To test the safety of a bridge, engineers rely on some pretty low-tech methods. One common way of doing it is to drag a chain across the bridge and listen in for the hollow-sounding spots. But, weirdly, an even-lower-tech method might speed things along: Have the rain do the work for you.
In the same way that structural deficiencies can be detected with something solid, two engineers from Brigham Young University--Brian Mazzeo and Spencer Guthrie--are listening in for the tell-tale acoustics by splashing bridges with water. They're looking for something called "delamination." In a concrete bridge deck, the layers used to build the bridge can become separated over time--it's a major concern with some aging bridges. Right now, some of the processes (like the chain-dragging) can take hours, and shut down lanes for that time.
The water solution is simple, and could potentially fix the traffic problem. One day, the researchers say, it might be as easy as misting a bridge as they cruise by in a car. (No, you don't have to wait for it to actually rain. Although that's more poetic than car-misting.) It might also make its way into related industries, like aircraft construction, where delamination of composite parts is a problem.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.