JP2003176503A - Elastic paving material and elastic paving structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic paving material formed to have the coefficient of sliding friction on the wet road surface at the vehicle speed of 70 km/h being 0.4 or more, the difference between the coefficients of sliding friction in a wet state and a dry state being 0.8 or less, and the inflection point of the coefficient of sliding friction being 20 km/h or more. <P>SOLUTION: The paving material 10 is formed by mixing a binder of urethane base or the like and a third component material in rubber chips and molding a mixture. The third component material is to satisfy three conditions that the hardness is JIS A 90 or more, that the average grain diameter is 0.01-2.5 mm and that the mixed quantity is 5-35 wt.% to the total mixed quantity including the rubber chips and the binder. As for the binder, at least one of the maximal values at the temperature dependent curve of a damping coefficient tanδ needs to exist at 10°C or higher, and it is preferable to be urethane-based. It is further preferable to provide a drainage ditch at the contact face of the paving material with the subgrade. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic paving material used for paving general roads and the like and an elastic paving structure for roads and the like using the same.

[0002]

2. Description of the Related Art Conventionally, as a paving material for drainage elastic pavement of this kind, as shown in, for example, Japanese Patent No. 2789805, elastic aggregates such as rubber chips obtained by crushing rubber products such as discarded tires of automobiles are used. It is known to be molded by mixing a binder such as urethane, epoxy or the like. This pavement material is more elastic than ordinary asphalt pavement due to the use of elastic aggregates.
By setting the porosity to 0%, water permeability can be obtained, the generation of air pumping noise generated from the tire can be suppressed by the void, and the sound of a specific frequency propagating from the traveling vehicle can be absorbed. By reducing the tire impact noise and pattern vibration noise generated by the impact when the road surface comes into contact with the road surface, it is possible to significantly reduce traffic noise.

[0003]

By the way, when the road surface is dry, the above-mentioned pavement material is used when the tire surface of the vehicle and the road surface are attracted at the molecular level, that is, the cohesive force, and when the rubber is deformed and then restored. The frictional force is generated by the hysteresis loss that occurs in the, and the sliding friction coefficient increases. However, when the pavement material is wet due to rainfall or the like, the adhesion force becomes almost zero due to the formation of the water film, so that only the frictional force due to the hysteresis loss occurs and the sliding friction coefficient becomes extremely small. Furthermore, when it rains, all the water inside the pavement material is not drained, the elastic road surface is deflected by the load when the vehicle is running, and the water floats around the tires, which further reduces the sliding friction coefficient during braking. become. For that reason,
There is a problem that the braking distance at the time of braking the vehicle is extended in the case of rainfall or the like. On the other hand, if the porosity of the pavement material is significantly increased in order to improve the drainage property, the rigidity of the elastic pavement material is reduced, so that the sense of stability during traveling of the vehicle is impaired.

In the case of conventional concrete or asphalt pavement, when a water film is formed on the road surface due to rainfall or the like, the edge effect of the tread formed on the tire of the automobile breaks the water film to expose the road surface. The tire's adhesion to the road surface is restored. However, in the case of the above-mentioned elastic pavement material, since elastic aggregate such as rubber chips is used, it is softer than concrete etc., and the edge effect of the tire tread becomes small, and it does not lead to breaking the water film. There is. Therefore, in the elastic pavement material, it is necessary to further improve the sliding friction coefficient when wet due to rainfall or the like.

Specifically, in the case of asphalt pavement, the coefficient of sliding friction on a wet road surface tends to decrease with speed, and is about 0.3 at 70 km / h, but a higher value is required. There is. In the case of an elastic pavement material using elastic aggregate, the sliding friction coefficient on a wet road surface is high in the low speed range, but tends to become constant at around 0.25 at a speed of 20 km / h or more. The point is about 10 km / h. On the other hand, the target values that the Japan Highway Association has approved as a guideline for road maintenance and repair are 0.25 at 80 km / h for motorways and 60 for general roads with heavy traffic.
It is 0.25 at km / h. Therefore, even in the case of elastic pavement material, it is necessary to have a sliding friction coefficient larger than 0.3 even in the case of rainfall and the like, and it is desired that the inflection point thereof has a higher speed. In order to put the elastic pavement material into practical use, it is desirable that the tensile strength thereof be 10 kgf / cm ² or more as a measure of its durability, and since it is easy to manufacture, it shows whether the workability is good or not during stirring. It is also necessary that the dispersion state of the component is good.

[0006] Here, the inventor of the present invention adds a specific amount of at least one kind of third component (for example, silica sand) having a specific particle size to the elastic aggregate, and mixes and molds using a specific binder. It was found that there is a correlation that the sliding friction coefficient in the wet state is 0.4 or more and the difference between the sliding friction coefficient in the wet state and the dry state is 0.8 or less. It came to my thoughts. Therefore,
The present invention is intended to solve the above problems, and has a sliding friction coefficient of 0.4 or more on a wet road surface at a vehicle speed of 70 km / h, and a sliding friction coefficient of a wet state and a dry state. It is an object to provide an elastic pavement material and an elastic pavement structure having a difference of 0.8 or less and an inflection point of a sliding friction coefficient of 20 km / h or more.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the structural feature of the invention according to claim 1 is that the elastic aggregate, the binder and the third component material are mixed and molded. A pavement material that is laid on the roadbed of a road to form an elastic pavement, wherein the third component material has a hardness of JI.
90 or more in S A standard, average particle size is 0.01 to 2.5 m
m, and the compounding amount satisfy the three conditions of 5 to 35% by weight with respect to the total compounding amount including the elastic aggregate and the binder, and the sliding friction coefficient in the wet state is 0.4. The above is the fact that as the binder, a binder having at least one of the maximum values in the temperature dependence curve of the damping coefficient tan δ at 10 ° C. or higher is used.

This elastic pavement material is usually formed by mixing the elastic aggregate crushed to about 1 to 20 mm, the binder, and the third component material, and molding the mixed material. As the elastic aggregate, a rubber material such as natural rubber or synthetic rubber, or a synthetic resin material having elasticity such as thermoplastic elastomer or foamed polyurethane is used. Among them, it is produced from waste tires from the viewpoint of resource reuse. A rubber chip or the like is preferably used. The shape of the tip includes a spindle type, a mesh type, a rough type and the like. Urethane, epoxy, or the like is used as the binder.

In the invention according to claim 1 configured as described above, the elastic aggregate and the binder have a hardness of J
90 or more by ISA standard, average particle size is 0.01 to 2.5
mm third component is added, and the addition amount is 5 to 35% by weight with respect to the total compounding amount including the elastic aggregate and the binder, so that the sliding friction coefficient in a wet state of the paving material Can be set to a high value of 0.4 or more, and the inflection point of the sliding friction coefficient can be shifted to the high speed side. As a result, according to the invention of claim 1, while ensuring the noise absorbing property and the drainage property of the pavement material, the braking of the vehicle on the wet road surface such as at the time of precipitation is changed to the braking of the vehicle on the dry road surface. It is possible to bring them closer to each other, and the slip prevention effect is enhanced, and it is possible to secure driving stability in the event of rainfall.

As a binder, the damping coefficient tan
At least one of the maximum values in the temperature dependence curve of δ is 10
By using a binder having a temperature of ℃ or more, it is possible to further increase the sliding friction coefficient when the road surface is wet and to shift the inflection point to a higher speed side.

The third component is not limited to inorganic materials and organic materials, but inorganic materials such as silica sand, sand, silica, mullite, glass and other ceramic materials, and organic materials such as nylon and urethane. At least one type is selected from among the resin particles of. The hardness of the third component is more preferably 95 or more according to JIS A standard. The average particle size is more preferably 0.
If it is 01 to 0.5 mm, and less than 0.01 mm, the workability of the pavement material deteriorates, and if it is greater than 2.5 mm, the strength of the pavement material decreases. Further, the blending amount is more preferably 15 to 30% by weight based on the total blending amount.

Further, the structural feature of the invention according to claim 2 is that in the elastic pavement material according to claim 1, the difference in sliding friction coefficient between a wet state and a dry state is 0.8. It is in the following.

In the invention according to claim 2 configured as described above, the difference in the sliding friction coefficient between the wet state and the dry state is set to 0.8 or less, so that the brake is applied suddenly in the dry state. The risk of moving forward is reduced.

Further, the structural feature of the invention according to claim 3 is a paving material which is formed by mixing and molding elastic aggregate and a binder and is laid on a roadbed of a road to form an elastic pavement. As the binder, a binder in which at least one of the maximum values in the temperature dependence curve of the damping coefficient tan δ exists at 10 ° C. or higher is used, and the sliding friction coefficient in the wet state is 0.4 or higher. .

In the invention according to claim 3 configured as described above, by using as the binder, at least one of the maximum values in the temperature dependence curve of the damping coefficient tan δ exists at 10 ° C. or more, the road surface can be improved. It is possible to increase the sliding friction coefficient in the wet state,
The inflection point can be shifted to the high speed side.

Further, the constitutional feature of the invention according to claim 4 is that in the elastic pavement material according to claim 3, the difference in sliding friction coefficient between a wet state and a dry state is 0.8. It is in the following.

In the invention according to claim 4 configured as described above, the difference in the sliding friction coefficient between the wet state and the dry state is set to 0.8 or less, so that when the vehicle is suddenly braked in the dry state. The risk of moving forward is reduced.

Further, the structural feature of the invention according to claim 5 is that in the elastic pavement material according to any one of claims 1 to 4, drainage is applied to a contact surface of the pavement material with a roadbed. There is a groove.

In the invention according to claim 5 configured as described above, the drainage groove is provided on the contact surface of the pavement material with the roadbed, so that the water drained by the pavement material is drained during rainfall or the like. Since it is efficiently performed by the drainage ditch, it is possible to prevent the water from protruding from the pavement material while the vehicle is traveling. As a result, according to the invention of claim 5, in addition to the effects of the inventions of claims 1 to 4, it is possible to more effectively suppress a decrease in the sliding friction coefficient of the road surface during braking of the vehicle,
The hydroplaning phenomenon can be suppressed. Further, since the drainage is smoothly performed, it is possible to suppress the decrease in the strength of the pavement material and the adhesion strength with the roadbed.

Further, a structural feature of the invention according to claim 6 is that an elastic pavement material for a roadbed is provided with the elastic pavement material according to any one of claims 1 to 5. There is a drainage groove on the contact surface.

By configuring the invention of claim 6 as described above, the drainage groove provided on the roadbed can efficiently drain the water absorbed by the elastic pavement material during rain or the like. It is possible to prevent the water from protruding from the pavement material while the vehicle is running. As a result, in addition to the effects of the elastic pavement material according to claims 1 to 5, it is possible to further suppress a decrease in the sliding friction coefficient of the road surface during braking of the vehicle,
The hydroplaning phenomenon can be suppressed. Further, since the drainage is smoothly performed, it is possible to suppress the reduction in the strength of the elastic pavement material and the adhesion strength with the roadbed.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an elastic pavement material (hereinafter,
2 and 3 are a plan view and a cross-sectional view showing an elastic pavement structure in which the pavement material is laid on a roadbed.

The paving material 10 is a flat plate having a thickness of 20 to 50 mm, and rubber chips (spindle type,
Mesh type, rough type, etc.), a urethane-based binder, and silica sand as a third component material. The silica sand has a hardness of 90 or more according to JIS A, an average particle diameter of 0.01 to 2.5 mm, and a compounding amount of 5 to 35% by weight with respect to the total compounding amount including elastic aggregate and a binder.
It satisfies the following three conditions: The third component material is not limited to silica sand, and may be other inorganic material or organic material, and may be a mixture of a plurality of types without being limited to one type of material. Regarding the binder, it is necessary that at least one of the maximum values in the temperature dependence curve of the damping coefficient tan δ exists at 10 ° C. or higher, and a urethane type is preferable, but other epoxy type binders are not particularly limited. These three types of materials are mixed by a stirrer, for example, weighed so that the porosity is 40%, put into a mold, and heat-treated at 150 ° C. for 20 minutes by a hot press to form a cured product. It However, molding conditions (molding method,
The temperature and time) are not limited to this.

The paving material 10 is provided with a drain groove 11 having a semicircular cross section with a predetermined radius (for example, about 10 mm when the paving material has a thickness of about 30 mm) on the contact surface side with the roadbed 13. As shown in FIG. 2, it is desirable to incline the drainage groove 11 at an angle such that it cannot be stepped on by both wheels of the vehicle at the same time, and the wheel on the side of the road center C of the vehicle should move the drainage groove 11 ahead of the wheel on the side of the road shoulder K. It is set at an angle so that it can pass through. The pavement material 10 is laid by adhering it to a concrete or asphalt roadbed 13 provided on the ground surface 14 with an adhesive 12 such as an epoxy-based or urethane-based material to form a drainage elastic pavement structure.

By the silica sand contained in the pavement material 10 satisfying the three predetermined conditions, the sliding friction coefficient in the wet state of the pavement material is a high value of 0.4 or more, and the wet state and the dry state. It is possible to make the difference in the sliding friction coefficient at 0.8 or less and to shift the inflection point of the sliding friction coefficient to the high speed side. Therefore, while ensuring noise absorption and drainage of the pavement material, braking the vehicle on a wet road surface such as during precipitation can be approximated to braking the vehicle on a dry road surface, and the slip prevention effect is enhanced. As a result, it is possible to ensure operational stability even during rainfall. Also, as a binder, the damping coefficient t
By using a binder in which at least one of the maximum values in the temperature dependence curve of an δ exists at 10 ° C. or higher, the sliding friction coefficient can be further increased when the road surface is wet, and its inflection The point can be shifted to the higher speed side.

Further, by providing the drainage groove 11 on the pavement material 10, the water soaked in the pavement material 10 can be drained, and the pavement material 1 can be driven by the running of a car during rain or the like.
It is possible to suppress the water from rising to the surface of 0, to secure the strength of the pavement material 10 and to suppress the decrease of the sliding friction coefficient during braking of the automobile. In particular, the drainage groove 11 should be inclined at an angle such that it cannot be stepped on by both wheels of the vehicle at the same time, and the wheels on the side of the road center C of the vehicle should pass through the drainage groove 11 before the wheels on the side of the road shoulder K. As a result, there is a time difference in pressing the drain grooves 11 on both wheels, so that the water in the drain grooves 11 can be efficiently drained to the road shoulder K side by the left and right wheels.

In the above embodiment, the paving material 10 is used.
(1) contains silica sand that satisfies the three conditions, and (2) at least one of the maximum values in the temperature dependence curve of the damping coefficient tan δ of the binder exists at 10 ° C. or higher, and (3) drainage There are grooves, but of these,
It is also possible to satisfy only (1) and (2). As a result, similarly to the embodiment, the sliding friction coefficient in the wet state of the pavement material has a high value of 0.4 or more, and the difference between the sliding friction coefficient in the wet state and the dry state is 0.8 or less. In addition, the effect of shifting the inflection point of the sliding friction coefficient to the high speed side can be obtained.

As a second embodiment, a paving material which does not contain the third component and is formed by mixing and molding only elastic binder such as rubber chips and a binder, and the binder may satisfy the condition (2). . As a result, the sliding friction coefficient can be increased when the road surface is wet, and the inflection point can be shifted to the high speed side.

Next, specific examples of the above embodiment will be described. (1) The above three conditions of the third component (hardness, average particle size, compounding amount with respect to all compounding materials), (2) At least 1 of the maximum value in the temperature dependence curve of the damping coefficient tan δ as a binder.
Exists at 10 ° C or higher, and (3) drainage gutter (hereinafter,
Four types of Example 1 to Example 4 in which the three requirements of providing a drain) are combined are prepared. Moreover, seven comparative examples were prepared with respect to Examples 1 to 4. Table 1 below shows the combinations of the requirements for these examples, and Table 2 below shows the combinations of the requirements for the comparative examples. In Tables 1 and 2, the arrow ← indicates that the numerical value and the like on the left side are the same.

[0030]

[Table 1]

[0031]

[Table 2]

As shown in Table 1 above, in Examples 1 and 2, the third component such as silica sand was not contained, and the maximum value in the temperature dependence curve of the damping coefficient tan δ of the binder was the above requirement. (2) is satisfied, but no drain is provided. Regarding Example 3, requirements (1) and (2) are satisfied, but no drain is provided. Regarding Example 4, requirement (1) to requirement (3)
Meets all.

In Comparative Examples 1 and 7, as shown in Table 2, the third component was not contained, and the maximum values in the temperature dependence curve of the damping coefficient tan δ of the binder were -40 ° C and 5 ° C.
The requirements (2) are not met and there is no drain. In Comparative Examples 2 to 6, one is deviated from the requirement (1), and the maximum value in the temperature dependence curve of the damping coefficient tan δ of the binder is −4.
The temperature is 0 ° C and there is no drain.

In the above-mentioned examples and comparative examples, the tensile strength showing the adhesive strength of the elastic pavement material 10 to the roadbed 13, the coefficient of sliding friction when the road surface is wet, its inflection point, and the road surface are dry. The sliding friction coefficient, the difference between the sliding friction coefficient between the dry state and the wet state, and the workability were tested. For the measurement of sliding friction coefficient, 50c
m × 50 cm × 30 mm thick flat plate test piece (after molding,
ASTM (measured in the area of 80 km / h or less) using a DF tester (manufactured by Sunny Kken Co., Ltd.) while leaving it at room temperature for 3 days or more)
It carried out according to E1911-98. The tensile strength was measured according to JIS K6251. Further, the workability was judged by the dispersion state of the material when stirring. The test results are shown in Tables 1 and 2 above.

As is clear from Example 4, if the requirements (1), (2) and (3) are all satisfied, the coefficient of sliding friction when the road surface is wet is 0.55. A very good result with a bending point of 30 km / h was obtained, and the difference in the sliding friction coefficient between the dry state and the wet state was 0.6.
It was 5. The tensile strength was 17 kgf / cm ² , and the workability was good. For Example 4 and Comparative Example 1, the relationship between the speed (km / h) and the sliding friction coefficient in the wet state is shown in FIG. In addition, Example 3
As shown in, even if the requirements (1) and (2) are satisfied, the sliding friction coefficient is 0.52 when the road surface is wet, and the inflection point is 27 km / h, which means that it is dry. A very good result was obtained with a difference in sliding friction coefficient of 0.65 in a wet state, and tensile strength and workability were also good.

Further, as is clear from Examples 1 and 2, even if the third component material is not contained and no drain is provided, the damping coefficient tan as a binder is obtained.
At least one of the maximum values in the temperature dependence curve of δ is 10
If the requirement (2) of existence above ℃ is satisfied,
The coefficient of sliding friction when the road surface is wet is 0.43 or more, the inflection point is 24 km / h or more, and the difference between the coefficient of sliding friction in the dry state is 0.75.
It was 0.78. The tensile strength and workability were also good.

On the other hand, in Comparative Examples, Comparative Examples 3 and 4
And 6, the coefficient of sliding friction when the road surface was wet was 0.
Although a good value of 4 or more was obtained, the workability of Comparative Examples 3 and 6 was remarkably poor, and the tensile strength of Comparative Examples 4 and 6 was as low as 5 kgf / cm ^2. It was unsuitable for use as wood. In other comparative examples, the sliding friction coefficient itself was insufficiently below 0.4.

From the above examples and comparative examples, by satisfying the above requirements (1) and (2) or requirements (1) to (3), the sliding friction coefficient of the paving material in a wet state is 0.4. With the above, the difference between the sliding friction coefficient in the dry state and the wet state is 0.8 or less, and the inflection point of the sliding friction coefficient in the wet state can be further shifted to the high speed side, It was revealed that a pavement material having a strength of 10 kgf / cm ² or more and good workability can be obtained.
On the other hand, when none of the above requirements (1), (2), and (3) is satisfied, the sliding friction coefficient of the paving material in a wet state is 0.4 or more, and the tensile strength is 10 kgf / cm ^2.
As mentioned above, it was a result that the thing which can be used as a pavement material cannot be obtained because either of the good workability is lacking.

As a third embodiment of the present invention, FIG.
As shown in, the drainage groove 15 is provided on the contact surface of the roadbed 13 on which the elastic paving material 10 shown in the above embodiment is laid, with the paving material 10. By the drainage groove 15 provided in the roadbed 13, like the drainage groove 11 provided in the pavement material 10, the water absorbed in the pavement material 10 can be efficiently drained at the time of wet weather such as rain. It is possible to prevent the water from protruding from the pavement material while the vehicle is running. Therefore, in addition to the effect of providing the paving material 10, it is possible to further suppress a decrease in the sliding friction coefficient of the road surface during braking of the vehicle. In addition, the smooth drainage ensures that
It is possible to suppress a decrease in the strength of the elastic pavement material and the adhesion strength with the roadbed. In addition to providing the drainage groove 15 on the roadbed 13, if the strength of the pavement material 10 is not affected, the drainage groove 11 can be provided on the pavement material 10, thereby further improving drainage performance. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view showing an elastic paving material according to an embodiment of the present invention.

FIG. 2 is a plan view showing an automobile road having an elastic pavement structure in which an elastic pavement material is laid.

FIG. 3 is a cross-sectional view showing an elastic pavement structure.

FIG. 4 is a graph showing the relationship between the speed of an automobile and the coefficient of sliding friction when the road surface is wet for Example 4 and Comparative Example 1.

FIG. 5 is a sectional view showing an elastic pavement structure according to a third embodiment.

[Explanation of symbols]

10 ... Elastic pavement material, 11 ... Drainage channel, 12 ... Adhesive agent, 13
… Roadbed, 14… Ground, 15… Drains.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuji Narasaki             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business (72) Inventor Shimon Fumonari             Tokai Rubber Works, Higashi 3-chome, Komaki City, Aichi Prefecture             Business F term (reference) 2D051 AA03 AA08 AE05 AF09 AG03                       AG13 AG14 AH02 AH03

Claims (6)

[Claims] 1. A pavement material which is formed by mixing and molding an elastic aggregate, a binder and a third component material and is laid on a roadbed of a road to form an elastic pavement, wherein the third component material is a hard material. Is 90 or more on the JIS A standard, the average particle size is 0.01 to 2.5 mm, and the compounding amount is 5 to the total compounding amount including the elastic aggregate and the binder.
It satisfies the three conditions of 35% by weight, has a sliding friction coefficient of 0.4 or more in a wet state, and further has a maximum value on the temperature dependence curve of the damping coefficient tan δ as the binder. An elastic pavement material, wherein at least one of the binders is present at 10 ° C. or higher. 2. The elastic pavement material according to claim 1, wherein a difference in sliding friction coefficient between a wet state and a dry state is 0.8 or less. 3. A pavement material that is formed by mixing and molding elastic aggregate and a binder and is laid on a roadbed of a road to form an elastic pavement, wherein the binder is a temperature dependence curve of a damping coefficient tan δ. The elastic pavement material is characterized by using a binder having at least one of the maximum values of at least 10 ° C., and having a sliding friction coefficient of 0.4 or more in a wet state. 4. The elastic pavement material according to claim 3, wherein the difference in coefficient of sliding friction between the wet state and the dry state is 0.8 or less. 5. The drainage groove is provided on a contact surface of the paving material with the roadbed, and the drainage groove is provided.
The elastic pavement material according to any one of 1. 6. The method according to any one of claims 1 to 5.
The elastic pavement structure is characterized in that a drainage groove is provided on a contact surface of the roadbed on which the elastic pavement material is laid down according to the item.