JP2006118327A - Permeable pavement using sandbag having water absorption for base and sandbag for the base of the permeable pavement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permeable pavement capable of having an effect on the control of a heat island phenomenon and, at the same time, having durability even in a soft or a violently vibrating ground; to provide a sandbag capable of having water absorption for the most suitable base for realizing the permeable pavement like this. <P>SOLUTION: Problems such as the control of the heat island phenomenon of the pavement, etc. are solved by the permeable pavement constituted of a permeable material having a titanium dioxide film on the water retentive base and the surface. Especially, a sludge cake of a purification plant is cracked, and it is used as the base formed by laying a sandbag filling granulating powder manufactured by adding a cement to the cracked cake to make it granulate into a bag having permeability, a permeable plate having the hydrophile-titanium dioxide film on the surface of a porous concrete body constituted of a binder course formed of crushed stone coarse aggregate and porous ceramic coarse aggregate and a surface course formed of a fine aggregate main body is used for the permeable plate laid on the base to effectively solve the problems. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-permeable pavement constituted by using a sandbag having water absorbency for a roadbed and paving a water-permeable material thereon, and a sandbag for roadbed of the water-permeable pavement.

    Conventionally, the performance required for pavement in sidewalks and bicycle paths as permeable pavement (hereinafter simply referred to as sidewalk pavement) is basically excellent in water permeability, slip resistance, Flatness is required. In addition to these performances, pavement excellent in landscape and protection of roadside trees is required. (See Non-Patent Document 1).

Furthermore, a porous concrete body with a purifying function that decomposes and removes toxic gases such as NOx in the atmosphere has been proposed as a water-permeable plate for sidewalk pavement. (See Patent Document 1)
However, in summer, there has not yet been proposed a so-called “heat island phenomenon” in pavements such as sidewalk pavements, plazas surrounded by buildings, shopping center squares, and the like so as to be practically low-cost. Conventional permeable pavement using crushed stone as the roadbed and permeable blocks can infiltrate rainwater underground, but the problem that the pavement surface becomes extremely hot at midday in midsummer has not been solved.

In addition, on the sidewalk along the roadway with large traffic of large vehicles, in addition to the high content of toxic gases such as NOx in the atmosphere, the roadbed layer of the sidewalk pavement easily loosens due to vibration caused by the traffic of large vehicles, There was a problem that the flatness of the sidewalk pavement was impaired due to the tilting and sinking of the permeable plate laid on the roadbed.
In the sidewalk pavement formed on the soft ground, the problem of tilting and sinking of the water permeable plate is likely to occur.

Book title “Pavement Design and Construction Guidelines”, Editorial “Japan Road Association”, publisher, “Maruzen Publishing Division”, publication date “November 1, 2002”; page 109 JP 2003-026486 A

  The present invention has been made in view of the above-described conventional problems, and is effective in suppressing the heat island phenomenon of pavements in summer such as sidewalks, squares surrounded by buildings, shopping center squares, etc. To provide a water-permeable pavement having sufficient durability without impairing the flatness of the pavement even on a pavement formed on a sidewalk and a soft ground along a roadway with a large amount of traffic of large vehicles at a cost. It is in. In addition, an optimum roadbed for realizing such a water-permeable pavement is provided.

  As a result of earnest research to solve the above-mentioned problems, the present inventor found that the above object can be achieved by using a sandbag having water absorbability for the roadbed, and completed the present invention. That is, the present invention provides the following water-permeable pavement and a roadbed for roadbed of water-permeable pavement.

[1] A water-permeable pavement composed of a roadbed formed by burying a sandbag filled with a water-absorbing material in a water-permeable bag and a material having water permeability.

[2] The water-permeable pavement according to [1], wherein the bag having water permeability is a bag manufactured by knitting chemical fibers.

[3] The water-permeable pavement according to [1], wherein the water-absorbing material according to [1] is a porous granulated powder granulated using a hydraulic binder as a binder.

[4] The water-absorbing material according to [1] is a granulated powder produced by pulverizing a dewatered cake of a water purification plant mud and adding a hydraulic binder and granulating it [1] The water-permeable pavement described in 1.

[5] The water-permeable pavement according to [3], wherein the porous granulated powder according to [3] has a particle size of 20 mm or less.

[6] The dehydrated cake described in [4] is a dehydrated cake produced by dehydrating water purification plant mud without adding lime, and the hydraulic binder is blast furnace cement according to [4] The water-permeable pavement described.

[7] The water-permeable pavement according to [1], wherein the water-permeable material according to [1] is a material having a water permeability coefficient of 1 × 10 ⁻⁵ cm / second or more.

[8] The water-permeable pavement according to [1], wherein the water-permeable material according to [1] is a water-permeable plate having a titanium dioxide film formed on a surface thereof.

[9] The porous plate in which the water permeable plate according to [8] is composed of a base layer portion mainly composed of crushed coarse aggregate and porous ceramic coarse aggregate and a surface layer portion mainly composed of fine aggregate The water-permeable pavement according to [8], wherein the water-permeable pavement has a hydrophilic titanium dioxide film formed on the surface of the concrete body.

[10] The water-permeable pavement according to [9], wherein the titanium dioxide film according to [9] is a film formed of anatase ultrafine particles having a particle diameter of 20 nm or less.

[11] The maximum particle size of the coarse crushed aggregate and the porous ceramic aggregate according to [9] is 5 mm or less, and the maximum particle size of the fine aggregate is 3 mm or less [ 9].

[12] It is characterized by pulverizing a dewatered cake of water purification plant mud in a bag manufactured by knitting chemical fibers, adding a hydraulic binder, granulating and manufacturing the granulated powder, and forming it. Soil for roadbed with permeable pavement.

  Since the water-permeable pavement of the present invention uses a sandbag with excellent water absorption and water storage for the roadbed, rainwater penetrates the water-permeable material during summer and rain, and the water is retained in the roadbed. Water is stored. During sunny weather, the road surface temperature of the pavement is heated and rises with the irradiation of sunlight and the temperature, but the water stored in the roadbed layer evaporates from the road surface, and the increase in road surface temperature is suppressed by the heat of vaporization due to moisture evaporation. The occurrence of the heat island phenomenon is prevented. Since the amount of water retained and stored in the roadbed layer is large, an increase in road surface temperature is suppressed over a long period of time.

    In addition, the water-permeable pavement using a water-permeable plate with a hydrophilic titanium dioxide film on the surface as a water-permeable material has good wettability of titanium dioxide and efficiently evaporates moisture from the road surface. It is prevented even more effectively.

    In addition, the surface of the porous concrete body composed of the base layer part mainly composed of crushed stone coarse aggregate and porous ceramic coarse aggregate and the surface layer part mainly composed of fine aggregate is hydrophilic as the water permeable plate When using a water permeable plate with a titanium dioxide film, it has water absorption and water retention in addition to water permeability, as well as basic characteristics such as slip resistance. Is replenished to the hydrophilic titanium dioxide film to enable efficient water evaporation from the titanium dioxide film, so that the occurrence of the heat island phenomenon is extremely effectively prevented.

    Further, it is possible to provide a beautiful water-permeable pavement free from dirt by the action of the hydrophilic titanium dioxide film. Furthermore, when a titanium dioxide film with excellent photocatalytic activity is used, organic matter such as dog feces is decomposed in addition to decomposition and purification of toxic gases in the atmosphere, and water-permeable pavements such as sidewalks with excellent air purification and antifouling effects Provided. Furthermore, the fading of the water-permeable pavement such as a sidewalk is prevented, and the effect that the color tone of the water-permeable pavement such as the initial sidewalk is maintained for a long time can be obtained.

    The roadbed soilbag of the present invention is formed by pulverizing a dewatered cake of water purification plant mud, adding a hydraulic binder, and granulating the granulated powder, so that it is extremely excellent in water absorption and water storage. At the same time, a roadbed having strength and stability as a roadbed is formed. The sidewalk pavement can be maintained flat even on sidewalks along the roadway where large vehicles are passing and on sidewalks formed on soft ground.

  Hereinafter, although the best form for implementing the water-permeable pavement and roadbed sandbag of this invention is demonstrated concretely, this invention is not limited to the following embodiment.

The water-permeable pavement of the present invention is a water-permeable pavement constituted by laying a material having water permeability on a roadbed formed by burying a sandbag filled with a water-absorbing material in a bag having water permeability. .
As a bag having water permeability, for example, a sandbag manufactured by knitting chemical fibers such as polyethylene and polypropylene can be used.

  The water-absorbing material is preferably a porous granulated powder granulated using a hydraulic binder as a binder. In particular, the dewatered cake produced by dewatering without adding lime to the water purification plant mud is crushed, granulated by adding cement, and granulated by classifying through a sieve to 20 mm or less, which is extremely excellent in water retention. It is particularly preferable because it has strength.

  When using the porous granulated powder produced with cement as a binder directly as the roadbed material, the porous granulated powder is compacted with a roller by a conventional method to form the roadbed, but to obtain a roadbed with a predetermined strength Needs to use porous granulated powder produced with a large amount of cement. In this case, since it is a porous granulated powder at the expense of water absorption characteristics, the water absorption and water storage of the roadbed formed are lowered.

  However, in the present invention, since the roadbed is formed using a sandbag filled with a water-absorbing material in a bag having water permeability, porous granulated powder with increased water absorption at the expense of strength, that is, Even a porous granulated powder granulated with a minimum amount of cement is packed in a sandbag, and the roadbed formed by the sandbag has a predetermined strength as a roadbed. Therefore, it is characterized in that a roadbed with extremely excellent water absorption can be obtained.

  Porous granulated powder granulated using a hydraulic binder as a binder can produce granulated powder with maximum water retention by appropriately setting the amount of binder to be added, forming a roadbed with extremely excellent water retention This is preferable.

In addition, when producing porous granulated powder, the reason for using a dewatered cake produced by dewatering without adding lime to the water purification plant mud as a preferred embodiment is that the water purification plant sludge uses lime to improve drainage. In addition, filter press may be used to make a dehydrated cake, but when such a dehydrated cake is used, it becomes sludge when crushed, requiring a large amount of cement for granulation, resulting in high costs and water absorption characteristics. It is because it falls.
In a preferred embodiment of the present invention, the water purification plant sludge is filter-pressed without injecting lime.

  When blast furnace cement is used, granulated powder having a pH value of 8.5 to 9.0 is obtained, and the roadbed formed by a sandbag filled with such granulated powder is filled with water stored in the roadbed. It is close to the nature and preferable in terms of good vegetation such as street trees. To produce porous granulated powder using a hydraulic binder as a binder, a kind of bread mixer, a mixer equipped with a complex function of crushing, mixing and granulating, for example, trade name: Pelegaiya mixer (manufacturer ; Kitagawa Iron Works Co., Ltd.). The dewatered cake obtained by dewatering the water purification plant sludge with a filter press is put into a Pelegaiya mixer, and after pulverization, a predetermined amount of cement is put and granulated with mixing.

  Water-retaining properties of porous granulated powder obtained by pulverizing dewatered cake from water purification plant mud and adding 5% of blast furnace cement, for example, are extremely high, and extremely high at 165 wt% based on the Dry state (wt%). Has water-containing properties.

Next, a material having water permeability, which is a constituent requirement of the present invention, will be described.
The material having water permeability is preferably a material having a water permeability coefficient of 1 × 10 ⁻⁵ cm / second or more. This is because the rainwater that pours onto the road surface penetrates without delay. Examples of the material having water permeability include a porous plate obtained by cementing crushed stone particles with cement, a block or pavement, an open-graded asphalt pavement, a porous plate or block produced by firing, and natural gravel and rubber chips solidified with a resin binder. A porous plate, block or pavement, a porous plate obtained by solidifying soil with slaked lime, a block or pavement, or the like can be used.

  In particular, a water permeable plate having a titanium dioxide film formed on the surface is preferable. This is because the wettability of titanium dioxide is good and the water is efficiently evaporated from the road surface, so that the occurrence of the heat island phenomenon is more effectively prevented.

  In addition, the surface of the hydrophilic titanium dioxide film is likely to be wet, preventing the adhesion and fixation of dirt such as tar in exhaust gas discharged from automobiles. In the case of anatase type titanium dioxide film, a photocatalyst Due to the action, organic matter deposits such as dog excrement are decomposed, and as a result, it is possible to provide a clean and clean sidewalk. That is, a sidewalk pavement excellent in antifouling effect is provided.

Furthermore, a sidewalk pavement is provided that decomposes nitrogen oxides and the like in the atmosphere by the photocatalytic action of the titanium dioxide film and has an excellent air purification function. In the case where the titanium dioxide film is formed of anatase ultrafine particles having a particle diameter of 20 nm or less, it has excellent hydrophilicity and photocatalytic properties, and the above-described effects of suppressing the heat and island phenomenon, the antifouling effect, and the air purification effect are further improved. ,preferable.
Moreover, the fading by the time-dependent change of the sidewalk pavement colored with the pigment is prevented, and the special effect that the color tone is maintained for a long time can be obtained.

Further, in the present invention, as the water permeable plate, a porous layer composed of a base layer portion mainly composed of coarse aggregate of crushed stone and coarse aggregate of porous ceramic and a surface layer portion mainly composed of fine aggregate. A water permeable plate having a hydrophilic titanium dioxide film on the surface of the concrete body is preferred.
Water retention is given by the porous ceramic coarse aggregate mixed in the base layer part that constitutes the water permeable plate, so that the water storage amount of the water permeable plate itself increases and the base layer part absorbs moisture from the roadbed. The surface layer portion supplies the water content of the base layer portion to the hydrophilic titanium dioxide film by capillary action. That is, since it is a water-permeable plate with capillary action, the stored water retained on the roadbed is sucked up by the water-permeable plate, and water is efficiently evaporated from the hydrophilic titanium dioxide film surface. This is because the rise is suppressed.

  The base layer retains water in the roadbed, sucks up the stored water, stores the water in the base layer, replenishes the surface layer, replenishes the hydrophilic titanium dioxide film, and further evaporates the water from the titanium dioxide film. Enable sustainability. When raining or humid, water is retained by a water-permeable plate and roadbed, and during fine weather or drying, water evaporation from the titanium dioxide film is continued as described above.

    In addition, as the porous ceramic coarse aggregate, the coarse aggregate obtained by crushing the waste material of the ceramic pipe for sewage manufactured using sewage sludge incineration ash as the raw material is used, and it is excellent in strength and water retention, and cost reduction. Is possible. Moreover, the particle size of the coarse crushed aggregate and the porous ceramic coarse aggregate is 2.5 to 5 mm. The fine aggregate constituting the surface layer portion is round silica sand of 3 mm or less. By using such fine aggregate, a soft feeling is given to the pedestrian. Furthermore, when the pigment is added to form a colored surface layer portion, an effect is obtained that the color tone of the pigment is not hindered if silica sand is used.

    The titanium dioxide film constituting the water permeable plate of the present invention is a film formed of anatase ultrafine particles having a particle diameter of 10 nm or less. This titanium dioxide film is a titanium dioxide film formed by spraying a titanium dioxide solution onto the surface of the surface layer portion in an uncured state by a spraying method. Titanium dioxide fine particles collide with the cement surface in a pseudo-hardened state, partially bite into or adhere to the cement, and as the hardening reaction of the cement proceeds, the bonding with the cement is strengthened.

An embodiment of the water-permeable pavement of the present invention will be described with reference to FIG.
As shown in FIG. 1, the water-permeable pavement of the present invention is a roadbed 2 formed by burying the sandbag 6 of the present invention filled with a water-absorbing material 9 in a water-permeable bag 8 shown in FIG. 3. When laying the water permeable material 3, it is preferable to use a small amount of leveled sand 5 on the roadbed 2.

  As the bag 8 having water permeability, a sandbag 8 knitted with polyethylene fibers is used. As the water-absorbing material 9, a porous granulated powder obtained by crushing a dewatered cake of water purification plant mud, adding 5% of blast furnace cement, granulating it, and sieving to 200 mm or less is used. As the material 3 having water permeability, a water permeable plate of 300 mm × 300 mm × 60 mm is used.

  As shown in FIG. 3, the water-permeable plate 3 is a porous concrete body 15 having a two-layer structure of a base layer portion 10 having a thickness of 50 mm mainly formed of coarse aggregate and a surface layer portion 11 having a thickness of 10 mm mainly formed of fine aggregate. Is 15 to 25%, and a narrow groove 16 having a width (t1) of 1 to 2 mm and a pitch (t2) of about 8.5 mm is formed on the surface of the surface layer portion 11 of the porous concrete body 15. .

Further, a titanium dioxide film 4 is formed on the outermost surface 11a of the surface layer portion 11, the surface 11b of the narrow groove, and the hole wall near the surface.
Since the water permeable plate 3 is provided with the narrow groove 16 on the surface in this way, the titanium dioxide film 4 formed on the surface 11b of the fine groove and the hole wall near the surface except the outermost surface 11a of the water permeable plate 3. Is not peeled off by pedestrians. Further, the provision of the narrow groove 16 prevents slipping during walking. Table 1 shows the measurement results of the sliding resistance value of the water permeable plate 3. It has a value of 70 BPN or more and excellent slip resistance.

  In the method for producing the porous concrete body 15, the surface layer portion 11 is formed following the formation of the base layer portion 10. Since both are molded by the pressure vibration molding method, it is possible to achieve high productivity, cost reduction, and minimum use of cement.

Table 2 shows typical raw material blending examples when the base layer portion 10 is molded. As shown in Table 2, as a unit amount (Kg / m ³ ), 1180 parts by weight of coarse aggregate (A) which is crushed stone, and skeleton which is a recycled material of high ceramic pipe for waterworks manufactured using sewage sludge incineration ash 393 parts by weight of the material (B), 400 parts by weight of cement, and 90 parts by weight of water are kneaded using a forced biaxial mixer.

  The reason for using the forced twin-screw type mixer is that it is important that the aggregate surface is uniformly coated with the minimum amount of cement and water. The kneaded product is put into a mold placed on the table vibrator of a pressure vibrator, and the upper pressurizing jig is vibrated for 1 to 2 seconds with a pressing force more than 10 times the amount of the kneaded material charged. Press molding. It stops when the upper pressurizing jig reaches a predetermined position. The cement adhering to the surface of the aggregate is given fluidity and slurried to such an extent that it does not sag between the aggregates, thereby forming a predetermined continuous void between the aggregates. (Hereinafter, the pressure vibration molding of the base layer portion is referred to as a primary press.)

  Subsequent to the formation of the base layer portion 10, the surface layer portion 11 is formed. Table 3 shows typical raw material blending examples for forming the surface layer portion 11 as the surface layer portion 11. As shown in Table 3, 1496 parts by weight of fine aggregate No. 3 cinnabar, 22.5 parts by weight of pigment, 6.75 parts by weight of whitening inhibitor, 450 parts by weight of cement, and 100 parts by weight of water are forced biaxial type. Kneading using a mixer. The kneaded material is put on the upper surface of the base layer portion in the mold, leveled, and then subjected to pressure vibration molding while vibrating the table vibrator and the upper pressurizing jig with the same pressure as that for molding the base layer portion. The pressure vibration time is 3 to 5 seconds. The frequency is 3500 rpm. (Hereinafter, the pressure vibration of the surface layer portion is referred to as a secondary press.)

The molded body is released on the pallet in an uncured state after the pressure vibration molding.
Next, a titanium dioxide film 4 is formed by spraying a titanium dioxide solution onto the surface of the surface layer portion 11 in an uncured state. After forming the titanium dioxide film 4, the entire porous concrete body 15 is steam-cured to promote the cement reaction and to manufacture the water permeable plate 3.

  When the titanium dioxide film 4 is formed by spraying the titanium dioxide solution, the color tone of the pigment on the surface changes depending on the white color of titanium dioxide as the thickness of the titanium dioxide film 4 increases. If the amount of titanium dioxide sprayed is defined on the basis of a color sample, the thickness of the titanium dioxide film 4 can be made constant, and the thickness of the titanium dioxide film can be made sufficiently thick. Is prevented, and contributes significantly to cost reduction.

  Further, as the titanium dioxide solution, a dispersion in which ultrafine titanium dioxide is well dispersed, for example, titanium dioxide powder ST-1 (manufacturer: Ishihara Sangyo Co., Ltd.) having a particle diameter of 7 nm and excellent in photocatalytic activity is mixed with a dispersing agent. A titanium dioxide solution obtained by mixing in alkaline water and mixing is used.

The water permeable plate 3 manufactured in this manner has characteristics of a porosity of 15 to 25%, a water permeability of 1 to 8 × 10 −5 cm / second or more, a bending strength of 3 N / mm ² , and a water retention amount of 10.6 L / m 2 or more. Have.

  Table 4 shows the results of measuring the road surface temperature at high temperatures in summer for the water-permeable fitting 1 of the present invention having the above-described configuration.

In the conventional asphalt pavement, the road surface temperature reaches 60 ° C, and in the concrete board pavement, the road surface temperature reaches as high as 48 ° C. In the present invention example, the road surface temperature is 42 ° C. It was. Even when compared with a conventional water permeable plate having titanium dioxide having a photocatalytic function on the surface, the road surface temperature at 3 ° C. could be lowered.
Moreover, the said road surface temperature reduction effect of the water-permeable pavement of the present invention could last for 5 days. It was possible to prevent the heat island phenomenon from occurring for a long time.

It is a schematic diagram which shows the cross section of the water-permeable pavement of this invention. It is sectional drawing which shows the sandbag for roadbeds of this invention. It is a schematic diagram which shows the cross section of a water-permeable board. It is a perspective view of a porous concrete body. It is a local expanded sectional view of a narrow groove.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Water-permeable pavement of this invention, 2 ... Roadbed, 3 ... Material which has water permeability (water-permeable board), 4 ... Titanium dioxide film, 5 ... Local roadbed, 6 ...・ A sandbag (waterproof material for roadbed of the present invention) filled with a water-absorbing material in a bag with water permeability, 7... Leveling sand, 8... A bag with water permeability, 9. ... Base layer part, 11 ... Surface layer part, 12 ... Crushed stone coarse aggregate, 13 ... Porous ceramic coarse aggregate, 14 ... Fine aggregate, 15 ... Porous concrete body, 16 ... narrow groove,

Claims (12)

A water-permeable pavement composed of a roadbed formed by embedding a sandbag filled with a water-absorbing material in a water-permeable bag and a material having water permeability. The water-permeable pavement according to claim 1, wherein the bag having water permeability according to claim 1 is a bag manufactured by knitting chemical fibers. The water-permeable pavement according to claim 1, wherein the water-absorbing material according to claim 1 is a porous granulated powder granulated with a hydraulic binder as a binder. The water-permeable material according to claim 1, wherein the water-absorbing material according to claim 1 is a granulated powder produced by pulverizing a dewatered cake of a water purification plant mud and adding a hydraulic binder and granulating it. Pavement. 4. The water-permeable pavement according to claim 3, wherein the granulated powder according to claim 3 has a particle size of 20 mm or less. The water-permeable permeability according to claim 4, wherein the dehydrated cake according to claim 4 is a dehydrated cake produced by dehydrating water purification plant mud without adding lime, and the hydraulic binder is blast furnace cement. pavement. The water-permeable pavement according to claim 1, wherein the material having water permeability is a material having a water permeability coefficient of 1 × 10 ⁻⁵ cm / second or more. The water-permeable pavement according to claim 1, wherein the water-permeable material is a water-permeable plate having a titanium dioxide film formed on a surface thereof. The surface of the porous concrete body in which the water-permeable board according to claim 8 is composed of a base layer part mainly composed of crushed coarse aggregate and porous ceramic coarse aggregate and a surface layer part mainly composed of fine aggregate The water-permeable pavement according to claim 8, wherein the water-permeable pavement has a hydrophilic titanium dioxide film formed thereon. The water-permeable pavement according to claim 9, wherein the titanium dioxide film according to claim 9 is a film formed of anatase ultrafine particles having a particle diameter of 20 nm or less. The crushed stone coarse aggregate and porous ceramic coarse aggregate according to claim 9 have a maximum particle size of 5 mm or less, and a fine aggregate has a maximum particle size of 3 mm or less. Permeable pavement. A water-permeable pavement formed by pulverizing a dewatered cake from a water purification plant mud in a bag made by knitting chemical fibers, adding a hydraulic binder and granulating the granulated powder. Sandbag for roadbed.

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