Specifications

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• Design
• Features
• Specifications
• Installation
• Maintenance
• Management

The difference is in the details

More unique than rare features

When you buy a car to cover a lot of mileage, you pay attention to detail to ensure a comfortable journey and to save money over its lifetime; the same care is taken when buying a house to live in, so all major investments must be planned with this in mind, whether for private or public use.

Each project must be able to provide answers in terms of:

1. performance and safety for athletes features,
2. usability throughout the week, in relation to hours of play for a team of 25 players and the average age of each team as this may influence the maintenance budget and the durability over the year,
3. cost of management during the period of use and maintenance and availability of the necessary resources,
4. minimum guarantee period without constraints related to the natural grass care, 
5. environmental impact during installation and the period of its useful life,
6. hydraulic governance to mitigate damages related to soil erosion because of bad weather conditions,
7. charges for decommissioning and restoration to its original or better state at the end of its operation.

Through these answers, a well-structured design allows the selection of the best system to meet the contextual requirements of the area.

A good hybrid must also prove its effectiveness when subjected to intensive use because it is not enough to have a carpet with holes in it for it to really work.

Finally, an experienced installer and a diligent operator must be selected to ensure that the system is properly installed and maintained throughout its life cycle. POWERgrass maintenance is not easy to perform without training but is simple to learn if the operator is supported by an experienced technician. However, it has to be constant because correct routine maintenance prevents renovation and extraordinary costs.

The drainage system

Diagonal Drainage

The drainage system must remove excess rainwater and disperse much of it into the ground below to avoid burdening the sewerage system. In some cases the roots reach the drainage layer and manage to absorb the water in the underlying soil, thus saving the most precious resource.

Building an effective drainage system is very easy. The primary drainage is made after levelling and settling the ground, with two or four slopes. Then dig up to a depth of 40 cm and a width of about 40 cm around the perimeter of the area to be drained. As the water has to be dispersed along the excavation, it is sufficient to maintain the same level of excavation, thus slowing down the outflow towards the sewer. A 160 mm corrugated drainage pipe is then laid and covered with crushed stone up to the surface. Excess water can be discharged either directly into the groundwater via a sump or directly into the white water drains. POWERgrass recommends the installation of large storage tanks to contain the need for at least 5-6 irrigation cycles to save the most precious resource.

Inspection manholes placed at the points of intersection of the diagonal pipes with the perimeter pipes facilitate periodic maintenance cleaning. The channels are not necessary for drainage, as the background absorbs all the water that is dispersed or removes it through the pipes, but if the area is subject to heavy rainfall or is subject to heavy snowfall the channels collects the water that flows on the surface when the soil may be frozen.

Next, the secondary drainage must be made, then divide the field into the two axes every 10 metres or so and draw diagonally the first point on the vertical axis with the first point on the horizontal axis and so on to the end. The diagonal drains can be made with a mini-excavator or chain diggers with a section varying from 12 to 30 cm and up to 35 cm deep. A corrugated drainage pipe of 90 mm is then laid and covered with crushed stone up to the surface.

Depending on the type of ground (whether it is filtering or not), the rainfall in the area (light, slow rainfall or frequent heavy showers) and the budget available, you have to choose between a) a complete layer of fine crushed stones over the entire surface or b) micro-drains every 25-50 cm dug with special equipment and filled with coarse and very coarse sand.

The irrigation system

The watering system with 24 medium-range pop-up sprinklers is designed to distribute water more evenly than long-range sprinklers and to better rationalise water consumption.

At the top of the sprinkler there must be a small soft rubber cup to hold a small sod of natural grass installed at the same height as the playing field. In fact when the system is switched off it is difficult to locate the sprinklers in the ground.

The sprinklers can be connected to a solenoid valve individually and eventually connect two valves ad the same line of the controller having in mind to a) connect sprinklers with a uniform radius of action; for example on a football pitch there are usually sprinklers with three different radii of action at 90°, 180° or 360° and b) combine sprinklers if possible from non-contiguous areas, as a good rule is to alternate irrigation zones so that the water from the previous zone/sprinkler penetrates the ground.

The programming is done with a control box and 1, 2 or 4 sprinklers are started at the same time depending on the type of system, flow rate and water pressure. When the weather is hot, it is recommended to instal a pump that provides enough water and pressure to run 4 sprinklers, thus enabling the necessary water to be supplied in a short time.

The POWERgrass hybrid system consists of:

Cross section POWERgrass

A. a hybrid carpet with 60 mm high fibres, arranged in at least 6000 tufts of 12 strands ≈ 72000 monofilaments per m². The tufts are attached to the substrate with a tensile strength of ≥30 N using LC-HM technology without obstructing its permeability and softness. The hybrid carpet can be folded 180° at each intersection of the knots to remain elastic to the players' pressure. The backing and the seams of rolls stitched together must be strong with a tear resistance of ≥500 N to facilitate installation and durability.

• The fibres are of two shapes and colours, with 6 strong and soft mono-extruded filaments with a minimum cross section of 350 microns to increase wear resistance. The resilience of the filaments is ≥2.00 cN (calculated at 300 cycles using the Favimat R Textechno method).
• The primary backing is made of a rot-proof mesh, woven on a Raschel loom, which gives a three-dimensional shape with high porosity for approximately 320,000 irregularly shaped voids/sqm. The mesh allows air circulation and the passage of roots and at the same time limits the migration of sand, which would otherwise block the voids and cause hardening. The mesh is ladder-proof to maintain its structure after multiple punctures to aerate the underlying rhizosphere with 8 mm diameter tines.
• The secondary backing consists of a thermoplastic adhesive coated in line exclusively on the underside of the fibre tufts just, prior to compression with the heated roller to seal the fibres to the mesh, without clogging up the space between the rows of tufts. It also includes a lightweight geo-textile that provides an insulating effect to mitigate heat and frost stress.

B. a substrate complies with USGA standards based on silica sand mixed by volume at 7-10% with a mineral soil conditioner based on zeolite and a stabilised bovine compost in earthworm culture. After sewing the rolls, the hybrid turf is filled and raked with cork grains with a diameter of 0.5-2.5 mm and a weight of no more than 130 kg/m³ for approximately 7 mm, then filled and raked with the same mixture as before gradually until a 35 mm uniform layer is formed, to allow for the best interaction of the athlete's studs with the surface.

C. Greening with on-site seeding, fertilisation and management of all routine maintenance activities until the field is handed over for use. The choice of species depends on the climate and the sowing season, fertilisation must favour rapid grass establishement with a natural grass cover of no less than 95%. It is therefore imperative to develop a detailed plan of the activities carried out, with a list of the machinery and products available: seeds, growth promoting fertilisers, biological inoculants etc.