Final Report Summary - MULTITURF (Innovation in multifunctional artificial turf fields for sports: Development of new concepts using a new predictive design tool)
In recent years artificial turf has become more and more important in Europe as a sport surface. The advantages of artificial turf fields are obvious: much higher number of hours of use, lower maintenance costs, much more consistent performance and usable in a large variety of climates. However, until now only specialised artificial turf fields for single sport use have been developed, mainly for high-end purposes such as top hockey fields, top football fields, etc. The project partners have learned from their market that in the near future there will be a need for more general-use fields. These include community fields, school fields, etc, where different users (children, seniors, and amateurs) and different sports (football, hockey, tennis, rugby, baseball etc.) would like to use the same field, but do not want to compromise their sporting and safety requirements.
Another important aspect for the project partners, in order to be ready for further future developments, is to have a tool, which will make it possible for them to design artificial turf fields much faster, thus in an economical favourable way, preventing 'trial and error' experiments. Current technology is not sufficient to answer these needs. Therefore, one of the main technical objectives for MULTITURF has been to develop a design tool that can predict a selection of sport technical properties for an artificial turf. This will result in a shorter time to market for new products as well as economic advantages. The effect that the artificial turf field can have on the human body will also be identified. This part of the tool will give a first indication of the safety of artificial turf fields.
Development of new concepts for multifunctional artificial turf fields includes multi-sport concepts. These involve combination of several types of sports into one field, for sport facilities which have to offer sport surfaces fulfilling competition standards and / or training requirements. Multi-purpose concepts involve a combination of sports with community events, like concerts and recreational activities. This is especially important for local communities, who have fewer finances and want to have comfortable and safe sport facilities which can also be used for other community events. The multi-user concept aims at a safe and functional surface for both children and adults. Currently standards for sport fields are based on adults.
In order to be able to actually produce the new concepts described new material and construction technologies were needed, resulting in innovations in materials and field construction. The information database that has been developed contains information concerning the requirements for all relevant sports fields, field constructions currently used for these sports and standard test methods for relevant sports. The database is a very useful tool for finding information about all types of artificial turf fields in an easy way.
The design tool has been developed to make it possible to predict the most critical properties of an artificial turf field. These include shock absorbing properties, HIC (head injury criterion) and ball bounce. The tool is based on theoretical descriptions (analytical formulas) of the different layers of an artificial turf field. The rubber infill and the e-layer are important parts of this construction, but also the yarn and the sub-base have been modelled. By choosing the details of a field construction, the design tool automatically calculates the force reduction, energy restitution, deformation, HIC-value and ball re-bounce. The predictions by the tool have been compared with experiments in the laboratory and show a very good resemblance within boundaries.
Improvements in material and constructions include developing a new type of fibre with improved resilience together with good durability. By building systems on lab scale a lot of knowledge has been gained about the interaction between all field construction parts. This has been useful in the development of the football-hockey system. After having evaluated a number of snow removal methods like mechanical removal, the use of chemicals and the use of a tent over the field, researchers have concluded that their new heating system can be used for extending the period of use of artificial turf fields in Scandinavia. This system is based on a conducting film which is put underneath the grass carpet.
Partners are also seeking to use cryogenically recycled rubber, which has the advantage of less smell and less leaching to the environment compared to normal recycled rubber. The material is cryogenically processed into rubber granules which are then used in artificial turf, in horse arenas, asphalt and several other rubber applications. In addition partners have succeeded in reducing the cost of installation of artificial turf fields in developing a sub-base layer which needs to be only 20 cm deep instead of the normally used 50 cm. Furthermore, the system has very good shock absorbing characteristics, which make it possible to use less rubber in the top-layer.
Another important aspect for the project partners, in order to be ready for further future developments, is to have a tool, which will make it possible for them to design artificial turf fields much faster, thus in an economical favourable way, preventing 'trial and error' experiments. Current technology is not sufficient to answer these needs. Therefore, one of the main technical objectives for MULTITURF has been to develop a design tool that can predict a selection of sport technical properties for an artificial turf. This will result in a shorter time to market for new products as well as economic advantages. The effect that the artificial turf field can have on the human body will also be identified. This part of the tool will give a first indication of the safety of artificial turf fields.
Development of new concepts for multifunctional artificial turf fields includes multi-sport concepts. These involve combination of several types of sports into one field, for sport facilities which have to offer sport surfaces fulfilling competition standards and / or training requirements. Multi-purpose concepts involve a combination of sports with community events, like concerts and recreational activities. This is especially important for local communities, who have fewer finances and want to have comfortable and safe sport facilities which can also be used for other community events. The multi-user concept aims at a safe and functional surface for both children and adults. Currently standards for sport fields are based on adults.
In order to be able to actually produce the new concepts described new material and construction technologies were needed, resulting in innovations in materials and field construction. The information database that has been developed contains information concerning the requirements for all relevant sports fields, field constructions currently used for these sports and standard test methods for relevant sports. The database is a very useful tool for finding information about all types of artificial turf fields in an easy way.
The design tool has been developed to make it possible to predict the most critical properties of an artificial turf field. These include shock absorbing properties, HIC (head injury criterion) and ball bounce. The tool is based on theoretical descriptions (analytical formulas) of the different layers of an artificial turf field. The rubber infill and the e-layer are important parts of this construction, but also the yarn and the sub-base have been modelled. By choosing the details of a field construction, the design tool automatically calculates the force reduction, energy restitution, deformation, HIC-value and ball re-bounce. The predictions by the tool have been compared with experiments in the laboratory and show a very good resemblance within boundaries.
Improvements in material and constructions include developing a new type of fibre with improved resilience together with good durability. By building systems on lab scale a lot of knowledge has been gained about the interaction between all field construction parts. This has been useful in the development of the football-hockey system. After having evaluated a number of snow removal methods like mechanical removal, the use of chemicals and the use of a tent over the field, researchers have concluded that their new heating system can be used for extending the period of use of artificial turf fields in Scandinavia. This system is based on a conducting film which is put underneath the grass carpet.
Partners are also seeking to use cryogenically recycled rubber, which has the advantage of less smell and less leaching to the environment compared to normal recycled rubber. The material is cryogenically processed into rubber granules which are then used in artificial turf, in horse arenas, asphalt and several other rubber applications. In addition partners have succeeded in reducing the cost of installation of artificial turf fields in developing a sub-base layer which needs to be only 20 cm deep instead of the normally used 50 cm. Furthermore, the system has very good shock absorbing characteristics, which make it possible to use less rubber in the top-layer.
