Andrey Rudenko developed his own concrete 3d printer in the garage. It has a gantry motion and extrudes concrete paste combined in the optimal mixture.
In his latest demonstration he printed a 100m2 house in 48 hours. He claims his 3d printed structures are hurricane and tornado resistant due to monolithic design.
He also successfully 3d printed a hotel suite in the Philippines:
Here you can see the process and comparison to human builders:
He is well known for his 3d printed concrete castle:
His homepage with much more information:
PS: I like the technology, but 3d printing is not a solution to housing crisis in my opinion. Houses are cheap to build, what is expensive is land, permissions, architectural work by certified professionals, compliance etc. Houses also became financial instrument and not a physical object person lives in. It is a broad and complex issue.