Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C9/00—Special pavings; Pavings for special parts of roads or airfields
  • E01C9/004—Pavings specially adapted for allowing vegetation
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C13/00—Pavings or foundations specially adapted for playgrounds or sports grounds; Drainage, irrigation or heating of sports grounds
  • E01C13/08—Surfaces simulating grass ; Grass-grown sports grounds
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C13/00—Pavings or foundations specially adapted for playgrounds or sports grounds; Drainage, irrigation or heating of sports grounds
  • E01C13/08—Surfaces simulating grass ; Grass-grown sports grounds
  • E01C2013/086—Combination of synthetic and natural grass

Definitions

• the present invention relates to a sports field whereof the top layer consists only partially of artificial grass and consists partially of natural grass.
• This sports field is suitable for all kinds of field sports such as football, hockey, tennis and the like.
• a drawback of the use of artificial grass is that when there is frictional contact of the skin with the artificial grass, for instance in the case of a sliding tackle or unin­tended fall, the frictional resistance is so high that this contact is experienced as unpleasant and can cause wounds and injuries. Efforts have been made to lower the frictional resistance by changing the fibre structure of the artificial grass (frizzed fibres) or by applying a lubricant to the fibres.
• the present invention has for its object to avoid as far as possible the above mentioned drawbacks of an artificial grass field, wherein the advantages of the artificial grass field remain preserved and in addition the properties of the sports field according to the invention correspond more close­ly to those of a sports field with a grass surface.
• the sports field comprises a foundation which bears an artificial grass and which is rooted with roots of grass plants passing through the artificial grass surface.
• the sports field accord­ing to the invention therefore consists of a grass surface of artificial grass and natural grass, wherein the latter is preferably slightly longer by setting a specific mowing hei­ ght, whereby the natural grass lies partially over the artifi­cial grass, wherein however the artificial grass provides the natural grass with firmness and protection.
• the foundation usually has a simpler construction and requires a smaller investment. It is also once again possible to suffice with the usual chalk markings.
• the artificial grass for use according to the invention is provided over its surface with openings through which the grass plants grow from the foundation.
• Such an artificial grass can be manufactured in simple manner if the artificial grass is provided with a tuft cloth or canvas and the openings are either formed from yarn threads and/or weft threads missing in the tuft cloth or canvas or are punched in. Because of the openings now present in the tuft cloth no latex layer can be formed on the underside of the artificial turf at the location of these openings, so that it is scarcely or not necessary to adapt the normal manufacturing process of the artificial grass. In order to avoid the tuft cloth and ultimately the turf losing strength at the position of the openings through the omission of yarn threads and/or weft threads, it is recommended that yarn threads and/or weft threads adjoining the openings have a greater diameter than other tuft cloth threads. An optimal artificial grass according to the invention is provided on 30-60% of its surface with openings for grass plants.
• the foundation preferably comprises a mixture of sand and particle-form material with hooking resistance, which mixture contains 2-8% by weight of humus material.
• the particle-form, hooking mate­rial forms a skeleton providing the stability over the height of the foundation, wherein the sand and the humus material fill the hollow spaces and form there an environment for the grass plant roots.
• An optimum foundation mixture comprises sand and particle-form material in a weight ratio of 60-30 to 40-70.
• particle-form material can be used lava and ste­agranTM.
• damping particle-form material can be added to the mixture in a quantity of 15-60% by weight.
• This damping material preferably consists of rubber particles such as rubber fibres and rubber nuggets.
• the sand consists of low-­grade earth with a humus content of 2-8% by weight.
• grass seed has to be caused to germinate in one way or another.
• the foundation can be sown with grass seed which only germinates and eventually grows at the location of the openings in the grass covering.
• Another embodiment comprises the sowing of the artificial grass, wherein only the grass plants in the immediate vicinity of the openings in the grass surface can grow therethrough and penetrate into the foundation.
• grass plants can find their way through the back layer of the artificial turf to the foundation at places where in principle no openings are present.
• the foundation per se cannot be sown with grass seed, it is recommended to arrange the grass seed in a preferably biologically degradable germinating layer, for instance a layer of cellulose.
• the invention relates to methods for laying the above described sports field.
• the method comprises the steps of:
• the grass is preferably strewn with sand that contains 1-2% of humus material.
• the foundation may consist only of sand having added thereto 2-8% by weight of humus material.
• Low-grade earth may optionally be used consisting of sand with 2-8% by weight of humus material. If the stabi­lity must be further increased it is recommended that in addition to sand the foundation contains particle-form mate­rial having hooking resistance.
• These materials are known and comprise steagranTM with a particle diameter of 0-8 mm and lava 03 with a particle diameter of 0-3 mm.
• the ratio of sand to material with hooking resistance is 60-­30 to 40-70 on weight basis.
• damp­ing i.e. resilient material
• This material can be a synthetic elastomer material (polyurethane plastics), or rubber in the form of rubber fibres or particles. Materials known for this purpose are described for instance in the European patent applications 204.381 and 260.769.
• the foundation is brought in the usual ways to the desi­red density and initial stability.
• grass seed can be sown in the foundation or a layer containing grass seed can be arranged, for instance a germinating bed layer of cellulose, wherein the grass seed is arranged.
• This material is biologically degradable and disap­pears after a time leaving behind humus material.
• seed can be sown in the artificial grass, whereafter the germinated grass plants find a way to the foundation with their roots.
• the artificial grass that is used according to the inven­tion must have a relatively open character, which means that 30 to 60% of the artificial grass surface must be provided with holes having a diameter in the order of magnitude of approximately 1-3 mm. These holes can be arranged afterwards, but an elegant manner of production results if the holes or openings are already left free in the tuft cloth. This can take place through interweaving the mutual yarn or weft threa­ds or by omitting yarn- and/or weft threads. At the point of these openings no artificial grass fibres can be arranged on the tuft cloth. Moreover, when the latex underlayer is ar­ranged, the latex will not form a film at the position of the openings and will leave the holes open.
• the artificial grass according to the invention can thus be manufactured with existing apparatus. It is noted that a conventional artificial grass already possesses a good water permeability so that no additional steps are required for sufficient adding of water to the grass plants.
• the artificial grass is arranged on a foundation already provided with a layer of grass seed, it is recommended not to strew sand in the artificial grass or to do so only partially and to strew sand to the required height after the grass seed has germinated and the grass shoots have grown out above the artificial grass. Further, it is advantageous to strew sand with a diameter of 0-310 ⁇ m containing 1-2% of humus material. This contributes to a good growth of the grass plants.
• the natural grass After germinating of the grass plants the natural grass has to be mown during maintenance to a length that is slightly longer than the length of the fibres of the artificial grass.
• the artificial grass fibres have a length of 15-35 mm. This means that with straight artificial grass fibres with a length of 15-25 mm or with frizzed artificial grass fibres with a length of 15-35 mm the grass must be mown to a grass length of 30-35 mm.
• the sports field according to the invention has to watered regu­larly in dry periods and provided with nutrients.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Road Paving Structures (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19854819

Family Applications (1)

Country Status (2)

Cited By (24)

Citations (11)

• 1989
  • 1989-06-12 NL NL8901484A patent/NL8901484A/nl not_active Application Discontinuation
• 1990
  • 1990-06-08 EP EP90201493A patent/EP0403008A1/de not_active Withdrawn

Patent Citations (11)

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