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
Modular storage tank for tight spaces
16.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Smart homes will “LISTEN” to your voice
17.01.2017 | EML European Media Laboratory GmbH
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy