A research team of the University School of Technical Architecture of the University of Granada [http://www.ugr.es], supervised by professor Antolino Gallego Molina is in charge since several years ago of listening to the laments of the materials using a technique, called acoustic emission, that auscultates the structural elements to get to know what happens inside from the emitted ultrasound.
This system can find out from an imperceptible fissure for the human eye to other damage by placing piezoelectric sensors that pick up the ultrasounds and send them afterwards to a computer system of information processing whose results can help to diagnose, restore and maintain any architectural collection.
The researchers, who are applying this technique in the field of Civil Engineering and construction, have only carried out laboratory tests until the moment, but their contacts with companies of construction materials will make their expansion to other problems of interest possible “before long”, according to professor Gallego, who adds that, although the acoustic emission technique can be used in diverse studies, his team will focus on two specific fields “fibre concrete quality control, especially used to supply uniform efforts with equal performance in all directions and avoid fragile fracture, such as in large elements, paving or tunnel or slope coating, and on the quality and functionality analysis of the mortars used to restore historical buildings”.
The professor of the Department of Applied Physics of the UGR [http://www.ugr.es], who works in collaboration with professors of materials and construction of the Department of Architectural Constructions and physicists of the University of Jaen, explains that, in the case of fibre concrete, (reinforced with steel or glass fibres, instead of the traditional steel bars) “is practically impossible” to do a fine quality control with the existing systems, as it is a material whose functionality can not be measured because it takes more or less time to brake after conventional tests with loading machines. Therefore, the use of the technique of acoustic emission would be advisable in these cases when ultrasound can reveal what is happening inside the material.
As regards quality analysis of mortars in restoration processes, Gallego says that in many cases, when new materials are added to restore a building, there are adhesion problems besides construction problems. It is very important considering that such adherence capacity guarantees the future maintenance of the recovered area. In this case, the technique of acoustic emission could also be promising to assess such adherence and, therefore, to determine if such adhesion will end up giving way or not.
Scarce presence in Spain
Despite the advantages of this method, its implementation in Spain is still very scarce. According to the physicist, only a private company located in Madrid is developing works with the technique of acoustic emission and the majority of them outside the country, specially set aside for corrosion detection in oil tanks and by-products. However, countries like the United States, Germany, England, France, Argentina, Brazil or Japan use that system in multiple areas from bridge vigilance to guarantee their security or the diagnose of historical buildings to earthquake prevention or the study of materials that compose oil and gas drums to prevent them from breaking, with the consequent problems for the economy and the environment.
In this sense, Gallego Molina points out that many of these applications should be developed here to guarantee the safety of all types of constructions such as bridges, port complexes or storage systems like the oil drums used in the oil mills of olive provinces like Granada, Jaen and Cordoba.
On the other hand, the supervisor of the research project also demands the organization of training courses, more attention on the part of the Spanish Association for Non-Destructive Tests, as there are not specialized experts in this field, and a major implication on the part of the Spanish System for Research, Development and Innovation.
Flexible protection for "smart" building and façade components
30.11.2016 | Fraunhofer-Institut für Silicatforschung ISC
Healthy living without damp and mold
16.11.2016 | Fraunhofer-Gesellschaft
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy