JPH10331108A - Water-permeable paving material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce separation of a surface layer from a base layer and reduce a manufacturing cost by forming a paving material into a double layer structure with the surface layer having master stones as aggregates and the base layer having general crushed stones as aggregates and setting the master stones and the crushed stones to preset size ranges and preset continuous porosity ranges as well. SOLUTION: A water-permeable paving material 10 is formed into a double layer structure with a surface layer (a) and a base layer (b). Master stones with a size range of 2.5-5 mm are used as aggregates for the surface layer (a) and general crushed stones with a size range of 2.5-5 mm are used as aggregates for the base layer (b). Both the surface layer (a) and the base layer (b) are molded with a continuous porosity of 10-20%. The surface layer (a) has a thickness in a range of 15-25% of a total thickness, keeps itself at a preset strength and eliminate the waste of the master stones to be used. In this way, a boundary between the surface layer (a) and the base layer (b) is hardly formed and separation from the boundary is reduced, resulting in the economical water-permeable paving material 10 in good appearance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-permeable pavement material having a function of absorbing surface water during rainfall and used as a pavement material.

[0002]

2. Description of the Related Art In recent years, in order to efficiently absorb and discharge surface water particularly during rainfall in an urban area, water-permeable pavement materials such as asphalt and blocks having continuous pores have been used. According to such a pavement material, water on the surface of the pavement material is quickly absorbed through the continuous pores, and puddles on the surface can be effectively prevented.

As one of such techniques, a large number of small-grain aggregates are singulated with a binder to form a plate having continuous pores having a porosity of 20 to 80%, and the surface of the plate is formed of bone. 2. Description of the Related Art A water-permeable floorboard that is cut and polished, including materials, and is smoothed is known.

In this permeable floorboard, epoxy resin, polyester resin, acrylic resin, cement and the like are used as a binder. Cement is more economical than a resin binder, but bone is used. When the bonding strength between the materials is poor, and the porosity is 20 to 80%, it is difficult to secure sufficient strength as a product. Furthermore, when using a seed stone such as granite, marble or coral to reproduce the state close to natural stone by polishing the surface, it is necessary to use a large amount of expensive seed stone because it is a single layer structure .

[0005] As a solution to such a problem,
JP-A-5-24955 describes a water-permeable concrete block comprising cement as a binder and two layers of a surface layer and a lower layer.

[0006] According to the publication, an expensive seed stone can be used only for the surface layer, and generally inexpensive crushed stone can be used for the lower layer, so that the cost of the entire product can be reduced. It is possible to obtain the same surface as that in which the seed stone is entirely mixed.

However, this permeable concrete block has a particle size range of 1.2 to 10 mm as a surface layer material.
Of crushed stone and lower layer material, particle size range 2.5 ~
5 mm is used, that is, the crushed stone used has a different particle size between the surface layer and the lower layer, so that a boundary surface is easily generated between the lower surface of the surface layer and the upper surface of the lower layer. This may cause peeling of the surface layer portion at the time of or after surface treatment. In particular, 4-379
As compared with the epoxy resin, polyester resin, acrylic resin, or the like used as a binder as disclosed in Japanese Patent Publication No. 21, the cement with a binder is inferior in bonding strength between crushed stones, as described above. Strong tendency to peel.

[0008]

A water-permeable pavement material used as a pavement material for roads, parks and the like has sufficient water permeability to fulfill its original function of quickly absorbing surface water even during rainfall. In addition, even when used for a long period of time, the surface layer does not peel off, and it is required to have strength that is not easily damaged, but this is currently achieved with a permeable pavement material using cement as a binder. Does not exist.

For example, if only the strength point such as peeling prevention is taken into consideration, all the parts are integrally formed of the same material as the surface layer, so that the conventional seam between the surface layer and the lower layer, that is, the so-called boundary layer is eliminated. As mentioned above, natural stones such as granite and marble, and seed stones such as coral, are used on the surface layer as a paving material, as described above, on the assumption that they will be polished due to problems with the landscape. Used, which causes an increase in cost.

Further, regarding the relationship between strength and voids, the strength generally decreases as the number of voids increases, and the strength increases as the number of voids decreases.
The desired water permeability cannot be obtained, and clogging occurs to reduce the water absorbing function.

An object of the present invention is to provide a water-permeable pavement material in which cement is used as a binder, the separation of the surface layer containing seed stones from the base layer is reduced, and the production cost is low.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention has made intensive studies and found that the seed stone in the surface layer and the general crushed stone in the base layer have the same particle size range. It was found that it is possible to satisfy both the requirements of water permeability and strength when cement is used as a binder by reducing the boundary surface between the base and the base layer and setting the continuous voids to a specific range. Thus, the present invention has been completed.

That is, the present invention relates to a water-permeable pavement material in which aggregates are joined together while maintaining a predetermined gap using cement as a binder, wherein the pavement material is a surface layer using seed stone as an aggregate. And a base layer made of general crushed stone as an aggregate, and the seed stone and the crushed stone having a particle size range of 2.5 to 5 mm, and further having a continuous porosity of 10 to 20 % Of the permeable pavement material. The pavement material has a thickness of, for example, about 20 to 100 mm, and preferably has a thickness of about 300 mm and a width of about 300 mm.

As described above, by setting the particle size range of the seed stone constituting the surface layer portion and the particle size range of the crushed stone constituting the base layer portion to be the same, the surface portion and the base layer portion are formed at the time of casting into the formwork. Is difficult to form, and separation from this boundary can be reduced. Furthermore, by setting the continuous porosity to 10 to 20%, even when cement having inferior bonding strength is used as a binder, a water-permeable pavement material maintaining a predetermined strength and having excellent water permeability can be obtained. When the continuous porosity is less than 10%, when used as a pavement material, clogging is likely to occur, the predetermined water absorption effect cannot be maintained for a long period of time, and when the continuous porosity exceeds 20%, Insufficient strength as paving material.

Here, the thickness of the surface layer is set to 15 times the total thickness.
By setting the range to ２５25%, the predetermined strength is maintained, and the use of the seed stone is not wasted. Therefore, the cost of the seed stone and the material used for the seed stone can be reduced, and the use of the seed stone can be continued. Even in the case where the base layer portion has a thickness that does not appear on the surface even if the surface layer portion is worn, it is unnecessary to replace the paving material for many years, and it is possible to obtain an economically permeable pavement material. it can.

Further, according to the above configuration, even when any of the polishing, sandblasting, shot blasting, and washing out treatments is performed, the surface layer is peeled off even when cement having poor bonding strength is used as a binder. A hardly permeable pavement material can be obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The permeable pavement material of the present invention will be described below in detail based on an embodiment shown in the drawings. FIG. 1 is a sectional view showing a water-permeable pavement material of the present invention, and FIG. 2 is a perspective view of the same.

In the figure, reference numeral 10 denotes a flat permeable pavement material having a two-layer structure of a surface layer a and a base layer b, and a seed having a particle size range of 2.5 to 5 mm as an aggregate of the surface layer a. (Granite)
And the particle size range is 2.5 as the aggregate of the base layer b.
General crushed stone of 5 mm is used. Both the surface layer portion a and the base layer portion b use ordinary Portland cement as a binder in an amount of 20 to 30% by weight of the aggregate and water in an amount of 7 to 9% by weight.

As a result, both the surface layer portion a and the base layer portion b
It is formed so that the continuous porosity is in the range of 10 to 20%. The surface (upper surface) of the surface layer portion a has been subjected to any of a polishing process, a sandblasting process, a shot blasting process, and a washing process. In addition, the flat permeable pavement material 1
Since the corner 10a of 0 is easily chipped, it is chamfered as shown in a partially enlarged view of FIG. In the present embodiment, the thickness L of the entire water-permeable pavement material 10 is 60 mm.
The thickness l ₁ of the surface layer portion a is 10 mm (after polishing), and the thickness l ₂ of the base layer portion b is 50 mm.

FIG. 3 is a flow chart showing the manufacturing process of the permeable pavement material 10. As shown in FIG. 3, the material of the surface layer portion and the material of the base layer portion are respectively blended, and the concrete of the base layer portion is first defined on the formwork. Pour in quantity. Then, the base layer concrete is filled in the formwork by applying a slight vibration, and the surface is made substantially flat to form a base layer portion. Next, concrete of the surface layer is poured from above and a prescribed amount is poured, and a force of about 80 kg is applied from above and press-formed. The pressed pavement material is immediately demolded and goes to a curing process. After curing and curing, it is transferred to each finishing step.

For example, in the case of polishing, after curing and curing,
Using a diamond grindstone, the surface of the surface layer portion a is roughly cut by about 0.8 mm, and # 400, # 800, and # 150
Polish by about 0.2 mm using 0 and # 3000 grindstones sequentially, and grind 1 mm in total. Thereby, the permeable pavement material 10 shown in FIGS. 1 and 2 is obtained.

[0022]

[Experimental Example] FIGS. 4 and 5 show the results of an experiment conducted on the relationship between the particle size and continuous porosity of the aggregate used for the surface layer portion and the base layer portion and the characteristics of the pavement material. The composition of the surface layer of the test material was 30 parts by weight of cement and 9 parts by weight of water with respect to 100 parts by weight of aggregate, and the composition of the base layer was 23 parts by weight of cement with respect to 100 parts by weight of aggregate. 7 parts by weight of water.
The thickness of the test material is 60 mm, and the thickness of the surface layer is 10 mm.
(After polishing), the thickness of the base layer portion is 50 mm.

FIG. 4 is a graph showing the relationship between the continuous porosity according to the particle size of the aggregate and the compressive strength, and FIG. 5 is a graph showing the relationship between the continuous porosity according to the particle size of the aggregate and the permeability. It is.

As shown in FIG. 4, aggregate having a particle size of 2.5 to 5 mm (corresponding to crushed stone No. 7) is converted to aggregate (6
(Compared to No. 5 crushed stone and No. 5 crushed stone)), the compressive strength is generally high, and the difference is large especially when the continuous porosity is in the range of 10 to 20%. Compressive strength decreases as the continuous porosity increases, but in the case of aggregate having a particle size of 2.5 to 5 mm,
The compressive strength when the continuous porosity is 20% is about 22 N / mm
² satisfies the minimum bending strength of 12 KN (thickness: 60 mm) required as a concrete slab for pavement and maintains a sufficient bonding force to prevent the occurrence of peeling of the boundary layer.

On the other hand, in order to obtain the same compressive strength as the aggregate having a continuous porosity in the range of 10 to 20%, the aggregate having the particle size of 5 mm or more is required to have the continuous void. Rate 1
Although it must be 5% or less, it is not easy to obtain a low porosity with a large particle size, so it is understood that an aggregate having a particle size of 5 mm or more is not suitable as a material for the water-permeable pavement material of the present invention.

As shown in FIG. 5, the particle size is 2.5 to 5 m.
The aggregate of m is stable compared to the aggregate having a particle diameter of 5 mm or more regardless of the change of the continuous porosity, and there is no large difference in the permeability, and even if there is some variation in the porosity of the product. Thus, a water-permeable pavement material having a uniform and good water-permeability function over the entire pavement surface can be obtained. In addition, the permeability coefficient 1.0 × 1 according to the standard of the permeable pavement material of the Japan Road Association.
0 ^-2 cm / s or more is sufficiently satisfied.

From the above, the particle size of the aggregate is 2.5 to 5
If it is within the range of mm, the binding power and the water permeability are in the best condition and have sufficient strength, that is, a strong binding force between the aggregates, so there is no peeling of the aggregates, and a good water permeability function In addition, a permeable pavement material having a good balance between strength and permeability can be obtained.

[0028]

According to the present invention, the following effects can be obtained.

(1) By making the seed stone forming the surface layer portion and the crushed stone forming the base layer portion have the same particle size range, it becomes difficult to form a boundary between the surface layer portion and the base layer portion at the time of casting into a mold. Therefore, the separation from the boundary can be reduced.
Furthermore, by setting the particle size range of the aggregate to 2.5 to 5 mm and the continuous porosity to 10 to 20%, it is possible to maintain a predetermined strength and water permeability and obtain a good-looking water-permeable pavement material. Can be.

(2) The thickness of the surface layer is 15 to 25 of the total thickness.
%, An economically permeable pavement material can be obtained while maintaining the predetermined strength.

(3) When any one of the polishing, sandblasting, shot blasting, and washing-out processes is applied to the surface of the surface layer, the surface layer is less likely to peel off.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a water-permeable pavement material of the present invention.

FIG. 2 is a perspective view of the water-permeable pavement material shown in FIG.

FIG. 3 is a flowchart showing a manufacturing process of a permeable pavement material.

FIG. 4 is a graph showing the relationship between the particle size and continuous porosity of the aggregate and the compressive strength.

FIG. 5 is a graph showing the relationship between the particle size and continuous porosity of aggregate and water permeability.

[Explanation of symbols]

 10 Permeable pavement material a Surface layer b Base layer

Claims (3)

[Claims] 1. A water-permeable pavement material in which cement is used as a binder and aggregates are joined together while maintaining a predetermined gap, wherein the pavement material is a surface layer using a seed stone as an aggregate and a general crushed stone. A two-layer structure consisting of an aggregate and a base layer portion, and a particle size range of 2.5 to
5 mm and a continuous porosity of 10 to 2
Permeable pavement material with a range of 0%. 2. The thickness of the surface layer portion is set to 15 to 25 of the total thickness.
The water-permeable pavement material according to claim 1, wherein the water content is in the range of%. 3. The water-permeable pavement material according to claim 1, wherein the surface of the surface layer is subjected to one of a polishing treatment, a sand blast treatment, a shot blast treatment, and a washing treatment.