Porous Road Material from Butts May Help Biz Manage Stormwater Runoff

by | Aug 16, 2017

This article is included in these additional categories:

Cigarette butts, all roughly 1.2 million metric tons of them, pile up annually and the waste shows no sign of tapering off. But an enterprising engineering researcher from RMIT University in Melbourne, Australia, might have figured out an effective and productive way to recycle them. The resulting material could help businesses manage stormwater runoff — and lessen the heat island effect in paved areas.

Over the past five years, Abbas Mohajerani, a researcher and senior lecturer at RMIT’s School of Engineering, has been leading a team to solve the mounting cigarette butt issue. Turning them into a road surface might seem like a complete disaster since cigarette butts contain many toxic chemicals that already inadvertently get released into waterways and oceans.

However, in order to turn the cigarette butts into a useful material, Mohajerani and his colleagues encapsulated the waste with paraffin wax and then bitumen, the sticky black petroleum-based part of roadways we usually call asphalt. This technique fully trapped the chemicals to prevent leaching, Mohajerani said in an announcement from the university. Then the researchers mixed the coated cigarettes butts with hot asphalt mix to create different samples.

The team recently reported in the journal Construction and Building Materials (abstract), that making asphalt concrete from the encapsulated cigarette butts actually reduced the bulk density of the final material. Having more porous asphalt concrete can in turn reduce the heat island effect in urban areas, lowering greenhouse gas emissions.

For businesses that manage stormwater runoff, using a porous kind of concrete currently tends to be a fairly expensive up-front investment, but it’s one that can lead to long-term savings depending on how strict the stormwater runoff rules are locally. Property owners seeking new ways to manage stormwater runoff are swapping impervious concrete pavers for porous pavement that allows rain to pass through the material and gather in a collection area underneath.

Ignoring stormwater management rules can be costly, as one lumber company in Tacoma, Washington, discovered earlier this year. The EPA ordered Manke Lumber to pay $65,000 for waterway restoration.

Using cigarette butts as a material for new products could be a boon because they show no signs of disappearing. Researchers at RMIT University expect that the number of cigarettes produced and butts discarded worldwide will increase by more than 50% by 2025 due to increases in global population.

If Mohajerani’s name sounds familiar, that could be because he previously did something similar last year with cigarette butts and bricks. Adding cigarette butts to bricks cut the energy required to fire them by up to 58%. At the time, Mohajerani’s research showed that if just 2.5% of the world’s annual brick production incorporated 1% of cigarette butts, the process could completely offset annual worldwide cigarette production.

Additional articles you will be interested in.

Stay Informed

Get E+E Leader Articles delivered via Newsletter right to your inbox!

This field is for validation purposes and should be left unchanged.
Share This