Constructing Domes By Inflating Hardened Concrete

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A new system has been created to develop an inflatable concrete structure using much fewer resources than ever before by researchers at TU Wien University.

Thousands of years ago, concrete was used for the construction of glorious structures by ancient civilizations. Its usefulness has survived the test of time and it has turned out to be an integral component of modern-day construction.

Concrete, once hardened, has the ability to withstand compressive forces that reach and exceed 4000 PSI to 10,000 PSI, depending on the application and purpose. On the other hand, it cannot bear up flexion and altercation after it’s hardened. Hence, it must be poured in its final shape. Nowadays, constructions that involve concrete depend on wooden frames and other support systems to contain concrete as it cures. This process is brilliant for the construction of vertical structures despite the fact that all buildings are not like that.

Constructing Domes By Inflating Hardened Concrete

Curved concrete shells are exquisitely strong and efficient; however, a great amount of resources and planning is necessary for the process of making. All the more so, the formwork containing just the wet concrete requires large amounts of material to be built. The building process is not at all efficient, although the structures are.

Now, the researchers at the TU Wien university have created a technique to inflate already hardened concrete into curved domes.

Dr. Benjamin Kromoser and Prof. Johann Kollegger at the Institute of Structural Engineering have developed this method named “Pneumatic Forming of Hardened Concrete (PFHC)”.  The idea is incredibly simple, but effective; place an air cushion underneath and support it with post-tensioning tendons to transform a flat concrete slab into a curved concrete shell. This technique assists in reducing the large amounts of labor and material, thereby bringing about noteworthy reductions in cost of constructions.

Constructing Domes By Inflating Hardened Concrete

The notion of the newly optimized construction method is fairly basic. Multiple wedge-shaped concrete slabs are cast on a flat surface. Once the concrete is cured an air cushion which is placed underneath is inflated. Post-tensioning tendons encircle the entire surface and add tension to prevent the slabs from sliding.

Only ‘2 hours’ were spent on the construction of a prototype building with a 1:2 scale. It reached 2.90 meters. In order to demonstrate the dexterity of the method, the design featured duel curves.

Benjamin Kromoser, one of the researchers, explained:

“We decided not just to create a simple, rotationally symmetric shape. Our building is a bit drawn-out, it cannot be described in simple geometric terms. We wanted to show that using our technology, even complex free-form structures can be created.”

Constructing Domes By Inflating Hardened Concrete

An exceptional freedom will be offered to architects to rise to highly efficient buildings with the help of this simple, but, effective process. The researchers aim to build very huge buildings even though the prototype was on a comparatively small scale.

Johann Kollegger stated:

“Building shells with a diameter of 50 meters is no problem with this technique”.

Constructing Domes By Inflating Hardened Concrete

It is expected that the inflatable construction method will see large implementations across several applications. The construction times, costs and labor will decrease considerably via this process. It is expected mostly to be utilized in building animal crossings, overpasses, in addition to numerous other architectural designs.

This new building technique has already been patented and has received a lot of interest from railway companies including the Austrian Federal Railways (OEBB-Infrastruktur AG). The future of curved construction is turning out to be possibly the most important invention that modern construction has seen in many years.