'Plastisoil' could mean cleaner rivers and less plastic waste
By Ben Coxworth
November 21, 2010
Plastisoil is a concrete-like substance made from discarded plastic bottles, that rain water can pass through instead of running into storm sewers
Image Gallery (2 images)A new cement-like material that could be used to form sidewalks, bike and jogging paths, driveways and parking lots, may be able to lessen two environmental problems, namely plastic waste and polluted rainwater runoff. The substance is called Plastisoil, and it was developed by Naji Khoury, an assistant professor of civil and environmental engineering at Temple University in Philadelphia. In order to make Plastisoil, discarded polyethylene terephthalate (PET) plastic bottles are pulverized and mixed with soil, and then that mixture is blended with a coarse aggregate and heated. The result is a hard yet non-watertight substance, similar to pervious concrete or porous asphalt.
With traditional concrete and asphalt paving, rainwater stays on the surface and runs into the storm sewers, accumulating oil and other road filth along the way. With pervious surfaces such as Plastisoil, that water is able to go down through them, and into the soil below. This certainly reduces the amount of pollutants entering the rivers, although Khoury and his team at Temple are currently trying to determine if Plastisoil could even serve as a filter, that removed pollutants as the water filtered through.
Khoury said that it uses less energy to produce one ton of Plastisoil than one ton of cement or asphalt, and that it’s less expensive to manufacture than similar products. It takes 30,000 PET bottles to make one ton of the material, although he is hoping to be able to use other types of plastic in the future.
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth
Questions:
1. In the formation phase, does the heated plastic release any toxic vapors?
2. When used as a surface, does the plastic pollute the rainwater that runs through it?
While I respect any attempts at dealing with the problem that the invention and widespread use of plastic has created, the stuff is so bad for the planet that it is almost not worth trying to work with. It might be better just to eject the crap into space. (And I would like to add, "along with it's creators".)
ForFreedom22nd November, 2010 @ 04:31 am PST
good idea well worth pursuing, how the new material can filter out pollutants without becoming blocked will be a big problem
robinyatesuk200322nd November, 2010 @ 04:52 am PST
For walkways and light-duty pavement this could make sense. One of the challenges with pervious surfaces (including those made pervious by cracking) is that when water reaches the subgrade soils they begin to break down (the subgrade is typically compacted before pavement is placed). As the subsoils become less rigid they fail to adequately support the pavement, causing it to crack even more. A downward spiral starts that can result in replacing both the pavement and the subgrade. So for heavy-duty use, probably a no-go. Otherwise it may have a place.
Bruce H. Anderson22nd November, 2010 @ 06:52 am PST
I'm also wondering Bill's second question; given high amounts of plastic-based endocrine disruptors already detected throughout ocean, I would like to know that the water they're filtering into the soil isn't further spreading BPA throughout our environment.
Lost22nd November, 2010 @ 07:29 am PST
I'd be really interested in seeing the long term (heck 6 - 18 months would be a start) studies of what is being leached from the plastisoil into the ground water. Sometimes, you need to be sure what you're trading... poisoning ground water may be worse than controlling run-off rainwater other ways. Engineers tend to measure everything... have the studies been done, are they available?
Facebook User22nd November, 2010 @ 03:03 pm PST
If water gets through it, that means grasses and weeds can sprout upwards through it too... Perhaps this needs a weed filter placed underneath?
Matt Rings22nd November, 2010 @ 06:31 pm PST
I had the same idea, only I called it Trashphalt instead of PlastiSoil.
Eletruk23rd November, 2010 @ 02:39 pm PST
the plastic probly wouldnt do well in winter i use bottles and fill them with water and freeze them and they crack. they have to use the certain platics because some are thicker then others the ones that wont work are milk jugs they crack after one time being froze but the thicker ones like pop bottles dont but after lick 40 to 50 times they do
Joshua T West25th November, 2010 @ 07:25 am PST
It might work in geographical areas with warm climates.
Adrian Akau25th November, 2010 @ 09:36 am PST
Nice, but will this plastisoil cause toxic by-product if certain petroleum product spill on it?
wow201025th November, 2010 @ 02:54 pm PST
So water goes through, taking pollutants with it into the soil below in stead of polluting the rivers... We just create another toxic waste repository under our homes. Good thinking!
BoilingOil25th November, 2010 @ 06:08 pm PST
It almost seems as though the stronger the feeling expressed by posters, the less knowledge they have. There is nothing toxic in PET. The epoxy which lines many 'tin' cans is made flexible in many cases by BHA, which mimics estrogen, but PET and epoxy are very different. See: http://earthnurture.com
BigCat26th November, 2010 @ 07:35 pm PST
"Is PET Toxic or Not?" by Dr. Casey Adams
http://www.associatedcontent.com/article/2584305/is_pet_toxic_or_not.html
ForFreedom29th November, 2010 @ 05:55 am PST
Seems like a good idea to me. Not sure why everyone is freaking out about PET all of a sudden... I'm not worried about plants growing under the bricks more worried about the freeze thaw. But to be honest any surface has to deal with this problem.
2 thumbs up from me which is rare...
oh and Dr. Casey Adams article was full of facts and details but no citations. Seems odd, surely a man of science would appreciate sourcing information. I would think the "DR" would make him an expert, I guess not.
Michael Mantion4th January, 2011 @ 07:00 pm PST
can it be used like 'shotcrete'? I can think of hundreds of lightweight 'concrete' things to make with it-mostly one-offs.
Kwazai29th May, 2012 @ 12:12 pm PDT
Matt Rings - Wonderful idea. The next modification they need to do is lace the entire product with certain mushroom spores. Oyster mushrooms do a great job at metabolizing motor oils and I would assume fuel as well. They will grow happily under the shade of parked cars and be fed by the moisture from the ground and the oil dripping down from above. I think that they also might break the plastisoil down over long time scales, but americans don't seem to want a permanent fix for anything anway..not enough profit to be had...
rwalker4th May, 2013 @ 04:28 pm PDT
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I wonder how this substance handle the freeze thaw cycles of the northern climates. It seems that the porous nature works against it in those situations (unless it's elastic enough to deform and reform). Can gizmag or the developers at Temple reply?
Bill de Iturrondo21st November, 2010 @ 04:49 pm PST