Researchers at the Queen's University Belfast and City University London have developed a corrosion sensor that can identify the earliest corrosion signs in concrete. The breakthrough sensor is a long lasting solution critical in monitoring the stability and safety of structures along the coastline, such as bridges.
In a project funded by the UK-based EPSRC (Engineering and Physical Sciences Research Council), the sensors were developed by the university researchers to withstand extended duration placement within concrete, the first of its kind, to continuously monitor and indicate the earliest signs of conditions resulting in damage. The carbon steel bars which are placed to reinforce concrete submerged in tidal zones are at a high level risk due to the wet conditions. With a corrosion sensor placed in the concrete, the issued warning is sent over the Internet by the maintenance team assigned to the structure.
Three probes form the core of the sensor –one probe monitors the pH and chloride levels, the second monitors humidity and the third monitors the temperature. Drastic changes in their parameters are indicative of destructive corrosion of the concrete structure. State-of-the-art optical sensors developed researchers at City University London have been integrated into the probes.
The Principal Investigator of the project at the professor of sensor engineering at City University, Professor Tong Sun explained that by closely monitoring the variation of the sensor data received from a sample study structure can result in a successful prototype of the sensor. The professor also added that the optical sensors can also be made of polymer, a more resistive material that can withstand the highly alkaline environments of the structure.
Professor Sun also explained that by using the sensors and conducting remedial repair required by any structure will be cost effective and a simpler process rather than waiting for visual indications that would require a thorough investigation.
Source: http://www.city.ac.uk/