Air-formed domes

The Binishell
Place a balloon on the ground. Cover it with wet reinforced concrete. Inflate the balloon. Let the concrete harden. Voilà - an indestructible concrete dome built in one day using 20% of the material and 20% of the energy of a normal home. Instead of concrete, a skeleton with hinged joints can be laid out on the ground, and the balloon inflated underneath it to lift it into place. Various geometries for such a skeleton will be found in the patents below.

When building a home, you must fight gravity to get the roof and walls into place. This takes work. In fact, the basic struggle of construction is fighting gravity with muscle-power, ladders, pulleys and cranes. What if instead of all that, you use air to lift the walls and roof? Dante Bini has said that he can lift 300 tons of concrete using air pressure equal to puffing on a cigarette.

"'I am able now to build a dome at lower cost even than a conventional structure in no time because it takes about 60 minutes to lift and shape to the final position a dome a big as the Pantheon in Rome' - Dante Bini'"

From Binishells website: "The Binishells may be the most innovative new system for construction since the introduction of prefabrication in the late 1800s. Our technology in based on the radical notion of replacing formwork and heavy machinery with air. This concept, developed by Dr. Dante Bini in the 60's uses low air pressure to lift and shape wet concrete and reinforcing steel. More than 1,600 buildings have been built using this concept in 23 countries. Our system has been recently improved to make them code compliant, simpler, greener and more architecturally flexible. Our three new technologies, Binishells Systems 4, 5 and 6 all use 1/2 the raw materials, have a fraction of the embodied energy and can have a carbon footprint 80% smaller than traditional construction, yet result in buildings that are far stronger and more affordable. The basic technology is described above. Please roll over each section to see pictures of a small square based Binishells being inflated. "

Videos:
 * Youtube: "Extreme Engineering..." (shows Bini's technology in detail)
 * Binisystems: Process and details of construction Space City Construction (video)
 * TriplePundit: "Back to the Future: The Binishell Returns"

Dante Bini's patents
US patents last 20 years, so these are all in the public domain now:
 * Method for Erecting Structures, issued 1969
 * Method for making domed skeletal structures of concrete, issued 1976
 * Permanent weather covers, issued 1981
 * Reticular spatial structure, issued 1989
 * Expandable Reinforcement Structure, issued 1972
 * Building construction and method utilizing modular components, issued 1987. Looks almost like an air-formed Hexayurt.

Other Patents

 * Rigid building frame with inflatable member, Norman A. Boyce, issued 1984. A balloon is inflated to lift a flat-pack geodesic dome.
 * Modular inflatable dome structure, Yen T. Huang, issued 1981.

Related technologies for dome building
Monolithic domes as well as ferrocement are other technologies to build concrete domes. Guastavino masonry, a very different technology, can also produce domes, does not use steel.