JP2013028958A - Water retentive pavement and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water retentive pavement which can maintain high water retentivity over a long period of time, has a practically sufficient compressive strength, and is excellent in initial water permeability, and a method of manufacturing the water retentive pavement.SOLUTION: A water retentive pavement 10 is provided with a porous water retentive layer 16 which contains an aggregate 20 having an American Foundry Society grain fineness number of 5 or more and 180 or less, and a surfactant. An organic binder 18 is suitably a polybutadiene-based organic binder, and the surfactant may be added after the formation of the porous water retentive layer 16.

Description

  The present invention relates to a water-retaining pavement and a method for producing the same.

  As a means of improving the thermal environment in urban areas, water-retaining pavement that can suppress the temperature rise on the road surface has attracted attention. Water-retaining pavement is intended to reduce the temperature of the road surface and its surroundings by making use of the endothermic effect when water is retained in the pavement by providing a gap in the pavement and the water retained over time evaporates. Is.

  For the purpose of improving the water absorption and water retention of the pavement, a water retentive block pavement in which a sand cushion layer is provided on the roadbed layer and a water guide sheet is installed on the top of the sand cushion layer has been proposed (for example, Patent Document 1, 2). This block pavement has a problem in compressive strength because it has a sand cushion layer. For example, even when it is applied to a sidewalk, the area through which the car passes for entering and exiting a garage or parking lot is depressed by a load. Alternatively, there is a problem that the sand cushion flows out due to rainfall / watering, and the smoothness of the road surface is lost and the water retention is lost over time.

  Also, a method using an aggregate whose surface is coated with a carbide powder having a particle size of 5 mm or less and cement or mortar in order to sufficiently secure water retention (for example, see Patent Document 3) has been proposed. However, since cement is used, white surface stains are generated on the surface, and there is a problem that water retention is reduced due to clogging inside.

  In addition, when there is a large amount of rainfall, the conventional pavement takes time to penetrate the water, and there is a problem that the road is submerged. However, by providing a layer with a gap near the road surface, rapid infiltration of rainwater is expected. Is done. However, if the initial water permeability in water-retaining pavement is low, the road is likely to be submerged, or the water does not penetrate sufficiently to the internal voids, and the amount of water that should be retained by rainwater or water spray is not sufficiently retained. There was a problem. For this reason, in addition to securing sufficient porosity to maintain water retention and strength to withstand vehicle traffic, it is also required to realize water retention pavement with excellent initial moisture permeability. is there.

JP 2004-204446 A Japanese Patent Laid-Open No. 2004-225311 JP 2008-2225 A

  The present invention has been made in consideration of these problems, and an object of the present invention is to maintain high water retention over a long period of time, to have a practically sufficient compressive strength, and to have an initial moisture permeability. It is in providing a water-retaining pavement excellent in the above and a method for producing the same.

As a result of intensive studies, the present inventors have found that the above problems can be solved by including a surfactant in a porous water-retaining layer using a specific aggregate and an organic binder, and have completed the present invention.
The configuration of the present invention is as follows.

<1> A water-retaining pavement having a porous water-retaining layer containing an organic binder, an aggregate having an AMERICA FOUNDRY SOCIETY particle size index of 5 or more and 180 or less, and a surfactant.
A porous water-retaining layer obtained by curing an aggregate having a specific particle size index with an organic binder contains a surfactant, so that moisture quickly penetrates into voids between aggregates suitable for water retention. The pavement has a sufficient compressive strength for practical use, and the moisture to be retained quickly reaches the deep part of the gap, so that more excellent water retention performance can be obtained.
<2> The water-retaining pavement according to <1>, wherein the organic binder is a polybutadiene-based organic binder.
By using a polybutadiene-based organic binder as the organic binder, the binder having moderate elasticity has flexibility suitable for pavement and higher compressive strength, and other organic binders can be used. It is possible to prevent a decrease in compressive strength when raining immediately after construction, which is a concern when used.
<3> The water-retaining pavement according to <1> or <2>, wherein the organic binder is contained in an amount of 0.3 part by mass or more and 20.0 parts by mass or less with respect to 100 parts by mass of the aggregate.
By setting the mixing ratio of the organic binder and the aggregate within the above range, both the porosity and the compressive strength in the pavement can be achieved at a higher level.
<4> Any one of <1> to <3>, wherein the porous water retention layer is a porous water retention layer obtained by curing a composition containing the organic binder, the aggregate, and the surfactant. It is a water-retaining pavement described in one.
As a method of including a surfactant in the porous water retention layer, the surfactant is uniformly dispersed in the porous water retention layer by blending the surfactant in the composition forming the porous water retention layer, and the water permeability It is possible to efficiently obtain an excellent porous water-retaining layer, and the local water permeability due to non-uniformity of the surfactant adhering to the surface of the aggregate or the surface of the coating formed by the organic binder. Reduction is effectively suppressed.

<5> The porous water retention layer is a porous water retention layer obtained by adding a surfactant to a porous water retention layer obtained by curing a composition containing the organic binder and the aggregate. <1 It is a water-retaining pavement as described in any one of>-<3>.
After forming the porous water-retaining layer, by adding a surfactant, the surfactant is adsorbed on the surface of the aggregate or the surface of the coating formed by the organic binder, and the initial permeability of moisture is further improved. In particular, it can be said that the effect is remarkable when water is supplied to the porous water retaining layer by the water supply pipe.
<6> The water retention pavement according to any one of <1> to <5>, wherein the surfactant is at least one selected from anionic surfactants and nonionic surfactants.
By using a surfactant selected from anionic surfactants and nonionic surfactants as the surfactant, water permeability at a higher level is achieved regardless of the porosity in the pavement.

<7> The surfactant is at least one selected from an alkali metal salt of a sulfonic acid bonded to a hydrocarbon group and an alkali metal salt of a sulfate ester bonded to a hydrocarbon group. <1> to <5> It is a water retention pavement as described in any one of these.
When the above-described surfactant is used as the surfactant, water permeability at a higher level is achieved regardless of the porosity in the pavement as compared with the case of using another surfactant.
<8> The water retention pavement according to any one of <1> to <7>, wherein the porous water retention layer includes a water supply pipe for supplying water to the porous water retention layer.
Since the porous water retention layer according to the present invention is excellent in water permeability, by applying it to a mode in which a water supply pipe is laid in the porous water retention layer, the water artificially supplied by the water supply pipe is promptly free of voids. Since it penetrates to the deep part, the supplied moisture can be used efficiently, and the temperature rise suppression effect of the road surface by the water-retaining pavement can be maintained for a desired period.
<9> AMERICAN FOUNDRY SOCIETY Kneading a mixture containing 0.3 to 20.0 parts by mass of an organic binder and a surfactant with respect to 100 parts by mass of an aggregate having a particle size index of 5 to 180 A method for producing a water-retaining pavement comprising a step, a step of placing a kneaded mixture on a roadbed, and a step of curing the mixture to form a porous water-retaining layer.
In the production of the porous water retention layer, a porous water retention layer excellent in water permeability is efficiently produced by using a composition containing a surfactant together with an aggregate and an organic binder.

<10> AMERICA FOUNDRY SOCIETY Kneading a mixture containing 0.3 to 20.0 parts by mass of an organic binder with respect to 100 parts by mass of an aggregate having a particle size index of 5 to 180, and kneaded Water-retaining pavement comprising a step of placing the mixture on the roadbed, a step of curing the mixture to form a porous water-retaining layer, and a step of imparting a surfactant to the formed porous water-retaining layer. It is a manufacturing method.
By applying a surfactant to the porous water-retaining layer in water-retaining pavements with excellent water retention and compressive strength after formation, the initial permeability of water can be easily and without concern about the decrease in compressive strength due to the addition of surfactants. It is advantageous that a porous water retaining layer excellent in the formation of the water is formed.
According to the configuration of the present invention, an organic binder is used in the porous water retention layer existing in the vicinity of the surface of the water retention pavement and contains no cementitious material. Since there is no generation | occurrence | production, it also has the advantage that generation | occurrence | production of the surface dirt with time is suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, high water retention is maintained over a long period of time, it has practically sufficient compressive strength, and the water retention pavement which is excellent in the initial water permeability, and its manufacturing method are provided. Since the water-retaining pavement of the present invention is excellent in moisture permeability, it is possible to lower the temperature of the road surface and its surroundings by utilizing the endothermic effect when moisture evaporates more efficiently.

It is the schematic sectional drawing which showed the 1st form of the water retention pavement which concerns on this invention. It is a schematic sectional drawing which shows the structure of the 2nd form of the water retention pavement of this invention provided with the water supply pipe in the porous water retention layer. (A) is the image which expressed the wet color area | region of the surface after the water supply start 60 minutes progress in black by image processing in the water retention pavement of Example 28, (B) is the water retention pavement of the comparative example 4. It is the image which image-processed the wet color area | region of the water-retaining pavement surface 60 minutes after the water supply start in and expressed with black.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and redundant description is omitted.

[First embodiment]
First, the structure of the water retention pavement which concerns on 1st embodiment is demonstrated. FIG. 1 is a schematic cross-sectional view showing one embodiment of the water-retaining pavement of the present invention.
As shown in FIG. 1, the water retention pavement 10 includes a roadbed 14 serving as a foundation on a roadbed 12, and a porous water retention layer 16 according to the present invention is installed on the surface thereof. In this embodiment, a water retention block 24 that is a water retention protective layer is disposed on the surface of the porous water retention layer 16. A base layer may be provided on the roadbed 14 for the purpose of improving the strength or for other purposes.
<Roadbed>
The roadbed 14 is constructed in the same manner as a conventional road. The roadbed 14 is formed by, for example, laying a material having a maximum particle size of 40 to 20 mm to a thickness of 200 to 800 mm and rolling it. Is done.

<Porous water retention layer>
The porous water retention layer 16 according to the present invention contains an organic binder 18, an aggregate 20, and a surfactant (not shown). That is, the aggregate 20 is a layer formed by bonding and curing with the organic binder 18 as a binder (binding material: adhesive) while holding the voids, and has a large number of voids 22 in the structure. The presence of a surfactant (not shown) on the surfaces of the aggregate 20 and the organic binder 18 film forming the surface makes it easier for the surface of the void 22 to get wet, and into a porous water retention layer of moisture such as rainwater or artificial water supply. The initial permeability is significantly improved, and rainwater or the like held in the gap 22 penetrates quickly to a deep portion, which is more useful for the retention. The retained moisture evaporates from the surface of the porous water retention layer over time, and lowers the temperature of the road surface and its surroundings by the endothermic effect during evaporation.
The porous water retention layer according to the present invention may be formed by mixing aggregate 20, organic binder 18 and surfactant, laying on roadbed 12 and curing organic binder 18, and aggregate. 20 and the organic binder 18 may be mixed and laid on the roadbed 12 to cure the organic binder 18 and may be formed by adding a surfactant to the porous water retention layer.
Hereinafter, each material which comprises a porous water retention layer is demonstrated.

-Aggregate-
Examples of the aggregate used for the porous water retention layer include fine aggregates such as silica sand, river sand, mountain sand, limestone crushed sand, crushed sand, slag crushed sand, and lightweight aggregate. Further, recycled aggregate such as glass cullet may be used.
A fine aggregate having an AFS particle size index of 5 to 180 is selected and used from the viewpoint of securing compressive strength and maximum water absorption. The AFS particle size index is more preferably from 20 to 120, and even more preferably from 30 to 70.
The AFS particle size index is an abbreviation for AMERICA FOUNDRY SOCIETY particle size index, and is a value measured according to JACT test method S-1 of the test method for molds and mold materials. The smaller the AFS particle size index, the larger the particle size, and the larger the AFS particle size index, the smaller the particle size. The AFS particle size index is Σ (W × AFS coefficient) / 100, where W is the mass fraction of fine aggregate that remains between each successive sieve.
Table 1 below shows the relationship between the sieve size and the AFS coefficient.

Here, by setting the AFS particle size index of the aggregate within the above range, the mixing ratio of the organic binder and the aggregate when cured while maintaining the voids is appropriately maintained to achieve a uniform mixed state. Thus, maintaining a sufficient gap for water retention and compressive strength are achieved.
When an aggregate having a fine particle size with an AFS particle size index too high is used, it is necessary to increase the content of an organic binder described later, which increases costs and makes it difficult to knead uniformly. On the other hand, when a coarse aggregate having a particle size whose AFS particle size index is too low is used, the formed voids become too large and the water retention capacity decreases.
In addition, in the fine aggregate generally used in Japan, No. 4 to No. 8 silica sand is more preferable because it is general-purpose, and No. 5 silica sand and No. 6 silica sand are water retention performance of the porous water retention layer. Is particularly preferable because of a good balance of strength. AFS particle size index of No. 4 silica sand is about 20, AFS particle size index of No. 5 silica sand is about 30, AFS particle size index of No. 6 silica sand is about 50, AFS particle size index of No. 7 silica sand is about 80, No. 8 Silica sand has an AFS particle size index of about 120, and belongs to the preferred range of the AFS index. Therefore, both are suitably used for forming a porous water-retaining layer in the present invention.

-Organic binder-
The organic binder according to the present invention has a function as a binder for bonding between the aggregates having the specific particle diameter, and can express any strength and durability necessary for water-retaining pavement. Can also be used.
Examples of organic binders that can be used in the present invention include polybutadiene organic binders, polyurethane resin binders, vinyl resin binders (for example, acrylic resin, methacrylic resin, vinyl ester resin, vinyl ether resin, etc.) And silylated polyurethane resin binders, modified silicone resin binders, and epoxy organic binders.
The organic binder is most preferably a polybutadiene-based organic binder described in detail below from the viewpoint of curability and high compressive strength of the formed porous water retention layer.
-Polybutadiene organic binder-
As the organic binder used in the porous water-retaining layer according to the present invention, a polybutadiene-based organic binder is most preferred because the final strength does not decrease even when it comes into contact with moisture before curing.
The polybutadiene-based organic binder in the present invention is a binder using polybutadiene as a curable component, and may hereinafter be referred to as a specific binder.
By fixing the above-mentioned aggregates with a specific binding material, voids between the aggregates are retained, and a porous layer having water retention is formed. Since the specific binding material uses polybutadiene as a curable main agent, a porous layer having water retention can be formed even if the content of the aggregate is a small amount compared to a general binding material. It is possible to develop a compressive strength that can withstand wheel loads that enable vehicle entry.

The polybutadiene used in the specific binder of the present invention is a polymer containing butadiene as a structural unit, and becomes a curable component of the polybutadiene-based organic binder. The structure of polybutadiene is preferably a copolymer containing 1,2-addition reaction units and 1,4-addition reaction units. The copolymer containing these units may be a random copolymer or a block. A copolymer may be used, but a random copolymer is preferred.
The polybutadiene used in the present invention can be appropriately adjusted in the proportion of 1,2-addition reaction unit and 1,4-addition reaction unit contained in the copolymer depending on the raw material feed ratio, polymerization conditions, etc. In the invention, these ratios are not particularly limited, and any ratio can be suitably used.
By using the polybutadiene-based organic binder, the strength is maintained while appropriately maintaining the gaps between the aggregates useful for water retention performance. Therefore, the formed porous layer has good water retention.

The polybutadiene used for the specific binder may be modified by introducing various functional groups depending on the purpose. Specifically, for example, a polar group may be introduced into the polybutadiene molecule. When a polar group is introduced into polybutadiene, the intermolecular interaction between the polybutadienes becomes strong and less likely to volatilize, thereby reducing the odor caused by the material.
Examples of polar groups that can be introduced include hydrophilic groups such as hydroxyl groups, maleic anhydride groups, and carboxy groups, and epoxy groups. The introduction amount is preferably about 0.5 to 30 on average per molecule of polybutadiene, more preferably about 1 to 20 on average, and particularly preferably about 2 to 10 on average.

  The molecular weight of polybutadiene is not particularly limited as long as it does not affect the compressive strength performance and water retention performance, but is preferably 800 to 6,000, and more preferably 1,000 to 3,500. When the molecular weight of the polybutadiene is within the above range, appropriate compressive strength performance is exhibited, and a decrease in miscibility with fine aggregate due to an increase in the viscosity of the polybutadiene itself is suppressed.

Polybutadiene may be a synthetic product or is commercially available.
Specific examples of commercial products that can be used in the present invention include Nippon Soda Co., Ltd., trade names NISSO PB B-1000, B-2000, B-3000, Evonik Degussa trade names Polyoil 110, Polyoi 1 130, and the like.
Moreover, as a specific example of the polybutadiene which has a hydroxyl group in a molecule | numerator, Nippon Soda Co., Ltd. brand name NISSO PB G-1000, G-2000, G-3000, JP-100, BN-1050, Kokkosha brand name PolybdR -15HT, PolybdR-45HT, KRASOL LBH2000, KRASOL LBH3000, KRASOL LBH-P3000, KRASOL LBH5000, KRASOL LBH-P5000, KRASOL LBH-2040, etc.
As a modified product of polybutadiene, polyisoprene, which can be called methylated polybutadiene, can also be used as a main component of the specific binding material in the same manner as the polybutadiene in the present invention. As a specific example of a commercially available product of polyisoprene, trade name “Polyip” manufactured by Kokosan Co., Ltd. may be mentioned.
Among these, from the viewpoint of good miscibility with fine aggregate and good compressive strength performance and water retention performance, Polyol 110, Polyoi 1 130, Polyvest OC 800S, and PolybdR-15HT manufactured by Evonik Degussa are suitable. Used for.

The viscosity of the polybutadiene is not particularly limited as long as it does not affect the compressive strength performance and water retention performance, but is preferably 1,000,000 mPa · s or less, more preferably 500,000 mPa · s or less, particularly preferably 100,000 mPa · s or less. preferable.
When the viscosity of polybutadiene is high, as described in detail below, when preparing a polybutadiene-based organic binder, in order to reduce the viscosity of the binder, a thickener described in detail below may be blended, The viscosity may be lowered by heating the binder when mixing with the material. In addition, since the blending of the viscosity reducing agent may affect the compressive strength performance depending on the material used and the amount added, it is necessary to blend within the allowable range of the compressive strength performance.

  The amount of the specific binder added is preferably 0.3 parts by mass or more and 20.0 parts by mass or less, and 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the aggregate. More preferably, it is most preferably 1.5 parts by mass or more and 5.0 parts by mass or less. In addition, although it may be added in excess of 20.0 parts by mass, the compression strength improvement effect by addition is hardly seen, and the water retention due to the decrease in porosity accompanying the increase in the binder may be reduced. is there.

-Other additives-
The polybutadiene-based organic binder according to the present invention uses various additives as long as the effects of the present invention are not impaired in order to increase the binding strength to fine aggregates and effectively develop the compressive strength performance. May be. Examples of the additive include a crosslinking aid for improving the curability of the binder, a curing catalyst for increasing the cross-linking property of polybutadiene and curing it efficiently, and an ultraviolet absorber for stabilizing the pot life. It is done.

(Crosslinking aid)
A silane-based crosslinking aid may be used for the specific binding material. The silane-based crosslinking aid in the present invention is an additive that effectively increases compressive strength performance by increasing the binding force to fine aggregates and efficiently crosslinking polybutadienes. As the silane-based crosslinking aid, those having both a functional group that reacts with polybutadiene and a functional group that reacts with aggregates such as sand are particularly preferably used.
Examples of the functional group that reacts with polybutadiene include alkenyl groups such as vinyl group, allyl group, and hexenyl group, acryloxy group, and methacryloxy group. Examples of the functional group that reacts with the aggregate include a reactive silyl group having a hydrolyzable group such as an alkoxy group or an acetoxy group.
Specific examples of the silane-based crosslinking aid having these functional groups include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, divinyldimethoxysilane, and divinyldiethoxysilane. Vinyltriacetoxysilane, allyltrimethoxysilane, hexenyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and condensation polymers having at least those as monomer units. . Among these, since the bond strength to the aggregate is good and the effect of efficiently cross-linking polybutadienes is high, it is possible to use vinyltrimethoxysilane, vinyltriethoxysilane, and at least a polycondensate containing them as monomer units. Coalescence is preferably used.
Silane-based crosslinking assistants having these functional groups are also available as commercial products, and in the present invention, commercially available products may be used.
Examples of commercially available products include trade names KBM-1003 and KBE-1003 manufactured by Shin-Etsu Chemical Co., Ltd., trade names Z-6161 and Z-6825 manufactured by Toray Dow Corning, trade names Dynasylan 6490 and Dynasylan 6498 manufactured by Evonik Degussa. It is done.

  When the silane-based crosslinking aid is used for the polybutadiene-based organic binder, the addition amount is preferably 0.1% by mass or more and 20.0% by mass or less, and 1.0% by mass or more and 15.15% by mass. 0 mass% or less is more preferable, and 2.0 mass% or more and 10.0 mass% or less is especially preferable. When the addition amount is in the above range, the effect of addition is sufficiently exhibited, and crosslinking is not inhibited and the curability is not impaired.

(Curing catalyst)
The curing catalyst that can be used for the specific binder is a compound having a function of promoting cross-linking of polybutadiene. Polybutadiene is cured by oxidative crosslinking by oxygen in the air when no curing catalyst is added, but in practice, it is preferable to add a curing catalyst to promote the crosslinking reaction.
As the curing catalyst, a conventionally known curing catalyst used for crosslinking and curing of a compound having an unsaturated group may be used, and a typical example thereof is a metal dryer. Specific examples of the metal dryer include iron catalysts, bismuth catalysts, zirconium catalysts, cobalt catalysts, manganese catalysts, zinc catalysts, copper catalysts, and the like. These metal catalysts include various catalysts having various complexes or carboxylic acid metal salt structures, but the catalyst structure is not particularly limited, and any catalyst that promotes oxidative curing can be used. it can.

Curing catalysts are available as commercial products, and in the present invention, these commercial products may be used. Examples of commercially available products include those manufactured by Nippon Kagaku Kogyo Co., Ltd., trade names such as naphthex Zn series, Nikka octix Zn series, naphthex Ca series, Nikka octix Ca series, naphthex K series, Nikka octix K series, Nikka octix Bi series. , Neodecanoic acid Bi series, Pecat series, PA series, naphthex Zr series, Nikka octix Zr series, naphthex Fe series, Nikka octix Fe series, naphthex Co series, Nikka octix Co series, naphthex Mn series, Nikka octix Mn series, naphthex Mg series, naphthex Li series, naphthex Cu series, naphthex Ba series, Nikka Octix Earth series, Nikka Ok Chicks Ni series, Hope Pharmaceutical Co., Ltd., trade name octene Taupe series, and the like.
Among these, Nikka Octix Bi series, Pcatt series, Naftex Co series, Nikka Octix Co series, Naphtex Mn series, Nikka Octix Mn series, Nikka Octix made by Nippon Chemical Industry Co., Ltd. Fe series is preferably used.

The curing catalyst may be used alone or in a solution dissolved in a solvent.
The addition amount is preferably 0.001% by mass or more and 5.0% by mass or less, more preferably 0.01% by mass or more and 3.0% by mass or less, and more preferably 0.1% by mass or more and 1% by mass or less. .5% by mass or less is particularly preferable.
When the addition amount is in the above range, the curing accelerating effect is sufficiently exhibited, and coloring of the specific binder due to the addition of the catalyst does not occur.

(Thickening agent)
The porous water-retaining layer in the present invention is obtained through a mixture preparation step in which the mixture of the aggregate and the polybutadiene organic binder is kneaded. In order to improve the miscibility and dispersibility during the kneading, May further use a thinning agent. The viscosity reducing agent in the present invention is a liquid organic compound that is compatible with polybutadiene, such as cyclohexane, various isoparaffins, methylcyclohexane, toluene, mineral oil, and other volatile organic compounds at room temperature and normal pressure, or dioctyl phthalate, phthalate Organic compounds having low volatility at room temperature and normal pressure, such as dinonyl acid, LANXESS brand name Mezamol, and Big Chemie brand name DISPERBYK series can be used.
The amount of the thinning agent added is not particularly limited as long as the required performance can be maintained, but in the case of the volatile liquid organic compound at room temperature and normal pressure described above in consideration of the curability and the strength of the porous water retaining layer, etc. It is preferably 20% by mass or less in the total mass of the mixture, and in the case of the above-mentioned liquid organic compound having poor volatility at normal temperature and normal pressure, it is preferably 5% by mass or less in the mixture.

Moreover, the said viscosity reducing agent may not only be added in the case of the said mixture preparation process, but may be previously added to the said polybutadiene type organic binder. By adding in advance, the viscosity of the polybutadiene organic binder is lowered, and the miscibility and dispersibility during kneading are improved.
The amount of the thickener added in advance is not particularly limited as long as the required performance can be maintained, but in consideration of the curability and the strength of the porous water retaining layer, etc. In the case of a volatile liquid organic compound, it is preferably 80% by mass or less in the total mass of the mixture, and in the case of the liquid organic compound having poor volatility at normal temperature and normal pressure, it is 20% by mass or less in the mixture. More preferably.

(UV absorber)
The porous water retention layer in the present invention may contain an ultraviolet absorber.
As the ultraviolet absorber, conventionally known compounds having ultraviolet absorbing ability can be used, and among them, benzophenone-based, triazine-based, salicylate-based and benzotriazole-based ultraviolet absorbers are preferable. These ultraviolet absorbers absorb light (ultraviolet rays) in the vicinity of a wavelength of 320 to 350 nm, at which polymer compounds are most susceptible to degradation, and convert them into harmless vibration energy and heat energy, thereby degrading polymer compounds due to ultraviolet rays. It works to suppress.
A commercial item can also be used as said ultraviolet absorber. Commercially available UV absorbers that can be used in the present invention include: Adeka Stub LA series manufactured by Asahi Denka Kogyo Co., Ltd .; Tinuvin series manufactured by BASF, Chimassorb series; Hostabin series manufactured by Clariant Japan; Examples include, but are not limited to, the JF series.

The specific binding material is prepared by mixing polybutadiene and the silane-based crosslinking aid, a curing catalyst, an ultraviolet absorber, a viscosity reducing agent, and the like, which are used together as required.
The viscosity of the polybutadiene-based organic binder containing the above components is not particularly limited as long as it does not affect the compressive strength performance and water retention performance. From the viewpoint of improving uniform miscibility with aggregates, the viscosity is 100,000 mPa · s. The following is preferable, 50,000 mPa · s or less is more preferable, and 10,000 mPa · s or less is particularly preferable.
In order to make the viscosity in the above range, a polybutadiene having a viscosity in the above range may be selected and used, and after mixing polybutadiene, a curing catalyst, etc., a specific binder is added by adding a viscosity reducing agent. You may adjust the viscosity of the composition containing this to the said range.

-Surfactant-
The porous water retention layer of the present invention contains a surfactant. The porous water retention layer obtained by containing the surfactant is excellent in the initial moisture permeability.
The surfactant is not particularly limited as long as it can be adsorbed on the surface of the aggregate 20 or the surface of the organic binder 18 layer that bonds the aggregates 20 together to promote water permeability. In view of the above, one or more selected from anionic surfactants and nonionic surfactants are preferred.
Examples of the anionic surfactant used in the present invention include a carboxylate, a sulfonate, a sulfate, a sulfate ester, and a phosphate bonded to a hydrocarbon group. Examples thereof include organic salts such as metal salts, ammonium salts, and alkanolamines.
Of these, sulfonates, sulfates, sulfate esters and the like bonded to hydrocarbon groups are preferred, alkali metal salts of sulfonic acids bonded to hydrocarbon groups, and alkali metals of sulfate esters bonded to hydrocarbon groups. One or more selected from salts are more preferred. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, but is preferably an aliphatic hydrocarbon group, particularly a higher fatty acid, such as an alkyl group having about 10 to 18 carbon atoms. .

Specific examples of suitable anionic surfactants include alkyl sulfates, alkylbenzene sulfonates, alkylphenyl sulfonates, alkyl naphthalene sulfonates, higher fatty acid salts, sulfate esters of higher fatty acid esters, and sulfonic acids of higher fatty acid esters. Salts, sulfates of higher alcohol ethers, sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, higher alkyl phosphate esters, phosphate esters of higher alcohol ethylene oxide adducts, and their derivatives. .
More specifically, for example, dialkylsulfosuccinate, alkyl ester sulfate, dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, monobutylbiphenylsulfone Acid salt, dibutylphenylphenol disulfonate, and the like.
Of these, triethanolammonium lauryl sulfate, lithium lauryl sulfate, sodium oleyl sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium dodecylbenzenesulfonate, polyoxyalkylene ether, ammonium alkyl ether sulfate and the like are preferable.
A commercially available product may be used as the anionic surfactant, for example, manufactured by Taiko Oil Chemical Co., Ltd .: trade name TIPOL NLT-42 diluent (active ingredient 15%), TYPOL NLL-27 (active ingredient 27%). TYPOL NOS-35 (active ingredient 35%), TYPOL NOES-340 (active ingredient 40%), manufactured by Kao Corporation: Brand name Neoperex G-65 (active ingredient 20%), Daiichi Kogyo Seiyaku Co., Ltd .: Product names Aqualon HS-10 (active ingredient 100%), Aqualon KH-05 (active ingredient 100%) and the like can be mentioned.

Nonionic surfactants include polyethylene glycol ester type, polyethylene glycol ether type, polyethylene glycol amine, amide type surfactant, polyhydric alcohol fatty acid (partial) ester surfactant, etc. For example, polypropylene glycol ethylene oxide adduct, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, Polyoxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, aliphatic alkanol alcohol De, glycerol esters, sorbitan esters, and the like.
Of these, polyoxyalkylene ether, polyoxyethylene-1- (allyloxymethyl) alkyl ether ammonium sulfate, and polyoxyethylene isotridecyl ether are preferable.
Nonionic surfactants are also available as commercial products. For example, NOF Corporation: trade name Dispanol TOC (active ingredient 100%), Daiichi Kogyo Seiyaku Co., Ltd .: trade name Aqualon HS-10 (active ingredient) 100%), Aqualon KH-05 (active ingredient 100%), manufactured by Nippon Emulsifier Co., Ltd .: Brand name New Coal 2308LY (active ingredient 100%), and the like.

  There is no restriction | limiting in particular in the quantity of surfactant which exists in a porous water retention layer, According to the addition method of surfactant, it selects suitably. A preferable addition amount will be described in detail below.

-Formation of porous water retention layer (1)-
The first embodiment of the method for forming a porous water retention layer according to the present invention will be described.
In the production method according to the first aspect, after sufficiently kneading the mixture of the organic binder, the aggregate, and the surfactant, after laying on the roadbed and compressing the surface to be smooth as desired, The organic binder is cured to form a porous water retention layer containing a surfactant. In preparation of the composition for forming a porous water retention layer, an organic binder is added in an amount of 0.3 parts by mass to 20.0 parts by mass with respect to 100 parts by mass of the aggregate to prepare a mixture.
The addition amount of the surfactant is selected according to the purpose, but there is a concern that the effect is insufficient when the amount of the active ingredient is less than 0.05 parts by mass with respect to 100 parts by mass of the organic binder. Although the initial permeability of moisture is improved as the amount rises, even if added in excess of 10.0 parts by mass, the effect is not so much improved, and there is a concern that the curability of the organic binder may be hindered. It is preferable to set it as 0.05 mass part or more and 10.0 mass part or less.
The kneading can be performed by a conventional method, for example, using a device such as a mortar mixer (pan type, tilting cylinder type).
Further, the mixing time is preferably 30 seconds to 10 minutes in view of construction efficiency. Furthermore, since it is necessary to lay the organic binder on the roadbed before it is completely cured, the pot life after mixing is preferably in the range of 3 to 18 hours.
First, the aggregate and the organic binder may be sufficiently mixed, and then a surfactant may be added to form a mixture. According to this method, the water permeability of the obtained porous water retention layer is further improved. Although this effect is not clear, after thoroughly mixing the aggregate and the organic binder, by adding a surfactant, the surface of the aggregate where the surfactant is in contact with the void, or the coating of the organic binder This is because it tends to be unevenly distributed on the surface.

-Formation of porous water retention layer (2)-
The formation method according to the second embodiment of the porous water retention layer will be described.
In the production method according to the second aspect, the mixture of the organic binder and the aggregate is sufficiently kneaded, spread on the roadbed, and compressed so that the surface becomes smooth as desired. Curing to form a porous water retention layer. Then, the porous water retention layer containing surfactant is formed by providing a surfactant to the formed porous water retention layer.
The preferable content of the aggregate and the organic binder in the composition for forming a porous water-retaining layer is the same as that in the first aspect.
There is no particular limitation on the method of applying the surfactant to the porous water retention layer. For example, a method of spraying an aqueous solution containing a surfactant from the surface of the porous water retention layer, a method of coating, and a pressure device such as a pump. Or a method of infiltrating an aqueous solution containing a surfactant using a water supply pipe arranged in a porous water retention layer.
The addition amount of the surfactant is selected according to the purpose, but there is a range in which the amount (effective amount) of the surfactant is 0.0001 parts by mass or more and 0.2 parts by mass or less with respect to 100 parts by mass of the aggregate. Practically preferred. Further, the dilution ratio of the aqueous solution containing the surfactant is not particularly limited as long as it can be easily dispersed in relation to the effective application amount and the viscosity. For example, the active ingredient is 100 ppm or more and 10 masses. % Or less.

The inclusion of a surfactant in the porous water retention layer can be confirmed by the following method.
For example, after the cured porous water retaining layer is immersed in clean water for a predetermined time, the surfactant dissolved in and extracted from the water is analyzed and identified, so that the surfactant is present in the porous water retaining layer. I can confirm that. In addition, the presence of the surfactant can be estimated by conducting a water permeability test and measuring the initial moisture permeability. For example, for a porous water retention layer that is a test object, drop one to several drops of water on the surface of the porous water retention layer after curing with a dropper or the like, and the time until the water drops penetrate into the porous water retention layer. The presence of the surfactant can also be estimated from the measurement and the time being 300 seconds or less. This is because, in general, a porous water-retaining layer that does not contain a surfactant usually requires at least 600 seconds when the above test is performed.

Although the thickness of the porous water retention layer 16 formed on the roadbed 14 is selected according to the purpose, it is generally in the range of 10 mm to 60 mm in consideration of the balance between the water retention effect and the strength. Preferably, it is in the range of 20 mm to 40 mm.
For the purpose of improving the water retention effect, a water impermeable sheet may be disposed on the roadbed 14. By disposing the water-impervious sheet, the outflow of rainwater or the like to the roadbed is suppressed, and moisture is effectively retained in the voids of the porous water retention layer 16. The water shielding sheet does not necessarily have to be disposed on the entire surface of the roadbed 14, and may be partially disposed as necessary.
The water-impervious sheet is particularly useful when the porous water-retaining layer 16 is used for the purpose of maintaining water retention and thereby reducing the temperature of the road surface. On the other hand, in the usage mode in which the porous water retaining layer 16 is used for the purpose of promoting drainage of the road surface, it is preferable not to use the water shielding sheet or to use it locally as long as the drainage performance is not impaired.

  Since the porous water retention layer of the present invention contains a surfactant, it is excellent in initial moisture permeability. The initial moisture permeability in the present invention is to measure about 1 to several drops of water with a dropper or the like on the surface of the porous water retention layer after curing, and measure the time until the water drops penetrate into the porous water retention layer. Confirmed by As mentioned above, it is evaluated that the time until the water droplet permeates is 300 seconds or less is excellent in water permeability.

It is preferable to have a water retention protective layer 24 on the surface of the porous water retention layer 16.
As the water retention protective layer 24, a known layer is appropriately used. Examples of the water retention protective layer include a water retention block, a water permeable rubber mat, a wood chip layer, and a natural stone resin pavement. By providing the water retention protective layer 24, the surface of the porous water retention layer 16 is not directly exposed, local stress concentration is suppressed, and durability is improved. Moreover, since this protective layer 24 is also excellent in water retention, durability can be improved without impairing the effect of the porous water retention layer.
The water retention block used as the water retention protective layer includes, for example, a porous ceramic block, a porous block formed by curing glass cullet, waste concrete pulverized material, and the like with a binder, and the like. The solid block which has the space | gap for ensuring and has the intensity | strength as a pavement material is mentioned. Examples of commercially available water-retaining blocks include FUJI (trade name) series manufactured by Entec.
A water-permeable rubber mat is a flexible mat formed by bonding rubber chips obtained by crushing rubber with a binder. The size of the rubber chip, the type and amount of the binder (adhesive), and the mat By selecting the thickness or the like, desired water retention, water permeability, and flexibility can be obtained. Furthermore, a rubber mat excellent in design can be obtained by using a rubber chip colored in a desired hue as a raw material or by devising a shape of a mold for molding the mat.
The water-permeable rubber mat is also available as a commercial product, and examples thereof include the Ryl (trade name) series manufactured by Oki Rubber Industry, and the ISO Rubber Brick (trade name) series manufactured by Daisei.

The wood chip layer is a water-retaining layer formed by bonding and curing various types of wood chips (crushed wood such as thinned wood) with urethane-based binders. It is a water- and water-permeable surface pavement that uses physical properties. By adjusting the material of the wood forming the wood chip, the size and shape of the chip, the type and amount of the binder, the strength, water retention, appearance, etc. can be controlled. The wood chip used for forming the wood chip layer may be one produced by pulverizing wood, or a commercially available product.
The natural stone resin pavement is a pavement in which various natural stones are laid in place of the wood chips, and the natural stone is bonded and cured with a binder (resin). As the organic binder, for example, a urethane-based organic binder is preferable from the viewpoint of durability. It becomes a water-retaining and water-permeable pavement due to the gap between natural stones.
What is necessary is just to use what is called a gravel as a natural stone used for pavement, and should just select the size of a gravel in consideration of required intensity | strength and water retention. In general, amorphous natural stones having a diameter (maximum diameter if not spherical) of about 1.5 mm to about 20 mm are used. Natural stones can also be paved with excellent design by selecting the size and hue. Examples of commercially available products used for natural stone pavement include jade gravel made by Nippon Silver Sand Co., Ltd.

  The thickness of the water-retaining protective layer 24 is selected according to the type and purpose of the protective layer, but is preferably in the range of 5 mm to 80 mm from the viewpoint of strength.

Hereinafter, a more detailed method for forming the water-retaining pavement 10 will be described by taking a case where a polybutadiene-based organic binder is used as an example.
On the road bed 12 whose surface is leveled by rolling or the like, for example, for sidewalks, the particle size material is laid to a thickness of 100 to 150 mm and rolled to adjust the roadbed 14. To form. This process is carried out in the same way as normal road construction.
Thereafter, the aggregate used for the porous water retention layer 16 is dry mixed. Dry mixing is performed for about 30 seconds so that the aggregate can be uniformly dispersed. The mixing time is selected according to the purpose. For example, when a plurality of types of aggregates having different particle sizes are used, the mixing time is determined according to the type.

  A specific binder is prepared in a separate process from dry mixing. In the preparation, a crosslinking assistant, a curing catalyst, and an ultraviolet absorber that are optionally added are added to the polybutadiene main ingredient and mixed for about 30 seconds. If it is necessary to adjust the viscosity of the polybutadiene material to be contained, a thickener is added and mixed for about 30 seconds. Note that. There is no particular limitation on the mixing time.

  Thereafter, the specific binder and surfactant prepared in the aggregate are added and wet mixed for about 180 seconds to obtain a mixture for forming the porous water retention layer 16. The mixing time is determined so that the aggregate and the binder are uniformly dispersed, and is not limited to 180 seconds.

The obtained mixture for forming a porous water-retaining layer is placed on the roadbed 14 using an apparatus such as human power or a concrete finisher. Thereafter, the spread paving material is rolled using human power (a trowel) and a machine (roller and vibro plate) to form a porous water retaining layer 16 having a thickness of 20 mm to 40 mm. However, when a water retention block or the like is used for the water retention protective layer 24, the mixture for forming the porous water retention layer is spread, a water retention block is laid immediately after compaction, and the finish is blocked with a vibro plate or the like There is a case of rolling from above. Thereafter, the water-retaining pavement 10 is completed by curing for about 24 hours. The curing time may be adjusted for convenience according to the curing rate of the binder.
In this embodiment, a water retention protective layer 24 such as a water retention block may be formed on the surface of the formed porous water retention layer 16, but the water retention protective layer 24 is not necessarily required.

  According to the manufacturing method as described above, the porous water-retaining layer 16 is easily formed by a simple operation of previously mixing the aggregate 20 and the polybutadiene organic binder 18 and laying the obtained mixture. Thus, the water-retaining pavement 10 having practically sufficient strength and water retention can be easily obtained, and a high water retention function and high compressive strength can be obtained over the entire water retentive pavement 10.

[Second Embodiment]
Next, the structure of the water retention pavement which concerns on 2nd embodiment is demonstrated. FIG. 2 (A) is a schematic cross-sectional view showing a second best mode for carrying out the water-retaining pavement according to the present invention.

As shown in FIG. 2A, the water retention pavement 26 </ b> A is provided with a water supply pipe 28 for supplying water into the porous water retention layer 16. The water supply pipe 28 is a hollow pipe made of metal or resin, and has fine holes formed at regular intervals in the length direction or at random, and is connected to a water supply facility (not shown). Even when the weather is good and there is no water supply by rainwater, the effect of lowering the temperature of the road surface can be maintained by periodically supplying water into the porous water retaining layer 16 through the water supply pipe 28.
The water supply pipe 28 used here is preferably disposed in the layer when the porous water retention layer 16 is formed from the viewpoint of easy construction and the water supply pipe 28 being protected by the cured porous water retention layer 16. .
The water supply pipe 28 may be any of resin pipes such as polyethylene, polystyrene, and polyester, fiber reinforced resin pipes, metal pipes, etc., but in terms of flexibility, durability, and cost. A resin pipe such as polyethylene resin is preferred.
The diameter of the water supply pipe is appropriately selected, but generally, a pipe having a diameter of about 10 mm to 20 mm and a pipe thickness of about 0.5 mm to 1.0 mm is used.
What is necessary is just to select the opening part for water supply suitably in the range of 10 cm-100 cm according to the desired degree of water retention, when making the space | interval constant. Moreover, you may arrange | position randomly and the magnitude | size of an opening part and the number of the opening parts formed per unit length of a pipe | tube are suitably selected according to the objective of a porous water retention layer.
It is preferable to select the shape and size of the opening provided in the water supply pipe so that it does not clog over time.In addition to selecting the shape of the opening, for example, the opening is periodically washed with high-pressure water. It may be possible to prevent clogging or to have a structure that prevents clogging by disposing an infusion nozzle in the opening.
The water supply pipe is also available as a commercial product, and examples thereof include drip tube DL2000 (trade name) manufactured by Toro Company.
At least one end of the water supply pipe is used by being connected to a water supply device such as a water supply tank, a water supply pump, and a water tap as needed.
In addition, for the purpose of performing effective water retention with the water replenished from the water supply pipe 28, the above-described water-impervious sheet 29 may be disposed on the roadbed 14 where the water supply pipe 28 is disposed. FIG. 2B is a schematic cross-sectional view showing an embodiment in which a water shielding sheet 29 is disposed between the roadbed 14 and the water supply pipe 28.
According to the present embodiment, the water supplied from the water supply pipe 28 does not flow to the roadbed 14 but is retained on the water-impervious sheet 29, so that the water is gradually diffused and retained in the voids of the porous water retention layer 16. Therefore, the supplied water is used more effectively for reducing the temperature of the road surface.

  In supplying water through the water supply pipe 28, the initial water permeability of the porous water retaining layer 16 is important. That is, the artificially supplied water quickly permeates and diffuses into the gaps 22 in the porous water retaining layer 16 and spreads over a wide range, so that the water retained in the gaps 22 is an excellent road surface in the water retaining pavement. However, if the initial permeability is low, the water supplied from the water supply pipe 28 does not sufficiently permeate and diffuse into the gap 22 and flows out in the direction of the roadbed 14. There is a concern that the effect of water supply cannot be sufficiently obtained. For this reason, for example, when the aqueous solution containing the surfactant is supplied from the water supply pipe 28 in the initial water supply, the aqueous solution of the surfactant efficiently permeates and diffuses into the gap 22, so that the porous water retaining layer 16 is interfaced. An activator will be contained and the water retention efficiency by subsequent water supply will be performed effectively. For this reason, it can be said that the formation of the porous water-retaining layer 16 by the second manufacturing method of the present invention is significantly effective when applied to the second embodiment.

[Other Embodiments]
In the configuration of the water retention pavement according to the present invention, in addition to the above, a water retention roadbed may be provided between the porous water retention layer 16 and the roadbed 12. By providing the water-retaining roadbed, rainwater that has permeated through the porous water-retaining layer 16 is held in the water-retained roadbed, and the temperature lowering effect of the road surface in the water-retaining pavement is maintained for a long period of time.
The water retention roadbed is a roadbed formed by mixing fine particles such as fine silica sand and coal ash as a water retention material in addition to a normal roadbed material. The fine silica sand refers to a fine particle having a particle diameter in the range of 0.005 mm to 0.1 mm that is discharged in the process of manufacturing silica sand as a raw material for ceramics and glass. Coal ash is a residue generated after burning pulverized coal at a coal-fired power plant.
The content of the fine particles having a particle size of 0.1 mm or less in the water-retaining roadbed is preferably 10% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 20% by mass or less. In the above range, both water retention and roadbed strength are compatible.
In the case of providing a water retaining roadbed, the thickness is preferably in the range of 100 mm to 400 mm from the viewpoint of effect and strength. The water retention roadbed may be installed in place of a normal roadbed, or may be further installed on the roadbed.

EXAMPLES Hereinafter, although an Example of this invention is given and this invention is demonstrated concretely, this invention is not restrict | limited to these.
(Preparation of organic binder)
Polyoil 110 (Evonik Degussa polybutadiene, molecular weight 2,200, viscosity 850 mPa · s at 20 ° C.) 100 parts by mass, KBM-1003 (Shin-Etsu Chemical vinyltrimethoxysilane) 5 parts by mass, Nikka Octix Mn8 % (T) (trade name), manufactured by Nippon Kagaku Sangyo Co., Ltd .: Manganese 2-ethylhexanoate catalyst (about 50% by mass solution) is mixed with 0.3 part by mass to obtain polybutadiene organic binder A. Obtained.

(Examples 1-4, Comparative Example 1)
1. Production of water-retaining pavement (production of mixture)
No. 6 silica sand is used as the aggregate, and 100 parts by mass of the aggregate, 1.0 part by mass of the polybutadiene-based organic binder A and surfactant (lithium lauryl sulfate (active ingredient 27%): Typol NLL-27 (product) Name), 0.04 parts by mass of Taiko Yushi Chemical Co., Ltd.) was added and mixed for a total of 5 minutes with a mortar mixer to prepare a mixture for forming a porous water retention layer (mixture for Example 1).
In addition, as for the blending method of the surfactant, the aggregate and the organic binder were first kneaded for 3 minutes to homogenize, and then the surfactant was added and further kneaded uniformly for 2 minutes.
Moreover, the mixture for Examples 2-4 was obtained like Example 1 except having made the addition amount of the organic binder A into the quantity of following Table 2. Further, a mixture for Comparative Example 1 was obtained in the same manner as in Example 1 except that the surfactant was not added.

(Examples 5 to 8, Comparative Example 2)
In the case where 2 parts by mass of the organic binder A is used with respect to 100 parts by mass of the aggregate and the surfactant is blended in the amounts shown in Table 3 below, the same mixing method as in Example 1 (Examples 5 and 6) Then, an aggregate, an organic binder, and a surfactant were added at the same time, and a mixture was obtained by a method of mixing for 3 minutes (Examples 7 and 8). Further, a mixture for Comparative Example 2 was obtained in the same manner as in Example 5 except that the surfactant was not added.

(Formation of porous water retention layer)
The mixture 1 obtained above is placed on the roadbed 14, the surface is compressed by human power (trowel) so as to have a thickness of 30 mm, spread, and a porous water-retaining layer 16 having a thickness of 30 mm is formed on the roadbed. Formed. The surface of the formed porous water-retaining layer 16 is provided with a water-retaining block 60 mm thick (made of ceramics, a block having a specific gravity of 1.85: size 200 mm × 100 mm × thickness 60 mm) 24 as shown in FIG. A water-retaining pavement 10 of Example 1 having the same layer configuration was formed.

2. Evaluation of pot life At 23 ° C., the time from immediately after mixing raw materials until the mixture could not be applied was defined as the work efficiency (pot life). About the feasibility of construction, it evaluated by handling with a metal spatula, and the time when handling became impossible was evaluated as the time when construction was impossible.
3. Evaluation of compressive strength For evaluation of compressive strength, the obtained mixture for Examples 1 to 8 and the mixture for Comparative Examples 1 and 2 were placed in a mold, and the surface was flattened and cured. Then, the compressive strength of the molded body obtained at 2 days of age and 7 days of age was measured according to JIS R 5201. The curing temperature was set to room temperature 23 ° C. In this evaluation, when the compressive strength at the age of 7 days is 1.4 N / mm ² or more, when it is used for a sidewalk, a practical compressive strength that can withstand the load of an automobile passing through the surface is achieved. evaluate.
4). Evaluation of water permeability The obtained mixture for Examples 1 to 8 and the mixture for Comparative Examples 1 and 2 were placed in a mold, and the surface was flattened and cured under the same conditions as above. I let you. One drop of water was dropped onto the surface of the obtained porous water retaining layer after curing using a dropper, and the time until the water droplet penetrated into the porous water retaining layer was measured. It is evaluated that water penetrability is excellent when the time until a water droplet penetrates is 300 seconds or less.
5. Evaluation of the maximum water absorption rate The maximum water absorption rate test was conducted in accordance with the Pavement Survey and Test Method Handbook, Japan Road Association.
These evaluation results are shown in Tables 2 and 3 above.
From Table 2 and Table 3, the water-retaining pavement of the present invention maintains practically sufficient compressive strength, has a high maximum water absorption rate, and does not contain a surfactant in the porous water-retaining layer. Comparative Example 1 and Comparative Example 2 On the other hand, it can be seen that the initial permeability of water is greatly improved, and the time until water permeates is less than 300 seconds, and excellent water permeability is achieved. Moreover, it turns out that the initial water permeability which is one of the effects of the present invention is particularly remarkable when the amount of the specific organic binder added to 100 parts of the aggregate is in the range of 1 part to 8 parts. Further, from the comparison between Example 5 and Example 7, in the production of the porous water-retaining layer, the aggregate and the organic binder are mixed and homogenized, and then the surfactant is added to the aggregate and the organic. It can be seen that the water permeability is more improved than when the binder and the surfactant are mixed simultaneously.

(Examples 9 to 11)
For forming a porous water-retaining layer of Example 9 in the same manner as in Example 1 except that the amount of polybutadiene-based organic binder A used in Example 1 was changed to 3.0 parts by mass with respect to 100 parts by mass of the aggregate. A mixture of was made.
Further, the porous water retaining materials of Examples 10 and 11 were the same as Example 9 except that the following silica sand 5 and silica sand 4 were used instead of “silica sand 6” as the aggregate. A mixture for layer formation was prepared.
The mixtures for forming a porous water-retaining layer in Examples 9 to 11 were evaluated in the same manner as in Example 1. The results are shown in Table 3 below.

  As shown in Table 4, it can be seen that the porous water-retaining layer according to the present invention exhibits excellent effects even if the particle size of the aggregate is changed.

(Example 12 to Example 19, Comparative Example 3)
1. Production of water-retaining pavement (production of mixture)
A water-retaining pavement was produced in the same manner as in Example 1 except that the amount of the polybutadiene-based organic binder and the surfactant were changed as shown in Table 5 below. The details of the surfactant used are shown below. Further, as Comparative Example 3, a water-retaining pavement was produced in the same manner as in Example 1 except that water was added in an amount shown in Table 5 below without adding a surfactant.
[Surfactant]
・ Typol NLT-42 diluted solution (15% active ingredient) (trade name: manufactured by Taiko Yushi Chemical Co., Ltd.) Triethanolammonium lauryl sulfate (anionic surfactant)
・ Typol NOS-35 (active ingredient 35%) (trade name: manufactured by Taikou Yushi Chemical Co., Ltd.): sodium oleyl sulfate (anionic surfactant)
・ Typol NOES-340 (active ingredient 40%) (trade name: manufactured by Taikou Yushi Chemical Co., Ltd.): sodium polyoxyethylene lauryl ether sulfate (anionic surfactant)
Neoperex G-65 (active ingredient 20%) (trade name: manufactured by Kao Corporation): sodium dodecylbenzenesulfonate (anionic surfactant)
Newcol 2308LY (active ingredient 100%) (trade name: manufactured by Nippon Emulsifier Co., Ltd.): polyoxyalkylene ether (nonionic surfactant)
Aqualon HS-10 (active ingredient 100%) (trade name: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): polyoxyethylene nonylpropenyl phenyl ether ammonium sulfate (anionic surfactant)
Aqualon KH-05 (active ingredient 100%) (trade name: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): polyoxyethylene-1- (allyloxymethyl) alkyl ether ammonium sulfate (anionic surfactant)
Dispanol TOC (100% active ingredient) (trade name: NOF Corporation): polyoxyethylene isotridecyl ether (nonionic surfactant)
About the obtained mixture for forming a porous water-retaining layer and water-retaining pavement using the same, it was evaluated in the same manner as in Example 1.
The results are shown in Table 6 below.

  From the results shown in Table 6, all of the water-retaining pavements of Examples 12 to 19 according to the present invention have compressive strength performance that can withstand wheel loads that enable vehicle entry at a material age of 7 days (curing at 23 ° C.). In addition, it was confirmed from the result of the water absorption rate that a gap capable of maintaining water retention was provided. It can also be seen that even when the type of surfactant to be added is changed, the initial permeability of water is very excellent as compared with Comparative Example 3 in which no surfactant was added.

(Example 20 to Example 27)
(Preparation of organic binder B to organic bond I)
In the same manner as the binder A used in Example 1, binders B to I were prepared according to the formulations shown in Table 7 below.
In addition, the detail of each component shown in Table 7 is as showing below.
[Polybutadiene]
Polyoil 110: Polybutadiene (molecular weight 2,200, viscosity 850 mPa · s at 20 ° C.) manufactured by Evonik Degussa
Poly bd R-45HT: Idemitsu Kosan Co., Ltd. hydroxyl group-containing polybutadiene (molecular weight 2,800, viscosity at 30 ° C., 6,600 mPa · s, hydroxyl group content: about 2 per molecule)
・ Kraysol LBH-P 5000: Idemitsu Kosan Co., Ltd. hydroxyl group-containing polybutadiene (molecular weight 5,300, viscosity at 30 ° C. 19 Pa · s, hydroxyl group content: about 2 per molecule)
Polyves OC 800S: Evonik Degussa's maleic anhydride group-containing polybutadiene (molecular weight 2,200-2,600, viscosity at 20 ° C., 6,000-9,000 mPa · s, maleic anhydride group content: about 1 per molecule 1.9)
-NISSO PB JP-100: Epoxidized polybutadiene manufactured by Nippon Soda Co., Ltd. (molecular weight 1,300, viscosity 220 Pa · s at 45 ° C., epoxy group content: about 5.6 per molecule)
[Crosslinking aid]
· KBM-1003: Shin-Etsu Chemical Co., Ltd. vinyltrimethoxysilane · Dynasylan 6490: Evonik Degussa methoxy group-containing oligomeric reactive vinyl siloxane · Dynasylan 6498: Evonik Degussa ethoxy group-containing oligomeric reactive vinyl siloxane [curing catalyst]
Nikka octix Mn 8% (T): Manufactured by Nippon Chemical Industry Co., Ltd. 2-ethyl hexanoic acid manganese-based catalyst (about 50% by mass solution)
Nikka Octics Co 12% (T): Nihon Kagaku Sangyo Co., Ltd. 2-ethylhexanoic acid cobalt-based catalyst (about 75% by mass solution)
8% Octope Fe: 2-ethylhexanoic acid iron-based catalyst (approximately 70% by mass solution) manufactured by Hope Pharmaceutical Co., Ltd.

Using the binding material B to binding material I listed in Table 7, using No. 6 silica sand as an aggregate, and 100 parts by mass of the aggregate, as shown in Table 8 below, the polybutadiene-based organic binding material B to organic Each 2.0 parts by mass of the binder I was added and mixed for 3 minutes with a mortar mixer to prepare a mixture for forming a porous water retention layer.
For evaluation of compressive strength, the obtained mixture for forming a porous water-retaining layer was placed in a mold, and the surface was leveled on a flat surface and cured. Was measured according to JIS R 5201. The curing temperature was set to room temperature 23 ° C. Further, the initial permeability of water was evaluated in the same manner as in Example 1.
The obtained molded product was immersed in a 100-fold diluted solution of Typol NLL-27 (active ingredient 0.27%) for 1 hour, and then dried at room temperature (25 ° C.) for 1 day to give a surfactant. A porous water-retaining layer molded body was obtained.
The compressive strength of the obtained porous water-retaining layer molded body was measured according to JIS R 5201. Further, in the same manner as in Example 1, the maximum water absorption rate and the initial water permeability were evaluated. The results are shown in Table 9 below.

  From the results shown in Table 9, even when a surfactant is added after the formation of the porous water-retaining layer, excellent initial water permeability is exhibited as in the case where a surfactant is added to the mixture during the formation of the porous water-retaining layer. I understand that

(Example 28)
Similar to the one shown in FIG. 2B, a water shielding sheet 29 is disposed on the entire surface of the horizontal roadbed 14, and a water supply pipe [trade name: Drip Line XF series (XFD06-made by Rainbird) is used on the water shielding sheet 29. 12-100)] 28 was placed across the center of the 2 m × 2 m porous water-retaining layer. Thereafter, in the same manner as in Example 1, with respect to No. 6 silica sand and 100 parts by mass of aggregate, 2.0 parts by mass of polybutadiene organic binder A and 0.04 mass of surfactant (Typol NLL-27) were used. Part of the mixture was added to prepare a mixture for a porous water-retaining layer, and a porous water-retaining layer 16 was formed to form a water-retaining pavement. In addition, the water retention protective layer 24 shown in FIG. 2 (B) was not used.
(Comparative Example 4)
In the formation of the porous water retention layer 16, the porous water retention layer of Comparative Example 4 was formed in the same manner as in Example 28 except that the surfactant was not added to the mixture for forming the porous water retention layer. It was.

For the water-retaining pavement obtained at a material age of 7 days, the initial water permeability was evaluated as follows.
As for water supply, 3 L of water was supplied to the water supply pipe 28 per minute and continuously supplied for 60 minutes during the water-retaining pavement.
After the start of water supply, the wet color area ratio on the surface of the porous water retaining layer after 20 minutes and 60 minutes passed was calculated by forming an image displayed in black by image processing and measuring the area of the black region. .
FIG. 3 (A) is an image in which the wet color area ratio after 60 minutes from the start of water supply on the water-retaining pavement surface of Example 28 is processed and displayed in black, and FIG. 3 (B) is a comparison. The wet color area | region of the water retention pavement surface 60 minutes after the water supply start in the water retention pavement of Example 4 is image-processed, and the image displayed in black is shown.
Table 10 shows the measurement results of the wet color area ratio of the water-retaining pavement surface after the start of water supply. The higher the wet color area ratio, the better the initial water permeability.

  From the result of Table 10, since the wet color was observed over the wide area of the pavement surface with respect to the water retention pavement of the comparative example 4, the water supplied from the water supply pipe was quick. It can be seen that it spreads wet and is excellent in initial water permeability.

(Examples 29 and 30, Comparative Examples 5 and 6)
As the organic binder J, a two-pack type epoxy resin binder was prepared. Main agent: bisphenol A type epoxy resin, curing agent: polyamine mixture, nonvolatile content: about 100%. As in Example 1, No. 6 silica sand was used as the aggregate, and 100 parts by mass of the aggregate was combined with the organic binder J in parts by mass shown in Table 11 below and a surfactant (lithium lauryl sulfate (active ingredient 27% ): 0.04 parts by mass of Taipol NLL-27 (trade name, manufactured by Taiko Yushi Chemical Co., Ltd.) was added and mixed for a total of 5 minutes with a mortar mixer to prepare a mixture for forming a porous water-retaining layer.
In addition, as for the blending method of the surfactant, the aggregate and the organic binder were first kneaded for 3 minutes to homogenize, and then the surfactant was added and further kneaded uniformly for 2 minutes.
Further, a mixture for Comparative Example 5 was prepared in the same manner as in Example 29 except that the surfactant was not added, and a mixture for Comparative Example 6 was prepared in the same manner as in Example 29 except that the surfactant was not added. Respectively.

  As is apparent from Table 11, also in Examples 29 and 30 using other organic binders in place of the polybutadiene-based organic binder, the water-retaining pavement of the present invention maintains a practically sufficient compressive strength and is porous. It can be seen that the initial water permeability is significantly improved compared to Comparative Example 5 and Comparative Example 6 in which the surfactant layer is not contained in the quality water retaining layer.

10, 26 Water retentive pavement 12 Road bed 14 Roadbed 16 Porous water retentive layer 18 Organic binder 20 Aggregate 22 Void 24 Water retentive block (water retentive protective layer)
28 Water supply pipe 29 Water shielding sheet

Claims (10)

  A water-retaining pavement comprising a porous water-retaining layer containing an organic binder, an aggregate having an AMERICA FOUNDRY SOCIETY particle size index of 5 or more and 180 or less, and a surfactant.   The water retention pavement according to claim 1, wherein the organic binder is a polybutadiene organic binder.   The water-retaining pavement according to claim 1 or 2, wherein a content of the organic binder with respect to 100 parts by mass of the aggregate is 0.3 parts by mass or more and 20.0 parts by mass or less.   The porous water retention layer according to any one of claims 1 to 3, wherein the porous water retention layer is a porous water retention layer formed by curing a composition containing the organic binder, the aggregate, and the surfactant. Water-retaining pavement as described.   The porous water-retaining layer is a porous water-retaining layer obtained by adding a surfactant to a porous water-retaining layer obtained by curing a composition containing the organic binder and the aggregate. Item 4. The water-retaining pavement according to any one of items 3 to 4.   The water-retaining pavement according to any one of claims 1 to 5, wherein the surfactant is at least one selected from an anionic surfactant and a nonionic surfactant.   6. The surfactant according to claim 1, wherein the surfactant is at least one selected from an alkali metal salt of a sulfonic acid bonded to a hydrocarbon group and an alkali metal salt of a sulfate ester bonded to a hydrocarbon group. Water-retaining pavement according to item 1.   The water retention pavement according to any one of claims 1 to 7, further comprising a water supply pipe for supplying water to the porous water retention layer in the porous water retention layer.   Kneading a mixture containing 0.3 to 20.0 parts by mass of an organic binder and a surfactant with respect to 100 parts by mass of an aggregate having an AMERICA FOUNDRY SOCIETY particle size index of 5 to 180; A method for producing a water-retaining pavement comprising a step of placing a kneaded mixture on a roadbed and a step of curing the mixture to form a porous water-retaining layer.   AMERICA FOUNDRY SOCIETY A step of kneading a mixture containing 0.3 to 20.0 parts by mass of an organic binder with respect to 100 parts by mass of an aggregate having a particle size index of 5 to 180, and a kneaded mixture A method for producing a water-retaining pavement comprising a step of placing on a roadbed, a step of curing the mixture to form a porous water-retaining layer, and a step of imparting a surfactant to the formed porous water-retaining layer .