Making Better Asphalt with Nanoclays
Undesirable ruts in asphalt roadbeds. Photo courtesy of Michigan Tech.
As summer road crews get to work filling ruts and potholes, we are reminded of the shortcomings of modern asphalt. Although one might expect this material to be superior to past technologies, it is important to remember that fragments still remain of Babylonian roadbeds constructed in 600 BCE—some 2,700 years ago.
Zhanping You, a scientist at Michigan Technological University, speculated about the possibility of adding nanoclays to modern asphalt in order to extend its useful life. “Asphalt is now made from petroleum, so it’s very expensive,” said professor You. “As a result, a lot of people are looking at ways to make it more durable.”
Nanoclays are nanoparticles of layered mineral silicates that may be combined with polymers and other substances to make high-performance nanocomposites. Professor You added various small amounts of nanoclays—between 2 and 4 percent—to asphalt and tested its performance. The durability results were notable. “It improved the viscosity significantly,” You said. “That means it will provide better stiffness, which means that it won’t deform as much in hot weather or under heavy traffic.”
You and his research colleagues recently published their research in an article titled "Nanoclay-Modified Asphalt Materials: Preparation and Characterization" in the journal Construction and Building Materials.