Printing a Building 112
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.'"
lack of real-world experience (Score:3, Informative)
Civil engineers would reject any concrete structure design proposed with 3-D printing. They despise cold joints, and if a vertical support consisted of dozens of cold joints, that's a no-go from the beginning. That's just one dimension of this flawed concept. Comparing a flexible material like a palm tree to an absolutely rigid material like concrete is pure folly. Concrete structures don't bend under load. They crack and break.
Seth
Re:Pretty neat... (Score:2, Informative)
That "cute trick" needs no revival, it's been used in just about every large scale construction project since well, the Pantheon. This is something wholly different though, since it would allow you to actually vary the density of the concrete within a single application, rather than just stacking progressively lighter applications.
Re:lack of real-world experience (Score:5, Informative)
actually, there are flexible composite concretes, some that even self-heal if stressed to cracking. And of course maybe 3D printing around support system could allow reinforced concrete printing. We're talking about research for future tech, what an old civil engineer would complain about might have no relevance at all if new materials and methods used. Advancement of civilization is all about new materials and new methods of using them.