New device can see into concrete pillars from a distance of up to 10 metres (30 feet).

Massachusetts Institute of Technology engineers have developed a revolutionary new tool that allows inspectors to see inside a concrete pillar or pier without even touching it. Called FAR-NDT, which stands for “far-field airborne radar non-destructive testing”, the handheld device can check the health of concrete structures behind fibreglass-polymer jackets or wrapping.

The handheld device is a mini-radar that can not only detect damage within the concrete but also whether composite wrapping, used to strengthen older buildings against damage from earthquakes, has broken away from the concrete structure. It gives immediate on-site diagnosis, allowing inspectors to make quick decisions regarding safety if required.

The new tool allows inspection of a structure without having to redirect traffic or interrupt traffic flows. Previous tests required inspectors to get access to the structure and often required samples of the wrapping to be tested.

"The use of radar for detecting hidden defects and deterioration behind covered surfaces offers great potential for wide-range use in assessing the safety of bridges and buildings that have been retrofitted with composite materials," said Professor Oral Buyukozturk of the Department of Civil and Environmental Engineering (CEE). "This technique would allow the engineers to perform reliable, in-situ inspection for visualizing and characterizing hidden damages from distances without having to endanger the structure by taking specimens from it, and at the same time, without disturbing the traffic or service," said CEE student Tzu-Yang Yu, who will use this research as his Ph.D thesis.

However, while the initial experiments performed by researchers at MIT have been proven, more work on portable radar equipment needs to be done before it can become a regular sight on buildings and bridges around the world.