Substructure for an artificial lawn

Abstract

The present invention relates to a substructure for an artificial lawn, comprising a top layer of artificial grass fibres and a number of underlying layers including a base layer, one or more intermediate layers and possibly other layers. The aforesaid substructure preferably comprises a water-permeable shock-absorbing layer, wherein said shock-absorbing layer is separated from said top layer of artificial grass fibres by one or more intermediate layers, wherein said one or more intermediate layers are selected from the group consisting of crushed stone, lava and sand, or a combination thereof.

1 . A substructure for an artificial lawn, comprising a top layer of artificial grass fibres and a number of underlying layers including a base layer, one or more intermediate layers and possibly other layers, characterised in that the aforesaid substructure is surrounded by an envelope, wherein said envelope is constructed so that the level of the water present within the envelope is vertically adjustable, wherein the adjustment of the aforesaid level can be carried out by using a pipe system positioned within the aforesaid envelope, through which pipe system water can be passed, wherein water can be withdrawn from the aforesaid substructure using the aforesaid pipe system, which water can exit to the aforesaid layers of the substructure. 
     
     
         2 . A substructure according to  claim 1 , characterised in that the aforesaid pipe system is located near the bottom side of the aforesaid envelope. 
     
     
         3 . A substructure according to either one or both of  claims 1 - 2 , characterised in that the pipes of the aforesaid pipe system are spaced a regular distance apart and that the pipe system extends substantially over the entire area of the aforesaid substructure. 
     
     
         4 . A substructure according to one or more of the preceding claims, characterised in that the aforesaid pipe system is separated from said one or more layers by means of a water-permeable film. 
     
     
         5 . A substructure according to one or more of the preceding claims, characterised in that aforesaid envelope is made of a water-impermeable film, in particular a film selected from the group consisting of high density polyethylene (HDPE) and ethylene propylene diene monomer (EPDM). 
     
     
         6 . A substructure according to one or more of the preceding claims, characterised in that the aforesaid substructure comprises a water-permeable shock-absorbing layer, wherein said shock-absorbing layer is separated from said top layer of artificial grass fibres by one or more intermediate layers. 
     
     
         7 . A substructure according to  claim 6 , characterised in that the shock-absorbing layer is made up of a number of separate shock-absorbing layers comprising one or more components selected from the group consisting of SBR rubber, ground plastic particles, polyethylene, polypropylene, polyamide, polyester or a mixture thereof, preferably polyethylene foam, possibly in combination with one or more binders. 
     
     
         8 . A substructure according to one or more of the preceding claims, characterised in that the aforesaid one or more intermediate layers comprise sand, wherein the sand comprising intermediate layer is made up of at least two sublayers, wherein the first sublayer comprises a sand fraction having a particle size greater than that of the sand fraction of the second sublayer, wherein the first sublayer with the coarser sand fraction is positioned near the top layer. 
     
     
         9 . A substructure according to  claim 8 , characterised in that the at least two sublayers of the aforesaid sand layer are separated from each other by means of a separation layer. 
     
     
         10 . A substructure according to one or more of the preceding claims, characterised in that the aforesaid one or more intermediate layers comprise sand, wherein said sand has a particle size distribution wherein 25-75 wt. % of the sand passes through a 0.250 mm sieve, in particular wherein 90-99% of the sand passes through a 1 mm sieve. 
     
     
         11 . A substructure according to one or more of the preceding claims, characterised in that one or more of the aforesaid intermediate layers and/or shock-absorbing layers are separated from each other by a separation layer 
     
     
         12 . A substructure according to one or more of  claims 9 - 11 , characterised in that the aforesaid separation layer is selected from the group consisting of cloth, fibre fabric, mat and geotextile. 
     
     
         13 . A substructure according to one or more of  claims 6 - 12 , characterised in that the aforesaid shock-absorbing layer is embedded between two separate sand layers. 
     
     
         14 . A substructure according to  claim 13 , characterised in that the two sand layers are of the same type. 
     
     
         15 . A substructure according to one or more of  claims 6 - 14 , characterised in that the shock-absorbing layer is made up of at least two separate shock-absorbing layers. 
     
     
         16 . A substructure according to  claim 15 , characterised in that one or more intermediate layers are present between the aforesaid shock-absorbing layers, wherein the aforesaid one or more intermediate layers comprise sand. 
     
     
         17 . A substructure according to  claim 16 , characterised in that the aforesaid sand is made up of at least two sublayers, wherein the first sublayer comprises a sand fraction having a particle size greater than that of the sand fraction of the second sublayer, wherein the sublayer with the coarser sand fraction is located near the top layer. 
     
     
         18 . A substructure according to  claim 16 , characterised in that the aforesaid sand has a particle size distribution wherein 25-75 wt. % of the sand passes through a 0.250 mm sieve, in particular wherein 90-99% of the sand passes through a 1 mm sieve. 
     
     
         19 . A substructure according to one or more of  claims 8 - 18 , characterised in that the particles of the sublayer with the coarse fraction have a particle size such that at least 80% of the particles have a particle size that ranges from 0-32 mm, preferably 1-32 mm, in particular 1-8 mm, more in particular 1-4 mm. 
     
     
         20 . A substructure according to one or more of  claims 8 - 19 , characterised in that the thickness of the sublayer with the coarse fraction is 50-200 mm, in particular 75-125 mm. 
     
     
         21 . A substructure according to one or more of  claims 8 - 20 , characterised in that the second sublayer comprises sand particles of which at least 80% have a particle size greater than 80 μm, preferably greater than 100 μm, in particular greater than 125 μm. 
     
     
         22 . A substructure according to one or more of  claims 8 - 21 , characterised in that the second sublayer comprises sand particles of which at least 50% have a particle size greater than 125 μm, preferably greater than 150 μm, in particular greater than 200 μm. 
     
     
         23 . A substructure according to one or more of the preceding claims, characterised in that the total thickness of layers located under the top layer of artificial grass fibres is 40-150 cm. 
     
     
         24 . A substructure according to one or more of the preceding claims, characterised in that the pipe system is provided with pressure-reducing means for creating an underpressure in the pipe system, wherein the pipe system further comprises a water reservoir provided with one or more connection openings, an adjustable overflow for adjusting the water level in said reservoir, water level measuring means and a controllable water supply with the necessary piping, pumps and valves. 
     
     
         25 . A substructure according to  claim 24 , characterised in that the pressure reducing means comprise water level reducing means for reducing the water level in the reservoir, wherein in particular the water level reducing means comprise a plunger pump. 
     
     
         26 . A substructure according to either one or both of  claims 24 - 25 , characterised in that the water reservoir is in particular incorporated in a circuit which further comprises a buffering vessel and an overflow. 
     
     
         27 . A substructure according to one or more of  claims 24 - 26 , characterised in that the water reservoir is connected to the substructure via one or more connection openings, which connection openings abut the water-impermeable layer. 
     
     
         28 . A substructure according to one or more of  claims 24 - 27 , characterised in that use is made of solar energy and/or wind energy for driving the pumps, valves and control means. 
     
     
         29 . A substructure according to one or more of the preceding  claims 1 - 28 , characterised in that the top layer is provided with a so-called infill material having a good water-permeability, preferably sand of the type that has a particle size distribution wherein 25-75 wt. % of the sand passes through a 0.250 mm sieve, in particular wherein 90-99% of the sand passes through a 1 mm sieve.