Sports field construction

Abstract

A sports field has a stable, impermeable substrate, a water distributing layer provided over the substrate and an artificial turf layer over the water distributing layer. A bund defines a perimeter of the sports field and extends from the substrate to at least the height of the artificial turf layer. A drain channel having inlets at a height to communicate with the water distributing layer is provided such that water can flow from the water distributing layer into the drain channel and vice versa. As a result of this constructions, there is formed a containment, defined by the bund surrounding the field and by the substrate. Water can be held within the containment in the water distributing layer allowing for water attenuation and cooling of the sports field.

The invention claimed is: 
     
       1. A sports field comprising:
 a stable, impermeable substrate; 
 a water distributing layer provided over the substrate; 
 an artificial turf layer over the water distributing layer; 
 a bund defining a perimeter of the sports field and extending from the substrate to above the height of the artificial turf layer to form an impervious containment having a volume above the water distributing layer; 
 a drain channel having inlets at a height to communicate with the water distributing layer; 
 a water management facility comprising a buffer reservoir chamber having a capacity equal in volume to at least said volume above the water distributing layer, the buffer reservoir chamber connected to the drain channel and to a valve flow gate and a pump such that water can flow from the water distributing layer into the drain channel and such that water can flow from the drain channel into the water distribution layer to fill the impervious containment with water to a depth sufficient to immerse the artificial turf layer over the full area of the sports field. 
 
     
     
       2. The sports field according to  claim 1 , wherein the drain channel is integrally formed with the bund. 
     
     
       3. The sports field according to  claim 1 , wherein the water management facility is arranged to control the height of the water within the drain channel to determine whether water flows from the water distributing layer into the drain channel or vice versa. 
     
     
       4. The sports field according to  claim 1 , wherein the drain channel extends below and above the water distributing layer. 
     
     
       5. The sports field according to  claim 1 , wherein the stable impermeable substrate comprises a stabilised soil substrate. 
     
     
       6. The sports field according to  claim 1 , wherein the stable impermeable substrate comprises an impervious membrane or coating. 
     
     
       7. The sports field according to  claim 1 , wherein the upper surface of the water distributing layer is substantially horizontal, preferably having no gradient greater than 1 in 100 and optionally less than 1 in 300. 
     
     
       8. The sports field according to  claim 1 , wherein the water distributing layer comprises recycled plastic granules and a binder and has a Young's modulus in compression of between 1MPa and 10 MPa. 
     
     
       9. The sports field according to  claim 1 , wherein the water distributing layer has a void ratio of between 20% and 70%, optionally around 45%. 
     
     
       10. The sports field according to  claim 1 , wherein the water distributing layer has a depth of between 10 mm and 100 mm, optionally around 40 mm. 
     
     
       11. The sports field according to  claim 1 , further comprising a resilient layer provided between the water distributing layer and the artificial turf layer. 
     
     
       12. The sports field according to  claim 1 , wherein at least the upper extremity of the bund comprises resilient material. 
     
     
       13. A method of constructing a sports field comprising:
 providing a stable, impermeable substrate; 
 providing a water distributing layer over the substrate comprising recycled plastic granules with a void ratio of between 20% and 70%; 
 installing an artificial turf layer over the water distributing layer; 
 forming a bund defining a perimeter of the sports field and extending from the substrate above the top of the water distributing layer and to at least the height of the artificial turf layer to form an impervious containment wherein the bund comprises hollow curb-stones, forming 
 an integral drain channel communicating with the water distributing layer such that water can flow from the water distributing layer into the drain channel and such that water can flow from the drain channel into the water distribution layer to fill the impervious containment with water to a depth sufficient to fill the void spaces within the water distributing layer and immerse at least part of the artificial turf layer over the full area of the sports field. 
 
     
     
       14. The method of  claim 13 , wherein providing the substrate comprises stabilisation of the existing on-site soil to a CBR of greater than 15 and preferably to a depth of at least 100 mm. 
     
     
       15. The method of  claim 13 , wherein forming of the substrate comprises providing an impermeable membrane or coating over a stabilised base. 
     
     
       16. The method of  claim 13 , wherein providing the water distributing layer comprises in-situ laying of a semi-fluid mass comprising recycled plastic granules and a binder, levelling the semi-fluid mass and allowing the semi-fluid mass to solidify to form a rigid porous layer. 
     
     
       17. The method of  claim 13 , wherein providing the water distributing layer comprises paving the substrate with pre-formed porous slabs of recycled plastic granules.