Intensive efforts are underway all over the world to get 'more road for your money' by developing better methods for both design and quality control of materials. One problem is that today there are no good methods for checking how robustly and safely the roads were built.
Therefore they often don't last as long as they were supposed to and more money has to go to road construction. But now a young scientist has developed a method where sound waves can reveal what a road looks like underneath and thereby show whether it is being properly built.
According to the Swedish Road Administration, the method, which is expected to become the new standard, may entail major quality enhancements and cost savings.
Damage to bridges, tunnels, dams, and nuclear power plants can be uncovered using this technology, and dangerous accidents can thereby be prevented. Today most prognoses are based on educated guesses from previous experience, which often prove to be wrong. Since a road consists of many different materials - gravel, bitumen, air, water - it's difficult to predict how it will respond to future traffic and environmental loads. Because roads, unlike buildings, for instance, are 'built into' the ground, it's hard to inspect them visually.
"But with sound waves, roughly as with x-rays and ultrasound, you can obtain information about the composition and stiffness of the material on a computer screen. This allows you to monitor whether work is being done properly, thus ensuring that the road will last as long and withstand loads as well as projected. Today inspectors typically have to drill cores and break up asphalt and concrete samples, instead of using this non-destructive type of testing," explains Nils Rydén, a researcher in engineering geology at the Faculty of Engineering, Lund University, who developed the technology.
Some roads only hold up for a couple of years, according to Nils Rydén, either because the materials were not sufficiently compacted, because the road bed was too soft, or because it was raining when the road was built, weaknesses that were then not discovered when the final inspection took place.
Major portions of the country's infrastructure were constructed 40 to 50 years ago and will soon need to be repaired, on the one hand, because they are worn out and, on the other, because they were dimensioned for 40 years, which was the standard back then. That time has now gone by and the question arise if and for how long the structure can be used. The concrete foundations of the Swedish nuclear power stations are in the same situation. Here, too, there have been no methods for inspecting and verifying whether they are in good condition.
"A road can't collapse into the earth and constitute the same safety risk as a bridge or a hydropower facility, which can in fact collapse, as has recently happened in the US and Russia," says Nils Rydén, who for the last couple of years has been busy, alongside his research, helping the Road Administration and various construction companies by tuning his technology so they can use it for their particular needs.
Nils Rydén was inspired to test the possibility of inspecting roads with sound when he wrote his master's thesis in 2000. At that time there were similar projects underway abroad, in the US, for instance, but today the Swedish method is the most advanced technology, according to Nils Rydén. Sound waves have previously been used to inspect material in the auto and aircraft industry and to find oil and gas deposits underground.The technology in brief:
For more information, please contact Nils Rydén, PhD in engineering geology, Department of Electrical Measurements and Industrial Electrical Engineering and Automation, Faculty of Engineering, Lund University,phone: +46 (0)46-222 74 24; cell phone: +46 (0)733-37 49 36; e-mail: Nils.Ryden@tg.lth.se
Kristina Lindgärde | idw
New, forward-looking report outlines research path to sustainable cities
24.01.2018 | National Science Foundation
Magnetic liquids improve energy efficiency of buildings
16.01.2018 | Friedrich-Schiller-Universität Jena
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.
Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
19.04.2018 | Materials Sciences
19.04.2018 | Physics and Astronomy
19.04.2018 | Physics and Astronomy