JP7285560B2 - Construction method of roadbed, roadbed and artificial turf pavement - Google Patents

Description

TECHNICAL FIELD The present invention relates to a roadbed construction method, a roadbed, and an artificial turf pavement, and more particularly to a roadbed construction method, a roadbed, and an artificial turf pavement having excellent water permeability.

Conventionally, asphalt pavement, which has excellent stability and smoothness, has been used as a roadbed for road surfaces and artificial turf. Asphalt pavement is constructed to be watertight so as to prevent rainwater and the like from passing through the ground.

On the other hand, for example, in a field where artificial turf is laid, water permeability (drainage) is particularly required for the roadbed that serves as the base. If the roadbed is not permeable, rainwater will accumulate on the surface of the ground during and after rainfall, causing the artificial turf to flow and the rainwater on the ground surface to freeze in winter, forcing the suspension or cancellation of the competition. In addition, if the road surface is impermeable to water, it will be difficult for pedestrians and the like to pass through due to freezing and flooding.

In addition, asphalt becomes hot under the influence of solar heat, which not only poses a danger to the human body, but also causes surface deformation of road surfaces and the like.

In response to the high temperature of asphalt pavement, for example, Patent Document 1 discloses a water-retentive roadbed formed of a roadbed material whose main material is water-retentive aggregate, and a water-retentive asphalt pavement laid above the water-retentive roadbed. Disclosed is a water-permeable asphalt pavement structure comprising:
The technology disclosed in Patent Document 1 forms the water-retentive roadbed below the water-retentive asphalt pavement, so that even in the summer when the asphalt pavement tends to reach high temperatures, the water retained in the water-retentive roadbed evaporates. It exhibits the effect of sprinkling water and reduces the temperature rise of the asphalt pavement.

Japanese Patent Application Laid-Open No. 2000-120010

However, although the water-permeable asphalt pavement structure disclosed in Patent Document 1 has a water-permeable asphalt pavement and a water-retentive roadbed, if rain continues, the water-retentive roadbed in the lower layer eventually reaches the water retention limit, As a result, rainwater accumulates on the surface. In particular, in the case of an artificial turf ground, when rainwater accumulates on the surface, the artificial turf planted on the roadbed rises and flows out due to the rainwater, requiring a great deal of labor and expense for maintenance and repair.

In addition, asphalt pavement is suitable for securing the stability (fixing force) of the pavement surface, but on the other hand, cushioning is required, for example, in the case of an artificial turf ground on which competitions are held. There are also situations where asphalt pavement is not suitable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a roadbed construction method, a roadbed, and an artificial turf pavement that achieve both excellent water permeability and both stability and cushioning of the roadbed surface. aim.

The roadbed construction method according to the present invention includes a laying step of laying and leveling a roadbed composition containing aggregate, and aggregate layer formation of rolling and compacting the laid roadbed composition to form an aggregate layer. and a mixed layer forming step of applying and permeating asphalt emulsion onto the surface of the aggregate layer to form the upper region of the aggregate layer as a porous mixed layer.

Thus, in the present invention, a laying step of laying and leveling a roadbed composition containing aggregate, and an aggregate layer forming step of rolling and compacting the laid roadbed composition to form an aggregate layer. and a mixed layer forming step of applying and permeating the asphalt emulsion onto the surface of the aggregate layer to form the upper region of the aggregate layer as a porous mixed layer. It is possible to bridge the gaps between the aggregates through the asphalt emulsion while leaving voids, which has the effect of achieving water permeability and achieving both fixing force and cushioning properties on the surface of the aggregate layer (roadbed). In addition, since no asphalt is used, it has the effect of suppressing the temperature rise of the roadbed surface.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the artificial turf pavement which concerns on 1st Embodiment, (a) is sectional drawing, (b) is a partial enlarged end elevation in the A part of (a). 4 is an operation flow chart showing a method for constructing an artificial turf pavement according to the first embodiment; It is an operation|movement flowchart which shows the construction method of the artificial turf pavement body which concerns on 2nd Embodiment.

Embodiments of the present invention will be described below. Also, the same reference numerals are given to the same elements throughout the present embodiment. Further, in the present invention, "-" is used to mean including the numerical values before and after it as lower and upper limits.

(First embodiment)
A roadbed according to the first embodiment and an artificial turf pavement provided with the roadbed will be described. FIG. 1 is a diagram showing a schematic configuration of an artificial turf pavement according to this embodiment, (a) is a cross-sectional view, and (b) is a partially enlarged end view of part A of (a).

As shown in FIG. 1, an artificial turf pavement 1 according to the present embodiment includes a roadbed 20 having water permeability and an artificial turf 30 on a roadbed 10 serving as a base.

The roadbed 20 comprises an aggregate layer 22 made of a roadbed composition containing aggregates 21, and a porous mixed layer 24 formed by cross-linking the aggregates 21 with an asphalt emulsion 23.

The aggregate 21 in the aggregate layer 22 and the mixed layer 24 is not particularly limited, and may be natural aggregate (gravel, sand), crushed stone, crushed sand, slag aggregate, recycled aggregate, lightweight aggregate, and mixed aggregate of these. material, etc. can be used. Both coarse aggregate (average particle diameter of 2.36 mm or more) and fine aggregate (average particle diameter of less than 2.36 mm) can be used (combinedly). Further, the aggregate layer 22 and the mixed layer 24 may be different in aggregate type, but from the viewpoint of construction efficiency, it is preferable to use the same type of aggregate.
In addition to the aggregate 21, the roadbed composition may also contain a filler for improving dry strength. Fillers include sand, fly ash, calcium carbonate, slaked lime, and the like.

In the mixed layer 24, the aggregate 21 in the upper region of the aggregate layer 22 is crosslinked with the asphalt emulsion 23 in the construction process of the roadbed 20, as will be described later, and the porous structure is maintained similarly to the aggregate layer 22. layer. Here, the "upper region of the aggregate layer 22" refers to a predetermined depth from the surface of the aggregate layer 22 before forming the mixed layer 24 to the depth at which the asphalt emulsion 23 penetrates. Although it cannot be generalized depending on the type of material, the composition ratio of coarse aggregate and fine aggregate, etc., it is preferably a region from the surface of the aggregate layer 22 to a depth of 30 mm.

As shown in FIG. 1(a), the boundary surface between the aggregate layer 22 and the mixed layer 24 is not flat, but is wavy depending on the degree of penetration of the asphalt emulsion 23. As shown in FIG.

As shown in FIG. 1(b), the asphalt emulsion 23 applied to the surface of the aggregate layer 22 penetrates the surface of the aggregate 21 while partially or entirely forming a film. The coating of the asphalt emulsion 23 forms a cross-linking point or a cross-linking surface depending on the distance between the surfaces of the adjacent aggregates 21 to cross-link the aggregates 21 . When the aggregates 21 are already in contact with each other due to the compaction of the aggregates 21, which will be described later, the surroundings of the contact portions are covered with the asphalt emulsion 23, resulting in stronger cross-linking.
When the distance between the surfaces of the adjacent aggregates 21 is large, the coatings of the asphalt emulsion 23 formed on the surfaces of the aggregates 21 cannot contact each other, so that the aggregates 21 are not crosslinked. The spaces where the coatings cannot contact each other remain as voids 25 of the mixed layer 24 even after the asphalt emulsion 23 is applied and permeated. Due to the gaps 25, the mixed layer 24 (roadbed 20) exhibits water permeability.

As the asphalt emulsion 23, cationic asphalt emulsion (hereinafter referred to as cationic emulsion) can be used.
A cationic emulsion is obtained by emulsifying a bituminous substance obtained by mixing one or more of natural asphalt, petroleum asphalt, heavy oil, tar, pitch, etc. with a cationic emulsifier.
Cationic emulsifiers include aliphatic or alicyclic monoamines, diamines, triamines, amidoamines, polyaminoethylimidazolines, long-chain hydroxyalkyldiamines, rosinamines, ethylene oxide adducts of these amines, and amines having long-chain alkyl groups. Examples include oxides, water-soluble or water-dispersible salts obtained by reacting these amine-based surfactants with acids such as hydrochloric acid, sulfamic acid, and acetic acid, and quaternary ammonium salts of these amine-based surfactants.

As described above, by cross-linking the aggregate 21 with the asphalt emulsion 23, the roadbed 20 as a whole becomes porous, so that the water permeability of the roadbed 20 can be ensured.
Further, a fixing force (restraining force) between the aggregates 21 on the surface of the roadbed 20 can be obtained, and durability against external force applied to the surface of the roadbed 20 can be obtained. Like an artificial turf ground, when a competition is being held, the external force applied to the surface of the roadbed 20 is large, but the piles (especially long piles) reduce the external force, so the surface with the alpha alt emulsion 23 Sufficient durability can be ensured even when fixed. At the same time, since the aggregates 21 on the surface of the roadbed 20 are constrained only by cross-linking with the asphalt emulsion 23, the surface of the roadbed 20 can be cushioned.
Furthermore, since asphalt is not used in the construction process of the roadbed 20, it is possible to suppress the temperature rise of the roadbed surface, which is a conventional problem.

The artificial turf 30 has a plurality of piles 32 planted on a sheet-like base material 31 at predetermined intervals. A filling material 33 is filled between the piles 32 . The artificial grass 30 has water permeability.

As the sheet-shaped base material 31, a known base material (base fabric) for artificial grass can be used, and examples thereof include plain weave fabric made of polypropylene or polyethylene.

As the pile 32, a known pile for artificial turf can be used, including a monofilament pile, a film yarn pile, a slit yarn pile, a split yarn pile, and the like.
Moreover, the material of the pile 32 is not particularly limited, and examples thereof include olefin-based synthetic resins such as polyethylene and polypropylene, and various synthetic resins such as polyamide, polyvinylidene chloride, and polyester.

The filling material 33 functions as a cushioning material as well as for the purpose of protecting the piles 32 , and is preferably filled between the piles 32 .
As the filler 33, an elastic filler or a hard filler can be used. Elastic fillers include elastic materials such as rubber and resin. Sand etc. are mentioned as a hard filler.

Next, a construction method of the artificial turf pavement 1 having the roadbed 20 will be described. FIG. 2 is an operation flow chart showing the construction method of the artificial turf pavement according to the present embodiment.

In the laying step (Step S100), a roadbed composition containing aggregates 21 is laid and leveled on the roadbed 10 as a base by a finisher of a floating screed.

In the aggregate layer forming step (step S110), the roadbed composition laid on the roadbed 10 is rolled and compacted using tandem rollers to form the aggregate layer 22 .

In the mixed layer forming step (step S120), the asphalt emulsion 23 is applied to the surface of the compacted aggregate layer 22 and permeated, and the aggregate 21 in the upper region of the aggregate layer 22 is crosslinked by the asphalt emulsion 23.
The amount of the asphalt emulsion 23 applied to the surface of the aggregate layer 22 is preferably in the range of 0.3 to 1.2 L/m ² , and considering the actual site environment, etc., it is 0.4 to 1.0 L/m. It is more preferably within the range of ^m2 .
The coating temperature of the asphalt emulsion 23 is preferably in the range of 10 to 80.degree. C., more preferably in the range of 15 to 60.degree.
In this way, the upper region of the aggregate layer 22 is formed as a mixed layer 24 exhibiting the same porous state as the aggregate layer 22 .

In the artificial turf forming step (step S130), after the sheet-like base material 31 having a plurality of piles 32 planted thereon is arranged on the roadbed 20 (mixed layer 24), the piles 32 are raised by a rotating brush, and the space between the piles 32 is raised. is filled with a filler 33 to form an artificial turf 30 .
The pile 32 is continuously planted on the sheet-like base material 31 using a tufting machine, and dried in a high-temperature environment using a packing agent applied to the back surface of the sheet-like base material 31 . fixed to

As described above, it is possible to construct the roadbed 20 and the artificial turf pavement 1 that are excellent in water permeability and have both stability and cushioning properties on the surface of the roadbed 20 .

As described above, in the present invention, in the mixed layer forming step, the coating amount of the asphalt emulsion 23 is set within the range of 0.3 to 1.2 L/m ² . As well as being able to cross-link at an appropriate depth, it is possible to suppress excessive clogging of the space between the aggregates 21 by the asphalt emulsion 23, so that the water permeability of the roadbed 20 can be sufficiently ensured.

As described above, in the present invention, since the asphalt emulsion 23 is a cationic emulsion, the state of the asphalt emulsion 23 is maintained without breaking the bond between the core asphalt and the emulsifier after the asphalt emulsion 23 is applied. Since the aggregates 21 are cross-linked with each other as they are, the porous structure of the mixed layer 24 can be more reliably formed, and the water permeability of the roadbed 20 can be ensured.

Thus, in the present invention, since the aggregate layer 22 made of the roadbed composition containing the aggregate 21 and the mixed layer 24 formed in a porous state by cross-linking the aggregate 21 with the asphalt emulsion 23 are provided, , the aggregates 21 can be cross-linked via the asphalt emulsion 23 while leaving the voids 25 between the aggregates 21 in the mixed layer 24, water permeability is obtained, and the surface of the aggregate layer 22 (roadbed 20) is improved. It has the effect of achieving both a fixing force and a cushioning property. In addition, since asphalt is not used, there is an effect that the surface temperature of the roadbed 20 can be suppressed.

Thus, in the present invention, the roadbed 20 has the aggregate layer 22 made of the roadbed composition containing the aggregate 21, and the mixed layer 24 formed in a porous state by cross-linking the aggregate 21 with the asphalt emulsion 23. and the artificial turf 30 arranged on the roadbed 20 and having a plurality of piles 32 planted on the sheet-like base material 31, rainwater accumulates on the surface of the artificial turf pavement 1 due to the water permeability of the roadbed 20. Therefore, it is possible to prevent the piles 32 and the filling material 33 filled between the piles 32 from floating and flowing out due to rainwater. It has the effect of not impairing the cushioning property.

(Second embodiment)
A method of constructing an artificial turf pavement according to the second embodiment will be described with reference to FIG. FIG. 3 is an operation flow chart showing a method for constructing an artificial turf pavement according to this embodiment.

The construction method of the artificial turf pavement according to the present embodiment differs from the construction method of the artificial turf pavement according to the first embodiment in that it has a drying process for drying the surface of the aggregate layer. It is a point.
The mixed layer forming step (step S120) and the artificial turf forming step (step S130) are the same as those in the first embodiment, and therefore descriptions thereof are omitted.

In the laying step (step S200), a roadbed composition containing aggregates 21 is laid and leveled on the subgrade 10 as a base by a floating screed finisher, and in the aggregate layer forming step (step S210), the road The roadbed composition laid on the floor 10 is rolled and compacted using tandem rollers to form the aggregate layer 22 . At this time, the composition of the roadbed composition, construction time, etc. are adjusted so that the water content ratio of the aggregate layer 22 is within the range of 8 to 20%.

Here, the "water content ratio" according to the present embodiment is a value measured in accordance with JIS A 1203:2009 (furnace drying method), and the mass of the sampled roadbed composition before and after drying in the furnace. Calculated.
As a real-time measurement method at a construction site, there is an RI measurement method. The RI measurement method is a measurement method for measuring the density and water content of soil with a radioisotope-based instrument. Details are specified in the Japanese Geotechnical Society Standard (JGS 1614-2012, soil density test method using an RI instrument). there is Since the RI measurement method covers not only the water content obtained by the oven drying method, but also all water content in the soil, including crystal water and adsorbed water, the amount equivalent to crystal water and adsorbed water is calculated. to correct.

In the drying step (step S220), the water content in the upper region of the aggregate layer 22 adjusted to the range of 8 to 20% is preferably within the range of 5 to 10%, more preferably 6 to 8%. Adjust within the range of The range (depth) in which the water content ratio is adjusted in the upper portion of the aggregate layer 22 and the penetration depth of the asphalt emulsion 23 in the subsequent mixed layer forming process do not necessarily match.
As a method for drying the upper region of the aggregate layer 22, the roadbed composition is laid under conditions where it does not rain, and then dried, or a curing sheet is covered from above the rolled aggregate layer 22. can. Moreover, air drying, heat drying, etc. can be suitably used.

After the drying process (step S220), the mixed layer forming process (step S120) and the artificial turf forming process (step S130) are performed, whereby the artificial turf pavement 1 can be constructed.

As described above, the present invention further includes a drying step for drying the upper region of the aggregate layer 22 between the aggregate layer forming step and the mixed layer forming step. %, the water content in the upper region of the aggregate layer 22 is adjusted within the range of 5 to 10%, so that the compaction of the aggregate layer 22 is maintained and the asphalt emulsion 23 is used as the aggregate. It is possible to moderately permeate the upper region of the layer 22, and it is possible to increase the fixing force of the surface of the aggregate layer 22 (roadbed 20) while ensuring the water permeability of the roadbed 20.

In the present invention, the construction of the roadbed 20 described above is the minimum construction, and may have other known layers applicable to the roadbed 20 .
Also, the configuration of the artificial turf 30 in the artificial turf pavement 1 is an example, and a configuration of conventionally known artificial turf having water permeability can be appropriately employed.

1 Artificial Grass Pavement 10 Roadbed 20 Roadbed 21 Aggregate 22 Aggregate Layer 23 Asphalt Emulsion 24 Mixed Layer 25 Cavity 30 Artificial Grass 31 Sheet-like Base Material 32 Pile 33 Filler

Claims (5)

A laying step of laying and leveling a roadbed composition containing an aggregate;
an aggregate layer forming step of rolling and compacting the laid roadbed composition to form an aggregate layer;
a drying step of drying the upper region of the aggregate layer;
a mixed layer forming step of applying and permeating an asphalt emulsion onto the surface of the aggregate layer to form an upper region of the aggregate layer as a porous mixed layer ;
The method for constructing a roadbed, wherein the drying step adjusts the moisture content in the upper region of the aggregate layer adjusted to the range of 8 to 20% to the range of 5 to 10%. In the roadbed construction method according to claim 1,
The roadbed construction method , wherein in the mixed layer forming step, the coating amount of the asphalt emulsion is within a range of 0.3 to 1.2 L/m ² . In the roadbed construction method according to claim 1 or 2,
A roadbed construction method , wherein the asphalt emulsion is a cationic emulsion . an aggregate layer made of a roadbed composition containing aggregate;
A mixed layer formed on the aggregate layer in a porous state by cross-linking aggregates with a water content ratio within the range of 8 to 20% to within the range of 5 to 10% with an asphalt emulsion. A roadbed comprising: An aggregate layer made of a roadbed composition containing aggregate, and an asphalt emulsion on the aggregate layer, the aggregate having a water content within the range of 8 to 20% and reduced to the range of 5 to 10%. a roadbed having a porous mixed layer crosslinked by
An artificial turf pavement, comprising an artificial turf arranged on the roadbed and having a plurality of piles planted in a sheet-like base material.

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