Using air as their form work, Binishells are inherently green because they provide highly efficient building envelopes. They are also naturally strong and flexible in terms of shape and size. They are highly affordable because they use less labor and material in construction and also because they cost less to operate. Applications range from high-end residential, to schools, gymnasiums, commercial buildings, low cost housing, emergency shelters, storage and an infinite variety of other typologies. They were invented in the 1960s by the Italian architect, Dante Bini
This video gives much more detail.
Construction of Binishell domes begins with placing a concrete anchorage beam circular in plan with a molded recess. A slab on grade is also poured at this time to act as the floor of the dome. The anchorage device of the inflatable neoprene-coated nylon membrane is placed within the recession in the beam. Steel springs of various strengths are then stretched across the membrane at which time reinforcing bars are inserted inside the springs.
|2.) Pouring the concrete|
A thin layer of concrete is then poured over the membrane, covering the springs and reinforcement. The concrete is then covered with light PVC sheeting which is also secured to the anchorage. Once the sheeting is in place, the spool and roller vibrators are placed at the center of the membrane.
|3.) Inflating the membrane|
Now, the membrane is inflated through the ducts under the membrane. Although the pressure in the membrane is very low, the entire mass of the wet concrete, springs and reinforcement rise. As the pneumatic form fills with air, the different tensions in the springs control the lifting speed and shape of the dome. The springs also ensure the location of the reinforcement as the dome is lifting.This process takes roughly 1-3 hours.
|4.) Using the roller virbators|
When the dome has reached the desired height and shape, the rolling vibrators are pulled over the exterior of the surface to re-consolidate the concrete. When this is completed, the height of the dome is held constant by maintaining the pressure in the dome for 1-3 days depending on the size of the structure. During this time the PVC sheeting can be removed. Once the dome has reached sufficient strength, the form is deflated, leaving the 3 day old Binishell to support itself.
The construction process has been further developed and patented by Binisystems. Certain techniques have been implemented to have a more accurate structure in an effort to ensure the strength of the completed domes.