Printing a Building

RedEaredSlider writes "Researchers at the Massachusetts Institute of Technology are trying to push 3-D printing technology even further. Their goals: create whole working machines and perhaps even buildings. Thus far, 3D printing has been used to make shapes of plastic or metal that can be assembled later. These folks want to change that. One idea is to use concrete in a novel way: 'Not only would it be possible to create fanciful, organic-looking shapes that would be difficult or impossible using molds, but the technique could also allow the properties of the concrete itself to vary continuously, producing structures that are both lighter and stronger than conventional concrete. To illustrate this, Keating uses the example of a palm tree compared to a typical structural column. In a concrete column, the properties of the material are constant, resulting in a very heavy structure. But a palm tree’s trunk varies: denser at the outside and lighter toward the center. As part of his thesis research, he has already made sections of concrete with the same kind of variations of density.'"

Pretty neat...

[fuzzyfuzzyfungus]

I suspect that, if made practical on a larger scale, this 3D printing will make variable-property concrete substantially more common, cheap, and swift to put up; but it deserves mention that the Roman architects who constructed the dome of the Pantheon actually used a similar strategy of progressively lighter aggregate mixes as they went further up the dome, resulting in a substantially lighter and more durable structure... A very cute trick that would be handy to see revived.

Re:lack of real-world experience

[nschubach]

I'm not sure you'd do the entire building in one print.

Maybe you print out the foundation "skin", drop some re-bar in specific locations (that are also printed in place) then have a truck come in later to pour the filling concrete. You avoid having to setup/tear down/transport forms. You can make the foundation any size or shape (again, without special forms) and even color without having to dye the entire batch of concrete. (From what I hear, concrete guys love dyed concrete.../sarcasm)