ASET Services recently evaluated an 8 year old competition track at a Division I NCAA University. The title of this post includes the word ‘deterioration,’ and in some ways the track had deteriorated during 8 years. However visually the track was still flat it did not show excessive signs of wear, and the surface was sound with good drainage. A visual inspection simply showed that lane one had slightly greater wear than the rest of the track and that the lines had started to fade. Our more in depth testing provided evidence that key properties have deteriorated significantly during those 8 years and this post outlines the current status of the track.
The system that was installed was certified by the IAAF to deliver IAAF performance during lab testing. Our field tests were to be used to determine if the track could be repainted or if it should be resurfaced. We asked several people (university and architectural staff) if the facility had been IAAF certified or if the surface had simply been selected because it was IAAF certified. None of them could provide an answer. Internet searches yielded several articles stating that the facility had indeed been certified to IAAF rules and that it received a Level 2 certification. Based on this information, and based on the product information available on line the original installation should have conformed to the following:
- Force Reduction: between 35% and 50%
- Thickness: 13 mm
The IAAF recommends installing the track slightly thicker than the sample that was tested for the lab trials. “The IAAF Product Certificate for a synthetic surface material indicates the absolute thickness at which a sample of the material, tested in a laboratory, complied with these Specifications. The overall thickness laid will probably have to be greater to ensure that no in-situ test result will fail.”
- Exceptionally thin sections are those that are less than 80% of those on the Product Certificate (In this case 10.4 mm)
- Force Reduction requirements apply to life of product and to resurfaced tracks
The IAAF rules state that a surface is ‘excessively thin’ when the thickness is less than 80% of the thickness from the laboratory sample, or in this case 10.4 mm. The current thicknesses are shown in the chart below. The green range at the top of the chart indicates the region above the 13 mm used in lab tested, and reflects the range suggested by IAAF to ensure compliance. The red range at the bottom of the chart indicates the region that would be considered excessively thin under the IAAF definitions.
Three test points produced thicknesses that were within the definition of excessively thin. Given repeatability and reproducibility limits an additional 7 points were either within the excessively thin region or so close to it that they could not be excluded from it. The average thickness using all of our test points was only 10.6 mm. This means that if the track was originally installed to a thickness of 13 mm, it has lost 2.4 mm on average.
The track fared little better where Shock Absorption was concerned. NEED TO FILL IN THis PARA
The results show that here is a strong correlation between the thickness of the surface and the level of shock absorption it provides. It shows that a lack of 3 mm in the surface of the track resulted in a 15% to 20% reduction in the shock absorption level of the track. Keep in mind that the track did not loose 3 mm across the entire surface. Rather it has lost crumbs in the top layer that provided peaks and voids allowing the shock absorption levels to increase.
While IAAF’s performance requirements apply for the life of the track. ASET suspects that too often track owners test their facility one time, if even then, and then fail to monitor how the performance changes over time.
The fact is that not that very few tracks within North American receive IAAF certification, but the vast majority are promoted as providing beneficial shock absorption and vertical deformation levels. Performance levels are common within product literature and manufacturer provided specifications. This study has implications for every facility:
- Without commission testing of your new surface there is no way to be certain it delivers the performance you specified.
- This study shows that even slightly thinner surfaces have large effects on shock absorption and other key properties. The lack of commission testing makes it possible to apply slightly less product than required to delivered the promised performance.
- Track properties change over time, therefore ensuring that new surfaces perform as specified is one way to help the track perform better for years to come.
Contact ASET Services, Inc with any questions you may have with regard to your track surface. We can help verify that new surfaces perform as specified. We can also evaluate older track surfaces so that schools can quantitatively evaluate how much better a new or resurfaced track would perform compared to their existing one.
The italic information in this post was obtained from the following source: 2016 Track and Runway Synthetic Surface Testing Specifications: Published by IAAF