Bridge Monitoring

For many people in the United States, driving over one or more of the nation’s 602,000 highway bridges is part of their daily commute, and recent statistics from the Federal Highway Administration indicate that more than 145,500 of these bridges are either structurally deficient or functionally obsolete. To help assess the structural stability of these and other highway bridges so that structural issues are pinpointed and necessary maintenance and repairs can be planned to ensure bridge safety and longevity, Resensys has developed its wireless structural healthmonitoring solution for existing bridges and bridges under construction that features small, low-cost, easy-to-install wireless sensors that measure a variety of variables affecting the performance of a bridge.

Loading test performed on Robert Norris Bridge, VirginiaData collected from the sensors can provide bridge owners with diverse information on bridge structural health such as overstrain, changes in load conditions, deformation, excessive vibration, crack development and growth, and conditions that are conducive to corrosion. Resensys monitoring system is unique in that it is extremely low power. For example, an individual sensor needs only 4 μW to operate.

Resensys' SenSpot™ sensors are also capable to monitor specific variables that indicate favorable conditions for corrosion of reinforcing steel in concrete, moisture, electrochemical activity, and chloride concentration. These sensors possess a small probe that is inserted into the concrete at a depth that enables close proximity to the reinforcing steel. The type of probe used on the sensor corresponds with the conditions being monitored in the concrete (i.e., the amount of moisture, the concentration of chloride ions, or the presence of an electrochemical current between the steel and the concrete).