May 1996 Embedded Sensors Spotting damage before it is too late. Most collapses occur on shorter spans, but many largebridges, their maintenance long underfunded, also are riddledwith cracks and weak spots.
Concrete bridges are at higher riskthan steel, because their flaws are often less apparent.
So itissomewhat surprising that technology is rarely used to routinelymonitor the health of concrete bridges. All the more soconsidering how cheaply and easily it could be done. Her strategy was deceptively simple. Then place electrodes at each end of the bridge and measure its resistance. Taking just a few basic measurements, Chung was able to deduce with surprising accuracy the extent of fractures within a bridge, the consequent reductionin its strength, and the probability that it had suffered serious damage.