Question Your World: How Can Coffee Make Eco-Friendly Roads?

Posted: May 31, 2017

Coffee and humanity have a pretty close relationship. Currently, it’s the second most traded good around the globe next to petroleum. Here in the United States we consume a little over 400 million cups a day. Most people start their day with that first cup and then head to work. More often than not the commute to work will involve a paved road. This is a pretty remarkable story of how coffee is becoming part of making our roadways more eco-friendly. This week let’s tackle the big question: How can coffee make eco-friendly roads? 

First of all, there are a lot of roads in the United States. We have a little over 2,300,000 miles of paved roads, enough to circle the Earth almost a hundred times. That’s a lot of asphalt. While traditionally paved asphalt roads are ideal for driving to grandma’s house, they are also some of the frequent contributors of CO2 in the atmosphere. Here’s where the first question pops up: how do we make more eco-friendly roads? 

Creative solutions don’t always show themselves immediately. Sometimes it takes years, decades, and even centuries to reach the right answers. In this case, scientists considering a more sustainable road construction practice needed to find something that was abundant, going to waste, and affordable. Perhaps after a few cups of coffee, the idea finally jumped into the minds of these big thinkers. Coffee grounds, of course! 

Right now, coffee grounds are discarded once we’ve made our delicious morning drink. More often than not they end up in landfills, rivers, and oceans. This does no good for anyone and the grounds are considered a common pollutant in our natural water systems. Once these coffee grounds are approached as engineering materials instead of an environmental problem, the big picture starts to become more clear to researchers working on this project. 

A city of about 4 million people produces a lot of coffee grounds. By taking these grounds, mixing them with slag (left overs from steel production), and baking them in an oven for a few days scientists were able to create robust and sturdy slabs to act as roadways. The mix is 70% coffee and 30% slag, not bad! According to these researchers, a city about the size of LA (4 million population) could easily produce up to 3 miles of roadways a year using this technique.

While this study is still in its early stages, it could be a big game changer for the road construction industry. Perhaps our daily morning caffeine source could one day pave the way for more sustainable construction practices. Also, the remarkable part is that it’ll prevent the congestion on I-95 as well! Just kidding about that last part - it seems like not even science can help there! 

Need more on the science behind coffee? Check out the clip below!