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image of a curved building made with carbon concrete in Dresden, Germany

November 10, 2022

Researchers in Germany Construct the World’s First Carbon Concrete Building

Reinforced with carbon fiber instead of steel, this two-story research building introduces the world to a stronger, more energy-efficient construction material.

By: Petra Loho

Called the “Cube” and located on the Dresden University of Technology (TU Dresden) campus in Germany, the first building made of carbon-reinforced concrete was inaugurated in September after two and a half years of construction.

In contrast to steel-reinforced concrete, carbon-reinforced concrete replaces steel rebar with carbon fiber rods and mats. The resulting structure is stronger, lighter, and can take on even more fanciful shapes.

photo of concrete siding of carbon concrete building in Dresden, Germany

The Cube consists of two volumes, the “Box” and the “Twist”, the latter consists of a load-bearing shell, an insulating layer, and a weather shell and was manufactured onsite with shotcrete and formwork. The Box, on the other hand was prefabricated, demonstrating the material’s range of applications.

“The big advantage is that you no longer need concrete to protect the steel from corrosion,” Professor Manfred Curbach says. Curbach is the director of the Institute for Concrete Structures at the TU Dresden and the Cube’s project director.

interior of carbon concrete building in Dresden, Germany

Since carbon is about four times lighter and five to six times stronger than steel, the concrete cover can be reduced to a few millimeters and the thickness of walls by up to two centimeters, allowing very slim and filigree forms.

“We save 50 percent on material,” Curbach says about using sand, cement, and water in carbon concrete buildings, resulting in an overall decrease of CO2 emissions by up to 70 percent. Moreover, it boasts a lifespan of over 200 years, compared to 40 to 80 years for reinforced concrete structures. As carbon is electrically conductive, carbon concrete modules can also be equipped with additional functions such as insulation, heating, or monitoring to enable “intelligent networking” in buildings.

detail of carbon-reinforced concrete beam and traditional beam
A comparison between two concrete structural beams, the beam on the left is reinforced with steel, and the beam on the right is reinforced with carbon, allowing it to use less material to support the same loads. © BMBF Innovation & Strukturwandel Thilo Schoch
mason assembling carbon concrete piece
The carbon fabric is worked into fine concrete in several layers. © Jörg Singer

Germany’s construction industry is already applying the Cube’s lessons to new buildings. Elsewhere in Dresden, a school gymnasium is on the way, and 70 miles away in Leipzig, a seven-story residential building is planned to be constructed with the material.

But the possibilities for carbon concrete extend far beyond new construction, engineers and architects are exploring how the new material can support restoration projects. And in Northern Italy, where earthquakes are common, experts are researching how carbon concrete may offer improved seismic performance.

With around 70 million cubic meters of reinforced concrete used every year in Germany, one thing is certain: A strong, light-weight material like carbon concrete won’t stay experimental for long.

exterior of carbon concrete building in Dresden, Germany

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