In the last years, the tunnel fires have shown that the tunnel support structure is severely damaged at an extremely high fire impact. “In some tunnels, up to two thirds of the tunnel inner shell are shattered by explosion. The leftover concrete suffers a severe thermal damage. This combination can lead to structure collapse in the case of one-shell tunnels that are close to upper areas,” clarifies Matthias Zeiml of the Institute for Mechanics of Materials and Structures (IMWS) of the Vienna Universisty of Technology.
He and his colleague from Munich, Roman Lackner (lecturer at IMWS), analyzed, as part of a three-year FWF-project, the “transportation processes in concrete at high temperatures.” “The blowup of the concrete sticks is a consequence of the thermal wedging and of the steam pressure, which develops in the heated concrete and which cannot escape.
These flattenings sometimes reach far behind the reinforced steel,” explains Zeiml. At the same time, University of Technology Professor Ulrich Schneider of the Institute for Building Construction and Technology and the Research Institute of the Austrian Cement Industry (VÖZFI) analyzed the effect of minuscule polypropylene fibers (carpet fibers) which are blended into the concrete. When the concrete is warmed up, adding a few millimeter-long fibers produces channels through which the water steam can escape. This way, flatennings can be effectively prevented.
The results of this fundamental research are now useful to researchers for the KIRAS-Project (Austrian Support Program for Safety Research) of the BMVIT, which received a grant in June. This research project benefits from the participation of a consortium that consists of University Institutes of the Vienna University of Technology and the Vienna University of Natural Resources and Applied Life Sciences, infrastructure construction developers (ÖBB, ASFiNAG, Wiener Linien) as well as engineering companies and research laboratories. At the forefront of research there is the development of a new evaluation pattern which for the first time facilitates the prognosis of the vital processes which are influenced by the structure support behavior. “Our project partners - ÖBB, ASFiNAG, and Wiener Linien – are interested in a close to reality prognosis of the tunnel safety level under fire impact. Moreover, we have to answer questions regarding issues such as the need for a temporary support and the extent of the necessary restructuring measures for different fire scenarios,” adds Lackner.
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
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences