World's Largest 3D Printed Building Made with Real Concrete Is Now Open

A collaborative effort between a building materials company and an automation provider for additive manufacturing has put together the world's largest building 3D printed with real concrete, 3DPrint.com reported. 

We have been covering updates from the world of 3D printing and how it is now being used with a wide range of starting materials including steel. However, when it comes to constructing, the "ink" used is usually a proprietary dry mix of mortar materials that not only limits the scale of adoption of the technology but also increases the costs of construction.

A Mexican company CEMEX provides materials for conventional construction of buildings and worked with Denmark-based Construction of Buildings on Demand (COBOD), a technology provider for 3D printing, to address this issue. Their solution reduces the proprietary ink in 3D printing of buildings to a mere one percent of the cement mixture, making it highly scalable, 3DPrint reported. 

Previous attempts at 3D constructions using concrete have used special mixes to address the slow drying of regular concrete during the construction process. This is a major hurdle since wet concrete does not have the same weight-bearing capacity as its dry counterpart and does not support construction. CEMEX and COBOD's answer to this problem is a new cement mix called D.fab which consists of a special additive that allows the concrete to be poured while another additive added during the printing process, speeds up the curing process.  

In a statement from 3DPrint, Henrik Lund-Nielsen, founder and General Manager of COBOD, said that the method allowed for the use of locally sourced materials in construction. Although this might not address the concerns of carbon emissions associated with concrete usage, it does drop the carbon footprint while sourcing construction supplies. 

An added advantage is the drastic reduction in the costs of construction. While dry mix mortars used for 3D printing cost €700-900 ($791-1,018) per cubic meter of construction, using D.fab could bring the cost down to €60 - 90 ($ 67-101) for the same volume. In addition to this, further savings could be made with the reduced time needed for construction. 

The team demonstrated their technology by building a 2,100 sq ft (190 sq m) house, the largest so far using real cement, in Oman's capital city of Muscat. D.fab additives were sourced from Europe while the house was 3D printed in two stages. During the first stage, a local team was trained on the printing process which then carried out the second stage of printing entirely by themselves, 3DPrint.com reported.

Together, the entire project took just five days to complete while dropping the material cost to €1,600 ($1,810) as compared to the €20,000 ($22,627) it would have cost using the regular proprietary dry mixes used in 3D printing.