Crossing a Bridge

A course from Clemson University’s Joe Burgett has attracted both students and South Carolina transportation officials who want to learn how to operate drones, how the devices can improve bridge inspections and construction projects—and what they can’t do.

“A drone isn’t going to take the place of a person inspecting a bridge,” says Burgett, who teaches in Clemson’s Department of Construction Science and Management. For example, a drone can’t drag a chain across a bridge, listening for the telltale hollow sound that signals a problem. Over time, water can rust rebar—those embedded pieces of steel that strengthen concrete structures. As the rebar rusts, it expands, delaminating the concrete—or fracturing it into layers—so that “you can knock pieces off of it,” Burgett says.

What a drone can do, he says, is “observe 91 percent of all the inspection points and do it faster and safer than a person can. It’s just another tool.”

Offered for the first time last spring through a Federal Highway Administration grant, Burgett’s year-long course also focused on surveying. If workers are building a road, a drone can survey the work and photograph where water lines are. The images can become 3-D models in the class.

Not only did participants learn how useful drones can be; they also learned how to operate them. “You have to have a license to fly drones commercially,” Burgett says. “The first part of the class was on the software, with speakers coming in, and the second on actually flying the drones.” The students were somewhat reckless when doing drone simulations, Burgett says, but grew cautious when flying the real thing.

The advent of the novel coronavirus moved the course online in March. For the coming semester, Burgett expects to be teaching “a kind of hybrid,” combining online instruction with some hands-on practice outside.