JP2001011807A - Elastic pavement and elastic pavement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic pavement having 0.4 or larger in a sliding friction coefficient on a wet road face at a car speed of 70 km/h and 0.8 or smaller in the difference between a sliding friction coefficient in a wet condition and that in a dry condition and 20 km/h or larger in a point of inflection of a sliding friction coefficient. SOLUTION: In this pavement 10, a binder such as polyurethane or the like and a third component material are mixed with rubber chips and molded. The third component material satisfies three conditions that it is 90 or higher in JIS-A standard hardness and it has an average particle size of 0.01-2.5 mm and also it has such a mixing ratio that 3-35 wt.% of the material is mixed to the total propotion including the rubber chips and the binder. An urethane- based substance that at least one of maximum values in a temperature-dependent curve of an attenuation coefficient. tanδ exists in 10 deg.C or higher temperature, is preferable. Moreover, a drain ditch is preferably provided on the contact face of the pavement with the base course face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an elastic pavement material used for paving general roads and the like, and an elastic pavement structure for roads and the like using the same.

[0002]

2. Description of the Related Art Conventionally, as a pavement material for this kind of drainage elastic pavement, for example, as shown in Japanese Patent No. 2789805, elastic aggregates such as rubber chips obtained by pulverizing rubber products such as automobile waste tires are disclosed. What has been molded by mixing a binder such as polyurethane, urethane and epoxy is known. This pavement material has elasticity as compared with ordinary asphalt pavement due to the use of the elastic aggregate.
By setting the porosity to 0%, water permeability can be obtained, and the generation of air pumping noise generated from the tire due to the void can be suppressed, and a sound of a specific frequency transmitted from a traveling vehicle can be absorbed. By reducing the tire impact sound and the pattern excitation sound generated by the impact at the time of contact between the road and the road surface, there is an excellent characteristic that traffic noise can be greatly reduced.

[0003]

By the way, when the pavement material is dry, when the road surface is dry, the adhesion at the molecular level between the tire surface of the vehicle and the road surface, that is, the cohesion force, and when the rubber is deformed, the pavement material is restored. The frictional force due to the hysteresis loss occurring at the time acts, and the sliding friction coefficient increases. However, when the pavement material is wet due to rainfall or the like, the adhesive force becomes almost zero due to the formation of the water film, so that only the frictional force due to the hysteresis loss is generated, and the sliding friction coefficient becomes extremely small. In addition, during rainfall, all the water inside the pavement material is not drained, and the load during driving the vehicle causes the elastic road surface to bend and the water to come out around the tires, further reducing the sliding friction coefficient during braking. become. For that reason,
There is a problem that the braking distance of the vehicle during braking is extended during rainfall or the like. On the other hand, if the porosity of the pavement material is significantly increased to improve drainage, the rigidity of the elastic pavement material will be reduced, and the sense of stability during traveling of the vehicle will be impaired.

In the case of a conventional concrete or asphalt pavement, when a water film is formed on a road surface due to rainfall or the like, the water film is broken by an edge effect of a tread formed on an automobile tire to expose the road surface. It tries to recover the adhesion of the tire to the road surface. However, in the case of the above-mentioned elastic pavement material, since an elastic aggregate such as a rubber chip is used, the elastic pavement material is softer than concrete or the like, and the edge effect of the tire tread is reduced, so that the water film is not broken. There is. Therefore, in the case of the elastic pavement material, it is necessary to further improve the coefficient of sliding friction 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. I have. In the case of an elastic pavement using an elastic aggregate, the coefficient of sliding friction on a wet road surface is high in a low speed range, but tends to be constant at about 0.25 or more 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 Road Association has certified as a guide for maintenance and repair of roads 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 the elastic pavement material, it is necessary to make the sliding friction coefficient larger than 0.3 even during rainfall, and it is desired that the inflection point has a higher speed. In order to put the elastic pavement material into practical use, it is desirable that the tensile strength is 10 kgf / cm ² or more as a measure of its durability. It is also necessary that the dispersion state of the component is good.

Here, the inventor of the present invention added a specific amount of at least one third component having a specific particle size (for example, silica sand) to an elastic aggregate, and mixed and molded using a specific binder. The sliding friction coefficient is 0.4 or more,
In addition, they have found that there is a correlation that the difference between the sliding friction coefficient in the wet state and the dry friction state is 0.8 or less, and have reached the present invention. Accordingly, the present invention is intended to solve the above-mentioned problem, and has a vehicle speed of 70 km / h.
The coefficient of sliding friction on a wet road surface is 0.4 or more, the difference between the coefficient of sliding friction between a wet state and a dry state is 0.8 or less, and the inflection point of the coefficient of sliding friction is 20 km / h.
An object of the present invention is to provide an elastic pavement material as described above.

[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 the first aspect is that an elastic aggregate, a binder and a third component material are mixed and formed. A pavement material which is laid on a roadbed to form an elastic pavement, wherein the third component material has a hardness of JI.
90 or more based on SA, average particle size of 0.01 to 2.5 m
m, and the blending amount is 5 to 35% by weight based on the total blending amount including the elastic aggregate and the binder, and the coefficient of sliding friction in a wet state is 0.4%. That is all.

The elastic pavement material is formed by mixing an elastic aggregate, a binder and a third component material, usually ground to about 1 to 20 mm, 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 polyurethane foam is used. Among them, it is manufactured from waste tires from the viewpoint of resource reuse. Rubber chips and the like are preferably used. Examples of the shape of the chip include a spindle type, a mesh type, and a rough type. 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 further have a hardness of J.
90 or more based on ISA, average particle size of 0.01 to 2.5
mm of the third component, and the addition amount is 5 to 35% by weight based on the total amount of the elastic aggregate and the binder, so that the pavement material has a sliding friction coefficient in a wet state. Can be increased 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 first aspect of the present invention, the braking of the vehicle on a wet road surface such as at the time of precipitation can be used for the braking of the vehicle on a dry road surface while ensuring the noise absorption and drainage of the pavement material. As a result, the slip prevention effect is enhanced, and operation stability during rainfall and the like can be ensured.

The third component is not limited to an inorganic material or an organic material, but the inorganic material is preferably silica sand, sand, silica, mullite, glass or other ceramic materials, and the organic material is nylon, urethane or the like. At least one type is selected from the resin particles described above. The hardness of the third component is more preferably 95 or more according to JIS A standards. Further, the average particle size is more preferably 0.
When the thickness is from 0.01 to 0.5 mm, and less than 0.01 mm, the workability of the pavement material deteriorates, and when it is more than 2.5 mm, the strength of the pavement material decreases. Further, the compounding amount is more preferably 15 to 30% by weight based on the total compounding amount. ,

According to a second aspect of the present invention, in the elastic pavement material according to the first aspect, the difference in the coefficient of sliding friction between a wet state and a dry state is 0.8. It is to be as follows.

According to the second aspect of the present invention, the difference between the coefficient of sliding friction between the wet state and the dry state is set to 0.8 or less, so that the emergency braking in the dry state can be performed. The risk of falling ahead is reduced.

According to a third aspect of the present invention, in the elastic pavement according to the first or second aspect, the maximum value in the temperature dependence curve of the damping coefficient tan δ is used as a binder. At least one uses a binder present at 10 ° C. or higher.

According to the third aspect of the present invention, 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, so that the road surface is improved. Can further increase the sliding friction coefficient in a wet state, and can further shift the inflection point to a higher speed side.

A structural feature of the invention according to claim 4 is a pavement material formed by mixing and molding an elastic aggregate and a binder and laying on a roadbed 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 more, and the sliding friction coefficient in a wet state is 0.4 or more. .

In the invention according to claim 4 configured as described above, by using 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 more as the binder, The coefficient of sliding friction in a wet state can be increased, and the inflection point can be shifted to a higher speed side.

According to a fifth aspect of the present invention, in the elastic pavement material according to the fourth aspect, the difference between the coefficient of sliding friction in the wet state and the dry state is 0.8. It is to be as follows.

In the invention according to claim 5, the difference in slip friction coefficient between a wet state and a dry state is set to 0.8 or less, so that a sudden braking operation in a dry state can be performed. The risk of falling ahead is reduced.

According to a sixth aspect of the present invention, there is provided an elastic pavement material according to any one of the first to fifth aspects, wherein a drainage surface is provided on a contact surface of the pavement material with the roadbed. That is, a groove is provided.

According to the sixth aspect of the present invention, the drainage groove is provided on the contact surface of the pavement material with the roadbed, so that the drainage of water absorbed by the pavement material during rainfall or the like. Since the drainage is performed efficiently, it is possible to suppress the emergence of water from the pavement material when the vehicle travels. As a result, according to the invention of claim 6, in addition to the effects of the invention of claims 1 to 5, it is possible to more effectively suppress a decrease in the road surface friction coefficient during braking of the vehicle,
Hydroplaning phenomenon can be suppressed. Further, since the drainage is performed smoothly, it is possible to suppress a decrease in the strength of the pavement material and the adhesive strength with the roadbed.

According to a seventh aspect of the present invention, there is provided a structural feature of the invention, wherein the elastic pavement according to any one of the first to sixth aspects is in contact with an elastic pavement of a roadbed. That the surface has a drain.

With the above-described construction of the invention, the drainage grooves provided in the roadbed can efficiently drain the water absorbed by the elastic pavement material during rainfall or the like. It is possible to suppress the emergence of water from the paving material when the vehicle is running. As a result, in addition to the effects of the elastic pavement material according to claims 1 to 6, a decrease in the coefficient of sliding friction of the road surface during braking of the vehicle can be further suppressed,
Hydroplaning phenomenon can be suppressed. Further, since the drainage is performed smoothly, it is possible to suppress a decrease in the strength of the elastic pavement material and the adhesive strength with the roadbed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an elastic pavement material (hereinafter referred to as an "elastic pavement material") to be laid on a roadbed for driving a car.
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 the roadbed.

The paving material 10 is a flat plate having a thickness of 20 to 50 mm, and a rubber chip (a spindle type,
Mesh type, rough type, etc.), a urethane-based binder, and silica sand as the third component material. Silica sand has a hardness of 90 or more based on JIS A, an average particle size of 0.01 to 2.5 mm, and a compounding amount of 5 to 35% by weight based on the total compounding amount including the elastic aggregate and the binder.
Are satisfied. The third component material is not limited to silica sand, but may be another inorganic material or an organic material, and may be a mixture of a plurality of types without being limited to one type of material. The binder is desirably a urethane-based binder in which at least one of the maximum values in the temperature dependence curve of the attenuation coefficient tan δ is at 10 ° C. or higher, but is not particularly limited to an epoxy-based binder. These three types of materials are mixed with a stirrer, weighed so as to have a porosity of 40%, put into a mold, and the mold is placed in a hot press for 1 hour.
The film is cured by heating at 50 ° C. for 20 minutes. However, the molding conditions (molding method, temperature and time) are not limited thereto.

The pavement 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 thickness of the pavement material is about 30 mm) on the contact surface side with the roadbed 13. As shown in FIG. 2, it is desirable that the drain groove 11 is inclined at an angle that is not simultaneously depressed by both wheels of the vehicle, and the wheel on the road center C side of the vehicle is formed before the wheel on the road shoulder K side. It is provided at an angle that allows it to pass. The pavement material 10 is laid by adhering to a concrete or asphalt roadbed 13 provided on the ground surface 14 using an adhesive 12 such as an epoxy-based or urethane-based material, thereby forming a drainage elastic pavement structure.

Since the silica sand contained in the pavement material 10 satisfies the predetermined three conditions, the slip friction coefficient of the pavement material in a wet state is a high value of 0.4 or more, and the wet state and the dry state And the inflection point of the sliding friction coefficient can be shifted to a higher speed side. As a result, braking of vehicles on a wet road surface during rainfall etc. can be made closer to braking of a vehicle on a dry road surface while ensuring noise absorption and drainage of the pavement material, and the slip prevention effect is enhanced. As a result, operational stability during rainfall can be ensured. Further, as a binder, an attenuation coefficient t
By using a binder in which at least one of the maximum values in the temperature dependency curve of anδ exists at 10 ° C. or more, the coefficient of sliding friction in a wet state of the road surface can be further increased, and the inflection thereof can be achieved. Points can be shifted further to higher speeds.

Further, by providing the drainage grooves 11 in the pavement material 10, it is possible to drain water permeated into the pavement material 10, and the pavement material 1 is driven by the running of the vehicle during rainfall or the like.
0 can be prevented from floating on the surface of the pavement 0, the strength of the pavement material 10 can be ensured, and a decrease in the sliding friction coefficient during braking of the vehicle can be suppressed. In particular, the drain groove 11 is inclined at an angle that is not simultaneously depressed by both wheels of the vehicle, and is arranged such that the wheel on the road center C side of the vehicle passes through the drain groove 11 before the wheel on the road shoulder K side. As a result, there is a time difference between the pressing of the two wheels on the drain groove 11, so that the water in the drain groove 11 can be efficiently drained to the side of the road K by the left and right wheels.

In the above embodiment, the paving material 10
(1) contains silica sand satisfying the three conditions, (2) at least one of the maximum values in the temperature dependence curve of the attenuation coefficient tan δ of the binder exists at 10 ° C. or more, and (3) drainage There are grooves, but of these,
Only one of (1) and (2) may be satisfied. Also in this case, as in the embodiment, the sliding friction coefficient in the wet state of the pavement material is 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 0.1%.
8 and the effect of shifting the inflection point of the sliding friction coefficient to the high speed side can be obtained.

Next, a specific example according to the above embodiment will be described. (1) The above three conditions of the third component (hardness, average particle size, blending amount with respect to all blended materials), (2) at least one of the maximum values in the temperature dependence curve of the damping coefficient tanδ as a binder.
One exists at 10 ° C. or higher, and (3)
). Ten types of Examples 1 to 10 in which the three requirements of providing a drain were provided were prepared. Seven comparative examples were prepared for Examples 1 to 10. Combinations of the respective requirements for these examples are shown in Tables 1 and 2 below, and combinations of the respective requirements for the comparative examples are shown in Table 3 below. In Tables 1 to 3, arrows ←
Indicates that they are the same as the numerical values on the left.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

As shown in Tables 1 and 2, Examples 1 to 6
Are different values for the requirement (1), but satisfy the requirement, and the damping coefficient ta of the binder is satisfied.
For the maximum value in the temperature dependence curve of nδ, −40 ° C.
Requirement (2), and there is no drain. In Examples 7 and 8, 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 satisfied the above requirement (2). Not provided. Example 9
Satisfies requirements (1) and (2), but does not have a drain. Example 10 satisfies all requirements (1) to (3).

In Comparative Example 1, the third component was not contained, the maximum value in the temperature dependence curve of the damping coefficient tan δ of the binder was −40 ° C., and did not satisfy the requirement (2). Is not provided. In Comparative Examples 2 to 6, one of the requirements (1) was out of value, the maximum value in the temperature dependence curve of the damping coefficient tan δ of the binder was −40 ° C., and the drain was also Not provided. In Comparative Example 7, the third component was not contained, the maximum value of the damping coefficient tan δ of the binder in the temperature dependence curve was 5 ° C., which did not satisfy the requirement (2), and a drain was also provided. Absent.

In the above Examples and Comparative Examples, the tensile strength indicating the adhesive strength of the elastic pavement material 10 to the roadbed 13, the coefficient of sliding friction when the road surface is wet and its inflection point, and the inflection point when the road surface is dry Tests were performed on the coefficient of sliding friction of the steel, the difference between the coefficient of sliding friction between the dry state and the wet state, and workability. For measurement of sliding friction coefficient, 50c
mx50cmx30mm thickness flat test piece (after molding,
ASTM using a DF tester (manufactured by Sunny Koken Co., Ltd.) with water flowing over the sample surface in an area of 80 km / h or less using a sample that has been left at room temperature for 3 days or more.
Performed according to E1911-98. Further, the tensile strength was measured according to JIS K6251. Further, the workability was determined based on the state of dispersion of the material during stirring. The test results are shown in Tables 1 to 3 above.

As is clear from the tenth embodiment, if all of the requirements (1), (2) and (3) are satisfied, the coefficient of sliding friction when the road surface is wet is 0.55, which is a variation. A very good result of a curved 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. Further, the tensile strength was 17 kgf / cm ² , and the workability was also good. Example 10
FIG. 4 shows the relationship between the speed (km / h) and the sliding friction coefficient in a wet state for Comparative Example 1 and Comparative Example 1. Further, as shown in Example 9, even when the requirements (1) and (2) are satisfied, the sliding friction coefficient when the road surface is wet is 0.52, and the inflection point is 27 km / h. The difference between the coefficient of sliding friction in the dry state and the coefficient of sliding friction in the wet state was 0.65, which was a very good result, and the tensile strength and workability were also good.

As is clear from the above Examples 1 to 6, if only the requirement (1) is satisfied, the coefficient of sliding friction when the road surface is wet is 0.4 or more and the inflection point is 20 k.
m / h, and the difference in the sliding friction coefficient between the dry state and the wet state is 0.66 to
0.78. The tensile strength varied, but was 12 kgf / cm ² or more, and the workability was good.

Further, as is apparent from Examples 7 and 8, even if the third component material is not contained and the drain is not provided, the attenuation coefficient tan is used as a binder.
At least one of the maximum values in the temperature dependence curve of δ is 10
As long as the requirement (2) of being at or above C 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 between the dry state and the wet state is 0.76.
0.78. Also, the tensile strength and workability were good.

On the other hand, Comparative Examples 3 and 4
In Examples 6 and 6, the coefficient of sliding friction when the road surface is wet is 0.
Although good values of 4 or more were obtained, the workability of Comparative Examples 3 and 6 was significantly 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 a material. In the other comparative examples, the sliding friction coefficient itself was insufficient, being significantly lower than 0.4.

From the above experimental examples and comparative examples, by satisfying any one of the above requirements (1), (2) and (3), the sliding friction coefficient of the pavement material in a wet state is 0.4.
As described above, the difference in the coefficient of sliding friction between the dry state and the wet state is 0.8 or less, and the tensile strength is 10 kgf / cm.
It became clear that a pavement material having a workability of ² or more and good workability was obtained. On the other hand, the above requirements (1), (2),
If none of (3) is satisfied, any of the pavement material has a wet friction coefficient of 0.4 or more, a tensile strength of 10 kgf / cm ² or more, and good workability. Due to the chipping, a result that could be provided as a pavement material was not obtained.

As another embodiment of the present invention, FIG.
As shown in FIG. 2, a drain groove 15 is provided on a contact surface of the roadbed 13 with the pavement material 10 on which the elastic pavement material 10 shown in the above embodiment is laid. The drainage grooves 15 provided in the roadbed 13 can efficiently drain the water absorbed by the pavement material 10 when wet such as rainfall, similarly to the drainage grooves 11 provided in the pavement material 10, It is possible to suppress the emergence of water from the paving material when the vehicle is running. Therefore, in addition to the effect of providing the pavement material 10, a decrease in the sliding friction coefficient of the road surface during braking of the vehicle can be further suppressed. In addition, because drainage is performed smoothly,
It is possible to suppress a decrease in the strength of the elastic pavement material and the adhesive strength with the roadbed. In addition, when the strength of the pavement material 10 is not affected in addition to the provision of the drainage groove 15 in the roadbed 13, the drainage groove 11 can also be provided in the pavement material 10, thereby further improving drainage. be able to.

The use of the pavement material is not limited to road use, but can also be used for promenades, stadium fields, and the like.

[Brief description of the drawings]

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

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

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

FIG. 4 is a graph showing a relationship between a vehicle speed and a coefficient of sliding friction in a wet state of a road surface in Example 10 and Comparative Example 1.

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

[Explanation of symbols]

10 ... elastic paving material, 11 ... drain, 12 ... adhesive, 13
... roadbed, 14 ... ground, 15 ... drain.

Continued on the front page (72) Inventor Tetsuji Narazaki 3-1-1 Higashi-Higashi, Komaki-shi, Aichi Prefecture (72) Inventor Fumiari Shizumi 3-1-1 Higashi 3-chome, Komaki-shi, Aichi F-Term (Reference) 2D051 AA02 AA06 AA08 AE06 AF03 AF06 AF07 AF09 AG01 AG03 AG13 AG14 AG19 DA01 DA11 DB01

Claims (7)

[Claims] 1. A pavement material formed by mixing and molding an elastic aggregate, a binder, and a third component material and laying on a roadbed to form an elastic pavement, wherein the third component material is a hard material. Is 90 or more based on JIS A, 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.
An elastic pavement material which satisfies the three conditions of 35% by weight and has a coefficient of sliding friction of 0.4 or more in a wet state. 2. The elastic pavement material according to claim 1, wherein a difference in a coefficient of sliding friction between a wet state and a dry state is 0.8 or less. 3. An extinction coefficient tan as the binder.
At least one of the maximum values in the temperature dependence curve of δ is 10
The elastic pavement material according to claim 1 or 2, wherein a binder present at a temperature of at least C is used. 4. A pavement material formed by mixing and molding an elastic aggregate and a binder, and laying on a roadbed to form an elastic pavement, wherein the binder has a temperature dependence curve of an attenuation coefficient tan δ. An elastic pavement material characterized by using a binder in which at least one of the maximum values is present at 10 ° C. or higher, and having a sliding friction coefficient in a wet state of 0.4 or higher. 5. The elastic pavement material according to claim 4, wherein a difference in a sliding friction coefficient between a wet state and a dry state is 0.8 or less. 6. The pavement material according to claim 1, wherein a drain groove is provided on a contact surface of the pavement material with the roadbed.
The elastic pavement material according to any one of the above. 7. The method according to claim 1, wherein
An elastic pavement structure, characterized in that a drainage groove is provided on a surface of a roadbed on which the elastic pavement material according to the above item is laid, in contact with the elastic pavement material.