JP2761711B2 - Stadium pavement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pavement material for an athletic field used for laying and paving at an athletic field. It is related to paving materials for places.

[0002]

2. Description of the Related Art In recent years, most of the approved athletic stadiums have been converted from natural grounds to all-weather artificial grounds. Paving a surface layer made of polyurethane elastomer on a substrate made of asphalt concrete. However, since the construction cost of artificial grounds is quite high, most of them are not constructed on general school playgrounds. For this reason, it is not possible for the athletic athletes to practice sufficiently on the officially recognized ground, and this has hindered the discovery and strengthening of new athletes, as well as school physical education. Therefore, in order to solve this, pavement materials that can easily obtain a state close to the ground, which is the same as that of the officially-certified all-weather stadium, have been studied simply by laying them on the existing natural sports ground. Japanese Patent Publication No. 290101 proposes a pavement material in which polyurethane chips of the same kind are fixed in a semi-buried state on the surface of a polyurethane sheet.

[0003] In the case of an officially recognized stadium, it is of course considered to reduce the burden on the human legs as the above-mentioned paving material, but it is inevitable to extend the record and to enable more delicate play. The pursuit has been made with the main purpose of.

[0004]

However, the condition of the pavement material that is optimal for the purpose of extending the recording is not necessarily the same as the condition that has little adverse effect on the human body.

That is, the above-mentioned pavement material can be said to be a convenient pavement material for a full-fledged athlete to use for the purpose of practicing in a state close to an official competition, but specially trains the body for competition. Certified all-weather stadium, even in situations where normal people do not use it (for example, athletic meet, jogging, etc.) Paving materials with specifications that pursue records close to are not sufficient in terms of preventing accidents such as adverse effects on bones and joints and falls during running. Therefore, there has been a demand for a pavement material that can maintain the performance required to extend the record as much as possible, has little adverse effect on the body, and can further prevent an accident such as a fall.

[0006] For the purpose of preventing falling, it is necessary to further increase the stability of the heel during running. In order to stabilize the heel, it is better that the amount of displacement of the heel when the leg reaches the pavement material (sink of the heel) is small.
However, there is generally a contradictory point that a material having a small displacement amount has a physical property that the impact energy absorption rate is small and a load is applied to the leg.

Further, conventional pavement materials generally have a high coefficient of friction when the weather is dry and are unlikely to slip, but have a problem that when wet, the coefficient of friction is extremely low and slips easily.

The present invention has been made in view of the above-mentioned situation, and in order to cope with the situation, in particular, paying attention to the characteristics of the pavement material, and finding the preferable characteristics thereof, the heel is stable and hard to fall down during running. The purpose of the present invention is to minimize the adverse effect on the joints and joints, prevent slipping even in rainy weather, and improve safety.

[0009]

That is, the present invention, which achieves the above-mentioned object, comprises an EPDM (ethylene-propylene-gen-monomer) of 20% or more and a high-elasticity rubber of 5% or more in the total rubber.
A vulcanized rubber sheet containing 0% or more, with a maximum displacement of 5.
4 to 6.6 mm, impact energy absorption rate is 67 to 70%, surface hardness is 43 to 48 ° JIS A, and 0.3 to
A 1.5mm height uneven pattern is provided to increase the coefficient of friction from 0.9 to 1.1.
It is a pavement material for the stadium.

According to a second aspect of the present invention, the pavement material is transferred and formed by bringing a woven cloth having an uneven pattern on the surface into contact at the time of vulcanization.

In the present invention, EPDM imparts weather resistance to the sheet, imparts displacement and hardness, and the high elastic rubber increases the impact energy absorption rate.

Here, the high-elasticity rubber refers to a rubber having a high elasticity among rubbers, for example, NR (natural rubber), SB
R (styrene-butadiene rubber), BR (butadiene rubber), IR (butyl rubber), silicone rubber, urethane rubber.

The thickness of the sheet-like material of the present invention is preferably at least 5 mm from the strength-retaining surface, and the thickness of the upper layer is preferably at least 2 mm for sufficient strength, weather resistance and an uneven pattern.

Usually, only the upper layer is colored for the purpose of design of the ground and track separation, but a suitable coloring material such as brownish red bengara can be used.

On the other hand, the scissors woven fabric used in the second aspect of the present invention is a fabric woven by a chopped weave, and usually, warp threads and weft threads appear long on the face of the woven fabric to produce square irregularities. It has the appearance of a honey nest or a square. However, a material patterned with a woven fabric other than a staple woven fabric can be sufficiently used as a pavement material, and a method of forming a pattern with a die stamped with a pattern can also be used.

[0016]

The pavement material of the present invention has a high impact energy absorption rate to prevent injury to the body, and has a small amount of displacement and a short impact time to improve the stability of the heel during sprinting.
The present invention provides a pavement material for a stadium suitable for improving safety in rainy weather due to an increased unevenness pattern and a higher coefficient of friction when wet.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pavement material according to an embodiment of the present invention;
And a lower layer 2 made of a vulcanized rubber sheet, and formed on the surface of the upper layer 1 side by forming an uneven pattern P formed by abutting a patterning woven fabric such as a lass woven fabric. I have.

FIG. 2 shows a state in which the above-mentioned pavement material is laid on a substrate 4 made of asphalt concrete. The same pavement material consisting of an upper layer 1 and a lower layer 2 is placed on the substrate 4 via an adhesive such as an epoxy adhesive 3. Laying and construction.

Next, specific examples of the present invention will be described with reference to Experimental Examples 1 and 2.

(Experimental Example 1) After mixing at the mixing ratio shown in Table 1 below, the mixture was uniformly kneaded, the upper layer was 4 mm thick, and the lower layer was 9
mm, and the upper layer is abutted with a woven fabric for patterning, continuously vulcanized by the roto-cure method, the woven fabric is peeled off from the vulcanized sheet, and the upper A pavement material according to an example of the present invention having a two-layer structure was obtained.

[0021]

[Table 1]

The physical properties of the thus obtained pavement material of the present invention were measured and found to be as follows, all of which were included in the physical property range of the present invention.

Maximum impact acceleration (G) 31.3 ± 0.13 Maximum displacement (mm) 6.0 ± 0.55 Impact energy absorption rate (%) 69.1 ± 1.62 Impact time (ms) 6.3 ± 0.51 Hardness (Shore A) 46.4 ± 1.02 Thickness (mm) ) 14.3 ± 0.13

On the other hand, as Comparative Example 1, a urethane pavement material formed by pouring liquid urethane into a sheet was used. As Comparative Example 2, liquid urethane was poured into a sheet and a rubber chip material was semi-submerged on the surface. The urethane pavement material formed by molding was used, and as a comparative example 3, the rubber part of the compounding was set to 50 parts by weight of NR and 50 parts by weight of SBR.
The maximum impact acceleration, the maximum displacement, the impact energy absorption, the impact time, the hardness, and the thickness were measured in the same manner using the paving material manufactured in the same manner as in the example except that the PDM was not blended. Table 2 shows the results.

[0025]

[Table 2]

From the above results, it can be seen that the embodiment of the present invention has a smaller maximum displacement and a shorter shock time in spite of the fact that the shock absorption energy is equal to that of the comparative example. this is,
For example, since the impact energy applied to the human leg when running is small, the burden on the leg is suppressed to the same extent as the comparative example, and the heel sinking due to displacement of the pavement material is small. Therefore, the heel stability is high, and the friction coefficient when wet is relatively high.

[Methods for Measuring the Physical Properties] (1) The four items of maximum impact acceleration, maximum displacement, impact energy absorption rate, and impact time were measured using a drop impact tester. In the drop impact test, the weight of the falling weight was 10 kg.
And free-fall from 60mm directly above the pavement material. The test items are the movement amount and the acceleration. The amount of movement was detected by a laser on the side of the tester. The acceleration was detected by an accelerometer attached to the side of the falling weight. The above four items were derived from these two measured values.

(2) The coefficient of friction was measured with a sliding friction tester. Sliding friction tester is James A. Masishi (James)
Machine), and can be measured up to a maximum static friction coefficient of 1.2. The sliding friction test was performed according to ASTM (D204
7, 1988).
In the test, a weight of 25 lbs (lb) was loaded from just above the paving material, and the test table was moved forward at a speed of 30 mm / sec. With this movement, the vertical component gradually decreases, and the maximum static friction coefficient is measured. The surface of the paving material was uniformly wetted with water. In addition, foam rubber (JIS A:
62, 5.5 mm in thickness). The sliding friction test measures the maximum static friction coefficient of the pavement material and the foamed rubber when wet.

[Experimental Example 2] Next, a comparison was made between the case where the surface pattern of the pavement material according to the embodiment of the present invention in Experimental Example 1 was applied by using a woven cloth having a surface pattern and the case where a putter was applied by using another woven cloth. Table 3 below shows the compared data.

In Examples 1 to 3, only the pattern on the surface was changed, and all of them are products of the present invention. Comparative Example 4 is a comparative product in which the maximum pattern depth is increased, and Comparative Example 5 is a comparative product in which a rubber chip is semi-buried in a pavement material made of urethane to form a pattern.

[0031]

[Table 3]

From the above table, it can be seen that the pavement material having a woven weave pattern has a greater coefficient of friction when wet, and can maintain safety even in rainy weather, as compared with a material having a pattern formed with another woven fabric.

[0033]

According to the present invention, there is provided a pavement material having the above-mentioned structure, and by blending EPDM and a high elastic rubber, the impact energy absorption rate as well as the weather resistance, the displacement and the hardness are increased, and the obstacle to the body is prevented. The amount of displacement is small, the shock time is short, the stability of the heel during sprinting is increased, and the friction coefficient in wet conditions is increased by the uneven pattern on the surface to improve the safety in rainy weather. It can be said that the heel is stable and hard to fall down, and that it is a pavement material that has very little adverse effect on bones and joints.

Further, when the surface pattern according to the second aspect is woven with a weave, the effect of further enhancing the wet friction coefficient and improving the safety is exhibited.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing one example of a pavement material according to the present invention.

FIG. 2 is a cross-sectional view of the pavement material of the present invention in a laid state.

[Explanation of symbols]

 1 upper layer 2 lower layer P uneven pattern

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeto Masai 4-1-23 Kitahama, Chuo-ku, Osaka-shi Inside Mitsuno Corporation (72) Inventor Hiroshi Kiyokawa 4-1-23-Kitahama, Chuo-ku, Osaka-shi Mitsuno Inside (72) Inventor Sada Ikeda 4-1-1, Hamazoe-dori, Nagata-ku, Kobe Mitsuboshi Belting Co., Ltd. (56) References JP-A-61-141737 (JP, A) JP-A-52-134229 (JP, A) JP-A-2-167903 (JP, A) JP-A-54-153144 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) E01C 13/00

Claims (2)

(57) [Claims] 1. A vulcanized rubber sheet containing at least 20% EPDM (ethylene-propylene-gen-monomer) and at least 50% high-elasticity rubber in the total rubber, and having a maximum displacement amount.
5.4-6.6mm, shock energy absorption rate 67-70%,
The surface hardness is 43-48 ° JIS A, and 0.3
An uneven pattern with a height of ~ 1.5 mm is provided and the coefficient of friction is 0.9 ~ 1.
Pavement material for the stadium as 1. 2. The pavement material for an athletic field according to claim 1, wherein the uneven pattern on the surface is a pattern transferred by bringing a woven woven fabric into contact at the time of vulcanization.