MRI-like scan to give Bridges a quick check-up

SUYUN HAM can't take his eyes off a scanner. "Lower the sensors a little bit more," Ham urges an assistant. Then a barrage of data floods in, filling computer screens for a diagnosis. But Ham isn't a medical doctor. Nor is his "patient" a living creature. An engineering professor from the University of Texas at Arlington, he is experimenting with a novel approach in bridge inspection.

- COCO LIU

Ham's mobile-scanning system is part of efforts to make US infrastructure more heat-resilient. Unlike floods and tornadoes that can quickly destroy bridges, extreme heat is a silent killer that harms them over time, experts say. "If temperatures are out of range, bridges can get damaged unexpectedly," says Ham. "With our 'MRI,' we can see what's inside a bridge quickly."

Bridge materials expand and contract in response to temperature fluctuations. While most are equipped with features to accommodate that movement, they were designed to withstand historically cooler temperatures, says Paul Chinowsky, a professor emeritus of civil engineering at the University of Colorado Boulder.