JP2000319501A - Elastic paving material for low noise and execution of elastic paving for low noise - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic paving material for a low noise having a structure in which hard aggregate is bonded to elastic aggregate with a urethane binder, in relating to paving applied to a driveway and characterized by a low noise and a vibration-reducing effect caused by the elasticity, air permeability and noise-absorbing property. SOLUTION: This elastic paving material for a low noise is composed of hard aggregate, elastic aggregate and a urethane binder bonding them, and a content of the hard aggregate in the whole aggregate is 10-75 vol.% and a two pack-type urethane binder is used as the urethane binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pavement which is applied to a road and is characterized by low noise and vibration reduction effect by elasticity, air permeability and sound absorbing property, wherein a hard aggregate and an elastic aggregate are bonded with a urethane binder. TECHNICAL FIELD The present invention relates to a low-noise elastic pavement material having a reduced structure and a construction method thereof.

[0002]

2. Description of the Related Art Conventionally, pavement materials in which rubber chips are combined with a binder are characterized by high elasticity, and have been mainly used on sidewalks and stadiums in terms of shock absorption when walking and safety when falling down. I have. On the other hand, there is a drainage pavement as a pavement material for a road that exhibits low noise properties, and it is known that tire noise is reduced by air permeability and sound absorption due to the presence of a gap.

However, a pavement material in which rubber chips are bonded with a binder has a large amount of deflection against a load, and has a problem in the handling stability of a vehicle when used for a road, and a problem that the tire becomes slippery when wet. There is.
Further, there is a problem that it is difficult to be applied to a road due to low strength.

[0004] On the other hand, drainage pavement generally has a noise reduction effect of about 3 dB in noise level in order to reduce tire noise due to air permeability and sound absorption due to voids.
It is difficult to obtain a further noise reduction effect.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an elastic, rigid and elastic aggregate bonded by a urethane binder.
It is an object of the present invention to provide a low-noise elastic pavement material having a low noise property due to air permeability and sound absorption properties and a vibration reducing effect due to elasticity, and a method for constructing the same.

[0006]

A first gist of the present invention is as follows.
A hard aggregate, an elastic aggregate, and a urethane binder binding them are used. The proportion of the hard aggregate in the total aggregate is 10 to 75% by volume, and a two-component urethane binder is used as the urethane binder. A second aspect of the present invention is a low-noise elastic pavement material in which a road surface is cut and / or blasted by shot blasting, and then a primer is applied to the surface. Aggregate, elastic aggregate, urethane binder and the like are mixed by a mixer to obtain a mixture, the mixture is laid on the road surface, and thereafter, a pavement construction method in which compaction is performed. Of which hard aggregate accounts for 10 to 75% by volume
And a low noise elastic pavement construction method using a two-component urethane binder as the urethane binder.

In the present invention, 10 m is used as the elastic aggregate.
It is preferable to use a rubber chip material having a size of not more than m, and a colored rubber chip can be used as a part or all of the rubber chip material. On the other hand, a hard aggregate having a component passing through a 1.18 mm sieve in a weight of 5% or more is preferable. On the other hand, as the binder, a two-component urethane binder is used, which uses a polyol for the isocyanate group-terminated prepolymer.
It is advisable to add weight percent of organosilane.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described mainly with respect to the first invention.
The main noise is caused by the vibration generated by the contact between the tire tread and the road surface, and the noise caused by the vibration of the tread pattern and sidewalls and the resonance between the sound generated by the grooves such as rib grooves and lug grooves and the road surface. Source.

However, when there is a gap on the road surface such as a drainage pavement, resonance in the latter groove is less likely to occur, so that the noise itself is reduced, and the noise is reduced by the effect of sound absorption.

In the pavement material of the present invention, excellent elasticity is imparted, so that the vibration is interfered and the former noise is reduced, and the same noise reduction effect as the drainage pavement material due to the void can be expected. It is.

With respect to elasticity, a pavement material in which rubber chips are bonded with a binder is rich in elasticity and has a high noise reduction effect by providing an air gap, but has a large amount of deflection against a load. In this case, the turning response of the vehicle at the time of steering is delayed due to the deflection of the road surface, and the steering stability of the vehicle is significantly impaired, and the slip resistance when wet is lower than that of a normal road surface. There is. Further, the strength is not enough.

Here, in terms of slip resistance, the amount of hard aggregate determines the slip resistance, and hard bone is required to secure a slip resistance of BPN (measured with a portable skid resistance tester) of 60 or more. It is necessary that the amount of the aggregate be 10% or more of the whole aggregate (Fig. 7). If this ratio is small, not only the slip resistance but also the amount of deflection due to the vehicle weight increases, which affects the steering stability. give. On the other hand, if the amount of the hard aggregate is too large, the elasticity is impaired and the low noise performance is adversely affected (FIG. 7). Therefore, the amount of hard aggregate is 10% of the whole aggregate.
To 75% (volume ratio), preferably 50 to 75% (volume ratio). Further, as shown in FIG. 8 (slip resistance measured with a DF tester), the particle size of the hard aggregate is 1.1.
It is desirable that a fine particle component of 5% or more is contained as a weight ratio through an 8 mm sieve, and the fine particle component has a rough surface like a sandpaper and provides an anti-slip effect.

The hard aggregate generally includes, for example, natural aggregates such as river gravel and river sand and artificial aggregates such as crushed stone, slag, and ceramics, and is not particularly limited. The stone, sand, etc. used for the hard aggregate ensure the strength and abrasion resistance of the pavement material, and are exposed on the surface to obtain an anti-slip effect. From the viewpoint of slip resistance, it is desirable that the particle size of the hard aggregate contains a fine particle component of 5% or more as a passing weight ratio of 1.18 mm. The surface is rough and provides an anti-slip effect.

The rubber chip, that is, a small piece or powder of rubber gives elasticity to the pavement, and a fine particle having a particle size of 1 mm or less to about 10 mm is suitable. It is preferable because it is effective for forming properties and gaps. The rubber chip may be either natural rubber or synthetic rubber, and may be formed by mechanically pulverizing a vulcanized rubber product such as a waste tire. Note that the hardness in the present invention is JIS A hardness, hard aggregate is 95 degrees or more, and elastic aggregate is 90 degrees or less in hardness. And the hardness of the waste tire is usually 60
It is about 70 to 70 degrees, and about 80 to 90 degrees if it receives heat.

The urethane binder is used for binding the aggregate to form a pavement material. It is preferable to use a two-component urethane dider, and the isocyanate group-terminated prepolymer and the polyol are prepared in an equivalent ratio of hydroxyl group / isocyanate group. For example, they are mixed at 0.2 to 0.8. As an example of the isocyanate group terminal prepolymer, the isocyanate content is 5 to 25%, and the viscosity is 1000 to 5000.
The average number of functional groups of CP (25 ° C.) and isocyanate terminal prepolymer is 2-3. Examples of the isocyanate for the prepolymer include diphenylmethane diisocyanate-based polyisocyanate. As the active hydrogen compound used for the modification, usually, a polyalkylene glycol having a molecular weight of 1,000 to 3,000 is used.

On the other hand, as an example of the polyol, it is preferable that the average number of functional groups is 2 to 6, the average molecular weight is 1,000 or less, and from the reactivity, at least half of the hydroxyl groups are primary hydroxyl groups, and ethylene glycol, diethylene glycol,
And polyalkylene ether glycols.

In many cases, the curing time is determined from the temperature at the time of construction and the time until traffic is opened, so that the curing time can be adjusted by the mixing ratio of the isocyanate group-terminated prepolymer and the polyol. For example, the equivalent ratio of hydroxyl group / isocyanate group Can be appropriately selected in the range of 0.2 to 1.0. In addition,
Although it is conceivable to use a one-component urethane binder as the binder, it is very difficult to adjust the curing time and it is not versatile. In comparison, a two-component urethane binder has an easy setting time. Another advantage is that the curing time can be generally shortened. Therefore, the present invention specifies that a two-component urethane binder is used. It is also possible to adjust the curing speed using a known amine-based or metal-based curing accelerator. It is desirable that the amount of the binder be mixed in the range of 15 to 30% by volume based on the bonding strength of the aggregate.

Further, by adding the organic silane to the urethane binder in an amount of 0.1 to 10% by weight, the bonding strength between the urethane binder and the aggregate can be increased, and the strength and durability can be improved. As the organic silane, an epoxy silane, a mercapto organic silane, or the like is used.

Further, when it is required to color the pavement material, it is possible to color the urethane binder by mixing a coloring agent. In that case, the colorant is preferably mixed with 1 to 10% by weight of the urethane binder. In addition, as a coloring agent, for example, carbon is used for black, and titanium is used for white. It is also possible to color the pavement material using colored rubber chips as elastic aggregates, for example, EPDM color rubber chips, or using artificial aggregates such as colored ceramics.

In the construction method, a binder is added and mixed to a place where hard aggregate and elastic aggregate are mixed to prepare a pavement material. The urethane binder may be a premix of an isocyanate group-terminated prepolymer, a polyol, a coloring agent, an organic silane, a curing accelerator, and the like, if necessary, or a mixture separately added and mixed. The method of adding the aggregate and the binder at the time of mixing may be any method as long as it can uniformly adhere. The temperature at the time of adding and mixing the binder may be room temperature, but if the temperature is low, the curing is delayed, and if the temperature is high, the curing is accelerated, so that the temperature may need to be adjusted.

[0021]

EXAMPLES The pavement was carried out according to the working steps described in the examples. FIG. 1 shows the outline of the working steps of the second low-noise elastic pavement construction method of the present invention. (1) Road surface cutting (cases 1 and 2): An existing pavement is cut to a predetermined depth by a road surface cutting machine. (2) Semi-flexible pavement construction (Case 1): After cutting existing asphalt pavement, semi-flexible pavement construction is performed. (3) Abrasive: Abrasive blasting by shot blasting (projection density 150 kg / m 2) is performed and used as a foundation for construction. (4) Primer work: Primer application is performed with a roller brush. (5) Mixture production: A hard aggregate, an elastic aggregate, a urethane binder and the like are mixed with a mixer to produce a mixture. The production of the mixture is performed in the vicinity of the construction site while moving together with the asphalt finisher. (6) Laying work: The mixture is spread at a rate of 0.5 to 1 m per minute by an asphalt finisher in anticipation of the excess. (7) Compaction work: Compaction is performed using a 2.5-ton tandem roller and a vibrating tumbler. (8) Open traffic: Open the traffic after confirming the curing of the mixture.

FIG. 2 shows the details of the mixture of the present invention. The measured slip resistance (BPN) and low noise (dB) are also shown in FIG. The low noise measurement was performed by measuring the noise near the tire when the vehicle was driven on a constructed road surface, and the difference (dB) between the noise level and the fine-grained pavement was defined as low noise. The higher the value, the better the noise reduction.

FIGS. 3 to 6 show structural examples of the construction cases 1 to 4 in FIG.

[0024]

According to the pavement material of the present invention, in addition to the air permeability and sound absorption due to the optimized voids, a great noise reduction effect can be obtained as compared with the porous pavement due to the excellent elasticity. It is.

[Brief description of the drawings]

FIG. 1 is a construction process diagram of a low noise elastic pavement material according to a second embodiment of the present invention.

FIG. 2 is a table showing details of a mixture according to the first embodiment of the present invention.

FIG. 3 shows a cross-sectional structure of a construction example case 1.

FIG. 4 shows a cross-sectional structure of a construction example case 2.

FIG. 5 shows a cross-sectional structure of a construction example case 3.

FIG. 6 shows a cross-sectional structure of a construction example case 4.

FIG. 7 is a graph showing a relationship between a hard aggregate content (%) in all aggregates and slip resistance (BPN) and low noise performance (dB).

FIG. 8 is a graph showing a relationship between a 1.18 mm sieve passing amount (%) and slip resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Fujita 3-13-1, Kyobashi, Chuo-ku, Tokyo Taisei Lo-Tech Co., Ltd. (72) Inventor Mandai Fukuda 3-3-1 Kyobashi, Chuo-ku, Tokyo Taisei Ro-Tech Co., Ltd. (72) Inventor Satoshi Kawasanada 2-403-1-18-302 (72) Inventor Kinji Masuda 3596-1 Maiokacho, Totsuka-ku, Yokohama-shi (72) Inventor Minoru Kuriki 1274-1-1-407 Totsuka-cho, Totsuka-ku, Yokohama F-term (reference) 2D051 AA06 AG03 AG13 AH03 FA01 FA06 FA10 4J002 AC002 CK021 DM006 EX007 FD012 FD016 FD097 GL00

Claims (11)

[Claims] The present invention comprises a hard aggregate, an elastic aggregate and a urethane binder which binds them, wherein the ratio of the hard aggregate to the total aggregate is 10 to 75% by volume, and the urethane binder is a two-pack type. An elastic pavement material for low noise, characterized by using a urethane binder. 2. The low noise elastic pavement material according to claim 1, wherein the elastic aggregate is a rubber chip material having a size of 10 mm or less. 3. The low-noise elastic pavement material according to claim 1, wherein a polyol is used as an isocyanate group-terminated prepolymer as a urethane component in the urethane binder. 4. The low noise resilient pavement material according to claim 1, wherein the hard aggregate has a weight of 5% or more passing through a 1.18 mm sieve. 5. The urethane binder has a content of 0.1 to 5%.
2. The low-noise resilient pavement material according to claim 1, wherein an organic silane is added in an amount of about 10% by weight. 6. The low noise resilient pavement material according to claim 1, wherein a coloring material is mixed with the urethane binder. 7. The low-noise elastic pavement material according to claim 1, wherein a colored rubber chip is used for part or all of the elastic aggregate. 8. A road surface surface is subjected to cutting and / or blasting by shot blasting, and then a primer is applied to the surface. On the other hand, hard aggregate, elastic aggregate, urethane binder and the like are mixed with a mixer. Mixing to obtain a mixture,
A pavement construction method in which the mixture is laid on the road surface and thereafter compaction is performed, wherein the ratio of hard aggregate to total aggregate is 10 to 75% by volume, and 2% as urethane binder. A low noise elastic pavement construction method using a liquid urethane binder. 9. The method of claim 8, wherein the elastic aggregate is a rubber chip having a size of 10 mm or less. 10. The hard aggregate having a weight of 5% or more passing through a 1.18 mm sieve is used.
The low-noise elastic pavement construction method according to the item. 11. The urethane binder has a content of 0.1 to 0.1%.
9. The low noise resilient pavement construction method according to claim 8, wherein 5% by weight of an organic silane is added.