Environment

Asphalt made of cigarette butts paves the road to less litter

Asphalt made of cigarette butt...
Discarded cigarette butts could soon be locked away inside asphalt roads and paths
Discarded cigarette butts could soon be locked away inside asphalt roads and paths
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Discarded cigarette butts could soon be locked away inside asphalt roads and paths
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Discarded cigarette butts could soon be locked away inside asphalt roads and paths

The 6 trillion cigarettes produced every year generate over 1.2 million tonnes of butt litter, and not only do the majority of them end up in the environment, but they're technically toxic waste. Now, researchers at RMIT University in Australia have found a new way to safely dispose of cigarette butts: seal them up inside roads and paths.

The idea comes from the same researchers that last year stashed old butts inside bricks. Not only is that an effective way to keep them from leaching their toxic chemicals into the environment, but they actually make for better bricks too: adding butts halves the amount of energy needed to fire the bricks, and improves the insulation properties of the end result.

Led by RMIT senior lecturer Abbas Mohajerani, the team has since gone on to investigate how asphalt might also benefit from the unusual construction material. First they encapsulated the butts in paraffin wax and bitumen, which locks the lethal chemicals inside and prevents them from leaching into the asphalt and eventually the environment. Then, the encapsulated butts are added to hot asphalt mix.

By testing samples of the butt-enhanced asphalt, the team found that not only could the material handle heavy traffic, it also tended to trap less heat from the Sun. That could help reduce the "urban heat island" effect that warms cities up to uncomfortable levels.

"This research shows that you can create a new construction material while ridding the environment of a huge waste problem," says Mohajerani. "Cigarette filters are designed to trap hundreds of toxic chemicals and the only ways to control these chemicals are either by effective encapsulation for the production of new lightweight aggregates or by incorporation in fired clay bricks."

The research was recently published in the journal Construction and Building Materials.

Source: RMIT University

4 comments
windykites
This is a good idea, butt...Sorry couldn't resist! The bricks are lighter in weight. Where are the butts collected from? Does someone trawl the pavements? Another idea: grind up waste plastic and use as aggregate in clay bricks.
watersworm
Hey ! Go on smocking guys (I'm kidding) Great idea, why not used tires ?
bergamot69
The problem with asphalt, surely, is that it gradually wears away from constant friction. Therefore the toxins would be gradually released over time and would enter groundwater. Encapsulating in bricks is probably a better way, although bricks need to be cut and drilled as required. I hope we can find a better way of disposing of them- although, happily, in the Western World at least, cigarette smoking is very much on the decline.
Rorschach
A similar method was applied by adding sawdust to the clay prior to firing many decades ago in Australia. Since no industrial acceptance was achieved all those lightweight and insulating bricks were exported to a USA client and nothing more was heard about this endeavor. Generally it takes around 50 years for a new technology to be accepted by the building and construction industry.