A few years back I attended a conference on advanced architectural structures and flexibel moulds at TU Eindhoven. A lot of interesting research projects and build structures were presented which were all well structured and academically well known- and then there was Enrico Dini - an Italian entrepreneur, designer and inventor who showed us, very passionately the long road to develop a 3d printer for printing buildings - rapid prototyping becomes rapid building.
The perspectives for 3d printing structures are obvious when when compared to the procedure of constructing formwork, pouring the concrete followed by throwing the formwork away...
[Image of a structure printed in sand and an inorganic binder - the material doesn't use cement and resembles sandstone]
" D_shape technology makes it possible to 3D print 6 by 6 by 1m parts. These parts could either be shipped to the construction site or the entire building could be 3D printed on location. The parts made by D_shape resemble 'sandstone.' They are comparable in strength to reinforced concrete and the ingredients are the binding material and any type of sand. D_Shape's materials cost more than regular concrete but much less manpower is needed for construction. No scaffolding needs to be constructed so overall building cost should be lower than traditional building methods.
The system works with a rigging that is suspended over the buildable part (you can see it at the top of the first image[below. A-M]). The system deposits the sand and then the inorganic binding ink. No water is necessary. Because the two components meet outside the nozzle, the machine does not clog up and can keep up its accuracy of 25 DPI. Enrico and D_Shape are currently talking to lots of construction & engineering companies and architects about their technology." from Shapeways.
[Image of the 3d printing machine developed by Enrico Dini, photo from Blueprint Mag.]
The images shown above Dini also presented at his presentation - they are photos of a structure to sit in a roundabout in Pisa. The technique alone will be really interesting to follow. Large is great of course - but I do see a more quickly applied use in fx intricate filligree structured screens for wonderfully transparent facades.
[Enrico Dini and architect Andrea Morgante's sculpture: Radiolaria ]
A similar technology is Contour Crafting - here the technique is printing concrete another composite material which, however needs cement. The web site hasn't changed since I don't know when - so I have no idea of where this project is going except for what's expressed here - of course it has to do with funding.
[Image of the principle in Contour Crafting]