Featured Research

from universities, journals, and other organizations

C2D2 fighting corrosion

August 22, 2014
ETH Zürich
Bridges become an infrastructure problem as they get older, as de-icing salt and carbon dioxide gradually destroy the reinforced concrete. A new robot can now check the condition of these structures, even in places that people cannot reach.

Robt checking a reinforced concrete bridge for signs of corrosion.
Credit: Image courtesy of ETH Zürich

Bridges become an infrastructure problem as they get older, as de-icing salt and carbon dioxide gradually destroy the reinforced concrete. A new robot can now check the condition of these structures, even in places that people cannot reach.

We rely on Switzerland's 3,500 motorway bridges -- plus thousands more on cantonal roads -- to carry us safely across valleys, streams, rivers and other roads. Most of these bridges have two factors in common: they are essential to Switzerland's transport infrastructure and they are made of reinforced concrete. This material makes them safe and durable -- until the onset of corrosion.

Corrosion jeopardises Swiss infrastructure

Corrosion occurs when chloride invades from de-icing salt and destroys the reinforcing steel inside concrete or when CO2 from the atmosphere lowers the concrete's normally high pH. The damage becomes worse over time and is often visible only at a very advanced stage. In the long term, this can jeopardise the usability and safety of bridges and other supporting structures made of reinforced concrete. Furthermore, restoring these bridges is very expensive: the greater the damage caused by the corrosion, the more costly the repair work. "In addition, many bridges in Switzerland are already more than 50 years old, which makes corrosion increasingly problematic for Switzerland's infrastructure," explains Bernhard Elsener, professor at the Institute for Building Materials at ETH Zurich.

That is why Professor Elsener and a team of researchers developed the technology 25 years ago to identify corrosion at an early stage, attaching an electrode to a wheel and wheeling it across the surface of the reinforced concrete. The sensor measures the electric potential difference in the reinforced concrete -- large differences mean that the reinforcement has already started to corrode in those areas. The data is transferred to a computer and then analysed.

This technology for measuring the potential variation has been used successfully for a long time in the inspection of bridges, says Elsener. But one problem remains: "The wheel electrode is attached to a stick and has to be wheeled manually. This means that many areas, such as supporting pillars and the undersides of high bridges, lie out of reach."

Detecting corrosion with a robot

To solve this problem, the Institute for Building Materials joined forces with the Institute of Robotics and Intelligent Systems and formed a project team consisting of Bernhard Elsener, Alexis Leibbrandt, Oliver Glauser, Ueli Angst and Robert Flatt from the Institute for Building Materials, as well as Gilles Caprari from the Autonomous Systems Lab at ETH Zurich. The aim was to develop a robot that could detect corrosion in all areas -- including sites inaccessible to people -- and at the earliest possible stage. The researchers did not have to search long for a solution: "The students in one of our focus projects developed a robot four years ago that can move not only on the ground, but also along walls and ceilings. This made it ideal for our project," explains Roland Siegwart, professor at the Institute of Robotics and Intelligent Systems and Vice President Research and Corporate Relations at ETH Zurich.

The robot's movement is based on Vortex technology, where a type of propeller is attached to the underside of the robot. The propeller rotates fast enough for a movable suction cup to stick the robot on to walls and ceilings, where it can then use its wheels to move along these surfaces. The robot is steered via remote control or a computer.

Paraswift now C2D2

"The robot was originally called Paraswift and was developed with a view to being used by Disney. When a camera is screwed on to the robot, it can easily film a room from all perspectives," explains Siegwart. For the new project, the team rechristened Paraswift as C2D2 (Climbing Corrosion Detecting Device) and modified it for use as a corrosion detector: "We made the casing and wheels more robust and incorporated the corrosion-identification technology," explains Elsener, who is spearheading the project.

The electrode is located on the underside of the robot and measures the potential difference of the reinforced concrete while the robot moves along the structure. A specialist then analyses the collected data. The engineers also attached a pink ball to the top of C2D2, which makes it easier for cameras to detect it and for researchers to control and locate it. This ball contains an additional camera that records the surroundings and enables the robot to identify and avoid any potential obstacles.

Successful initial tests

The team hope that by the end of the project in mid-2015, the robot will be able to identify and overcome such obstacles by itself. The researchers also intend to replace C2D2's manual steering with a navigation system, which will make the robot autonomous, and they are currently working on a software program that will analyse much of the data itself.

The project team patented the robot in 2012. Companies interested in a licence can contact ETH transfer, the technology-transfer office at ETH Zurich. C2D2 has already proved its worth during tests on various bridges in Switzerland. The engineers now need only to optimise the robot for use on vertical surfaces. They will conduct more tests before the end of the project. The Federal Roads Office (FEDRO), which is funding the project, will decide based on these results whether to use C2D2 for regular bridge inspections in the future. This is something that Elsener definitely recommends: "C2D2 can help to create a safe and sustainable infrastructure at a relatively low cost -- that was the motivation behind the project."

C2D2 won an award in the 'Prolongation of service life' category in an international competition at the Concrete Innovation Conference (COIN) on 13 June 2014. The competition was held for the first time this year.

Story Source:

The above story is based on materials provided by ETH Zürich. Note: Materials may be edited for content and length.

Cite This Page:

ETH Zürich. "C2D2 fighting corrosion." ScienceDaily. ScienceDaily, 22 August 2014. <www.sciencedaily.com/releases/2014/08/140822124520.htm>.
ETH Zürich. (2014, August 22). C2D2 fighting corrosion. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2014/08/140822124520.htm
ETH Zürich. "C2D2 fighting corrosion." ScienceDaily. www.sciencedaily.com/releases/2014/08/140822124520.htm (accessed October 20, 2014).

Share This

More Matter & Energy News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) — Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) — Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) — Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) — Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins