Compound Interest: What are the Olympics athletics tracks made of?

Infographic on the materials science of athletics tracks. The 2020 Olympics use a specially designed track surface made from rubber, which returns to its original shape when it's deformed. Vulcanisation (treatment of rubber with sulfur) increases rubber's rigidity by forming crosslinks between rubber polymer chains. Rubber granules embedded in the layers form bonds with the vulcanised rubber matrix, improving elasticity and shock absorption. The texture of the track surface improves slip resistance and traction, while the honeycomb layer of the bottom layers also aids shock absorption. Other types of running track bind rubber particles with a polyurethane polymer over an asphalt base, and these track surfaces are commonly used for school and community tracks. — Click to enlarge

The 2020 Olympics may have been a bit late arriving thanks to the pandemic, but there’ve been no signs of sluggishness from athletes on the track. World records have been tumbling over the past weeks, and one factor behind this could be the technology used in the track. I worked with Jess Wade on this graphic to take a closer look at the materials science behind the track surface.

Note: The original version of this graphic depicted sulfur linkages in vulcanised rubber attaching to one of the carbons in the double bond. This is incorrect – the sulfur linkages attach to methylene groups in the chain. The graphic has been amended accordingly.

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