Thanks to the joint efforts of a building materials company and an automation company, the world got the largest 3D printed building made of real concrete.
The Mexican company CEMEX manufactures conventional building materials and has partnered with the Danish company Construction of Buildings on Demand (COBOD), a provider of 3D printing technology. Their solution uses much less “ink” for printing buildings and works with only 1% of the cement mixture, which means it is very scalable.
In previous attempts to build 3D-printed concrete buildings, special mixtures were used to accelerate the drying of ordinary concrete during construction. This is a big obstacle because aerated concrete does not have the same capacity to carry weight as dry concrete and does not hold the structure. The answer of CEMEX and COBOD to this problem is a new cement mixture called D.fab, which consists of a special additive that allows the concrete to be poured, while another additive that is added during printing speeds up the drying process. .
Another advantage of the new mix is the drastically lower construction cost. If columns made of dry concrete used for 3D printing cost 700 to 900 euros per cubic meter, with D.fab that price comes from 60 to 90 euros for the same volume. In addition, it saves time by reducing construction time.
The team presented its technology on a 190 m2 building, which is the largest in the world ever printed with real concrete. The building is located in Muscat, the capital of Oman, and was printed in two phases. Together the whole project was completed in five days, and the construction materials cost 1,600 euros. If the same building were printed with the usual 3D printing mixes, it would cost $ 20,000.