JPS6128762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in pavement structures for all-weather athletic fields, such as tennis courts and racing tracks, which have an elastic surface layer mainly made of natural rubber, synthetic rubber, or synthetic resin. It is.

In recent years, when there is a large amount of rainfall,
In addition to the unavoidable suspension of competition due to the water content of the soil, there are also inconveniences in terms of maintenance and management of the stadium, such as having to wait for a long time even after the rain has stopped before competition can resume. Therefore, in order to solve this problem, a so-called all-weather pavement structure for sports stadiums (hereinafter simply referred to as an all-weather pavement structure) was proposed, which is made of water-impermeable elastic pavement made of natural rubber, synthetic rubber, etc. Its maintenance management is extremely easy,
It is attracting attention in the industry for its advantages such as less fatigue in athletes' legs due to its moderate elasticity.

Although the above-mentioned known water-impermeable elastic pavement structure has the advantage of being non-water-absorbing and extremely easy to remove water, it also has the advantage of being extremely easy to remove water. It is extremely slippery when worn, and the surface is covered with a water-impermeable elastic layer, so in summer or winter, the elastic surface layer partially lifts due to the expansion pressure caused by the evaporation or freezing of the moisture contained inside. There are disadvantages such as the phenomenon that occurs. Among these drawbacks, the problem of slipperiness due to water leakage can be solved to some extent by making the surface of the elastic surface layer anti-slip, but in the case of a small amount of rainfall as mentioned above, the problem of slipperiness due to water leakage can be solved to some extent. It is said that this type of pavement is more advantageous because it absorbs rainwater.In order to take advantage of this soil pavement structure, instead of the non-water permeable elastic pavement structure, a water permeable elastic surface layer containing extremely fine pores and its An all-weather pavement structure has also been proposed in which a permeable foundation layer such as an open-grained asphalt concrete layer or a millet layer is formed as the lower layer, and a drainage structure is formed in the lowest soil layer. (For example, see West German Patent Publication No. 1534345.) However, when adopting the above-mentioned structure with a permeable elastic surface layer and a permeable foundation layer, the soil bed layer forms a drainage structure due to the water that permeates through each layer. However, this may result in partial collapse or structural failure of the soil bed layer due to weakening or the washing away of soil through the drainage structure, as well as expensive and labor-intensive work to form an effective drainage structure. In addition, fine dust and water enter through the fine pores of the water-permeable elastic surface layer, causing clogging and eventually causing loss of water-permeable performance. moreover,
The elastic granules (rubber chips) that form the water-permeable elastic surface layer must form fine voids between each granule in order to improve the performance of the surface layer, so the bonding force between the granules becomes weaker. It is easy to peel off and scatter from the surface layer due to the intense movement of players, and even though the entire pavement structure is made permeable, rainwater does not completely permeate downward, and the water permeability Since some of the water that has permeated remains in the voids in the surface layer, there are drawbacks such as the residual water oozing out to the surface again due to pressure from a player or the like, reproducing a wet state.

On the other hand, in the case of a known stadium surface whose surface layer has a water-impermeable elastic structure, it does not have the above-mentioned drawbacks of a water-permeable elastic surface layer, but has the problem of partial lifting of the surface layer as described above.

The present invention eliminates the drawbacks of such conventional all-weather pavement structures, combines adhesion and breathability,
We propose an all-weather pavement structure with excellent structural stability and durability, especially for sports stadiums, which is well suited to Japan's rapidly changing climate such as strong sunlight in midsummer and harsh natural environment in winter. The all-weather pavement structure according to the present invention has a subgrade layer made of grain-sized crushed stone, etc. on the roadbed, and an open-grained asphalt layer having sufficient voids to absorb the expansion pressure of underground moisture.
An open pavement layer made of concrete or cement/concrete, and an impermeable elastic surface layer made of natural rubber, synthetic rubber, or synthetic resin as the main material, mixed with granular elastic bodies such as rubber particles, and other inorganic fillers. It is characterized by being constructed by sequentially laminating layers.

Hereinafter, the present invention will be explained with reference to an exemplary structure shown in the accompanying drawings. The all-weather pavement structure (for sports stadiums) according to the present invention is formed to a thickness of about 150 mm to 300 mm on a high-quality subgrade 1 as a foundation. A so-called water-permeable open-grain asphalt concrete is constructed by mixing a roadbed layer 2 made of grain-sized crushed stone, etc., aggregate with a maximum grain size of about 5 mm to 20 mm, and asphalt in an appropriate ratio, and containing fine voids. or an open pavement layer 3 made of water-permeable concrete mixed with the aggregate and cement in an appropriate ratio and similarly configured to contain microscopic voids, and natural rubber, synthetic rubber, or ethylene/vinyl acetate. Main material is synthetic resin such as copolymer resin, acrylic resin, urethane resin, epoxy resin, etc., and a water-impermeable elastic surface layer 4 made of mixed granular elastic material such as rubber particles and other inorganic fillers is sequentially laminated. and configured.

As shown in the figure, the open pavement layer 3 is a first layer 3a using aggregate having a relatively large diameter within the particle size range.
and a second layer 3b using relatively small-diameter aggregate, and the overall construction is approximately
Although the paving layer 3 was formed to have a thickness of 70 mm, it is an important requirement in the present invention that the pavement layer 3 has an appropriate amount of fine voids and is open.

As mentioned above, the water-impermeable elastic surface layer 4 is made of natural rubber,
The main materials are synthetic rubber and synthetic resin, but when forming the elastic surface layer, these main materials can be used in a latex mold and painted, or they can be formed in advance into a sheet mold of the required thickness. It is also possible to form a layer on the open pavement layer 3 via an adhesive layer.

The water-impermeable elastic surface layer 4 was formed to have a total thickness of about 6 mm, but in the illustrated example, the base elastic layer 4 was formed to a thickness of about 5 mm using rubber latex mixed with granular elastic material, and the same material. Thus, a three-layer structure was formed consisting of an intermediate layer for correcting the surface unevenness of the base elastic layer, and a surface layer whose surface was finished with a rubber-based paint colored in a desired color.

As explained above, the all-weather pavement structure for sports stadiums according to the present invention is made in particular by using natural rubber, synthetic rubber, or synthetic resin as the main material on the upper surface of the open-type pavement layer 3 containing appropriate microscopic voids. Since this is formed with a water-impermeable elastic surface layer 4 made by mixing granular elastic bodies such as rubber particles, it not only exhibits soft elasticity but also prevents rainwater etc. from penetrating into the lower layer. Therefore, structural instability such as the soil subgrade 1 becoming soft due to water absorption or partial collapse due to washed away earth and sand is eliminated, and forming a drainage structure on the subgrade 1 is expensive and time-consuming. Work can be omitted.

Furthermore, the fluid materials such as rubber latex, which is the main material of the water-impermeable elastic surface layer 4, and the adhesive layer penetrate into the voids of the open pavement layer 3 below, exerting an anchoring effect on the pavement layer. However, as the moisture contained in the ground evaporates in summer, the elastic surface layer 4
It is possible to prevent an inconvenient situation such as when a partial lifting phenomenon occurs.

The expansion pressure accompanying the evaporation of the moisture contained in the ground is also dispersed and pressurized toward the side of the open pavement layer 3 because it contains microscopic voids, and as a result, the elastic surface layer 4 is partially compressed. It is also possible to prevent the phenomenon of target floating.

In addition, in the pavement structure of the present invention, the asphalt content of the open-grained asphalt concrete used for the open pavement layer is usually set to coarse grain, dense grain,
Asphalt content in impermeable asphalt concrete such as modified Topeka is 6% to 8%.
However, since it was set at 4% to 5%,
It guarantees sufficient dimensional stability against the heat increase caused by strong sunlight in midsummer.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the all-weather pavement structure for an athletic stadium according to the present invention. 1... Roadbed, 2... Roadbed layer, 3... Open pavement layer, 3a... First layer, 3b... Second layer, 4... Impermeable elastic surface layer.

Claims (1)

[Claims] 1. On the roadbed, a roadbed layer made of granulated crushed stone, etc., and an open pavement layer made of open-grained asphalt concrete or cement concrete that has sufficient voids to absorb the expansion pressure of underground moisture;
It is characterized by being constructed by sequentially laminating natural rubber, synthetic rubber, or synthetic resin as the main material, and a water-impermeable elastic surface layer made of a granular elastic material such as rubber particles and other inorganic fillers mixed therein. Pavement structure for all-weather athletic fields.