Concrete is one of the most widely used materials in the world and is responsible for as much as nine percent of total carbon emissions. Scientists at Rice University have figured out a way to reduce that impact by converting waste from rubber tires into graphene that can, in turn, be mixed with concrete, making it stronger.
The majority of the 800 million tires discarded annually around the world are burned for fuel or ground up for other uses, with 16 percent of old tires winding up in landfills. Reclaiming even a fraction of those landfilled tires as graphene could significantly reduce the amount of waste that ends up in our already congested landfills.
The new study builds upon the “flash” process — a technique (introduced last year by the same team) that produces graphene by exposing carbon sources, including food waste and plastic, to a jolt of electricity. The end product is a form of graphene known as turbostratic graphene, which has misaligned layers and is soluble, making it easier to use in composite materials such as concrete.
Using the same process, the team turned discarded tires into graphene that was later added to a concrete mix. The researchers then found that by adding only a minute amount of graphene to Portland cement, the concrete produced from that cement improved in strength by 30 percent.
According to the researchers, on top of diverting waste tires away from landfills, the new graphene-reinforced concrete also has other environmental benefits — because it’s stronger, less of the material would be needed in structures, resulting in less production-associated carbon emissions.
