An alternative use for tires is Rubberized Asphalt. In the US, 48 out of 50 states have laws making it illegal to dispose of tires in the trash with other refuse. As an alternative to throwing the tires away, they can be recycled and re-purposed for a multitude of cool uses. Over 40 years ago, the German company BSW invented the technology to recycle rubber, essentially turning old, used-up tires into brand new rubber products. Although originally used to manufacture sheet rubber for flooring purposes, this technology has been adapted to allow the production of a huge variety of recycled rubber products. Over the next 4 weeks, we will highlight some of these alternative uses, starting with rubberized asphalt.
Ironically enough, a large portion of recycled tires make their way back onto our roads in some form or another. One of the leading ways that this rubber finds its way back on our roads is in rubberized asphalt. Through a blending process, rubber crumb (ground rubber tires) is combined with an unmodified asphalt binder. This produces rubber-modified liquid asphalt binder, which is then combined with hot asphalt in a mixer, which is then ready to be used on our streets and driveways.
Asphalt that is rubberized is generally considered to be more durable and require less maintenance than standard asphalt. Due to oxidization, traditionally paved asphalt will lose elasticity and resiliency over time. This loss in resiliency, combined with the stresses of changing temperatures will result in cracks on traditional asphalt. Rubberized asphalt has significantly higher resiliency properties than traditional asphalt, which helps prevent cracking. Meanwhile, the post-consumer rubber mixed into rubberized asphalt has anti-oxidants, which helps prevent the road from aging as quickly.
Rubber is a natural shock and sound absorbing material. When it is mixed in with asphalt, these properties are translated into the new rubberized asphalt. As a result, asphalt roads that are rubberized can reduce traffic noise by up to 5dB! Increased car traction is just another benefit of combining post-consumer rubber into rubberized asphalt.
Stay tuned next week to hear about some of the ways recycled rubber is used in industry!