PC steel wires on concrete and steel bridges now visible with terahertz waves
This is a photograph of typical extradosed bridge construction, in which one of the most important parts is the sustaining PC bundled steel cables sealed with invisible polyethylene. Credit: Yutaka Oyama
Researchers at Tohoku University have found a way to make covered or hidden PC steel wires visible, by developing a new terahertz wave light source featuring both light and radio-wave characteristics.
This new technology will be especially useful in the safety inspection of extradosed and other types of bridges that use PC steel wires hidden inside external cables covered by resin jackets. (see fig.1)
External cables are important structural elements for dispersing loads in extradosed bridges and they have extremely high levels of safety with regard to corrosion. This is due to the fact that they are protectively covered in polyethylene resin or similar resins.
Destructive inspections, in which the outer coating is removed from the cable, run the risk of water and other forms of moisture penetrating the wires and causing corrosion after the inspection has been completed.
The technology developed by Professor Yutaka Oyama and his team at the Graduate School of Engineering, is a unique optical measurement system comprising a digital device terahertz light source and a laser terahertz light source with high penetrative capabilities for polyethylene resin and similar resins.
This enables non-destructive imaging of the inside of PC steel wire to be carried out without removing the external resin cover by making use of the terahertz wave characteristics that efficiently reflect metal surfaces within the resin. (see fig. 2 and 3)
The team also found that contrary to the radioactive rays conventionally used for non-destructive detection purposes, the new terahertz waves have no adverse effects on the human body.
Part of the results of this research was first announced at the 2015 CLEO (Conference on Lasers and Electro-Optics) Pacific Rim Conference held in Busan, South Korea, in August.
Media Contact
All latest news from the category: Information Technology
Here you can find a summary of innovations in the fields of information and data processing and up-to-date developments on IT equipment and hardware.
This area covers topics such as IT services, IT architectures, IT management and telecommunications.
Newest articles
New organoid with all key pancreas cells
Researchers from the Organoid group (previously Clevers group) at the Hubrecht Institute have developed a new organoid that mimics the human fetal pancreas, offering a clearer view of its early development….
Unlocking the potential of nickel
New study reveals how to use single atoms to turn CO2 into valuable chemical resources. Nickel and nitrogen co-doped carbon (Ni-N-C) catalysts have shown exceptional performance in converting CO2 into…
‘Spooky action’ at a very short distance
Scientists map out quantum entanglement in protons. Particles streaming from collisions offer insight into dynamic interactions and collective behavior of quarks and gluons. Scientists at the U.S. Department of Energy’s…