Reshaping construction

A while ago, 3D printing was the center of attention. As a result, a new generation of entrepreneurs has emerged. They use the technology to create real commercial and artistic value that goes beyond the original hype.

Straight lines, constant repetition. Today’s construction is dominated by these two main principles. The small team of the Rotterdam based start-up Concr3de wants to get rid of these old paradigms. With their in-house developed 3D printer, customers will eventually be able to produce very detailed concrete parts at low costs and fairly fast – compared to standard 3D printing methods.

The company was founded two years ago by Eric Geboers (CEO, 27) and Matteo Baldassari (CTO, 31). They met when Geboers, an architect, worked on his salt project. Earlier, during his graduation, he tried to prevent desertification by separating seawater into fresh and salt water. He wanted to use the fresh water for greening the desert, the salt for building. Eventually Geboers developed a method to produce bricks out of salt and starch, strong enough to be used in small constructions.

Both Geboers and Baldassari are fascinated by shape and material. In the end, concrete drew their attention. ‘The production of cement (the main component of concrete, ed.) is responsible for up to 8 percent of global carbon dioxide emissions. That’s huge’, Geboers explains. ‘Our fascination with the material, and our wish to be able to use it differently, eventually led to the development of a machine.’  

Tinkering and testing

Within the walls of RDM Innovation Dock, the Conc3de team is working on 3D printers which use a technique called binder jetting (see textbox). They already developed – and patented – a liquid material used for the actual printing. It uses inorganic polymers, very different from the environmentally unfriendly binder in concrete, which is cement. As for printing powder they use a specific composition of byproducts from the coal and metal industry, such as fly ash and slag. According to Geboers, Concr3de’s approach reduces CO2 emissions by 85 percent compared to regular cement production.  

Their second machine is currently being developed at RDM Innovation Dock and a Delft University of Technology lab. At the moment they’re testing components separately, like powder density, inkjet system and the in-house written computer code. ‘All the parts are there. It’s our guess that when it works in our small machine it will also work in the big one.’ Plan is to assemble the new model as soon as possible. The printer fits in any small sized room, Baldassari says. It has a total print volume of 1.2 by 0.6 by 0.8 meter.

With this machine, Concr3de hopes to radically cut the costs of 3D printed and sustainable concrete parts. According to Geboers, manufacturing a figurine again – characteristic for the restoration of old churches – through available printing methods could easily amount to 8,000 euros. At a minimum, he says. ‘We can reduce the costs per statue to 500 euros and produce it four times faster.’ Also, the unique shapes the 3D printer is able to craft are very distinctive. Others can’t rival this, he says. And their sustainable concrete dries faster than normal concrete. ‘Compared to similar products, ours is the strongest out there right now.’

How does a binder jetting machine work?

Binder jetting is an additive manufacturing process. It’s a technique in which a binder is selectively positioned on a powder bed, binding the two together to form one solid piece. One layer at a time. Concr3de uses a patented and liquified inorganic polymer material. The powder is a specific composition of industrial byproducts such as fly ashes, additives and aggregates. After printing all layers, the object is encapsulated in the powder and left to harden. Next, the excess material can be removed and reused. Main advantages are the complex shapes a machine can print at relatively high speeds, in high resolution, at low costs.  

A strong partner

Last year Concr3de teamed up with TBI, a Dutch building company with an annual revenue of 1.7 billion euros (2017). In recent years this firm has seen a lot of 3D printers and their inventors, says Geboers. None of them seemed interesting enough. According to the entrepreneur, TBI was triggered by the complex shapes Concr3de’s first – small – printer has manufactured. A 3D printed piece of the Arch of Palmyra – an ancient Syrian city destroyed by terror group ISIS in 2015 – is one of the examples in the company’s portfolio.

The partnership with the building company opened-up a world of possibilities. Concr3de now has access to TBI’s network in construction and their knowledge. And with the funding the start-up company was able to hire new staff. They grew from four to nine employees. A young chemist with a PhD joined the ranks recently.       

Market launch

By the end of this year Concr3de expects to enter the market. They see a lot of opportunities in construction, new architectural shapes, restauration, industry and printing complex molds. Hard to choose where to begin, the entrepreneurs argue. And plenty has yet to be done. For instance, developing a marketing strategy, as well as a way to scale up production. At the same time, they’re thinking about how to take in pre sale orders, offer maintenance and develop their technology in the near future.

As a start the company aims at the domestic market: makerspaces, research institutions, production companies and universities of technology. Later on, it wants to tap into the European market. The estimated price of the big printer lies between € 300k-350k, including all support systems. There is still some doubt whether to launch a smaller version. One of the cons is the amount of small sized 3D printers already available.

In case Concr3de sells its machines abroad, they plan on building them in the Netherlands and ship them to customers. A licensing model sounds (as of yet) too complicated, Geboers says. ‘Perhaps we can locally produce our printing material. But it depends on the chemical composition of the residual product, which needs to be right. There aren’t that many suppliers who deliver standardized fly ash.’

‘Some people say to us: “Soon you’ll be printing apartment buildings.”’ But it doesn’t work like that, according to the entrepreneur. ‘We take responsibility for creating shapes that weren’t possible before and we add value, such as reduced costs and shorter lead times. Shapes we send to a construction site, will easily match with the other parts of a building. That’s our proposition.’’