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.