On February 8, Hyundai E&C make announcement written in ChosunBiz. Hyundai will apply for a patent to produce irregular big objects using 3D printing company. Together with 3D printing company 3D Factory.  They worked together since 2019 to apply 3D printing to construction.

The composite 3D printing using a large industrial 3D printer is not common. Two companies together developed printer and method. They can print with only maximum 0.001mm error an object of 2.5m in width, 5m in length, and 1.5m in height can be manufactured at once. With speed.

Hyundai research to produce tunnel segments for Tunnel Boring Machine (TBM) with this technology. Hyundai Research say  filling material that goes inside the steel formwork by 3D printing, which improves quality completion and significantly reduces production costs.

https://biz.chosun.com/site/data/html_dir/2021/02/08/2021020801084.html