In a collaboration project1 between Aarhus University (Aarhus, Denmark) and technological services company FORCE Technology (Brøndby, Denmark), researchers are aiming to develop an intelligent, self-powered sensor to monitor corrosion in steel-reinforced concrete structures.
According to the research team, many current sensors are prone to errors; based on slower technologies that are decades old; and relatively expensive. They describe many current sensors as “indicative” and “energy demanding,” adding that they can cost up to approximately $5,500 per measuring point.
Plaster Sensor Alternative
By contrast, the researchers are working to develop a more efficient alternative to those current sensors for assets comprised of steel-reinforced concrete.
“The aim of this project is to develop a plaster sensor, which is placed on the reinforcement and molded into the concrete construction,” says Jaamac Hassan Hire, a doctoral student at Aarhus working on the project. “The sensor and interfacing electronics are powered by means of energy-harvesting technologies to ensure continuous monitoring of the condition of the steel.”
They describe their innovation as a “smart patch” that can be applied to various assets.
Processed at Central Computer
The data collected is sent to a central computer where it is processed. The project, named DIGIMON, is being headed by Farshad Moradi, an engineering professor at the school. “Within this project, we will use ultrasonic waves generated locally in a self-powered sensor inside the concrete to monitor the corrosion,” Moradi says. “We want to be among the first—probably the first-ever—to develop a self-powered corrosion sensor.”
The project has been funded by Innovation Fund Denmark as a collaborative industrial project between ICELab at Aarhus University and IdemoLab at FORCE Technology.
“We’re working with monitoring today, and we see a lot of potential in being able to continuously monitor large constructions, even in harsh environments,” says Morten Wagner, head of department at FORCE Technology. “This would provide us with a clearer picture of the state of the construction or building. DIGIMON is a great example of mobile and energy-efficient modern technology that’s at the very front of the technological revolution, and I hope it can play its part in making structures safer in the future.”
Potential End Uses
The researchers pointed to the 2019 collapse of the Morandi Bridge in Genoa, Italy, as a leading example of what they are trying to improve with their sensor system. They explain that the harsh marine environments to which those types of steel-reinforced bridges are exposed often cause oxidation as part of a spontaneous electrochemical reaction.
“It’s extremely interesting to work on this project,” Hire concludes. “Structural health monitoring is a new and improved way of doing traditional nondestructive testing. It involves the integration of sensors, smart materials, data transmission, and processing. It’s currently receiving great technical and scientific interest, since awareness of structural integrity and safety, planning of repair works, and the associated costs have become a focus area for owners.”
Source: Aarhus University Engineering, ingenioer.au.dk/en.
1 “Smart, Self-Powered Patches to Put an end to EUR 2.3 Trillion Bill Caused by Rust Worldwide,” AU Engineering News, Dec. 6, 2019, https://ingenioer.au.dk/en/current/news/view/artikel/smart-self-powered-patches-to-put-an-end-to-eur-23-trillion-bill-caused-by-rust-worldwide/ (Jan. 20, 2020).