Obstacles to Europe's largest 3D-printed building

2023-06-09 08:54:00, Kuriozitete CNA

A new data center building being built in Heidelberg, Germany, is the largest European structure built with three-dimensional printing. The technology is promising, but the challenges remain great.

Usually data centers are not known for any extravagant architecture. But one building taking shape in Heidelberg, Germany, is sure to catch the eye. The facade resembles a wrinkled curtain that runs along the entire structure of the building. "With this form we wanted to reach the limits of the possible," says Hans-Jörg Kraus, managing partner of the Kraus group, the developers of the project. The creativity of the architects has been greater than usual, thanks to the special technique of creating constructions with printing three-dimensional, 3D.

Three-dimensional printing means that a computer-controlled sprayer places layers of the specified concrete mix one after the other, creating the walls of the building. Whereas horizontal elements, such as ceilings, are still built with traditional methods. When completed the one-story data center will be 54 meters long, 11 meters wide and nine meters high. According to the Kraus group, the building, which is expected to be completed in July, will be the largest building in Europe built with three-dimensional printing.

3D printing saves labor, time and waste

In addition to the extravagant arched shape, some of the advantages of 3D printing can be seen in the building constructed in Heidelberg. Most of the time, there are only two workers operating the printer at the workplace. Unlike conventionally cast concrete, precast concrete retains its shape, making casting molds unnecessary.

Eliminating casting molds reduces the time for their creation and teardown, thus providing a "huge advantage" for 3D printing, one of the building's architects, Jan van der Velden-Volkmann, told Deutsche Welles.

According to PERI 3D Construction, a company involved in the project, it only takes 140 hours to print the building's vertical elements. However, printing has to be done on vacation due to other finer processes, so the final printing hand can be given after four months of work.

Obstacles remain but 3D technology is increasingly being used

Although the technology has been developing for two decades, 3D printed buildings are rare. According to COBOD, a manufacturer of 3D printing technology, by 2022, 130 buildings with an area of ??more than ten square meters will be built with 3D printing, of which 55 were built last year alone. One reason for the slow uptake of the technology is the lack of standards to check the stability of printed structures, says Arnaud Perrot, a professor of civil engineering at France's Southern Brittany University. Without these standards it is very difficult to demonstrate to authorities that printed buildings are safe, he told Deutsche Welles.

But even if standards are created, 3D printing faces challenges, especially when it comes to erecting tall buildings.

Tall concrete structures usually require reinforcement with steel to withstand the forces they encounter. This is difficult for 3D-printed structures, says Manu Santhanam, a professor in the civil engineering department at the Indian Institute of Technology, Madras in Chennai. So "3D printing is not an option" for buildings with more than two or three stories, Santhanam told Deutsche Welles.

Perrot është më optimist, sidomos kur flitet për afat të gjatë. "Nga perspektiva teknike, nuk ka asgjë që të pengojë printimin e ndërtesave me shumë kate,” thotë ai. Tani për tani, ai mendon se kombinimi i printimit 3D me teknikat koncencionale të ndërtimit është rruga më e lehtë për të ndërtuar ndërtesa të larta. Kjo gjë ka ndodhur në Hajdelberg, ku për të përmirësuar stabilitetin e ndërtesës muret bosh, të krijuara me printim janë mbushur me beton të forcuar me hekur të hedhur me metoda konvencionale. Ku pra janë avantazhet më të mëdha për printimin 3D? Sa i përket Indisë, Santhanam mendon se potencialin më të madh printimi 3D e ka jashtë zonave urbane, aty ku nevoja për të ngritur ndërtesa të larta është më e vogël, sidomos në komunitetet shumë të mëdha që zhvillohen në zonat rurale. "Nëse printoni një radhë shtëpish, le të themi prej 20 ose 30 shtëpish, atëherë printimi 3D është teknologjia më e mirë sepse me të ekziston mundësia e përshtatjes individuale të çdo shtëpie,” thotë Santhanam. Sipas Perrot-it dhe van der Velden- Volkmann, printimi 3D mund të përdoret edhe për parafabrikimin në fabrika të elementëve përbërës të ndërtesave.

Betoni prodhohet duke emetuar shumë dioksid karboni

Sidoqoftë teknologjia mbështetet tek betoni, i cili është me probleme për shkak të ndikimit ndaj mjedisit. Betoni përmban si lidhës çimenton, prodhimi i së cilës është përgjegjës për prodhimin e 7 përqind të emisioneve të dioksidit të karbonit të krijuar në botë në vitin 2022, thotë Robbie Andrew nga Universiteti i Oslos.

Researchers have tried printing with other alternative materials that produce less carbon dioxide, such as clay. But according to Santhanam, concrete's special qualities such as strength and durability make it "certainly dominate" 3D printing in construction. For the data center being built in Heidelberg, a special concrete produced by Heidelberg Materials According to the company, their concrete has a binder that produces 55 percent less carbon dioxide than conventional cement./ DW