JP2020128676A - Asphalt pavement structure - Google Patents

Abstract

To provide an asphalt pavement structure that can aim at extending asphalt pavement life and improving durability of the whole pavement.SOLUTION: On an asphalt pavement which is laminated by a road bed 10, a road base 20 and a pavement layer 30, there are provided a road base mixture 26 in which the road base 20 is composed of composite road base reinforcement 25 and the composite road base reinforcement 25 supporting the pavement layer 30 includes asphalt, and a reinforcing grid 27 made of synthetic resin integrated with the road base mixture 26 by heat fusion.SELECTED DRAWING: Figure 1

Description

The present invention relates to an asphalt pavement structure applicable to an asphalt pavement road, a large-scale stockyard with asphalt pavement, an airfield with asphalt pavement, and the like.

On heavy roads and highways with heavy traffic, digging and cracks on the asphalt pavement frequently occur as heavy vehicles travel.
If the cracks generated on the road surface are left unattended, rainwater that permeates through the cracks damages the roadbed made of crushed stone, etc., and the cracks further develop due to damage to the roadbed, causing a vicious cycle.
Generally, when the damage on the road surface of asphalt pavement reaches the limit, surface overlays and repairs are performed.
Since most of the causes of damage to the asphalt pavement are due to insufficient strength of the surface layer, reinforcing sheets of various materials are embedded inside the surface layer to reinforce the surface layer itself (Patent Documents 1 and 2).

JP, 2007-23502, A JP-A-6-158607

The conventional asphalt pavement has the following problems.
<1> The method of repairing the damaged part of the asphalt pavement by cutting overlay or replacement is only repairing the damaged part by coping therapy, and contributes to prolonging the life of the surface layer and improving the durability of the entire pavement. Was not.
<2> In the method of embedding a reinforcing sheet inside the surface layer to reinforce, a sufficient reinforcing effect is not obtained due to poor adhesion between the reinforcing sheet and asphalt, and the interface between the reinforcing sheet and the surface layer Easy to peel off.
<3> Even if only the surface layer can be reinforced, if the roadbed or roadbed is weak, the load on the surface layer increases, and the surface layer is likely to sink or be damaged.
<4> In the past earthquakes and landslide accidents, large cracks and steps were generated on the paved road, and part of the paved surface on the surface was missing, obstructing the passage of emergency vehicles and hindering restoration work. .. Through these experiences, proposals for asphalt pavement that is resistant to disasters are required.

The present invention has been made in view of the above points, and an object of the present invention is to provide a structure of an asphalt pavement capable of extending the life of the asphalt pavement and improving the durability of the entire pavement.

The present invention is premised on an asphalt pavement having a roadbed, a roadbed formed by stacking on the roadbed, and a pavement layer formed by stacking on the roadbed, wherein the roadbed includes a layered asphalt. A composite reinforced roadbed having a synthetic structure capable of flexural deformation provided with a mixture and a reinforcing grid made of synthetic resin integrated with the roadbed mixture by heat fusion, and the pavement layer is supported through the composite reinforced roadbed. ing.
In the present invention, the composite reinforced roadbed can continuously support the pavement layer even when a part of the roadbed or the like is missing or the roadbed is soft ground, so that sudden collapse of the pavement layer can be suppressed.
In another embodiment of the present invention, the composite reinforcing roadbed has a reinforcing grid integrally attached to the surface or inside of the roadbed mixture.
As the attachment form of the reinforcing grid, a single or a plurality of reinforcing grids may be attached to either one of the upper and lower surfaces or the upper and lower surfaces of the roadbed mixture, or a single or a plurality of reinforcing grids may be provided in the surface layer portion of the roadbed mixture. It may be embedded laterally or a reinforcing grid may be embedded laterally in the center of the roadbed mixture.
In another aspect of the present invention, the reinforcing grid includes a plurality of core members arranged in one direction or two directions at intervals, and a coating resin formed in a grid shape by coating the core members.
In another mode of the present invention, the core material is made of high-strength long fibers, and the coating resin is made of a thermoplastic resin.
In another form of the present invention, brittle fracture of the composite reinforced roadbed may be suppressed by using a plurality of long fibers having different elongations for the core material.
In another aspect of the present invention, the melting point of the coating resin and the heating temperature of the roadbed mixture are related such that the coating resin melts out when the coating resin of the reinforcing grid contacts the roadbed mixture containing the heated asphalt. ing.
In another embodiment of the present invention, the roadbed may be constituted by a lower layer roadbed formed by laminating it on a roadbed and a composite reinforcing roadbed formed by being laminated on the lower roadbed, or the roadbed may be formed by composite reinforcement. You may comprise only a roadbed.

The present invention has at least one of the following effects.
<1> Just by arranging a composite reinforced subbase having a synthetic structure capable of flexural deformation just below the pavement layer, it is possible to extend the life of the asphalt pavement and improve the durability of the entire pavement.
<2> Since the composite reinforced roadbed secures the roadbed mixture and the reinforcing grid by heat fusion, a stronger adhesive force can be secured compared to the case where an adhesive is used, and a troublesome adhesive application work is unnecessary. Is.
<3> Even if a part of the roadbed is missing or the roadbed is soft ground, the composite reinforced roadbed can maintain the supporting function of the pavement layer.
Therefore, it is possible to prevent a sudden fall of the pavement layer.
<4> Supporting just below the pavement layer with a composite reinforced roadbed can provide asphalt pavement that is resistant to earthquakes and landslides.
<5> By using a plurality of long fibers having different elongations for the core material of the reinforcing grid, the effect of suppressing brittle fracture of the composite reinforced roadbed can be enhanced.

Whole perspective view of the asphalt pavement according to the present invention with a part broken away Cross section of asphalt pavement Illustration of reinforcing grid Explanatory drawing of the process of laying a reinforcing grid on the lower layer roadbed Explanatory drawing of the process of heat-bonding a reinforcing grid and a roadbed mixture (A) is a cross-sectional view of the asphalt pavement during normal operation, (B) is a cross-sectional view of the asphalt pavement when a part of the roadbed is missing (A) is a cross-sectional view of the asphalt pavement shoulder during normal operation, (B) is a cross-sectional view of the asphalt pavement shoulder when a part of the roadbed is missing FIG. 6 is an explanatory view of a composite reinforced roadbed according to another embodiment, (A) is a model diagram of a composite reinforced roadbed in which reinforcing grids are embedded inside the upper layer portion and the lower layer portion of the roadbed mixture, and (B) is the lower layer portion of the roadbed mixture. Or a model diagram of a composite reinforced roadbed in which a reinforcing grid is embedded in either one of the upper layers, (C) is a model diagram of a composite reinforced roadbed in which a reinforcing grid is embedded in the center of a roadbed mixture

The asphalt pavement will be described in detail below with reference to the drawings.

1. Configuration <1> Overview of Asphalt Pavement Referring to FIGS. 1 and 2, an asphalt pavement according to the present invention has a roadbed 10, a lower layer roadbed 21 formed on the roadbed 10 and a composite reinforced roadbed. 25, and a pavement layer 30 composed of a base layer 31 and a surface layer 32, which are laminated on the roadbed 20.
In this example, a form in which the range corresponding to the upper layer roadbed is formed as the composite reinforced roadbed 25 will be described, but the roadbed 20 may be formed only by the composite reinforced roadbed 25.

<2> Roadbed The roadbed 10 is a layer within a thickness of about 1 m below the pavement layer 30 that supports the load of the roadbed 20. The roadbed 10 is mainly composed of sand, and the surface is compacted by a tire roller, a macadam roller, etc. to correct the unevenness.

<3> Lower Roadbed The lower roadbed 21 is a lower roadbed when the roadbed is formed of two layers, and functions to transfer the load of the composite reinforced roadbed 25 to the roadbed 10.
As the material of the lower layer roadbed 21, an economically available granular roadbed material such as crushed stone, crusher lance slag, gravel, and sand is used, and the surface is compacted to a predetermined thickness (20 cm or less).

<4> Composite reinforced roadbed The composite reinforced roadbed 25 is a roadbed having not only a function as a base of the pavement layer 30 but also flexural deformation and excellent toughness, and is a composite roadbed capable of maintaining its own shape independently. Is.
The composite reinforcing roadbed 25 includes a roadbed mixture 26 formed in layers and reinforcing grids 27, 27 made of synthetic resin integrated on the upper and lower surfaces of the roadbed mixture 26 by heat fusion.

It is generally known that the reinforcing grid made of synthetic resin is embedded in the embankment to reinforce it, but this conventional method depends on the vertical stress between the soil and the reinforcing grid. This is a friction system strengthening method.
With the friction system strengthening method that depends on the vertical stress, it is difficult to exert a reinforcing effect on a roadbed that has a small soil cover (small vertical stress) and is easily affected by concentrated loads such as wheel loads.
Therefore, it has been attempted to use a solidifying material such as cement or lime and a reinforcing grid in combination, but a sufficient reinforcing effect cannot be obtained depending on the strain level (degree of deformation) and the difference in behavior.
The present invention has been made in view of the drawbacks of the conventional friction system strengthening method that depends on such vertical stress. The roadbed mixture 26 having an adhesive component and the reinforcing grid made of synthetic resin do not depend on the vertical stress. By using 27 together, the composite reinforced roadbed 25 excellent in bending rigidity and brittleness is manufactured on site.

<4.1> Roadbed mixture The roadbed mixture 26 is a mixture of aggregate 28 such as crushed stone and the asphalt 29 of which the particle size has been adjusted well, and the surface of the asphalt mixture in which the asphalt 29 is adhered to the aggregate 28 is compressed. It is formed to have an appropriate layer thickness.
As the roadbed mixture 26, for example, a bitumen stabilization treatment or an open particle size asphalt mixture can be applied.

<4.2> Reinforcing Grid The reinforcing grid 27 is a grid material having a function of increasing the bending strength of the roadbed mixture 26 and a function of increasing the toughness of the roadbed mixture 26.
In this example, a mode in which the reinforcing grids 27, 27 are attached to the upper surface and the lower surface of the roadbed mixture layer 26 by heat fusion will be described.

Explaining with reference to FIG. 3, the reinforcing grids 27 are arranged in one direction or two directions with a space therebetween, and a plurality of core members 27a having excellent tensile strength and a grid net shape formed by covering the core members 27a. Coating resin 27b.

The core material 27a is formed by stretching in the longitudinal direction (uniaxial) or in the longitudinal direction and the width direction (biaxial).
The core material 27a is made of high-strength long fibers having high strength and low elongation, and includes, for example, aramid fiber, polyester fiber (whole aromatic polyester fiber, etc.), polyethylene fiber (ultra high molecular weight polyethylene fiber, etc.), polyvinyl alcohol. Fibers, synthetic fibers such as polyacetal fibers, and inorganic fibers such as glass fibers and carbon fibers can be used.

As the coating resin 29, for example, a thermoplastic resin such as polyethylene or polypropylene that is softened by heating can be used.
Typical low density polyethylene has a melting point of 70 to 90°C, high density polyethylene has a melting point of 90 to 110°C, and polypropylene has a melting point of 100 to 140°C.

<4.3> Adhering Means for Reinforcing Grid Although a method of using an adhesive as an adhering means for attaching the reinforcing grid 27 and the roadbed mixture 26 can be considered, using an adhesive requires a lot of time and labor for applying the adhesive. However, there is a drawback that it is difficult to obtain sufficient adhesive strength.
Therefore, in the present invention, the heat applied to the roadbed mixture 26 at the time of construction is utilized to thermally fuse the roadbed mixture 26 and the reinforcing grid 27 made of synthetic resin.

<4.4> Relationship between melting point of coating resin of reinforcing grid and heating temperature of roadbed mixture When coating resin 27b of reinforcing grid 27 comes into contact with roadbed mixture 26 heated to a predetermined temperature, coating resin 27b is softened and melted. As shown, the melting point of the coating resin 27b and the heating temperature of the roadbed mixture 26 are related.
For example, since the heating temperature at the time of construction of the roadbed mixture 26 containing general asphalt is about 100 to 120° C., the material of the coating resin 27b of the reinforcing grid 27 has a property of melting at the heating temperature of the roadbed mixture 26. Just select the purpose.
By selecting the material of the coating resin 27b or selecting the construction temperature of the roadbed mixture 26 appropriately, it is possible to heat-bond the roadbed mixture 26 and the reinforcing grid 27 made of synthetic resin.

<5> Pavement layer The pavement layer 30 includes a base layer 31 and a surface layer 32.
The coarse-grained asphalt mixture forming the base layer 30 is a heated asphalt mixture composed of coarse aggregate, fine aggregate, filler, and asphalt, and has a synthetic grain size of 20 to 35% through a 2.5 mm sieve.
For example, 30% by weight of crushed stone No. 5 and 20% by weight of crushed stone No. 6 as coarse aggregate, 17% by weight of coarse sand as fine aggregate, 5% by weight of fine sand, 5% by weight of stone powder obtained by crushing limestone as a filler, and straight as asphalt 4.8% by weight of asphalt is used.
The base layer 30 can be omitted by making a simple pavement.

The dense-grained asphalt mixture forming the surface layer 32 is a heated asphalt mixture consisting of coarse aggregate, fine aggregate, filler, and asphalt, and has a synthetic grain size of 35 to 50% through a 2.5 mm sieve.
For example, 34% by weight of crushed stone of No. 6 and 24% by weight of crushed stone of 7 as coarse aggregate, 33% by weight of coarse sand as fine aggregate, 4% by weight of fine sand, 5% by weight of stone powder obtained by crushing limestone as a filler, and straight as asphalt 5.6% by weight of asphalt is used.

2. Construction method of asphalt pavement A construction method of asphalt pavement will be described with reference to FIGS.

<1> Construction of roadbed <1.1> Construction of lower layer roadbed The lower layer roadbed 21 is formed on the roadbed 10 by rolling and rolling the granular roadbed material on the roadbed 10.

<1.2> Construction of composite reinforced roadbed A lower reinforcing grid 27 is laid on the lower layer roadbed 21 without slack, and a roadbed mixture 26 containing asphalt heated to a predetermined temperature is laid on the reinforcing grid 27 in a predetermined manner. Scatter with layer thickness. When the roadbed mixture 26 is sprinkled out, it is heated at a predetermined temperature.
Further, after laying a lower reinforcing grid 27 on the upper surface of the roadbed mixture 26, the roadbed mixture 26 is compacted to construct the composite reinforced roadbed 25.
The rolling operation may be performed at once, or may be performed in multiple times.
When constructing the composite reinforcing roadbed 25, the reinforcing grid 27 may be wound around the side surface of the roadbed mixture 26 and heat-welded.

With reference to FIGS. 4 and 5, the mechanism of heat welding of the reinforcing grids 27, 27 and the roadbed mixture 26 during the construction of the composite reinforced roadbed 25 on site will be described in detail.
FIG. 4 shows a sectional model view of the reinforcing grid 27 laid on the lower layer roadbed 21, and the coating resin 27b of the reinforcing grid 27 is not heated.

FIG. 5 shows the reinforcing grid 27 in contact with a roadbed mix 26 containing heated asphalt 29.
When the reinforcing grid 27 is heated through the heated roadbed mixture 26, the surface coating resin 27b is softened and crushed into a flat shape.
Since the roadbed mixture 26 also enters the opening portion of the reinforcing grid 27, the coating resin 27b is heated over a wide range.
Since the coating resin 27b has the same properties as the adhesive component (asphalt component) of the roadbed mixture 26, the rolling force acts on the contact portion between the coating resin 27b softened and melted and the asphalt 29, and the reinforcing grid 27 Is heat-sealed to the roadbed mixture 26.
Thus, the composite reinforced roadbed 25 that is firmly integrated can be formed by a simple work of simply pressing the heated roadbed mixture 26 and the reinforcing grid 27 on-site.

Since the coating resin 27b and the roadbed mixture 26 are fixed to each other by heat fusion, a stronger fixing force can be secured as compared with the case where an adhesive is used, and a troublesome adhesive application work is unnecessary.
The reinforcing grid 27 only softens the surface coating resin 27b and melts the surface, and the entire coating resin 27b does not melt and disappear.

Although the heat fusion of the lower reinforcing grid 27 and the roadbed mixture 26 has been described above, the same applies to the heat fusion of the upper reinforcing grid 27 and the roadbed mixture 26.

<2> Construction of pavement layer The pavement layer 30 is formed by sequentially laminating the base layer 31 and the surface layer 32 on the upper surface of the roadbed mixture 26.

3. Characteristics of Asphalt Pavement Next, characteristics of the asphalt pavement including the composite reinforced roadbed 25 will be described.

<1> Function of Dispersing Loaded Load by Composite Reinforcement Roadbed As shown in FIGS. 1 and 2, in the asphalt pavement of this example, the pavement layer 30 is supported by the roadbed 20 including the composite reinforcement roadbed 25 and the lower layer roadbed 21. The roadbed 20 has a laminated structure that can be supported by the roadbed 10.
That is, the composite reinforcing roadbed 25 having excellent toughness is located immediately below the pavement layer 30, and has a support structure for transmitting the load of the pavement layer 30 to the composite reinforcing roadbed 25.
When the asphalt pavement is a road, a load applied via the wheels of the traveling vehicle locally acts on the pavement layer 30.
The local load transmitted to the composite reinforced subbase 25 through the pavement layer 30 is dispersed by the composite reinforced subbase 25 having a composite structure. Since the composite reinforcing roadbed 25 is covered with the reinforcing grid 27, local depression deformation is unlikely to occur on the surface of the composite reinforcing roadbed 25.
As described above, the load burden on the pavement layer 30 can be reduced only by arranging the composite reinforcing roadbed 25 immediately below the pavement layer 30, and the life of the asphalt pavement can be extended and the durability of the entire pavement can be improved.
When the entire circumference of the roadbed mixture 26 is held by the reinforcing grid 27, the elasticity of the composite reinforced roadbed 25 is increased and the cushioning property is improved.

<2> Support function of pavement layer by composite reinforced roadbed The composite reinforced roadbed 25 has strength equivalent to that of a rigid concrete floor slab and toughness superior to that of the concrete floor slab, but also has an independent shape maintaining function. doing.
Therefore, even if a part of the roadbed 10 is lost, the pavement layer 30 can be continuously supported by the composite reinforcing roadbed 25.

The support function of the pavement layer 30 by the composite reinforcing roadbed 25 will be described with reference to FIGS.
FIG. 6(A) shows a cross section of the asphalt pavement in a normal state, and FIG. 6(B) shows a cross section of the asphalt pavement when a part of the roadbed 10 is missing.

If the roadbed is composed only of the roadbed mixture 26, if the roadbed 10 is partly missing or the roadbed 10 is soft ground, it is difficult for the roadbed mixture layer 26 alone to maintain the roadbed function.

On the other hand, as shown in FIG. 6(B), even if a part of the roadbed 10 is missing or the roadbed 10 is soft ground, the composite reinforced roadbed 25 does not lose the roadbed function and does not lose the pavement layer. Since 30 can be continuously supported, it is possible to effectively prevent a sudden fall of the pavement layer 30.
At this time, the composite reinforcing roadbed 25 is somewhat flexed and cracked, but the composite reinforcing roadbed 25 does not collapse suddenly.
The pavement layer 30 supported by the composite reinforced roadbed 25 can be provisionally provided for the passage of vehicles until the asphalt pavement repair work is started.

FIG. 7(A) shows a cross section of the asphalt pavement shoulder under normal conditions, and FIG. 7(B) shows a cross section of the asphalt pavement shoulder when a part of the roadbed 10 is missing.
Even when the roadbed 10 on the road shoulder is missing, the function of the roadbed can be maintained without breaking the composite reinforced roadbed 25 itself as in the embodiment of FIG.
Therefore, it is possible to effectively prevent the road shoulder of the pavement layer 30 from suddenly collapsing.

As described above, when the reinforcing grid 27 is pressed through the roadbed mixture 26 in a heated state, not only the adhesive force between the roadbed mixture 26 and the reinforcing grid 27 is increased, but also the core material 27a that constitutes the reinforcing grid 27 and the coating are provided. Adhesion and integration with the resin 27b are promoted.
Therefore, the function of distributing the load by the composite reinforced roadbed 25 and the function of supporting the pavement layer 30 are significantly improved.

4. Repair of asphalt pavement When repairing asphalt pavement, the surface layer 30 and the composite reinforced subbase 25 are cut to newly form the composite reinforced subbase 25 to repair the asphalt pavement.
When cutting the composite reinforced roadbed 25, it is advisable to select the core material 27a in advance as a material that is easy to cut so that the reinforcing grid 27 does not become an obstacle.
It is also possible to set the strengths of the upper and lower reinforcing grids 27, 27 as different combinations.

[Other Embodiment 1]
In the previous embodiment, the configuration in which the reinforcing grids 27, 27 made of synthetic resin are heat-sealed to the upper and lower surfaces of the roadbed mixture 26 to form the composite reinforcing roadbed 25 has been described. It is not limited to the example.

Another example of attachment of the reinforcing grid 27 will be described with reference to FIG.
FIG. 8A shows a configuration in which the reinforcing grids 27, 27 are embedded inside the upper layer portion and the lower layer portion of the roadbed mixture 26 to form the composite reinforced roadbed 25.
By embedding the reinforcing grid 27 in the roadbed mixture 26, the upper and lower surfaces of the reinforcing grid 27 are heat-sealed to the roadbed mixture 26, so that the fixing force between the reinforcing grid 27 and the roadbed mixture 26 is significantly increased.
It has a unique effect.

FIG. 8B shows a mode in which the reinforcing grids 27 are embedded in either the lower layer portion or the upper layer portion of the roadbed mixture 26.
When the direction of bending deformation of the roadbed mixture 26 is predicted depending on the purpose of use, it is possible to economically reinforce the roadbed mixture 26 by embedding the reinforcing grid 27 on the tension side of the roadbed mixture 26.
It has a unique effect.

FIG. 8C shows a mode in which a reinforcing grid 27 is laterally embedded in the central portion of the roadbed mixture 26.
The reinforcing grid 27 embedded in the central portion of the roadbed mixture 26 functions for both up and down bending of the composite reinforced roadbed 25.
It has a unique effect.

The above-described forms of FIGS. 8A to 8C may be adopted independently, or a plurality of forms may be combined as appropriate.

[Other Embodiment 2]
In the above-mentioned embodiments, the core material 27a constituting the reinforcing grid 27 is described as being composed of one type of long fiber, but the core material 27a can also be used by combining a plurality of types of long fibers having different elongations. Is.
It is possible to change the elongation of the long fibers by combining different kinds of fiber materials or, in the case of the same kind of fibers, combining fibers having different diameters.

In this example, a large bending force was applied to the composite reinforced roadbed 25 by combining a plurality of long fibers having relatively different elongations (for example, low elongation, medium elongation, and high elongation long fibers). Since a plurality of long fibers having different elongations function in a stepwise manner, the effect of suppressing brittle fracture of the composite reinforced roadbed 25 can be enhanced.

10... Roadbed 20... Roadbed 21... Lower roadbed 25... Composite roadbed 26... Roadbed mixture 27... Reinforcement grid 27a... Core 27b・・Coating resin 28・・・・Aggregate 29・・・・・・Asphalt 30・・・・Pavement layer 31・・・・Base layer 32・・・・・・Surface layer

Claims (10)

An asphalt pavement having a roadbed, a roadbed formed by laminating on the roadbed, and a paving layer formed by laminating on the roadbed,
The roadbed comprises a roadbed mixture containing a layered asphalt, and a composite reinforced roadbed having a synthetic structure capable of flexural deformation, comprising a reinforcing grid made of synthetic resin integrated into the roadbed mixture by heat fusion,
A pavement layer is supported via the composite reinforced subbase,
Asphalt pavement structure. The structure of an asphalt pavement according to claim 1, wherein the composite reinforcing roadbed has a reinforcing grid integrally attached to the surface or inside of the roadbed mixture. The structure of an asphalt pavement according to claim 2, wherein one or more reinforcing grids are attached to either one of the upper and lower surfaces or the upper and lower surfaces of the roadbed mixture. The asphalt pavement structure according to claim 2, wherein one or a plurality of reinforcing grids are laterally embedded in a surface layer portion of the roadbed mixture. Structure of asphalt pavement according to claim 2, characterized in that a reinforcing grid is embedded laterally in the center of the roadbed mixture. The reinforcing grid is composed of a plurality of core members arranged in one direction or two directions at intervals, and a coating resin formed in a lattice shape by coating the core members. The asphalt pavement structure according to any one of 5 above. The asphalt pavement structure according to claim 6, wherein the core material is made of high-strength long fibers, and the coating resin is made of a thermoplastic resin. The asphalt pavement structure according to claim 7, wherein the core material is composed of a plurality of long fibers having different elongations. The melting point of the coating resin and the heating temperature of the roadbed mixture are related so that the coating resin heat-bonds when the coating resin of the reinforcing grid touches the roadbed mixture containing the heated asphalt. The structure of the asphalt pavement according to claim 7. The structure of an asphalt pavement according to claim 1, wherein the roadbed comprises a lower layer roadbed formed by laminating on a roadbed and a composite reinforced roadbed formed by laminating on a lower layer roadbed. ..

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