The large number of bridges makes it difficult to carry out comprehensive inspections, and that may sometimes result in tragedies like the collapse of the I-35 bridge in Minneapolis. A far more reliable solution would be that bridges be able to inspect themselves, and relay information to operators. This is what the University of Michigan is trying to achieve through a $19 million project.

The idea is to add four sensors to the bridges, which would be able to report any troubles to the concerned authorities. First in line is the use of conductive, high-performance, fiber-reinforced and bendable concrete. It is more durable than conventional concrete and any change to its conductivity will signal problems. Another sensor is a carbon nanotube-based “sensing skin,” which, when painted to hotspots, will use electric resistance to find cracks and corrosion invisible to the human eye.

The third sensor would be wireless nodes powered by vibrations on the bridge and radio waves; these sensors will detect strain or change in vibrations on the bridge. Finally, a sensor can be placed in vehicles that travel over the bridge; this sensor will test the reaction of the bridge to the strain a vehicle imposes.

Via: Gizmag433660