JP2920815B2 - Elastic perforated pavement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic porous road surface pavement used for the purpose of preventing freezing on a road surface such as a road on which vehicles pass.

[0002]

2. Description of the Related Art Conventionally, a drug has been used as a measure to prevent roads from freezing. This method requires trouble and cost to execute. Therefore, the present invention provides a freezing prevention measure that does not require any trouble. In other words, even if the road surface is given elasticity and freezes, the surface is deformed by the weight of the traveling vehicle, thereby breaking the ice on the surface and changing from a smooth ice pan state to a sherbet-like small ice aggregate. The state is changed to the following state.

[0003] Further, the present invention is to make the pavement porous and water-permeable so that the melted water or rainwater does not form a puddle, and to reduce the rebound of rain even during heavy rain.

Conventionally known elastic porous pavement is mainly used for the surface of an athletic field,
It does not withstand heavy loads such as the road on which vehicles travel. In addition, conditions such as water content and temperature are strict in the construction, and it is difficult to perform the construction under various conditions such as a road. Therefore, the present invention withstands heavy loads,
Further, the purpose of the present invention is to obtain an elastic porous pavement having gentle construction conditions.

[0005]

According to the present invention, a particle size of 4 to 2 is provided.
A large aggregate made of 0 mm stone, a stone having a particle size of less than 4 mm, a small aggregate made of sand and a small piece or powder of rubber ,
This is an elastic porous road surface pavement which is kneaded with a polyurethane having an appropriately set curing time and bonded to each other without forming bubbles .

As this polyurethane, a one-component moisture-curing type is suitable, and its curing time is preferably 30 minutes to 48 hours, more preferably 6 to 24 hours. As the one-component moisture-curable polyurethane, those having an isocyanate content of 20% by weight or less are suitable.

Hereinafter, the present invention will be described more specifically together with a construction method.

[0008] First, the ground is leveled in the same manner as ordinary asphalt pavement. The surface is gravel, sand,
In the case of renovation, asphalt and concrete pavement can be used as they are. It is desirable that the substrate has a water permeability or an appropriate gradient to speed drainage. The soil is not suitable because it is deformed by the load.

Next, a large aggregate made of a stone having a particle diameter of 4 to 20 mm, a stone having a particle diameter of less than 4 mm, a small aggregate made of sand, a small piece or powder of rubber, and polyurethane are kneaded. Aggregate is important for ensuring the strength and abrasion resistance of the finished pavement, and is also exposed to the surface to prevent slippage.
The large-sized aggregate forms a porous structure, and it is appropriate that the large-sized aggregate is sharp and hard such as crushed stone so as to mesh with each other to form a gap, and has a particle size of about 4 to 20 mm, preferably 6 to 15 mm. It is good to be about. The small aggregate is made of stone or sand having a particle size of less than 4 mm, and sand having a particle size of about 2 mm or less is desirable. The small rubber particles or powders impart elasticity to the pavement and are exposed to the surface to provide an anti-slip effect, and those having a fine particle size to about 20 mm are suitable. Fine particles are effective for reducing the amount of expensive polyurethane used, and have a particle size of 4-20.
Since a large-sized one having a size of mm is effective in forming a porous structure and providing elasticity similarly to a large-sized aggregate, it is desirable to use both a fine one and a large-sized one. This rubber may be any of natural rubber and synthetic rubber, and a rubber formed by grinding a waste tire or the like can be used. Polyurethane binds aggregate and rubber. Details will be described later.

[0010] The proportions of these components are generally as follows: large aggregate,
The weight ratio of the small aggregate, rubber, and polyurethane is preferably approximately equal, that is, about 1: 1: 1: 1. This ratio can, of course, be varied, with large aggregates of 6-40.
%, Small aggregate of 10 to 50%, rubber of 10 to 50%, and polyurethane of 8 to 30%.
Since the polyurethane binds the aggregate and the rubber, an appropriate amount of binding the polyurethane and the rubber so as not to be excessive is appropriate, and the specific ratio may be determined by experiments. Excessive polyurethane will fill gaps and reduce water permeability, so it is desirable to minimize it.

For kneading, as in the case of asphalt pavement, a pug mill type batch asphalt plant can be used as it is. Of course, other kneading devices can be used. At this time, each material may be usually at room temperature,
Depending on the properties of polyurethane, large aggregates and small aggregates having a large heat capacity may be heated.

Next, the kneaded material is laid on a base. At this time, the base does not need to be completely dry, but must not be in a water-soaked state. Moderate moisture is desirable for the pavement to stick. For this laying, a normal laying machine can be used as it is. The thickness of the pavement can be arbitrarily set, but is suitably about 15 to 25 mm. Rolling is not essential, but rolling with a lightweight roller is effective because it smoothes the surface and strengthens the mechanical engagement of the aggregate and rubber inside.

It is important that the polyurethane used in the present invention has no bubbles inside when cured. The presence of bubbles causes a decrease in strength, peeling and separation of large aggregates, and damage to the entire pavement. Polyurethane generates carbon dioxide at the time of curing, and has a property of easily generating bubbles. Therefore, in the present invention, it is necessary that the amount of generated carbon dioxide is small and the generated carbon dioxide is satisfactorily released to the outside.

As a polyurethane satisfying such requirements, a one-component moisture-curable polyurethane, particularly, a curing time of 30 minutes to 4 minutes
A time of 8 hours, preferably 6 to 24 hours is suitable. The two-component type cures quickly and generates bubbles. A moisture-curing type is convenient for use because it is gradually cured by moisture contained in the air or in stone, sand or the like. When the curing time is set as described above, the generation of carbon dioxide is gradual, the carbon dioxide is satisfactorily released to the outside, and no bubbles are generated. If the curing is too slow, it will be inconvenient for construction. To set the curing time as described above, the isocyanate content must be 20
It should be less than weight percent. The curing speed can be adjusted by using various commercially available additives. The specific components of the polyurethane are not particularly limited. For example, those obtained by polyaddition of poly-prepolymer-isocyanate and xylene and crosslinking reaction, that is, tetramethyl-xylene-di-isocyanate Can be used.

[0015]

The present invention will be specifically described below with reference to examples. Each material is kneaded in the following ratio (weight ratio). Large aggregate (average particle diameter 13 mm) 28% Small aggregate (sand and stone (average particle diameter 2 mm)) 30% Rubber (small pieces (average particle diameter 1.4 mm) and powder) 25% Polyurethane 17% Used here Polyurethane is, for example, "Polytan (P
polytan "" (trademark) (Polytan, Po
lytan). Additives that promote curing and suppress the generation of carbon dioxide, such as "INCOREZ 700" (trademark)
(Industrial Copolymers, UK
trial Copolymers Ltd. )
Is added in an appropriate amount, and the curing time is adjusted to 24 hours before use. In addition, the ratio of polyurethane can be changed to about 10 to 30% by weight according to the particle size of the aggregate and rubber.

The above kneaded material is put on a gravel substrate for 20 minutes.
Pave at a thickness of mm. The curing is completed in about 24 hours.
At this time, no bubbles are generated in the polyurethane. It was confirmed that when the vehicle passed over the pavement, the vehicle was dented by elasticity, and in a frozen state, the ice was broken by this deformation. Also, the water flows down very well and does not create puddles.

[0017]

As described above, the pavement of the present invention uses small pieces of rubber, powder, and polyurethane, and has an elasticity, but also contains aggregates such as stone and sand, and can withstand heavy loads. And has high abrasion resistance. In addition, since it has elasticity, when the surface freezes, it is deformed by the load of a passing vehicle, cracks the ice, makes it less slippery, and can be melted. Moreover, because it is porous,
It has water permeability, does not create water pools, and has little splash of water even in heavy rain.

Further, the use of the one-component moisture-curable polyurethane makes kneading and construction easy, and by setting the curing time relatively late, carbon dioxide can be satisfactorily released to the outside. The generation of bubbles can be prevented.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-195507 (JP, A) JP-A-5-93406 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E01C 11/24 E01C 7/30

Claims (3)

(57) [Claims] 1. A large aggregate made of a stone having a particle size of 4 to 20 mm, a small aggregate made of a stone having a particle size of less than 4 mm, a small aggregate made of sand, and a small piece or powder of rubber are cured for 30 minutes to 48 hours. Knead with a one-part moisture-curable polyurethane,
Elastic porous road surface pavement that is bonded to each other without forming bubbles . 2. A hardening time of a large aggregate made of a stone having a particle size of 4 to 20 mm, a small aggregate made of a stone having a particle size of less than 4 mm, a small aggregate made of sand and rubber or a powder is 6 to 24 hours. kneaded with one-pack moisture curable polyurethane, bubbles
An elastic porous road surface pavement that is bonded to each other without forming a surface. 3. The elastic porous road pavement according to claim 1, wherein the one-component moisture-curable polyurethane has an isocyanate content of 20% by weight or less.