Neat rows of asphalt cores fill the shelves of the Civil and Environmental Engineering Construction Materials Laboratory. Stacks of sealed black buckets filled with various construction materials splits the room in half. Of all the textures and tools lying around to pique visitors’ interests, the machine in the back corner commands the most attention.
Called the PURWheel, this box-like tracking device is one of only two of its kind in the country. It allows researchers to test samples of different kinds of pavement to see how it responds to extreme conditions.
“The worst situation for pavement is when it’s hot. It makes it more flexible and can lead to problems with rutting,” explained Ben Cox, a doctoral student who works in the lab.
The enclosed structure of the machine allows researchers to control temperature, which can exceed 150 degrees Fahrenheit, as well as test moisture conditions from dry to completely submerged. A built-in tracking wheel simulates the pressure of a large truck driving down the highway, rolling over the pavement sample thousands of times.
The result is a piece of pavement with a clearly defined tire rut that can be analyzed to determine the stability of the pavement mix.
Under the supervision of Isaac L. Howard, an associate professor and Materials and Construction Industries Chair in Civil and Environmental Engineering, the lab studies a wide variety of construction materials including asphalt, emulsions, concrete and stabilized soils.