Robotic Inspections Used for Nondestructive Testing on Concrete Bridges

New geophysical nondestructive inspection technology from robotics manufacturer and professional services engineering group Infrastructure Preservation Corp. (IPC) (Clearwater, Florida, USA) is aimed at improving the early detection of structural issues or degradation on bridges.

The company’s robotic systems utilize nondestructive test protocols to x-ray concrete and other infrastructure, making it possible to identify early-stage deterioration and allow recommendation of repairs before deterioration spreads and compromises a structure’s ability to carry its design loads.

“It’s very fortunate when an inspection does catch bridge structural issues,” says Doug Thaler, president of the company. “Traditional inspection methods, virtually unchanged for the past 50 years, often do not detect minute fractures and structural faults, especially ones inside of the concrete—which fortunately can now be detected by new technology.”

Technologies used in the comprehensive inspection service include ground-penetrating radar, laser scanning, magnetic testing, electromagnetics, tomography imaging, acoustic imaging, aerial imaging, ultrasonic, and infrared. According to the company, proper diagnosis allows improved planning and repair of early-stage deterioration, including crack progressions and the possible breakdown of protective coatings.

In addition to small stress cracks, the services provider cited improperly mixed grout used inside post-tension tendons holding up a bridge as a possible source of structural degradation. If the chloride content in the grout mixture is wrong, the high chloride content of the grout can cause steel cables to corrode prematurely.

Bridge inspections should be conducted every two years, the company explains. Current inspection methods, however, can be outdated and manual in nature—thus delivering subjective results. On the other hand, they say robotic inspection services provide quantitative data that allow transportation departments to better allocate existing assets within current maintenance budgets.

Source: IPC, www.infrastructurepc.com.