The skills of the designer are often underestimated when it comes to sports pitches because they look like simple structures. However, it requires cross-skills and precision in design because errors or omissions can generate additional costs throughout the life cycle of the work. Moreover, an area of 7-8 thousand square metres has a significant impact on public green assets.
As our president said, 'it's builder's time'. Indeed, there is a light at the end of the tunnel to overcome the most important crisis we have faced in decades, but we must be prepared because nothing will be the same as before. The design of public works is a central topic that few are prepared to approach with a holistic view. Most of the procedures laid down in the rules are ineffective because there is a tendency to distribute responsibilities to several parties, which in fact produces misunderstandings and disputes.
With regard to sports pitches, which have a relatively short life cycle, we refer to the distinction between ordinary and extraordinary maintenance as if one did not depend on the other. The main problem in Italy today is that while incentives and funding are offered for carrying out new works or upgrading existing infrastructure, ordinary maintenance is hardly ever funded.
A client working in the management of Banca Intesa San Paolo said that, in their projects, routine maintenance is part of the investment for the life of the asset, because it is the only way to guarantee performance and usability for a longer period.
Dr Niko Sarris
From a design point of view, for a project to be complete, the operating costs for the use and maintenance phase of the field must be taken into account, but also the environmental impact it produces during its life cycle. A feasibility study that is limited to the construction and decommissioning phase of the pitch is not sufficient to implement the circular economy. Very often, in an attempt to reduce maintenance costs, one risks making choices that are counterproductive in the medium to long term, entering into one of the blind spots of the circular economy. A seemingly eco-efficient project is not necessarily eco-efficient, so it may turn out to be contrary to the interests of the community because it is not compatible with the environment and the need to create skilled employment.
If we have learnt one lesson from this last pandemic, it is that only by caring for health, the environment and our community can we have sustainable economic development. The feasibility project must therefore also take into account the costs of use and maintenance, because this is the longest phase of the asset and we can have a significant impact. To achieve effective results, it is necessary to develop a digitised environmental management system for reporting on activities, production processes and monitoring measurable values on the results obtained by entrusting the task of managing the 'use and maintenance' period to qualified people.
Regarding intensive-use sports pitches, the latest 2019 ECHA (European Chemicals Agency) report highlighted the risk of microplastic pollution due to rubber granules in the infill of synthetic turf and proposed to the European Commission a total ban within a maximum of 6 years to give the industry time to find alternatives. Today, there are two alternatives: a) artificial turf with 100 % vegetal infill that allows intensive play by integrating a large part of the consumed infill, or b) the innovative POWERgrass hybrid grass system that offers the hours of play actually needed for matches and training and reduced maintenance costs.
Natural grass is the best playing surface and professional players confirm this because the sports surface is cooler and more stable for playing and reduces the risk of sprains, injuries and back pain. On the other hand, the number of hours of use is limited and maintenance costs are high.
In order to cope with the increasing demand for use and to reduce maintenance costs, operators prefer to install artificial courts, compromising the quality of the game because they essentially change the bounce and control of the ball and reduce the stability of the surface, especially in wet conditions. Spectator enjoyment decreases and the heat emanating from the artificial pitch is certainly not appreciated, but it is the players who lose out the most. Players' safety is compromised by factors such as premature fatigue on hot days, sprained anterior and posterior cruciate joints due to the reduced stability of the artificial surface, and strained muscles due to sudden slips on the wet surface. Several players complain of back pain when the court is hard and skin abrasions are frequent when temperatures exceed 30°C.
It is obvious that one plays better on the artificial course than on the natural course seeded with holes, but if we could have a durable natural turf for matches and training, we would have achieved the desired goal.
Dr Niko Sarris
Today, there are synthetic carpets with an open backing that allows the roots to penetrate and anchor themselves, thus achieving greater tear resistance. Synthetic fibres protruding on the surface above the infill protect the plants from intensive use, forming a durable playing surface in which natural grass prevails, also known as 'reinforced natural grass', 'hybrid grass' or 'mixed grass'.
On hybrid pitches, the game is played on natural grass and the presence of artificial turf is almost imperceptible, so they are equivalent to natural grass pitches in every respect. The studs of the shoes interact with the natural grass but do not raise the turf sod on hybrid pitches, so the game is played more safely and damage to the natural grass is limited, reducing post-match repair work in particular. When natural grass suffers damage, the synthetic fibres provide continuity of play until it grows back again, so the groundsman's job becomes quick and easy.
Hybrid grass systems are appreciated by professional players because they make the playing surface more stable by anchoring the grass to the synthetic backing, which would otherwise give way during play and form potentially dangerous holes. The player feels safer and gives his best, allowing for spectacular plays.
To ensure the effectiveness of a reinforced turf system, the growing conditions of the natural grass within the synthetic turf must be preserved from the first day after seeding, and then in the medium and long term. The expectations in terms of hours of use of the reinforced system are high, which makes the challenge of caring for natural grass even greater. It should also not be forgotten that the presence of the synthetic turf sometimes limits the possibility of mechanical intervention and often makes the surface too firm for both the game and the root development of natural grass.
Dr Niko Sarris
All reinforced natural grass systems should meet the expectations of increased strength and durability, but experience has always made the work of maintenance technicians more complex. The integration of a synthetic turf into natural grass has been a goal pursued by the industry for the past 25 years, but has not always been successful.
A good reinforced natural grass system must have very specific characteristics in order to preserve the ideal growing conditions of natural grass, provide the expected performance and playing safety, and require significantly less maintenance than a natural pitch. This is the only way to preserve playability, contain running costs and reduce environmental impact.
Natural turf experts try to stimulate a rich and deep root system to withstand intensive play and environmental stresses, so the presence of an artificial turf must not restrict deep root growth. A sand substrate must retain a good amount of capillary water, ensure air circulation and must not harden easily, because a penetration resistance of more than 1500 kPa limits root development.
By limiting the manual post-game work of restoring the raised turf, the reinforced natural field significantly reduces maintenance costs compared to a natural field. In effective hybrid pitches, maintenance is limited to the cultivation of the natural grass, taking care not to damage the reinforcement fabric, so that the system can be renewed several times during its life cycle without the need for costly replacement work on the entire system. To this end, three aspects are fundamental (a) the artefact must improve the growing conditions of the natural grass, (b) the artefact must be resistant to multiple deep aeration and intensive scarification operations, without affecting the structure and functionality of the artefact, and (c) the system must be easy to renovate because the artefact is durable and is installed in situ with the rolls of synthetic grass sewn together to form a single surface, without interruption, unlike the transplanting of pre-grown hybrid turf sods in nurseries.
The POWERgrass hybrid system was developed holistically. The synthetic backing has numerous uniformly arranged three-dimensional holes that limit sand migration, thus preventing the holes from clogging and hardening the system. The synthetic substrate is soft but resistant to tearing and deep aeration and retains its characteristics over time. The roots of natural grass grow deep from the first day of growth and, once through the backing, are protected from abiotic and biotic stresses.
The synthetic fibres are strong, resilient and thermally bonded to the three-dimensional backing to allow proper installation and facilitate maintenance so that they remain upright to truly protect the crowns of the plants. Once the system is installed, the synthetic fibres protrude approximately 20-25 mm into the surface before seeding.
ZOEsand is a sports soil conditioner that is the result of an in-depth study to improve the physical and chemical properties of sand. It consists of three essential components: an elastic, an organic and a mineral component to be mixed with USGA-type sand. ZOEsand makes the growing medium softer, more fertile and more resistant to soil compaction.
The POWERgrass hybrid turf system is a combination of a synthetic turf made from an ad-hoc backing, a sand-based substrate amended with elastic, organic and mineral elements such as ZOEsand, and natural grass seeded into the synthetic turf. The system is installed in situ by experienced personnel and the maintenance is developed by the team according to the POWERgrass experience following the principles of regenerative agriculture in order to also achieve a positive environmental impact.
The end result of a successful installation is a sports surface with greater traction, stability and softness, highly draining for playing safely even in the rain, even without natural grass and, above all, without dangerous holes.
The natural grass with its roots anchors itself in the holes of the backing and at the same time aggregates the sand to the artificial turf. The system is therefore functional and appropriate in flood-prone areas, takes into account the need for high permeability, but reduces the risk of dispersing waste or pollutants into the groundwater.
The lifespan of the system is indefinable, with no expiration date, if it is maintained regularly due to the self-repair capabilities of natural grass. In the context of running a sports centre between 10 and 20 years, it is the best choice because it reduces running costs and allows the field to be returned in a better state.
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POWERgrass hybrid turf field
Synthetic turf field