CHENNAI: A smart device will now help structural engineers detect cracks on large structures and bridges before it is too late — all from the comforts of their office. Scientists from CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi, have developed a portable device that will monitor weak structures and send alerts whenever a crack is observed.
The device called the ‘Triboluminescence (TL) Camera uses a light emitting compound and a smart camera that allows detection of cracks — invisible to the naked eye — on structures made of concrete, metal and fibre-reinforced plastic.
The compound when coated on a surface will emit light due to excessive pressure and the smart camera is programmed to capture it. The images can be shared through cloud storage or a mobile app, web browser or Bluetooth.
The TL camera device was among the many technologies developed by the Council of Scientific & Industrial Research (CSIR) laboratory and on display at an industrial conclave in the city recently.
Scientist R Monika, who demonstrated the technology to visitors at the conclave, said the chemical compound used in the device is in the form of a coarse powder. When it is coated on the surface of a structure, it has the capability to emit red light when rubbed, scratched, pulled or ripped.
“In the case of a bridge or a flyover, its central portion and beams are considered the weaker parts. These areas can be coated with the compound. When vehicles move on the structure and these portions come under pressure, a red light is emitted wherever there are cracks. These cracks may otherwise not be visible to the naked eye,” she explained. “At present, structural engineers have to physically check for the smallest of cracks.”
To keep a record of the detected cracks, scientists have developed a smart camera that is programmed with an image sensor analysis software. The camera identifies the light emitted by the compound and captures an image. “The images can be accessed with details like date and time and width of the crack,” said the scientist.
The technology could come in for departments like the railways where there are several old bridges. Former railway officer R Ramanathan said railway bridges were once inspected by engineers with hand-held lenses that helped them check stability of the structures. Now, there are various modern hand-held devices like X-ray equipment and laser doppler vibrometer that are used to inspect minor cracks and measure strength of structures. “Unlike flyovers and bridges on city roads, almost all railway bridges in the country are about a century old. Indian Railways maintains a bridge register where all details of inspections and maintenance conducted over the years have been recorded. These come handy during future inspections,” he explained. CSIR-CECRI helps the railways in checking corrosion levels of Pamban bridge and provides remedial measures.