1 The science behind Artificial Grass Pitches

NickMcLarenTo date, scientific research into the maintenance of artificial grass pitches has been rather overlooked. Save for some notable exceptions - such as the 2008 Cranfield University study - much of our accepted industry wisdom has been formed by experience and observation. This is set to change when the results are published of a scientific evaluation of artificial turf maintenance, a partnership between Loughborough University and artificial pitch maintenance specialists, Technical Surfaces Ltd.

The research is being led by Nick McLaren, who explains here to Christopher Bassett how his investigation has progressed so far and the direction his studies will take over the next two years, as well as his hopes for the future of artificial pitch maintenance and the role his research will likely play in further developing industry guidelines and recommendations


Nick McLaren is a man with a plan - to bring artificial pitch maintenance into the 21st century. He is currently a third of the way through the research programme of his Engineering Doctorate, due to finish in September 2014.

His project on 'Artificial Turf: Integrating Maintenance and Sport Surface Science' aims to present an objective evaluation of the accepted practices and conventional StGeorgesAGP2wisdom behind the maintenance of artificial grass pitches (hereafter referred to as AGPs). As a collaborative study between Loughborough University and Technical Surfaces Ltd, Nick's research has both academic and industrial aims: to develop a scientific approach to measuring and understanding the effects of maintenance on AGPs; and to provide the company with the technical knowledge to enhance their position in the maintenance market.

The research includes analysis of the degradation, and associated loss of performance, over time of non-filled, sand-filled/dressed and 3rd Generation AGPs (and 4th Generation as they become developed), as well as the benefits and limitations of maintenance on the rates of degradation. The relationship between degradation and play performance, and user safety, will also be investigated in relation to the performance requirements set down by sport's governing bodies. Overall, the study aims to discover whether maintenance can improve performance levels when compared to an AGP that is unmaintained, and indeed whether maintenance can extend the useful life of AGPs.

Despite the role of a sponsor company in the research project, Nick is keen to stress the independent and impartial nature of his studies, and the academic rigour with which he is assessed by Loughborough University is testament to this.

Throughout the course of his research, Nick reports back to both parties with regular updates as to his progress and, at the conclusion of his 4-year study, he will present his overall findings to both internal and external academic examiners, as well as an industrial examiner, by way of an oral examination or 'viva'.

Moreover, although his research will draw upon Technical Surfaces' wealth of data, resources and industry experience, Nick is mindful to ensure that this does not, in any way, influence the direction or findings of his inquiry. Rather, the company provides a focal point for Nick's research, offering a 'real world' environment for him to conduct his analysis.

"Much of what is currently known about artificial surface maintenance is wholly subjective," explains Dr. Fleming, Senior AGPFlowChartLecturer at Loughborough University. "It is our intention to convert the years of experience and observations gathered by the sponsor company into objective measurements. There are still gaps in knowledge within the industry and, as the technology behind artificial turf manufacture and construction continues to develop, it is important to collect good scientific data on how these surfaces degrade, how their playing performance-related properties change, and the extent to which maintenance can achieve a reduction in this inevitable degradation process."

"The Engineering Doctorate scheme is an excellent vehicle to enable this form of high quality applied research to be undertaken, instigated by the vision of Technical Surfaces combined with the academic support from the Sports Surface Research Group at Loughborough University."

We recently met up with Nick shortly before he was due to travel across the pond, to the 9th biennial conference of the International Sports Engineering Association (ISEA) hosted in Lowell, Massachusetts. There he will present his conceptual model for degradation in performance on AGPs, which provides him with a framework for knowledge and understanding throughout his EngD research programme.

CB: What's your background within the sports surfacing industry, and how did it bring you to this point?

NM: I studied for a BSc in Sport Technology at Sheffield Hallam University, and then started my industry experience with a post in the R&D division at Notts Sport. I was there for three years, and my focus during this period was on designing new products for the AGP market.

CB: So, what first sparked your interest in the maintenance of AGPs?

NM: Whilst with the company, I began to recognise the importance of maintenance on AGPs, but could see that there had, historically, been very little in the way of scientific research into the benefits and effects of maintenance. The very nature of the R&D work I was involved with raised many questions on maintenance that I felt needed answering, such as 'why does it need maintaining?', often followed by 'do I really need to invest that much money, time and resource to maintenance?'.

I was interested to see how the products we were developing would work and perform further down the line but, more than that, I wanted to understand the effects of maintenance, rather than simply observing them as a matter of course. Essentially, I realised that my interests lay in measuring the performance of AGPs over time, and the extent to which this is affected by various factors, and I was keen to investigate this further.

CB: And what made you decide to return to the academic world to do that?

NM: I'd had dealings previously with Dr Paul Fleming and, when the opportunity came up to study for the EngD within CICE [Loughborough University's Centre of Innovative and Collaborative Construction Engineering], it seemed perfectly suited to the direction my own interests were taking.

The EngD approach itself appealed to me ahead of a traditional PhD, as it combined research and theory with practical application. Working at the frontline of the industry allows me to gather data and information for the research, which I can then reinvest in the maintenance work the company carries out on AGPs. Yes, the EngD is lab-test work, but with real usage - taking theories and long-held accepted practices regarding AGP maintenance, and applying scientific fact. And this is a longitudinal study, which means I can repeatedly observe the same variables over a long period of time.

CB: You're now a third of the way through your research project - what stage have you reached so far?

NM: To gather evidence and lay the foundations for my research, I carried out a review of previous studies into AGPs, going back around twenty-five years. The information I gained from this then enabled me to develop the test criteria and protocols for my own research.

As well as studying the impact of various maintenance tasks on AGPs, I also needed to determine my own test methods and identify which equipment I would use to carry out the testing. I benchmarked highly portable test equipment against the official standardised equipment to compare the results. I've developed the degradation model to identify the key variables expected to cause degradation and decline in the performance of AGPs, and the physical effects they will have on the condition of an AGP. Basically, the majority of my time has so far been spent in the lab at the university, validating the direction my research will take.

CB: Would you say you've encountered any obstacles in your research to date?
StGeorgesAGP
NM: Thankfully not. I've been lucky working with Technical Surfaces, as they have assembled a wealth of data, which gives me access to the constructional details and historical maintenance records of hundreds of AGPs, going back around fifteen years. I think the only difficulty I've had so far is in obtaining data from clients on variables such as usage types and levels, but again the company has responded to the growing need for AGP owners/operators to log usage for warranty purposes with O.T.I.S [the company's unique Online Technical Information System, an interactive tool between the company, its customers and their original surface provider], so, going forward, I should be able to utilise this data in my research as well.

CB: How will you conduct your research over the next two years?

NM: With most of the groundwork now completed, I can begin the onsite testing and data collation in earnest. I will be taking readings of an AGP's infill depth, infill density, infill moisture and pile orientation, both before and after a particular maintenance task is completed, and I will be measuring how long it takes after maintenance is completed before an AGP returns to its pre-maintenance performance levels.

I will also be assessing whether results diminish over time - that is, will the benefits of, say, a decompaction on a 3G surface become less effective over time, and if so, for what reason? My onsite tests will allow me to evaluate the short-term effects of maintenance, assess the degradation of AGPs and investigate the long-term relationship between maintenance and degradation.

CB: What were your criteria for selecting your chosen AGPs for the onsite testing?

NM: Key items to consider when selecting a test environment include an AGP's age, usage, construction and maintenance regime. With this in mind, I will be working mainly with new AGPs to conduct my testing but, from time to time, will also go to sites where maintenance is being completed, as and when work relevant to my research is taking place.

A key site where I'll be working is St. George's Park [England's National Football Centre in Burton-upon-Trent]; they have two 3rd Generation AGPs, an outdoor pitch approximately ten years old, and a newly-built indoor pitch, which is exciting in itself, as it presents me with a rare opportunity to be involved from the start of an AGP's life. The indoor/outdoor contrast will also be of benefit to my research - the indoor pitch presents a controlled external environment, with consistent temperature and climatic conditions all year round.

By removing the influence of weathering from the equation, I can focus my analysis more specifically on the effects of usage and maintenance on AGP performance more reliably than I could on a surface that is open to the elements. That said, the outdoor pitch provides the real world features of the vast majority of AGPs, and data obtained from this surface will enable me to evaluate the effects of moisture, temperature and climate on their performance, as well as the impact of foreign detritus, such as leaves, dirt and debris.

Being able to conduct my research at St. George's Park is also of great benefit for another reason - as a prestigious site, the AGPs here will be maintained to the highest standard, and both usage levels and maintenance will be logged in accordance with FA requirements.

CB: That's interesting - so would you say that the FA and other governing bodies of sport have adopted a more proactive attitude towards artificial pitch maintenance in recent years?

NM: Undoubtedly. For example, the FA, along with the RFU and Football Foundation, recently introduced a Framework Agreement for the Provision of Artificial Grass Pitches, in which they emphasise the need for AGPs installed within the framework to satisfy certain performance criteria to ensure a high standard of play. Central to this, the framework states that the maintenance requirements of each one must first be identified, based on determining factors including pitch size and projected usage levels, and subsequently adhered to throughout the life of the AGP.

At St. George's Park, I am fortunate to be working with the Head Groundsman, Alan Ferguson, who takes particular pride AlanFergusonand interest in all the surfaces in his charge, including the AGPs. He is incredibly forward-thinking in his outlook on their maintenance. Alan's enthusiasm for my research and AGP maintenance means that he has been fantastic in putting his facilities and associated data at my disposal.

CB: Ultimately, what are you hoping to achieve by carrying out this research?

NM: At the highest level, my hope is that the results of my research will help the FA and other sporting bodies to develop their official guidance for groundscare maintenance programmes for both high-spec and community use AGPs, and in that regard being granted access to St. George's Park is central to my research.

Across the board, my findings could impact on how we view maintenance as an annual requirement - for example, analysis into the impact of weathering as a degradation factor may well throw up initiatives such as season-specific maintenance tasks or frequencies. Or else, it could lead to the development of new maintenance machinery and equipment, or influence future recommendations for maintenance frequencies.

The work I am doing with test equipment could also have implications for the groundscare industry - a portable piece of reliable testing equipment may well pave the way for grounds staff to carry out their own regular monitoring and testing of the condition of their AGPs. Of course, at this stage, I'm only speculating as to the specific results of the research - above all, being able to apply scientific fact to the way we approach maintenance is something that is long-overdue within the industry, and to be leading the research into this is very exciting.

Artificial Turf: Integrating Maintenance and Sport Surface Science is due to be published in late 2014.

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