Engineers often see opportunities for solutions where there are large, systemic challenges in society. Of the 34.5 million tons of plastic disposed each year, only about 10 percent is recycled, while over 90 percent is landfilled or incinerated.
Edwin G. Burdette Professor Baoshan Huang, Professor Qiang He, and Associate Professor Nick Zhou see an opportunity to incorporate some of the disposed plastic materials into asphalt mixtures to reduce plastic waste.
“We aim to develop a novel processing technique to co- stabilize recycled plastics and lightly pyrolized crumb rubber in asphalt,” said Zhou. “It’s important for us to create a high-performance product that finds compatibility between commodity plastics and asphalt systems and utilizes high- volume waste plastics from the municipal waste stream.”
Each year, about 350 million tons of asphalt concrete is produced in the US for pavement, representing an enormous potential to reuse the otherwise wasted plastics. The UT team has set out to develop and demonstrate a universal strategy to co-stabilize comingled waste plastics with waste tire rubber into asphalt binders and solve previous challenges in this area of research.
With the help of a 24-month $925,000 grant from REMADE Institute under the US Department of Energy’s Advanced Manufacturing Office, the team will work toward eliminating technical and economic barriers that have arisen in previous studies where poor solubility of polymers was found to limit the number of macromolecules able to form a swollen network with asphalt molecules.
The team includes research partners at Oak Ridge National Laboratory and Paragon Technical Services Inc. and has support from the Tennessee Department of Transportation and other industrial partners.
The new technique aims to coprocess two abundant waste materials—plastic and tire rubber—while reducing costs. Other potential benefits include better resistance to rutting and cracking, longer service life, reduced road noise, and reduced maintenance costs.
“We believe it is worthwhile to conduct this study so that we can overcome previous technical challenges,” said Huang. “The preliminary studies conducted have proven to be promising in regards to incorporating recycled polyethylene.
These advantages make this technology worth investigating.” The research team hopes to have a prototype ready by 2024.