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.
Construction Impact Guide
18.05.2018 | Hochschule RheinMain
New, forward-looking report outlines research path to sustainable cities
24.01.2018 | National Science Foundation
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
22.05.2018 | Trade Fair News
22.05.2018 | Life Sciences
22.05.2018 | Life Sciences