Conductive concrete

Die Anwendungsmöglichkeiten von leitfähigem Beton sind groß. So ist es beispielsweise möglich, im Winter Eis und Schnee von Gebäuden, Brücken usw. zu schmelzen und damit Materialschäden und Funktionsausfälle zu verringern. A 200-square-foot slab of seemingly ordinary concrete sits just outside the Peter Kiewit Institute as snowflakes begin parachuting toward Omaha on a frigid afternoon in late December. The snow accumulates on the grass surrounding the slab and initially clings to the concrete, too. But as the minutes pass and the snow begins melting from only its surface, the slab reveals its secret: Like razors, stoves and guitars before it, this concrete has gone electric Its designer, UNL professor of civil engineering Chris Tuan, has added a pinch of steel shavings and a dash of carbon particles to a recipe that has literally been set in concrete for centuries. Though the newest ingredients constitute just 20 percent of Tuan’s otherwise standard concrete mixture, they conduct enough electricity to melt ice and snow in the worst winter storms while remaining safe to the touch. Tuan’s research team demonstrates the concrete’s de-icing performance to the Federal Aviation Administration during a testing phase that runs through March 2016. If the FAA is satisfied with the results, Tuan said the administration will consider scaling up the tests by integrating the technology into the tarmac of a major U.S. airport. “To my surprise, they don’t want to use it for the runways,” Tuan said. “What they need is the tarmac around the gated areas cleared, because they have so many carts to unload - luggage service, food service, trash service, fuel service - that all need to get into those areas. ...” A unique bridge that resides about 15 miles south of Lincoln has given Tuan reason to feel confident . In 2002, Tuan and the Nebraska Department of Roads made the 150-foot Roca Spur Bridge the world’s first to incorporate conductive concrete. Inlaid with 52 conductive slabs that have successfully de-iced its surface for more than a decade, the bridge exemplifies the sort of targeted site that Tuan envisions for the technology. “Bridges always freeze up first, because  they’re exposed to the elements on top and bottom,” Tuan said. “It’s not costeffective to build entire roadways using conductive concrete, but you can use it at certain locations where you always get ice or have potholes.” Potholes often originate from the liberal use of salt or de-icing chemicals that can corrode concrete and contaminate groundwater over time, making the conductive concrete an appealing alternative with lower operating and maintenance costs. ... Tuan said the conductive concrete could also prove feasible for high-traffic intersections, exit ramps, driveways and sidewalks. Yet the technology offers another, very different application that doesn’t even require electric current. By replacing the limestone and sand typically used in concrete with a mineral called magnetite, Tuan has shown that the mixture can also shield against electromagnetic waves. The electromagnetic spectrum includes the radiofrequency waves transmitted and received by cellphones, which Tuan said could make the concrete mixture useful to those concerned about becoming targets of industrial espionage. Using the magnetite-embedded concrete, Tuan and his colleagues have built a small structure in their laboratory that demonstrates the material’s shielding capabilities. ... From materials provided by University of Nebraska-Lincoln; Science Daily

Vocabulary

Englisch	Deutsch
accumulate	sich (an) sammeln
appealing	ansprechend, reizvoll, attraktiv
capability	Leistungsfähigkeit, Können, Einsatzmöglichkeit
century	Jahrhundert
civil engineering	Tiefbau, Bauwesen
cling to	haften an, sich anklammern
concrete	Beton
conductive	leitend
confident	zuversichtlich, sicher
constitute	ausmachen, beitragen
contaminate	verunreinigen
corrode	zerstören, korrodieren, zersetzen
dash	Spritzer, Prise
de-ice	enteisen
during	während
entire	gesamt(e), vollständig(e)
envision	sich etwas vorstellen
espionage	Spionage
exemplify	als Beispiel dienen für etwas, veranschaulichen
(be) exposed to	etwas ausgesetzt sein
frigid	kalt, eisig, frostig
gated area	abgeschlossener Bereich, Torbereich
incorporate	integrieren, verbinden
ingredients	Zutaten
intersection	Kreuzung
limestone	Kalkstein
magnetite	Magnetit, Magneteisenstein
maintenance	Instandhaltung
melt	schmelzen
parachute	abspringen, herunter segeln
pinch	Quäntchen, Prise
pothole	Schlagloch
prove feasible	sich als machbar erweisen
razor	Rasierer
recipe	Rezept
remain	bleiben
reside	wohnen, sich befinden
reveal	enthüllen, aufdecken
scale up	vergrößern, heraufsetzen
seemingly	augenscheinlich
shield	Abschirmung, abschirmen
sidewalk	Bürgersteig
slab	Platte, Betonstreifen, Brett
steel shavings	Stahlspäne
stove	Ofen, Herd
targeted site	Standort, Zielgebiet
tarmac	Asphalt, geteerte Fahrbahn
unique	einmalig, einzigartig

Autor: P. Zillmer Lesen Sie den Artikel in unserem Facharchiv.