JP2007270487A - Water-retentive pavement structure and water-retentive block for pavement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-retentive pavement structure which stably exerts a water-retention/evaporation function over a long period of time, which has proper constructibility, which facilitates maintenance and which is excellent in economic efficiency, and a water-retentive pavement block for use in the structure. <P>SOLUTION: A plurality of trays 11 are installed on a roadbed 1. A base course material layer 3, which is composed of crushed stones 3a, is formed inside and outside the trays 11, and the porous water-retentive block 5 is installed via a water-absorbing material layer 4 such as dry-mixed mortar. When the temperature of a road surface rises in fine weather etc., moisture is evaporated from the surface of the water-retentive block 5, and the rise of the temperature of the road surface is suppressed by heat of evaporation, so that a heat-island phenomenon etc. can be prevented. Water, which is stored in the base course material layer 3, is supplied to the water-retentive block 5, the moisture of which is evaporated, through the water-absorbing material layer 4 by using the trays 11; a water-retained state is constantly maintained even under inclement weather conditions in summer; and the effect of suppressing the rise of the temperature of the road surface can be maintained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water-retaining pavement structure and a pavement water-retaining block suitable for it, and uses the heat of vaporization of water retained on the pavement surface portion to reduce the road surface temperature and suppress the heat island phenomenon. Is to create a thermally comfortable outdoor living space.

  As paving to improve the heat island phenomenon, establishment of water-retaining pavement and thermal barrier pavement technologies that can be expected to reduce road surface temperature is desired.

  Among these, water-retaining pavement is to reduce the road surface temperature by the heat of vaporization (latent heat) generated when the water stored in the water-retaining material in the pavement evaporates. There is a water-absorbing water-retaining pavement that continuously absorbs water from rainwater and the like, thereby improving the water retention maintenance function of the water-retaining pavement.

  Non-Patent Document 1 describes structures and principles as shown in FIGS. 12 to 14 as typical examples of such water-retaining pavements.

  The water-retaining pavement shown in FIG. 12 has an underground water storage tank on the road floor, and the water-retaining pavement constituting the road surface is kept moist by the water-retaining material in the water-retaining pavement formed in the impermeable layer. It is intended to reduce the road surface temperature.

  This water-retaining pavement has a gap between roadbed aggregates such as open-graded asphalt, and is expected to have a water-retaining ability of a water-retaining material that fills the gap. For example, as shown in the figure, it was derived from a side groove or the like Rain water or supply water is supplied to the water retention material in the water retention pavement through a water absorption sheet such as a nonwoven fabric or a water absorption material such as a sand cushion layer.

  The water retentive pavement of FIG. 13 lays a water retentive block on the road surface and uses the water retentive function of the water retentive block itself. In the example of the figure, a water absorbing material similar to that in the case of FIG. 12 is interposed between the road bed on which the water retention block is laid, and the water in the road bed is easily supplied to the water retention block.

  The water-retaining pavement of FIG. 14 is intended to actively supply water from the outside by a pump or the like instead of providing an underground water storage tank on the road floor as shown in FIG.

  In addition to this, in Patent Document 1, as a paved road surface construction method having water permeability and / or water retention, instead of a conventional sand cushion layer or in addition to a sand cushion layer under a water permeable block constituting the road surface, By forming a single-grain crushed stone layer by No. 7 single-grain crushed stone specified by JIS standards, the material and construction cost of water-permeable or water-retaining pavement are reduced, and the conventional sand cushion layer is washed away by sand flow. And a solution to the problem of damage to the block.

  Patent Document 2 describes a paving block and the like having excellent water retention, including crushed ceramic tiles by one of the applicants of the present application.

  In Patent Document 3, a tray-like water retention tank having an upper surface opened on the lower surface of the water permeable block is integrated, evaporated from the surface of the water permeable block by a nonwoven fabric suspended from the water permeable block, and the road surface temperature is set. What has been reduced is described.

  Patent Document 4 describes a porous ceramic having two or more layers having different fine pore diameters as a porous ceramic used for a paving material or an outer wall material.

Japanese Patent No. 3209717 JP 2004-019406 A Japanese Patent No. 2885085 JP 2002-187784 A “Detailed example of water-absorbing pavement” [online], Ministry of Land, Infrastructure, Transport and Tourism, Kanto Regional Development Bureau, Kanto Technical Office, [Search March 2, 2005], Internet <URL: http: //www.ktr .mlit.go.jp / kangi / hosou / detail01.html>

  The above-described method shown in FIG. 12 aims at a continuous effect based on the amount of water stored in the water tank, but there are problems with the location of the water tank, water quality management, and construction costs.

  The method of FIG. 13 is expected for the water storage function of the block of the water retention block itself, and has the advantage that it can be constructed by the conventional construction method, but it is effective for the amount of water retained in the block and the sustained effect after rainfall. There are limits.

  The method of FIG. 14 has an advantage that a timely effect can be expected by using a temperature sensor and a moisture sensor, but there are problems of securing a water source, problems of construction and maintenance, and the like.

  The invention described in Patent Document 1 intends to use the void formed by the single-grain crushed stone layer for water retention, but the water-permeable block on the surface only allows rainwater or the like to pass through, and accumulates in the crushed stone layer. There is no function to suck water. Therefore, normally, an air layer is formed between the upper part of the single-grain crushed stone layer having a high porosity and the back surface of the water permeable block, and evaporation on the road surface and the accompanying road surface temperature reduction effect cannot be expected so much. In particular, the effect is hardly obtained in a sunshine state where the road surface temperature reduction effect is most required.

  In the case of the invention described in Patent Document 3, water retention can be ensured, but the water retention tank portion in the pavement is structurally a large cavity, so that the water retention tank is considerably large to support the load acting on the water permeable block. Must have the strength of

  As described above, each technique has its own problems, and has not yet reached a stage that can be called an established technique.

  The present invention has been made based on such a background, and has a stable water retention function for a long time mainly using rainwater, has good workability, is easy to maintain and is economical. It aims to provide an excellent water-retaining pavement structure.

  The water-retaining pavement structure according to claim 1 of the present application is provided with a roadbed material layer that secures necessary gaps by adjusting the particle size of the roadbed material above the roadbed, and porous water retention above the roadbed material layer. A water-retaining pavement structure in which a water-blocking block is laid and a cooling effect of the pavement surface is obtained by evaporation of moisture from the surface of the water-retaining block, and an impermeable tray having an open upper surface is provided on the roadbed or the roadbed A plurality of them are installed in the material layer.

  The structure of the lower part of the roadbed is not particularly limited, and a conventional general structure can be applied.

  The roadbed material layer is expected to have a function to prevent unevenness on the road surface due to live loads and other external forces from the vehicle, etc., and thereby tilting or damaging the upper block. The necessary strength and layer thickness are required.

  Conventionally, crushed stone or the like has been used as the roadbed material, but it is not limited to crushed stone, and for example, a porous artificial lightweight aggregate having water retention per se can be used.

  In order to ensure a large amount of water retention, the layer thickness may be increased. However, the amount of roadbed material is increased accordingly, which causes restrictions in terms of construction and cost. Moreover, when the layer thickness is too large, it is disadvantageous in terms of sucking water from the roadbed to the block. Although it depends on the type of roadbed material, for example, in order to ensure a large porosity, when the JIS standard No. 7 single grain crushed stone described in Patent Document 1 is used, the preferred range of the thickness of the roadbed material layer Is about 50 to 200 mm.

  As a water retention block, as a countermeasure against the heat island phenomenon due to an increase in road surface temperature, a block having a smaller water permeability coefficient than the conventional water permeability block has been developed. The thing of patent document 2 mentioned above gives predetermined | prescribed water retention or water-permeability water retention, aiming at utilization of a waste material by using the crushing waste of earthenware tiles for the aggregate of a block. As water-retaining blocks that partially use waste materials, lightweight water-retaining blocks that contain recycled aggregates that are made by reducing the volume of used expanded polystyrene with hot air are also known.

  In addition, it is possible to improve the sucking performance by using a block in which the material composition is adjusted so that water stored in the roadbed as described later is quickly sucked up by capillarity.

  With regard to the function of the tray in the present invention, for example, in consideration of the case where summer clear weather continues for a long period of time, the water retention function needs to be maintained for a considerably long period depending on the installation location, the weather conditions of the land, and the like.

  In the present invention, the tray installed in the roadbed material layer further enhances the function of the roadbed material layer as a water retention part, and the water retention function can be maintained for a long time even in bad conditions such as during clear weather in summer.

  Since the roadbed material layer receives the load of pedestrians and vehicles, the tray is not required to be so strong, and may be any material that is not greatly damaged by aggregates filled inside, and the material is not particularly limited. In terms of performance, cost, light weight and easy handling, those made of soft or hard resin are suitable.

  A plurality of trays may be arranged on the top of the roadbed before the formation of the roadbed material layer, and then the aggregate of the roadbed material layer may be filled, or after a part of the aggregate is constructed on the roadbed, the tray is installed, Furthermore, it may be filled with aggregate in the upper part.

  Multiple trays can be installed at appropriate intervals, allowing excess water to be drained from the gaps. The dimensions and intervals of the trays are designed according to on-site construction and weather conditions. can do.

  This tray also has a function as a partition in the horizontal direction. The function as the partition facilitates the filling work of the aggregate in the construction of the roadbed material layer, and enables uniform filling. Moreover, the flow of the water in the horizontal direction in the roadbed material layer is suppressed for each range partitioned by the tray, and variations in the road surface temperature reduction effect due to the water retention function and moisture evaporation can be suppressed.

  The water-retaining pavement structure according to claim 2 is the water-retaining pavement structure according to claim 1, wherein the tray is partitioned into a plurality of compartments, and is formed of a material that can be easily cut at a laying site, or in a form that can be easily cut. It is characterized by being.

  Dividing the tray into multiple compartments makes it easier to apply the aggregate filled inside the tray, and increases the rigidity of the tray, making it easy to handle even when molded with thin soft resin It becomes. Moreover, even if there are holes in some of the compartments, the water retention as a whole can be maintained.

  Moreover, if it is a material that can be easily cut at the laying site, such as a thin-walled resin, it is possible to adjust the dimensions according to the construction site by cutting and using it at the boundary of the section. A form that can be easily cut is a form in which a large number of recesses are gathered, such as a plastic pot for planting. Need a thickness and strength suitable for filling the aggregate).

  According to a third aspect of the present invention, in the water-retaining pavement structure according to the first or second aspect, a drainage part is provided in a part of the tray.

  The amount of water retained can be adjusted by providing a drainage part in the tray, but it is also effective in preventing freezing and moss in winter, such as in cold regions and in the shade.

  In addition, a valve is provided in the drainage area, and in summer when the temperature is high, the valve is closed to maintain water tightness to fully demonstrate the storage function of the tray, and in winter when the temperature is low, the valve is opened to eliminate water tightness and free inside the tray. Water can also be discharged to the roadbed.

  Furthermore, if a valve that automatically opens and closes according to the temperature is used, switching between summer and winter is possible without requiring maintenance. As such a mechanism, for example, there is a greenhouse window opening and closing mechanism. In addition, an automatic opening and closing valve can be configured by using a temperature-sensitive fiber, a porous resin, a shape memory alloy, or the like.

  Claim 4 is a water-retaining pavement structure according to claim 1, 2, or 3, wherein a water-permeable block and / or a water-impermeable block are mixed in addition to the porous water-retaining block on the roadbed material layer. It is characterized by being laid.

  With respect to porous water permeable blocks, various materials and water permeability coefficients have been developed in the past in anticipation of the drainage function.

  In the invention which concerns on Claim 4, such a water retention block and a water-permeable block are used in combination. In addition to these water retaining blocks and water permeable blocks, a general road surface block having a low water permeability coefficient may be used in combination.

  As a merit to use in combination, rather than having uniform water permeation performance and drainage performance on the entire road surface of the water retentive pavement structure, use water permeation blocks for certain parts to promote drainage in rainy weather and water retention section As a part that promotes the supply of rainwater to the roadbed material layer, using a water retention block for some parts, emphasizing the reduction of the road surface temperature due to the heat of vaporization of moisture in that part, about some parts The total design of the entire pavement, such as using ordinary blocks in consideration of cost reduction and drainage from the road surface to side grooves, etc., makes it possible to optimize the design according to the design conditions.

  According to a fifth aspect of the present invention, in the water-retaining pavement structure according to the first to fourth aspects, the roadbed material is No. 7 single-grain crushed stone defined by JIS standards.

  As described in the section of the prior art, when a single-grain crushed stone layer is formed by No. 7 single-grain crushed stone, it is advantageous in terms of problems such as unevenness due to sand loss and block damage and cost in the conventional sand cushion layer. The combination of the water retention block and tray in the present invention provides a water retention pavement structure that is excellent in terms of long-term stable water retention function, workability, ease of maintenance, economy, and the like.

  According to a sixth aspect of the present invention, in the water retentive pavement structure according to any one of the first to fifth aspects, a concave portion for water storage is formed on the lower surface side of the porous water retentive block.

  Claim 6 is intended to further improve the water retention and suction function as a water retentive pavement structure by devising the shape of the water retentive block. Water can be stored in the recess on the lower surface side of the block. Moreover, since the water stored in the space is in a free water state, the water is quickly absorbed into the block. Therefore, the thickness and the amount of use of the roadbed material can be suppressed as long as the roadbed strength can be ensured, and the material and construction cost can be reduced.

  A seventh aspect of the present invention is the water-retaining pavement structure according to any one of the first to sixth aspects, characterized in that the porous water-retaining block has a pore diameter changing in the thickness direction that forms voids. It is.

  Regarding the relationship between the pore distribution in the block and the water retention or water permeability performance, the water permeability is high when the pore diameter is about 0.05 mm or more, and the ratio of capillary movement water is high between 0.006 mm and 0.05 mm. Or it becomes a block excellent in moisture absorption with many blocks non-moving water in the block excellent in wicking height, and 0.006 mm or less. By utilizing this relationship, the pore size of the pores of the water retention block is changed in the thickness direction, whereby the performance of the water retention block can be adjusted and a rational water retention pavement structure can be obtained.

  The water-retaining block for pavement according to claim 8 of the present application is a water-retaining block that can be used in the water-retaining pavement structure of the present invention, has a recessed part for storing water on the lower surface side, and has a vertical cross section outside the recessed part. It is characterized by having an arch shape.

  In addition to the water retention performance of the block itself, as described in the sixth aspect, water can be stored in the concave portion on the lower surface side of the water retention block. Therefore, the thickness and the amount of use of the roadbed material can be suppressed as long as the roadbed strength can be ensured, and the material and construction cost can be reduced.

  Further, in claim 8, the vertical cross section outside the recessed portion for storing water is made into an arch shape, so that despite the presence of the recessed portion as the gap, the supporting performance is improved by the arch effect against the vertical load, thereby reducing the cross section defect. It is possible to compensate for the decrease in strength due to.

  The water-retaining block for paving according to claim 9 of the present application is a porous water-retaining block that can be used in the water-retaining pavement structure of the present invention, and the pore diameter of pores forming voids is changed in the thickness direction. The bottom has a layer with a high water-sucking performance by capillary action with a relatively small pore diameter and a small porosity, and a water retention performance with a relatively large pore diameter and a large porosity compared to the bottom is high above it. It is characterized by having a layer.

  The relationship between the pore distribution in the block and the water retention or water permeability performance is as described in relation to claim 7. However, the pore diameter is not constant in each layer, but is also related to the characteristics of the material to be blended. The suction performance and water retention performance of each layer can be adjusted according to the pore distribution and porosity.

  In the present invention, by utilizing the capillary phenomenon, it is possible to improve the water suction performance and to maintain the pavement surface temperature reduction effect over a long period of time.

  According to the present invention, when the road surface becomes high temperature while satisfying the strength requirement as a pavement structure, the water retained in the aggregate is evaporated through the water retention block, and the heat of vaporization causes the road surface. An increase in temperature can be suppressed.

  In particular, water is stored in a tray installed on the roadbed or in the roadbed material layer, so that the water retention / evaporation function can be maintained for a long time even under adverse conditions such as long periods of fine weather in summer. .

  Also, if the fine pore diameter of the water retention block is changed in the thickness direction to increase the moisture absorption from the block surface or partially use the capillary phenomenon, the effect of reducing the rise in road surface temperature can be effectively extended over time. Can be maintained over time.

  The pavement water-retaining block having an arch-shaped recess formed on the lower surface can utilize the inside of the recess as a storage space while supporting a large load due to the arch effect.

  Thus, according to the present invention, it is possible to obtain a water-retaining pavement structure having a stable water retention / evaporation function for a long period of time, good workability, easy maintenance, and excellent economy.

  FIG. 1 shows a first embodiment of the present invention, and FIG. 2 shows an example of the arrangement of trays 11 in the first embodiment.

  In this example, a tray 11 to be described in detail later is installed on a normal roadbed 1 in pavement, a roadbed material layer 3 made of crushed stone 3a is formed inside and outside of the tray 11, and a water absorbing material layer 4 such as an empty kneaded mortar is formed. The water-retaining block 5 and the water-permeable block 6 are mixed and disposed.

  For the roadbed material layer 3, a crushed stone 3a such as No. 7 single-grain crushed stone is preferably used. You may fill the space | gap between the crushed stones 3a with the water retention material for improving water retention. In this case, the water retaining material includes those using various waste materials and others, and can be laid in a state of being mixed with the crushed stone 3a in advance. It can also be filled before or during rolling.

  The water-absorbing material layer 4 has a role of sucking up water retained in the roadbed material layer 3 and supplying water to the water-retaining water block 5 on the road surface while preventing the loss of joint sand and the like. A non-woven fabric or the like may be used.

  Rainwater flows into the roadbed material layer 3 with a part of the rainwater mainly penetrating from the water permeable block 6, and the other is drained from the road surface to a side ditch or other drainage facilities or permeates the ground.

  On the other hand, when the temperature of the road surface rises in fine weather, the water mainly evaporates from the surface of the water-retaining block 5, and the temperature rise of the road surface is suppressed by the heat of vaporization, which is effective in suppressing the urban heat island phenomenon. Connected.

  Further, in the present embodiment, a plurality of trays 11 are installed on the upper surface of the road bed 1, and the roadbed material layer 3 is formed inside and outside thereof as described above, and the rainwater entering from the water-permeable block 6 or joints is trayed. 11, so that water can be retained between the crushed stones of the roadbed material layer 3 for a long period of time.

  Water stored in the roadbed material layer 3 using the tray 11 is supplied to the water-retaining block 5 in which the internal moisture has evaporated through the water-absorbing material layer 4, so that the water-retaining state is always maintained even under severe weather conditions in summer. And the effect of suppressing the temperature rise on the road surface can be maintained.

  As the material of the tray 11, a soft or hard resin or the like is used. In this example, the size of the tray 11 is a square having a side of about 1 m, and the inside of the bottom portion 11a and the side portion 11b is divided into four by a large partition 11c arranged in a cross shape, and further, the inside is divided into four by a small partition 11d. It is divided into two.

  In the present embodiment, a gap 13 of about 5 cm is provided between the trays 11 via a spacer 12, which serves as a drain for excess water due to heavy rain, etc., and avoids overflow to the road surface. Yes.

  The tray 11 can be easily cut at the large partition 11c portion, and can be divided and used as necessary during construction. In addition, even in the case of partial construction due to road repairs, repairs and repairs in units of trays are possible.

  By laying single-grain crushed stones 3a having a large porosity (for example, a porosity of about 40%) inside the tray 11, a holding force as a roadbed is ensured and the amount of stored water is also maintained. Further, the load on the tray itself is also reduced and averaged, and the required strength of the tray 11 may be a minimum strength that can maintain water tightness.

  FIG. 3 shows a more specific form example of the tray 11 in the first embodiment described above. In this example, the tray 11 has a form in which a large number of concave portions are gathered like a planting vinyl pot, and can be used by being separated at a large partition 11c portion as necessary.

  FIG. 4 shows an example of the arrangement of the trays 11 in the second embodiment of the present invention. In this example, the water permeation holes 14 are provided in the tray 11 and used as a surplus water drainage portion. Therefore, it is not necessary to provide a gap between the trays 11 as in the first embodiment. However, it is possible to provide a gap between the trays 11 while providing the water permeable holes 14.

  In addition, a valve that automatically opens and closes according to the temperature as described above may be provided in the water permeable hole 14 so that the water retention capacity can be switched between summer and winter.

  5 and 6 show an example of a test body used in the performance test of the water-retaining pavement structure of the present invention.

  In this example, the water retaining block 5 is an arched block having a concave portion 5a having a semicircular cross section on the lower surface side, and is a porous block blended with mountain sand to provide water retaining property. The block dimensions are a rectangle of 200 mm × 100 mm in plan view and a height of 140 mm.

  A water-stopping synthetic resin sheet 22 assuming a tray is laid on the concave portion of the heat insulating frame 21 made of polystyrene foam having a thickness of 100 mm, and No. 7 single-grain crushed stone 3a defined by JIS standards is 10 mm thick on it. And 8 water-retaining blocks 5 were arranged on it. In addition to this model, several models including a comparative model were measured under different experimental conditions. The upper part between the water retention blocks 5 is clogged 23.

  As an experimental method, ten dispersed water was applied to each specimen, and the heat and water balance in the drying process of the block was measured. Specifically, the amount of evaporation was measured by weighing the specimen, and the surface wetting rate was measured using a near infrared moisture meter 25. The surface temperature and the cross-sectional temperature of the water retention block 5 were always measured with a thermocouple 26. After drying, sufficient watering was performed again and measurement was performed again.

  FIG. 7 shows the temperature difference between the surface temperature and the outside air temperature of the water-retaining block as a test result and the daily change of the surface wettability. The measurement period is from August 1 to September 12, 2005. It is.

  The temperature difference between the surface temperature of the water-retaining block and the outside air temperature is within 5 ° C, and the surface wetting rate (wet condition index with 0 as the absolute dry state and 1 as the saturated water content) is maintained at 0.7 or more over the test period. Long-term water retention / evaporation function and suppression of road temperature rise were demonstrated.

  FIGS. 8-10 shows the 3rd Embodiment of this invention, and based on said test result, the arch-shaped water retention block 5 which has the recessed part 5a was used as the water retention block 5. FIG. is there.

  In this example, a plurality of trays 11 are installed above the roadbed 1, and the water retaining blocks 5 are spread vertically and horizontally in the tray 11 to form a road surface on the top.

  In addition to the function of accumulating water in the tray 11, the concave portion 5 a is formed on the lower surface side of the water retention block 5 having its own water retention property, so that the water retention function can be maintained over a long period even in severe dry conditions in summer. Can be expected.

  Further, in the present embodiment, the step 5b is provided on the four circumferences so that the lower cross section of the water-retaining block 5 is inwardly depressed, and on the other hand, the latch 11 extends horizontally on the side 11b of the tray 11 and the upper end of the partition 11f. Since the portion 11g is provided, the water-retaining blocks 5 do not move, workability is improved, joints are almost eliminated, and inflow of dust can be prevented.

  FIG. 11 shows another embodiment of the water retention block. As described above, regarding the relationship between the pore distribution in the block and the water retention or water permeation performance, the block having a high water permeability when the pore diameter is about 0.05 mm or more, and the ratio of the capillary moving water between 0.006 mm and 0.05 mm A block excellent in water retention or sucking height with a lot of water, and a block excellent in moisture absorption with a large proportion of non-capillary moving water at 0.006 mm or less.

  For example, as shown in FIG. 11, by changing the pore distribution of each layer by changing the aggregate of the block at the surface layer portion, the middle portion and the bottom portion, the surface layer portion has hygroscopicity and water permeability, and at night Moisture absorption from the air and a large amount of rain permeation in the water, water permeability and water retention in the middle part, maximum water retention (for example, 40% porosity), and suction at the bottom It is conceivable to secure the maximum suction capacity and water retention amount (for example, porosity of 25%) by imparting water and water retention properties.

1 is a vertical sectional view showing a first embodiment of the present invention. It is a top view which shows the example of arrangement | positioning of the tray in 1st Embodiment. It is a perspective view which shows the specific form example of the tray in 1st Embodiment. It is a top view which shows the example of arrangement | positioning of the tray in the 2nd Embodiment of this invention. It is a vertical sectional view of the test body used for the performance test of the water-retaining pavement structure of the present invention. It is a top view of the test body of FIG. It is the graph which showed the temperature difference of the surface temperature and external temperature of a water retention block as a test result, and the daily change of the surface wetting rate. It is a vertical sectional view showing a 3rd embodiment of the present invention. It is a perspective view of the water retention block used for 3rd Embodiment. It is a vertical sectional view which shows the arrangement | positioning relationship between the tray and water retention block in 3rd Embodiment. It is explanatory drawing of the vertical cross section which shows other embodiment of a water retention block, and the principal part. It is a vertical sectional view showing a conventional example. It is a vertical sectional view showing another conventional example. It is a vertical sectional view showing still another conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Road bed, 3 ... Roadbed material layer, 3a ... Crushed stone, 4 ... Water absorption material layer, 5 ... Water retention block, 5a ... Recessed part, 5b ... Level difference, 6 ... Water permeability block,
DESCRIPTION OF SYMBOLS 11 ... Tray, 11a ... Bottom part, 11b ... Side part, 11c ... Large partition, 11d ... Small partition, 11e ... Recessed part, 11f ... Partition, 11g ... Locking part, 12 ... Spacer, 13 ... Gap, 14 ... Water-permeable hole,
21 ... heat insulation frame, 22 ... sheet, 23 ... clogging, 25 ... measurement position of infrared moisture meter, 26 ... thermocouple

Claims (9)

  A roadbed material layer that secures necessary gaps by adjusting the particle size of the roadbed material is provided above the roadbed, and a porous water-retaining block is laid above the roadbed material layer, from the surface of the water-retaining block. A water-retaining pavement structure that obtains a cooling effect on the pavement surface by evaporation of water, characterized in that a plurality of impervious trays having an open upper surface are installed on the roadbed or in the roadbed material layer. Water retentive pavement structure.   The water-retaining pavement structure according to claim 1, wherein the tray is partitioned into a plurality of sections, and is formed of a material that can be easily cut at a laying site or a form that can be easily cut.   The water-retaining pavement structure according to claim 1 or 2, wherein a drainage part is provided in a part of the tray.   4. The water retaining material according to claim 1, wherein a water permeable block and / or a water permeable block are mixed and laid on the roadbed material layer in addition to the porous water retaining block. Pavement structure.   The water-retaining pavement structure according to any one of claims 1 to 4, wherein the roadbed material is No. 7 single-grain crushed stone defined by JIS standards.   The water retention pavement structure according to any one of claims 1 to 5, wherein a concave portion for water storage is formed on a lower surface side of the porous water retention block.   The water retentive pavement structure according to any one of claims 1 to 6, wherein the porous water retentive block has pore diameters of pores forming voids changed in the thickness direction.   A water retention block for pavement characterized in that it has a concave portion for storing water on the lower surface side, and a vertical cross section outside the concave portion is formed in an arch shape. It is a porous water-retaining block in which the pore diameter of pores forming voids is changed in the thickness direction, and a layer with a high water suction performance by capillary action with a relatively small pore diameter and a small porosity at the bottom. A pavement water-retaining block having a high water-retaining performance layer having a relatively large pore diameter and a high porosity compared to the bottom portion.

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