountain sand was 2.57 × 10 ³ kg / m ³ , the water absorption was 2.33%, the actual volume ratio was 66%, and the coarse particle ratio was 2.67.

  A beam lamp 120W was used as an irradiation lamp, and a temperature measurement logger having a resolution of 0.1 ° C. and capable of measuring for 4 hours at 10 minute intervals was used. Moreover, what processed the commercial item was used for the heat insulating material which covers a test body.

(Test method)
Next, the test method will be described. 6A and 6B are a front sectional view and a side sectional view of the test body 500, respectively. As shown in FIGS. 6 (a) and 6 (b), laying sand was spread at a thickness of 30 mm to form a laying sand layer 150, and a water retaining interlocking block 170 was installed thereon. The surrounding area was covered with a heat insulating material 501 to prevent heat from escaping to the outside.

  In order to reproduce the rain conditions, the interlocking block 170 absorbed water for 24 hours in advance. It was taken out of the water before the test and adjusted to the surface dry state when it was used for the test. The laying sand was adjusted so that the surface water was about 1.5%.

  The experimental condition parameters are drainage conditions from the sand, one is a complete drainage condition in which water is not supplied after installation, and the other is a non-drainage condition in which water is absorbed after installation and water is added until the ground sand layer 150 becomes supersaturated. A structure in which water remains in the sand layer 150 was reproduced. That is, in the water-retaining pavement structure of the present invention, since the drain hole is provided so that the lower end is located at least 1 mm above the surface of the roadbed, water remains in the floor sand layer. This state was reproduced under non-drainage conditions.

  A temperature measuring sensor 502 was attached to the center of the water retaining interlocking block 170, and an aluminum tape was attached to prevent the temperature measuring sensor 502 from rising due to the irradiation lamp. The distance between the irradiation lamp and the block surface was 200 mm. The test was conducted in an environment of 20 ° C. and 60% RH. The irradiation lamp was turned on, and the surface temperature of the block was measured at 10 minute intervals. The measurement time was 9 hours.

(Test results)
As a result of the above tests, measurement data on the surface temperature of the interlocking block 170 was obtained. FIG. 7 is a table showing test result data, and FIG. 8 is a graph showing the block surface temperature with respect to the measurement time. After 80 minutes from the start of the test, a difference started to appear between the drainage condition and the non-drainage condition, and then the temperature difference showed a maximum of 5.7 ° C. It can be seen that, on average, a temperature reduction effect of about 5 ° C. is obtained, and the effect of water supply by sucking up water from the bed sand layer 150 is obtained over a long period of time.

100, 200, 300, 400 Water-retaining pavement structure 110 Road bed 120, 420 Road bed 121 Lower road bed 122, 422 Upper road bed 150 Laying sand layer 160 Joint sand 170 Interlocking blocks 180, 280, 380 Side grooves 183, 383 Groove parts 185, 285, 385 Grating 185a, 285a, 383a Drain hole 423 Waterproof sheet 500 Specimen 501 Heat insulating material 502 Sensor for temperature measurement

Claims (6)

A waterproof roadbed formed on the roadbed;
A water holding body provided on the roadbed and having a water retention layer, and a water retention body formed on the floor sand layer and formed by a water retention interlocking block that forms a road surface;
A water retention pavement structure comprising: a side groove having a drainage hole provided in contact with a side surface of the water retention body and having a lower end of an opening formed at a position of 1 mm or more from the surface of the roadbed.   The water-retaining pavement structure according to claim 1, wherein the laying sand layer is made of laying sand having a coarse particle ratio of 1.5 to 3.5.   The water retention pavement structure according to claim 1 or 2, wherein a lower end of the opening is formed at a position of 10 mm or more from the surface of the roadbed.   The water-retaining pavement structure according to any one of claims 1 to 3, wherein a road surface formed by the interlocking block is used as a sidewalk.   The water-retaining pavement structure according to claim 4, wherein the roadbed includes a roadbed body made of a water-permeable material and a waterproof sheet provided on a surface of the roadbed body.   The water retention pavement structure according to any one of claims 1 to 5, wherein the side groove includes a groove portion and a grating fitted in the groove portion, and the drain hole is formed in the grating.

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