MIT students have developed a method of strengthening concrete using plastic bottles.

By replacing around 1.5% of cement with irradiated plastic the students found that concrete’s strength was increased by 20%. Not only is this a good way of using plastics which would otherwise end up in landfill, it also cuts the industry’s carbon emissions.

“Concrete produces about 4.5% of the world’s carbon dioxide emissions. Take out 1.5% of that, and you’re already talking about 0.0675% of the world’s carbon dioxide emissions. That’s a huge amount of greenhouse gases in one fell swoop,” explained Michael Short, assistant professor in MIT’s Department of Nuclear Science and Engineering.

He added: “There is a huge amount of plastic that is landfilled every year. Our technology takes plastic out of the landfill, locks it up in concrete, and also uses less cement to make the concrete, which makes fewer carbon dioxide emissions. This has the potential to pull plastic landfill waste out of the landfill and into buildings, where it could actually help to make them stronger.”