Erik Schlangen presents a new design for “self healing asphalt”. His lab sought out to reformulate asphalt roadways to address many of the issues that currently exist. In current roadways, the binder that holds together the rocks breakdown from exposure to UV rays and usage. When that happens the rocks at the top get stripped off of the surface (raveling). Raveling can cause damage to windshield and paint jobs especially on highways when cars in front kick up the loose gravel. It also can lead to potholes. There are also issues with noise (roadways are loud and bounce back noise from cars driving) and puddles.
3:00 – 3:20
Schlangen’s approached involved creating a more porous roadway, ironically with less rather than more binder. The extra spaces and hollow areas that are left allow water and noise to pass through the surface rather and gather or bounce back out.
To address the fundamental problem of ravelling, they embedded the asphalt with small pieces of steel wool and used an induction machine to heat up the steel, thus heating the binder, and “healing” the roadway.
At the 3 minute mark he introduces the concept and problem of raveling. Schlangen uses not only the slides and speaking but also has a handful of aggregate (rocks) that he sprinkles on the ground. As silly as that seems I think its actually really helpful to educating the audience really quickly. Even though they probably never heard of the term raveling or been conscious of different states of roadway damage, the little rocks and images and raveled roadway are all things we’ve seen in our own lives. By actually having little samples and showing what it looks like, Schlangen manages to convey his point extremely quickly by linking it to the things we already know.
He also grabs the audiences attention by pretending to throw some into the crowd. That part brings some comedy and interest to a topic otherwise extremely dry and boring.
Schlangen again captures the audience’s attention by showing a funny image and immediately tying it back into his previous point on the risks and dangers of raveling.
He again explains the phenomenon extremely clearly by using a good visual. The diagram makes it very easy to understand the problem itself and how it causes the aggregate to release from the asphalt.